Change search
Refine search result
12 1 - 50 of 93
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Al-Awis, Suhail Najm
    et al.
    University of Technology, Iraq.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Fattah, Ali Y.
    University of Technology, Iraq.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Phenomenological Formula for Modelling of Physical Layer Impairments in Elastic Optical Networks2015In: Asia Communications and Photonics Conference 2015, 2015, article id ASu2A.75Conference paper (Refereed)
    Abstract [en]

    An empirical modelling technique is introduced to estimate impact of physical layer impairments in elastic optical networks, which can be used to evaluate transmission quality. The model has been verified experimentally with accuracy beyond (97.3%).

  • 2.
    Chen, XÍ
    et al.
    Huazhong University of Science and Technology, China.
    Lin, Rui
    Huazhong University of Science and Technology, China.
    Cui, Jingxian
    Huazhong University of Science and Technology, China.
    Gan, Li
    Huazhong University of Science and Technology, China.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jiang, Tao
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Chena, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    TDHQ Enabling Fine-granularity Adaptive Loading for SSB-DMT Systems2018In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 30, no 19, p. 1687-1690Article in journal (Refereed)
    Abstract [en]

    In this letter, we introduce time domain hybrid quadrature amplitude modulation (TDHQ) for the single sideband (SSB) discrete multi-tone (DMT) systems. Experimental results reveal that with a single precoding set and the proposed adaptive loading algorithm, the TDHQ scheme can achieve finer granularity and therefore smoother continuous growth of data rate than that with the conventional quadrature amplitude modulation (QAM). Besides, thanks to the frame construction and the tailored mapping rule, the scheme with TDHQ has an obviously better peak to average power ratio (PAPR).

  • 3.
    Cristofori, Valentina
    et al.
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francesco
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed Essghair
    University of Rennes 1, France.
    Bramerie, Laurent
    University of Rennes 1, France.
    Ding, Yunhong
    DTU Technical University of Denmark, Denmark.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Shen, Alexandre
    III-V Lab, France.
    Gallet, Antonin
    III-V Lab, France.
    Duan, Guanghua
    III-V Lab, France.
    Hassan, Karim
    CEA, France.
    Olivier, Segolene Gol Ne
    CEA, France.
    Popov, Sergei Yu
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Oxenlöwe, Leif Katsuo
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    University of Rennes 1, France.
    25-Gb/s transmission over 2.5-km SSMF by silicon MRR enhanced 1.55-μm III-V/SOI DML2017In: 30th Annual Conference of the IEEE Photonics Society, IPC 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, p. 357-360Conference paper (Refereed)
    Abstract [en]

    The use of a micro-ring resonator (MRR) to enhance the modulation extinction ratio and dispersion tolerance of a directly modulated laser (DML) is experimentally investigated with a bit rate of 25 Gb/s as proposed for the next generation data center communications. The investigated system combines a 11-GHz 1.55-m directly modulated hybrid III-V/SOI DFB laser realized by bonding III-V materials (InGaAlAs) on a silicon-on-insulator (SOI) wafer and a silicon MRR also fabricated on SOI. Such a transmitter enables error-free transmission (BER< 10 -9 )at 25 Gb/s data rate over 2.5-km SSMF without dispersion compensation nor forward error correction (FEC). As both laser and MRR are fabricated on the SOI platform, they could be combined into a single device with enhanced performance, thus providing a cost-effective transmitter for short reach applications.

  • 4.
    Cristofori, Valentina
    et al.
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francescos
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed E.
    FOTON Laboratory, France.
    Bramerie, Laurent
    FOTON Laboratory, France.
    Ding, Yunhong
    DTU Technical University of Denmark, Denmark.
    Pang, Xiadon
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Shen, Alexandre
    Thales, France.
    Gallet, Antonin
    Thales, France.
    Duan, Guang-Hua
    Thales, France.
    Hassan, Karem
    III-V Lab, France.
    Olivier, Segolene
    III-V Lab, France.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    Oxenløwe, Leif K.
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    FOTON Laboratory, France.
    25-Gb/s transmission over 2.5-km SSMF by silicon MRR enhanced 1.55-μm III-V/SOI DML2017In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 29, no 12, p. 960-963, article id 7917280Article in journal (Refereed)
    Abstract [en]

    The use of a micro-ring resonator (MRR) to enhance the modulation extinction ratio and dispersion tolerance of a directly modulated laser is experimentally investigated with a bit rate of 25 Gb/s as proposed for the next generation data center communications. The investigated system combines a 11-GHz 1.55-μm directly modulated hybrid III-V/SOI DFB laser realized by bonding III-V materials (InGaAlAs) on a silicon-on-insulator (SOI) wafer and a silicon MRR also fabricated on SOI. Such a transmitter enables error-free transmission (BER < 10-9) at 25 Gb/s data rate over 2.5-km standard single mode fiber without dispersion compensation nor forward error correction. As both laser and MRR are fabricated on the SOI platform, they could be combined into a single device with enhanced performance, thus providing a cost-effective transmitter for short reach applications.

  • 5.
    Da Ros, Francesco
    et al.
    DTU Technical University of Denmark, Denmark.
    Cristofori, Valentina
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed E.
    University of Rennes, France.
    Pang, Xiodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Galili, Michael
    DTU Technical University of Denmark, Denmark.
    Oxenløwe, Leif K.
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    University of Rennes, France.
    4-PAM dispersion-uncompensated transmission with micro-ring resonator enhanced 1.55-μm DML2017In: Optics InfoBase Conference Papers, 2017, article id STu1M.5.Conference paper (Refereed)
    Abstract [en]

    Real-time transmission of 14-GBd 4-PAM signal is demonstrated by combining a commercial 1.55-μm DML with a silicon MRR. BER below the HD-FEC threshold is measured after 26-km SSMF transmission without offline digital signal processing.

  • 6.
    Deniel, L.
    et al.
    C2N CNRS, France.
    Gay, M.
    University of Rennes CNRS, France.
    Pérez-Galacho, D.
    C2N CNRS, France.
    Baudot, C.
    STMicroelectronics, France.
    Bramerie, L.
    University of Rennes CNRS, France.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Boeuf, F.
    STMicroelectronics, France.
    Vivien, L.
    C2N CNRS, France.
    Peucheret, C.
    University of Rennes CNRS, France.
    Marris-Morini, D.
    C2N CNRS, France.
    Generation of O-band PAM-4 signal using a silicon modulator driven by two binary sequences2019In: Proceedings of SPIE - The International Society for Optical Engineering, SPIE , 2019Conference paper (Refereed)
    Abstract [en]

    Silicon photonics is a promising solution for next generation of short-range optical communication systems. Silicon modulators have driven an important research activity over the past years, and many transmission links using on-off keying modulation format (OOK) were successfully demonstrated with a large diversity of modulator structures. In order to keep up with the demand of increasing bitrates for limited bandwidths in Datacom applications, higher modulation formats are explored, such as quadrature phase shift keying (QPSK) or 4-level pulse amplitude modulation (PAM-4). However, driving the modulators to generate PAM-4 signals commonly require expensive and power-hungry electronic devices such as digital-to-analog converters (DACs) for pulse-shaping and digital signal processors (DSP) for nonlinearity compensation. Lastly, new solutions were studied to overcome this issue, including new driving methods based on the use of two different input binary sequences applied directly on the modulator. While most of the reported works are focused on the C-band of communication, the O-band can present a definitive advantage due to the low dispersion of standard single-mode (SSMF) fiber. For those reasons, we demonstrate the generation of a 10-Gbaud DAC-less PAM-4 signal in the O-band using a depletion-based silicon traveling wave Mach-Zehnder modulator (TWMZM). An open eye diagram was obtained, and a bit error rate (BER) of 3.8×10 -3 was measured for a received optical power of about-6 dBm.

  • 7.
    Estarán, Jose
    et al.
    Nokia Bell Labs, France.
    Mardoyan, Haik
    Nokia Bell Labs, France.
    Jorge, Filipe
    Nokia Bell Labs, France.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Konczykowska, Agnieszka
    Nokia Bell Labs, France.
    Riet, Muriel
    Nokia Bell Labs, France.
    Duval, Bernadette
    Nokia Bell Labs, France.
    Nodjiadjim, Virginie
    Nokia Bell Labs, France.
    Dupuy, Jean Yves
    Nokia Bell Labs, France.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Bigo, Sebastien
    Nokia Bell Labs, France.
    140/180/204-Gbaud OOK Transceiver for Inter- and Intra-Data Center Connectivity2019In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 37, no 1, p. 178-187, article id 8500133Article in journal (Refereed)
    Abstract [en]

    We report on an on-off keying intensity-modulation and direct-detection C-band optical transceiver capable of addressing all datacenter interconnect environments at well-beyond 100Gbaud. For this, the transmitter makes use of two key InP technologies: a 2:1 double heterojunction bipolar transistor selector multiplexer and a monolithically integrated distributed-feedback laser traveling-wave electro-absorption modulator, both exceeding 100-GHz of 3-dB analog bandwidth. A pre-amplified 110-GHz PIN photodiode prior to a 100-GHz analog-to-digital converter complete the ultra-high bandwidth transceiver module; the device under study. In the experimental work, which discriminates between intra- and inter-data center scenarios (dispersion unmanaged 120, 560, 960m; and dispersion-managed 10, and 80km of standard singlemode fiber), we evaluate the bit-error rate evolution against the received optical power at 140, 180, and 204Gbaud on-off keying for different equalization configurations (adaptive linear filter with and without the help of short-memory sequence estimation) and forward error correction schemes (hard-decision codes with 7% and 20% overhead); drawing conclusions from the observed system-level limitations of the respective environments at this ultra-high baudrate, as well as from the operation margins and sensitivity metrics. From the demonstration, we highlight three results: successful operation with >6-dB sensitivity margin below the 7% error-correction at 140Gbaud over the entire 100m-80km range with only linear feed-forward equalization. Then the transmission of a 180Gbaud on-off-keying carrier over 80km considering 20% error-correction overhead. And finally, 10-km communication at 204Gbaud on-off keying with up to 6dB sensitivity margin, and regular 7%-overhead error-correction.

  • 8.
    Gaiarin, Simone
    et al.
    DTU Technical University of Denmark, Denmark.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Jones, Rasmus Thomas
    DTU Technical University of Denmark, Denmark.
    Da Silva, Edson Porto
    DTU Technical University of Denmark, Denmark.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    High speed PAM-8 optical interconnects with digital equalization based on neural network2016In: Asia Communications and Photonics Conference 2016, 2016, article id AS1C.1Conference paper (Refereed)
    Abstract [en]

    We experimentally evaluate a high-speed optical interconnection link with neural network equalization. Enhanced equalization performances are shown comparing to standard linear FFE for an EML-based 32 GBd PAM-8 signal after 4-km SMF transmission.

  • 9.
    Gyger, Samuel
    et al.
    KTH Royal Institute of Technology, Sweden.
    Zeuner, Katharina D.
    KTH Royal Institute of Technology, Sweden.
    Jöns, Klaus D.
    KTH Royal Institute of Technology, Sweden.
    Elshaari, Ali W.
    KTH Royal Institute of Technology, Sweden.
    Paul, Matthias
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Hedlund, Carl Reuterskiöld
    KTH Royal Institute of Technology, Sweden.
    Hammar, Mattias
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Zwiller, Val
    KTH Royal Institute of Technology, Sweden.
    Reconfigurable frequency coding of triggered single photons in the telecom C–band2019In: Optics Express, Vol. 27, no 10, p. 14400-14406Article in journal (Refereed)
    Abstract [en]

    In this work, we demonstrate reconfigurable frequency manipulation of quantum states of light in the telecom C–band. Triggered single photons are encoded in a superposition state of three channels using sidebands up to 53 GHz created by an off-the-shelf phase modulator. The single photons are emitted by an InAs/GaAs quantum dot grown by metal-organic vapor-phase epitaxy within the transparency window of the backbone fiber optical network. A cross-correlation measurement of the sidebands demonstrates the preservation of the single photon nature; an important prerequisite for future quantum technology applications using the existing telecommunication fiber network.

  • 10.
    Hong, Xuexhi
    et al.
    KTH Royal Institute of Technology, Sweden.
    Zhang, Lu
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Guo, Changjian
    South China Normal University, China.
    Nordwall, Fredrik
    Tektronix AB, Sweden.
    Engenhardt, Klaus M.
    Tektronix GmbH, Germany.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Xiao, Shilin
    Shanghai Jiao Tong University, China.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    200-Gbps DMT Transmission over 1.6-km SSMF with A Single EML/DAC/PD for Optical Interconnects at C-Band2017In: European Conference on Optical Communication, ECOC, 2017Conference paper (Refereed)
    Abstract [en]

    We report on the first experimental demonstration of 200-Gbps (net rate 166.7-Gbps) 1.55-μm DMT IMDD transmission over 1.6 km fiber using a single monolithically-integrated-EML, DAC and photodiode, achieving an effective electrical spectrum efficiency of 4.93 bit/s/Hz. © 2017 IEEE.

  • 11.
    Hong, Xuezhi
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Guo, Changjian
    South China Normal University, China.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Junwei
    South China Normal University, China.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    1.55-jnm EML-based DMT transmission with nonlinearity-aware time domain super-nyquist image induced aliasing2017In: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate a DMT transmission system with 1.55-μm EML using nonlinearity-aware time domain super-Nyquist image induced aliasing. Compared with linear equalization, the capacity is improved by ∼16.8%(33.1%) with proposed method for 4(40) km transmission.

  • 12.
    Hong, Xuezhi
    et al.
    KTH Royal Institute of Technology, Sweden; South China Normal University, China.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Guo, Changjian
    South China Normal University, China.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Junwei
    South China Normal University, China.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei Yu
    KTH Royal Institute of Technology, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden; South China Normal University, China.
    1.55-μm EML-based DMT transmission with nonlinearity- aware time domain super-nyquist image induced aliasing2017In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2017Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate a DMT transmission system with 1.55-μm EML using nonlinearity-aware time domain super-Nyquist image induced aliasing. Compared with linear equalization, the capacity is improved by ~16.8%(33.1%) with proposed method for 4(40) km transmission. © 2017 OSA.

  • 13.
    Jia, S.
    et al.
    DTU Technical University of Denmark, Denmark.
    Lo, MC
    Universidad Carlos III de Madrid, Spain.
    Zhang, L.
    KTH Royal Institute of Technology, Sweden; Shanghai Jiao Tong University, China.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kong, D.
    DTU Technical University of Denmark, Denmark.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Yu, X.
    Zhejiang University, China.
    Xiao, S.
    Shanghai Jiao Tong University, China.
    Popov, S.
    KTH Royal Institute of Technology, Sweden.
    Chen, J.
    KTH Royal Institute of Technology, Sweden.
    Carpintero, G.
    DTU Technical University of Denmark, Denmark.
    Morioka, T.
    Universidad Carlos III de Madrid, Spain.
    Hu, H.
    DTU Technical University of Denmark, Denmark.
    Oxenlowe, L. K.
    DTU Technical University of Denmark, Denmark.
    Integrated Dual-DFB Laser for 408 GHz Carrier Generation Enabling 131 Gbit/s Wireless Transmission over 10.7 Meters2019In: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2019, article id 8697005Conference paper (Refereed)
    Abstract [en]

    A monolithically integrated dual-DFB laser generates a 408 GHz carrier used for demonstrating a record-high single-channel bit rate of 131 Gbit/s transmitted over 10.7 m. 16-QAM-OFDM modulation and specific nonlinear equalization techniques are employed

  • 14.
    Jia, Shi
    et al.
    Zhejiang University, China.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Yu, Xiobin
    Zhejiang University, China.
    Hu, Hao
    DTU Technical University of Denmark, Denmark.
    Yu, Jinlong
    Tianjin University, China.
    Guan, Pengyu
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francesco
    DTU Technical University of Denmark, Denmark.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Galili, Michael
    DTU Technical University of Denmark, Denmark.
    Morioka, Toshio
    DTU Technical University of Denmark, Denmark.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Oxenloewe, Leif K.
    DTU Technical University of Denmark, Denmark.
    0.4 THz Photonic-Wireless Link with 106 Gbit/s Single Channel Bitrate2018In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 36, no 2, p. 610-616Article in journal (Refereed)
    Abstract [en]

    To accommodate the demand of exponentially increased global wireless data traffic, the prospective data rates for wireless communication in the market place will soon reach 100 Gbit/s and beyond. In the lab environment, wireless transmission throughput has been elevated to the level of over 100 Gbit/s attributed to the development of photonic-assisted millimeter wave (MMW) and THz technologies. However, most of recent demonstrations with over 100 Gbit/s data rates are based on spatial or frequency division multiplexing techniques, resulting in increased system's complexity and energy consumption. Here, we experimentally demonstrate a single channel 0.4 THz photonic-wireless link achieving a net data rate of beyond 100 Gbit/s by using a single pair of THz emitter and receiver, without employing any spatial/frequency division multiplexing techniques. The high throughput up to 106 Gbit/s within a single THz channel is enabled by combining spectrally efficient modulation format, ultra-broadband THz transceiver and advanced digital signal processing (DSP) routine. Besides that, our demonstration from system-wide implementation viewpoint also features high transmission stability, and hence shows its great potential to not only decrease the system's complexity, but also meet the requirements of prospective data rates for bandwidth-hungry short-range wireless applications.

  • 15.
    Kakkar, Aditya
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Low complexity timing recovery algorithm for PAM-8 in high speed direct detection short range links2017In: Optics InfoBase Conference Papers, 2017, article id W2A.54Conference paper (Refereed)
    Abstract [en]

    We propose a low complexity timing algorithm for high order PAM. Experimental results demonstrate higher performance and lower complexity than conventional algorithms in a 32 Gbaud PAM-8 transmission over 4 km SMF links.

  • 16.
    Kakkar, Aditya
    et al.
    RISE, Swedish ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Louchet, Hadrien
    VPIPhotonics GmBH, Germany.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Comprehensive Study of Equalization-Enhanced Phase Noise in Coherent Optical Systems2015In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 33, no 23, p. 4834 -4841Article in journal (Refereed)
    Abstract [en]

    A thorough analysis of equalization-enhanced phase noise (EEPN) and its impact on the coherent optical system is presented. We show with a time-domain analysis that EEPN is caused due to the interference of multiple delayed versions of the dispersed signal, generated by intermixing of the received dispersed signal, and the noise side bands of the local oscillator (LO) in the photodetectors. We derive statistical properties such as the mean, variance, and error vector magnitude of the received signal influenced with EEPN. We show that in coherent optical systems utilizing electronic dispersion compensation, this noise corresponds to multipath fading in wireless communication systems. Closed-form expressions of necessary LO linewidth and/or mitigation bandwidth for a general system configuration and specified OSNR penalty are given. The expressions for system design parameters, validated with system simulations, show that higher order modulation formats, such as 16-quadrature amplitude modulation and beyond, put stringent demands on the LO linewidth unless a mitigation technique is used.

  • 17.
    Kakkar, Aditya
    et al.
    KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Louchet, Hadrien
    VPIphotonics GmBH, Germany.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Equalization enhanced phase noise in coherent optical systems with digital pre-and post-processing2016In: Photonics, ISSN 2304-6732, Vol. 3, no 2, article id 12Article in journal (Refereed)
    Abstract [en]

    We present an extensive study of equalization enhanced phase noise (EEPN) in coherent optical system for all practical electronic dispersion compensation configurations. It is shown that there are only eight practicable all-electronic impairment mitigation configurations. The non-linear and time variant analysis reveals that the existence and the cause of EEPN depend on the digital signal processing (DSP) schemes. There are three schemes that in principle do not cause EEPN. Analysis further reveals the statistical equivalence of the remaining five system configurations resulting in EEPN. In three of them, EEPN is due to phase noise of the transmitting laser, while in the remaining two, EEPN is caused by the local oscillator. We provide a simple look-up table for the system designer to make an informative decision regarding practicable configuration choice and design.

  • 18.
    Kakkar, Aditya
    et al.
    RISE, Swedish ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Louchet, Hadrien
    VPI Photonics GmBH, Germany.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Mitigation of EEPN in Coherent Optical Systems with Low Speed Digital Coherence Enhancement2015In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 27, no 18, p. 1942-1945, article id 7128718Article in journal (Refereed)
    Abstract [en]

    A method for mitigating local oscillator (LO) phase noise-induced impairment, also known as equalization-enhanced phase noise, in coherent optical systems is discussed. The method is suitable for real-time implementation and requires hardware with a bandwidth much lower than the signal baud rate, even for a system utilizing conventional semiconductor laser as LO. We evaluate the required parameters like interpolation technique, electrical signal-to-noise ratio at digital coherence enhancement (DCE) front end, for long haul transmission links having quadrature phase shift keying and 16-quadrature amplitude modulation formats. We show that the method can be implemented using a low-speed DCE front end and a simple digital linear interpolator with small (<1 dB) implementation penalty even in cases that would otherwise result inerror floor.

  • 19.
    Kakkar, Aditya
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Nordwall, Fredrik
    Tektronix AB, Sweden.
    Zibar, Dakar
    DTU Technical University of Denmark, Denmark.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Influence of lasers with non-white frequency noise on the design of coherent optical links2017In: Optical Fiber Communication Conference OSA Technical Digest (online) (Optical Society of America, 2017)Los Angeles, California United States19–23 March 2017, 2017, article id Th2A.55Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate for a 28 Gbaud 64-QAM metro link that the LO frequency noise causes timing impairment. Results show the existence of LO frequency noise spectrum regimes where different design criteria apply.

  • 20.
    Kakkar, Aditya
    et al.
    KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Nordwall, Fredrik
    Tektronix GmbH, Germany.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Influence of lasers with non-white frequency noise on the design of coherent optical links2017In: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate for a 28 Gbaud 64-QAM metro link that the LO frequency noise causes timing impairment. Results show the existence of LO frequency noise spectrum regimes where different design criteria apply.

  • 21.
    Kakkar, Aditya
    et al.
    KTH Royal Institute of Technology, Sweden.
    Olmedo, Miguel Iglesias
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE, Swedish ICT, Acreo.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Louchet, Hadrien
    VPIphotonics GmbH, Germany.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Overcoming EEPN in coherent transmission systems2016In: 2016 Conference on Lasers and Electro-Optics (CLEO), 2016, article id 7788753Conference paper (Refereed)
    Abstract [en]

    We for the first time experimentally demonstrate a simple technique to overcome EEPN. Performance recovery from above FEC to <1 dB penalty for 28 Gbd 16-QAM over 520 km with high LO linewidth is achieved.

  • 22.
    Kakkar, Aditya
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE, Swedish ICT, Acreo.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Olmedo, Miguel Iglesias
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Louchet, Hadrien
    VPIphotonics GmbH, Germany.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Design of coherent optical systems impaired by EEPN2016In: 2016 Optical Fiber Communications Conference and Exhibition (OFC 2016), 2016, article id 7537506Conference paper (Refereed)
    Abstract [en]

    We present experimental validation of novel analytical expressions essential for the design of coherent optical systems impaired by EEPN. These expressions enable a simple and accurate EEPN analysis for any system specification.

  • 23.
    Kakkar, Aditya
    et al.
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Louchet, Hadrien
    VPIphotonics GmBH, Germany.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    A path to use large linewidth LO in 28 Gbd 16-QAM metro links2015In: 2015 European Conference on Optical Communication (ECOC), 2015, article id 7341948Conference paper (Refereed)
    Abstract [en]

    We experimentally investigate the possibility to mitigate local oscillator induced Equalization Enhanced Phase Noise penalty. The results pave the way for the use of even 10 MHz linewidth local oscillator lasers in 28 Gbd 16-QAM metro links.

  • 24.
    Kakkar, Aditya
    et al.
    RISE, Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE, Swedish ICT, Acreo.
    Louchet, Hadrien
    VPIphotonics GmbH, Germany.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Impact of local oscillator frequency noise on coherent optical systems with electronic dispersion compensation2015In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 23, no 9, p. 11221-11226Article in journal (Refereed)
    Abstract [en]

    A theoretical investigation of the equalization-enhanced phase noise (EEPN) and its mitigation is presented. We show with a frequency domain analysis that the EEPN results from the non-linear inter-mixing between the sidebands of the dispersed signal and the noise sidebands of the local oscillator. It is further shown and validated with system simulations that the transmission penalty is mainly due to the slow optical frequency fluctuations of the local oscillator. Hence, elimination of the frequency noise below a certain cut-off frequency significantly reduces the transmission penalty, even when frequency noise would otherwise cause an error floor. The required cut-off frequency increases linearly with the white frequency noise level and hence the linewidth of the local oscillator laser, but is virtually independent of the symbol rate and the accumulated dispersion.

  • 25.
    Kerrebrouck, Joris Van
    et al.
    Ghent University, Belgium.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Lin, Rui
    Huazhong University of Science and Technology, China.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Lu
    Shanghai Jiao Tong University, China.
    Li, Haolin
    Ghent University, Belgium.
    Spiga, Silvia
    Technical University of Munich, Germany.
    Amann, MC
    Technical University of Munich, Germany.
    Gan, Ling
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Soignian
    Huazhong University of Science and Technology, China.
    Schatz, Rickhard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Tong, Weijun
    YOFC Yangtze Optical Fibre and Cable, China.
    Torfs, Guy
    Ghent University, Belgium.
    Bauwelinck, Johan
    Ghent University, Belgium.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Yin, Xin
    Ghent University, Belgium.
    High-speed PAM4-based Optical SDM Interconnects with Directly Modulated Long-wavelength VCSEL2018In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, p. 356-362Article in journal (Refereed)
    Abstract [en]

    This paper reports the demonstration of high-speed PAM-4 transmission using a 1.5-μm single-mode vertical cavity surface emitting laser (SM-VCSEL) over multicore fiber with 7 cores over different distances. We have successfully generated up to 70 Gbaud 4-level pulse amplitude modulation (PAM-4) signals with a VCSEL in optical back-to-back, and transmitted 50 Gbaud PAM-4 signals over both 1-km dispersion-uncompensated and 10-km dispersion-compensated in each core, enabling a total data throughput of 700 Gbps over the 7-core fiber. Moreover, 56 Gbaud PAM-4 over 1-km has also been shown, whereby unfortunately not all cores provide the required 3.8 × 10<formula><tex>$^-3$</tex></formula>bit error rate (BER) for the 7% overhead-hard decision forward error correction (7% OH HDFEC). The limited bandwidth of the VCSEL and the adverse chromatic dispersion of the fiber are suppressed with pre-equalization based on accurate end-to-end channel characterizations. With a digital post-equalization, BER performance below the 7% OH-HDFEC limit is achieved over all cores. The demonstrated results show a great potential to realize high-capacity and compact short-reach optical interconnects for data centers.

  • 26.
    Kerrebrouck, Joris Van
    et al.
    Ghent University, Belgium.
    Zhang, Liu
    KTH Royal Institute of Technology, Sweden; Shanghai Jiao Tong University, China.
    Lin, Rui
    KTH Royal Institute of Technology, Sweden; Huazhong University of Science and Technology, China.
    Pang, Xioadan
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Spiga, Silvia
    Walter Schottky Institut, Germany.
    Amann, Markus Christian
    Walter Schottky Institut, Germany.
    van Steenberge, Geert
    Ghent University, Belgium.
    Gan, Lei
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Liu, Di
    Huazhong University of Science and Technology, China.
    Tong, Weijun
    YOFC Yangtze Optical Fiber and Cable, China.
    Xiao, Shiyi
    Shanghai Jiao Tong University, China.
    Torfs, Guy
    Ghent University, Belgium.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Bauwelinck, Johan
    Ghent University, Belgium.
    Yin, Xin
    Ghent University, Belgium.
    726.7-Gb/s 1.5-μm single-mode VCSEL discrete multi-tone transmission over 2.5-km multicore fiber2018Conference paper (Refereed)
    Abstract [en]

    A 107Gb/s net-rate DMT optical signal was generated using a single-mode long-wavelength VCSEL with a modulation bandwidth of 23 GHz. We experimentally demonstrated a total net-rate up to 726.7Gb/s at 1.5&amp;#x03BC;m over 2.5km 7-core dispersion-uncompensated MCF.

  • 27.
    Lavrinovica, Ingrida
    et al.
    Riga Technical University, Latvia.
    Supe, Andis
    Riga Technical University, Latvia.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Porins, Jurgis
    Riga Technical University, Latvia.
    Exploration of Optical Amplifiers Based on Erbium (Er3+) and Ytterbium (Yb3+) Doped Fiber Segments and Its Emerging Applications2018Conference paper (Refereed)
    Abstract [en]

    This paper proposes the improvement of EDFA amplifier properties by adding additional segments of Yb<sup>3+</sup> doped fiber. Experimental demonstration of a combined erbium-ytterbium doped fiber amplifier (EYDFA) performance using 5 m long erbium-doped fiber (EDF) and 5 m long ytterbium-doped fiber (YDF) is presented.

  • 28.
    Lin, R.
    et al.
    KTH Royal Institute of Technology, Sweden; Huazhong University of Science and Technology, China.
    Gan, L.
    Huazhong University of Science and Technology, China.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Shen, L.
    Huazhong University of Science and Technology, China.
    Popov, S.
    KTH Royal Institute of Technology, Sweden.
    Tang, M.
    Huazhong University of Science and Technology, China.
    Fu, S.
    Huazhong University of Science and Technology, China.
    Tong, W.
    Yangtze Optical Fiber and Cable Joint Stock Ltd Co, China.
    Liu, D.
    Huazhong University of Science and Technology, China.
    Da Silva, T. F.
    National Institute of Metrology, Brazil.
    Xavier, G. B.
    Linköping University, Sweden.
    Chen, J.
    KTH Royal Institute of Technology, Sweden.
    Spontaneous Raman Scattering Effects in Multicore Fibers: Impact on Coexistence of Quantum and Classical Channels2019In: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2019, article id 8696422Conference paper (Refereed)
    Abstract [en]

    We measure spontaneous Raman scattering (SRS) effects in C-band and observe trench-assisted MCF is robust to SRS noise, making it possible to run quantum channels in the neighboring and/or the same core as data channels.

  • 29.
    Lin, Rui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Kerrebrouck, Joris Van
    Ghent University, Belgium.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Verplaetse, Michiel
    Ghent University, Belgium.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Lu
    KTH Royal Institute of Technology, Sweden.
    Gan, Lin
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Tong, Weijun
    YOFC Yangtze Optical Fiber and Cable, China.
    Keulenaer, Timothy De
    Ghent University, Belgium.
    Torfs, Guy
    Ghent University, Belgium.
    Bauwelinck, Johan
    Ghent University, Belgium.
    Yin, Xin
    Ghent University, Belgium.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Spatial division multiplexing for optical data center networks2018Conference paper (Refereed)
    Abstract [en]

    Emerging mobile and cloud applications drive ever-increasing capacity demands, particularly for short-reach optical communications, where low-cost and low-power solutions are highly required. Spatial division multiplexing (SDM) techniques provide a promising way to scale up the lane count per fiber, while reducing the number of fiber connections and patch cords, and hence simplifying cabling complexity. This talk will address challenges on both system and network levels, and report our recent development on SDM techniques for optical data center networks.

  • 30.
    Lin, Rui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Lu, Yang
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Cheng, Yuxin
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    First Experimental Demonstration of Physical-Layer Network Coding in PAM4 System for Passive Optical Interconnects2018In: European Conference on Optical Communication, ECOC, 2018Conference paper (Refereed)
    Abstract [en]

    We propose to implement physical-layer network coding (PLNC) in coupler-based passive optical interconnects. The PLNC over PAM4 system is for the first time experimentally validated, where simultaneous mutual communications can be kept within the same wavelength channel, doubling spectrum efficiency.

  • 31.
    Lin, Rui
    et al.
    Huazhong University of Science and Technology, China.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Kerrebrouck, Joris Van
    Ghent University, Belgium.
    Verplaetse, Michiel
    Ghent University, Belgium.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Lu
    KTH Royal Institute of Technology, Sweden.
    Gan, Lin
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Tong, Weijun
    YOFC Yangtze Optical Fiber and Cable, China.
    Keulenaer, Timothy De
    Ghent University, Belgium.
    Torfs, Guy
    Ghent University, Belgium.
    Bauwelinck, Johan
    Ghent University, Belgium.
    Yin, Xin
    Ghent University, Belgium.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Real-time 100 Gbps/lambda/core NRZ and EDB IM/DD Transmission over 10 km Multicore Fiber2018In: 2018 Optical Fiber Communications Conference and Exposition (OFC), 2018, p. 1-3Conference paper (Refereed)
    Abstract [en]

    A BiCMOS chip-based real-time IM/DD spatial division multiplexing system is experimentally demonstrated for short-reach communications. 100 Gbps/&amp;#x03BB;/core NRZ and EDB transmission is achieved below 7%-overhead HD-FEC limit after 10km 7-core fiber with optical dispersion compensation.

  • 32.
    Lin, Rui
    et al.
    KTH Royal Institute of Technology, Sweden; Huazhong University of Science and Technology, China.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Feng, Zhenhua
    Huazhong University of Science and Technology, China.
    Djupsjöbacka, Anders
    RISE, Swedish ICT, Acreo.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Performance evaluation of PAM and DMT for short-range optical transmission with high speed InGaAsP DFB-TWEAM2016In: 2016 Optical Fiber Communications Conference and Exhibition (OFC), 2016, article id 7537397Conference paper (Refereed)
    Abstract [en]

    We report on experimental results of 56-Gb/s OOK, PAM4 and 25-Gb/s DMT transmission with a high speed InGaAsP based monolithically integrated DFB-TWEAM, and evaluate different digital equalization implementations.

  • 33.
    Lin, Rui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Gan, L
    Huazhong University of Science and Technology, China.
    Shen, L
    Huazhong University of Science and Technology, China.
    Tang, M.
    Huazhong University of Science and Technology, China.
    Fu, S.
    Huazhong University of Science and Technology, China.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Yang, C.
    YOFC Yangtze Optical Fiber and Cable, China.
    Tong, W.
    YOFC Yangtze Optical Fiber and Cable, China.
    Liu, D.
    Huazhong University of Science and Technology, China.
    Silva, T. F. da
    National Institute of Metrology, Brazil.
    Xavier, G. B.
    Linköping University, Sweden.
    Chen, J.
    KTH Royal Institute of Technology, Sweden.
    Telecom Compatibility Validation of Quantum Key Distribution Co-Existing with 112 Gbps/$\boldsymbol{\lambda}$/core Data Transmission in Non-Trench and Trench-Assistant Multicore Fibers2018Conference paper (Refereed)
    Abstract [en]

    We experimentally characterize photon leakage from 112Gb/s data channels in both non-trench and trench-assistant 7-core fibers, demonstrating telecom compatibility for QKD co-existing with high-speed data transmission when a proper core/wavelength allocation is carried out.

  • 34.
    Lin, Rui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Gan, Lin
    Huazhong University of Science and Technology, China.
    Shen, Li
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Yang, Chen
    YOFC Yangtze Optical fiber and Cable, China.
    Tong, Weijun
    YOFC Yangtze Optical fiber and Cable, China.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Silva, Thiago
    National Institute of Metrology, Brazil.
    Xavier, Guilherme
    Linköping University, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Integrating Quantum Key Distribution with the Spatial Division Multiplexing Enabled High Capacity Optical Networks2018In: 2018 Asia Communications and Photonics Conference (ACP), 2018Conference paper (Refereed)
    Abstract [en]

    In this talk, we discuss integrating the quantum key distribution (QKD) with the spatial division multiplexing (SDM) enabled optical communication network for the cyber security.

  • 35.
    Lin, Rui
    et al.
    Huazhong University of Science and Technology, China; KTH Royal Institute of Technology, Sweden.
    Van Kerrebrouck, Joris
    Ghent University, Belgium.
    Pang, Xiaodan
    Ghent University, Belgium.
    Verplaetse, Michael
    KTH Royal Institute of Technology, Sweden; Ghent University, Belgium.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Lu
    KTH Royal Institute of Technology, Sweden.
    Gan, Lin
    Huazhong University of Science and Technology, China.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Sognian
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    Tong, Weijun
    YOFC Yangtze Optical Fiber and Cable, China.
    De Keulenaer, Timothy
    Ghent University, Belgium.
    Torfs, Gui
    Ghent University, Belgium.
    Bauwelinck, Johan
    Ghent University, Belgium.
    Yin, Xin
    Ghent University, Belgium.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Real-time 100 Gbps/lambda/core NRZ and EDB IM/DD transmission over multicore fiber for intra-datacenter communication networks2018In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, no 8, p. 10519-10526Article in journal (Refereed)
    Abstract [en]

    A BiCMOS chip-based real-time intensity modulation/direct detection spatial division multiplexing system is experimentally demonstrated for both optical interconnects. 100 Gbps/lambda/core electrical duobinary (EDB) transmission over 1 km 7-core multicore fiber (MCF) is carried out, achieving KP4 forward error correction (FEC) limit (BER < 2E-4). Using optical dispersion compensation, 7 x 100 Gbps/lambda/core transmission of both non-retunito-zero (NRZ) and EDB signals over 10 km MCF transmission is achieved with BER lower than 7% overhead hard-decision FEC limit (BER < 3.8E-3). The integrated low complexity transceiver IC and analog signal processing approach make such a system highly attractive for the high-speed intra-datacenter interconnects. (C) 2018 Optical Society of America under the terms oldie OSA open Access Publishing Agreement.

  • 36.
    Lu, Yang
    et al.
    KTH Royal Institute of Technology, Sweden ; Hangzhou Dianzi University, China.
    Agrell, Erik
    Chalmers University of Technology, Sweden.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Hong, Xuexhi
    KTH Royal Institute of Technology, Sweden.
    Lin, Rui
    KTH Royal Institute of Technology, Sweden.
    Cheng, Yuxin
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Matrix Receiving Scheme Supporting Arbitrary Multiple-Wavelength Reception for Optical Interconnects2017In: European Conference on Optical Communication, ECOC, 2017Conference paper (Refereed)
    Abstract [en]

    An arbitrary multiple-wavelength reception scheme using only a few fixed-wavelength filters is proposed for optical interconnects. Filter matrices design based on error-control coding theory is devised. The feasibility of the proposed scheme is demonstrated in a four-wavelength reception experiment.

  • 37.
    Lu, Yang
    et al.
    Hangzhou Dianzi University, China.
    Agrell, Erik
    Chalmers University of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Hong, Xuezhi
    South China Normal University, China .
    Lin, Rui
    KTH Royal Institute of Technology, Sweden.
    Cheng, Yuxin
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden ; South China Normal University, China .
    Multi-channel collision-free reception for optical interconnects2018In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, no 10, p. 13214-13222Article in journal (Refereed)
    Abstract [en]

    A multi-channel reception scheme that allows each node to receive an arbitrary set of wavelengths simultaneously (i.e., collision-free) is proposed for optical interconnects. The proposed scheme only needs to use a few receivers and fixed-wavelength filters that are designed based on error-control coding theory. Experiments with up to four channel collision-free reception units are carried out to demonstrate the feasibility of the proposed scheme.

  • 38.
    Mardoyan, Haik
    et al.
    Nokia Bell Labs, France.
    Jorge, Filipe
    III-V Lab, France.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Estaran, Jose Manuel
    Nokia Bell Labs, France.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Konczykowska, Agnieszka
    III-V Lab, France.
    Riet, Muriel
    III-V Lab, France.
    Duval, Bernadette
    III-V Lab, France.
    Nodjiadjim, Virginie
    III-V Lab, France.
    Dupuy, Jean-Yves
    III-V Lab, France.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Westergren, Urban
    KTH Royal Institute of Technology, Sweden.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Bigo, Sebastien
    Nokia Bell Labs, France.
    204-GBaud On-Off Keying Transmitter for Inter-Data Center Communications2018In: Optical Fiber Communication Conference Postdeadline Papers OSA Technical Digest (online) (Optical Society of America, 2018), paper Th4A.4, 2018, article id Th4A.4Conference paper (Refereed)
    Abstract [en]

    We demonstrate an on-off keyed transmitter with direct detection, at record symbol rates of 204Gbaud and 140Gbaud, over 10km and 80km, respectively, powered by a high-speed InP-based 2:1 selector and travelling-wave electro-absorption laser-modulator.

  • 39.
    Marinins, A.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Cylindrical polymer optical waveguides with polarization independent performance2017In: 2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings, 2017, p. 1-2Conference paper (Refereed)
    Abstract [en]

    Heating of poly(methyl methacrylate) ridge optical waveguides slightly above glass transition temperature minimizes surface roughness and provides cylindrical shape. We experimentally demonstrate propagation loss decrease and polarization insensitivity as a result of waveguide thermal treatment.

  • 40.
    Marinins, A.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Veinot, J.
    University of Alberta, Canada.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sychugov, I.
    KTH Royal Institute of Technology, Sweden.
    Linnros, J.
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    All-optical intensity modulation in polymer waveguides doped with si quantum dots2018In: Conference on Lasers and Electro-Optics OSA Technical Digest (online) (Optical Society of America, 2018), paper JW2A.31, 2018Conference paper (Refereed)
    Abstract [en]

    We demonstrate all-optical intensity modulation in integrated PMMA optical waveguides doped with silicon quantum dots. The 1550 nm probe signal is absorbed by free carriers excited in silicon quantum dots with 405 nm pump light.

  • 41.
    Marinins, Aleksandrs
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    KTH Royal Institute of Technology, Sweden.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Cylindrical polymer optical waveguides with polarization independent performance2017In: Optics InfoBase Conference Papers, 2017, article id SF1J.6Conference paper (Refereed)
    Abstract [en]

    Heating of poly(methyl methacrylate) ridge optical waveguides slightly above glass transition temperature minimizes surface roughness and provides cylindrical shape. We experimentally demonstrate propagation loss decrease and polarization insensitivity as a result of waveguide thermal treatment.

  • 42.
    Marinins, Aleksandrs
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Navarro, Jaime Rodrigo
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Thermal reflow engineered cylindrical polymer waveguides for optical interconnects2018In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 30, no 5, p. 447-450Article in journal (Refereed)
    Abstract [en]

    Integrated polymer photonics brings low cost and high fabrication flexibility to optoelectronic industry. However, this platform needs to overcome several issues to be effective enough for practical applications. In this work, we experimentally demonstrate a decrease of propagation losses and polarization sensitivity of polymer waveguide-based devices as a result of thermal treatment. Heating of poly(methyl methacrylate) strip optical waveguides above the glass transition temperature initiates a waveguide surface reflow due to a decrease of the polymer viscosity and surface tension energy. This results in a decrease of surface roughness and shape change from rectangular to cylindrical. Thus, scattering losses and polarization sensitivity are minimized. IEEE

  • 43.
    Navarro, Jaime Rodrigo
    et al.
    RISE, Swedish ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Olmedo, Miguel Iglesias
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Da Ros, Francesco
    DTU Technical University of Denmark, Denmark.
    Piels, Molly
    DTU Technical University of Denmark, Denmark.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    RISE, Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Two-stage n-PSK partitioning carrier phase recovery scheme for circular mQAM coherent optical systems2016In: Photonics, ISSN 2304-6732, Vol. 3, no 2, article id 37Article in journal (Refereed)
    Abstract [en]

    A novel two-stage n-PSK partitioning carrier phase recovery (CPR) scheme for circular multilevel quadrature amplitude modulation (C-mQAM) constellations is presented. The first stage of the algorithm provides an initial rough estimation of the received constellation, which is utilized in the second stage for CPR. The performance of the proposed algorithm is studied through extensive simulations at the forward error correction bit error rate targets of 3.8 10-3 and 1 × 10-2 and is compared with different CPR algorithms. A significant improvement in the combined linewidth symbol duration product (ΔnTs) tolerance is achieved compared to the single-stage n-PSK partitioning scheme. Superior performance in the ΔnTs tolerance compared to the blind phase search algorithm is also reported. The relative improvements with respect to other CPR schemes are also validated experimentally for a 28-Gbaud C-16QAM back-to-back transmission system. The computational complexity of the proposed CPR scheme is studied, and reduction factors of 24.5 | 30.1 and 59.1 | 63.3 are achieved for C-16QAM and C-64QAM, respectively, compared to single-stage BPS in the form of multipliers | adders.

  • 44.
    Navarro, Jaime Rodrigo
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Olmedo, Miguel Iglesias
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Carrier Phase Recovery Algorithms for Coherent Optical Circular mQAM Systems2016In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 34, no 11, p. 2717-2723Article in journal (Refereed)
    Abstract [en]

    The phase noise tolerance of circular multilevel quadrature amplitude modulation (C-mQAM) constellations employing different carrier phase recovery (CPR) algorithms is studied. A differential decoding scheme and a bit mapping for this type of constellations are proposed. A novel CPR scheme for C-mQAM constellations is also presented. The particular distribution of the constellation points in a C-mQAM signal is exploited to reduce the required Nth power for the removal of the modulation component by a factor of two. Hence, the computational complexity of the proposed algorithm is drastically reduced. The combined linewidth symbol duration product (??Ts) tolerance of different CPR algorithms for C-mQAM constellations is studied and compared with the proposed CPR scheme. The results are analyzed at 3.8e-3 and 1e-2 bit error rate forward error correction limits. The proposed CPR scheme achieves similar ??Ts tolerance compared to single stage BPS algorithm while its computational complexity is reduced by group factors of 27.2 | 32.3, and 30.5 | 32.6 (in the form of multipliers | adders) for C-16QAM and C-64QAM, respectively.

  • 45.
    Navarro, Jaime Rodrigo
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kakkar, Aditya
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Nordwall, Fredrik
    Tektronix AB, Sweden.
    Louchet, Hadrien
    VPIphotonics GmbH, Germany.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    High performance and low complexity carrier phase recovery schemes for 64-QAM coherent optical systems2017In: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Conference paper (Refereed)
    Abstract [en]

    We experimentally validate two novel CPR schemes outperforming existing CPRs in complexity and performance. A complexity reduction of at least a factor of 4 is reported compared to the BPS algorithm for a 64QAM system.

  • 46.
    Navarro, Jaime Rodrigo
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Kakkar, Aditye
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Blind phase search with angular quantization noise mitigation for efficient carrier phase recovery2017In: Photonics, ISSN 2304-6732, Vol. 4, no 2, article id 37Article in journal (Refereed)
    Abstract [en]

    The inherent discrete phase search nature of the conventional blind phase search (C-BPS) algorithm is found to introduce angular quantization noise in its phase noise estimator. The angular quantization noise found in the C-BPS is shown to limit its achievable performance and its potential low complexity implementation. A novel filtered BPS algorithm (F-BPS) is proposed and demonstrated to mitigate this quantization noise by performing a low pass filter operation on the C-BPS phase noise estimator. The improved performance of the proposed F-BPS algorithm makes it possible to significantly reduce the number of necessary test phases to achieve the C-BPS performance, thereby allowing for a drastic reduction of its practical implementation complexity. The proposed F-BPS scheme performance is evaluated on a 28-Gbaud 16QAM and 64QAM both in simulations and experimentally. Results confirm a substantial improvement of the performance along with a significant reduction of its potential implementation complexity compared to that of the C-BPS.

  • 47.
    Navarro, Jaime Rodrigo
    et al.
    RISE, Swedish ICT, Acreo.
    Olmedo, Miguel Iglesias
    KTH Royal Institute of Technology, Sweden.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Phase Noise Tolerant Carrier Recovery Scheme for 28 Gbaud Circular 16QAM2015In: 2015 European Conference on Optical Communication (ECOC), 2015, article id 7341657Conference paper (Refereed)
    Abstract [en]

    We propose a novel carrier phase recovery scheme for circular 16QAM coherent transmission systems. Experimental results show low penalties (<;1.4 dB) even for linewidths where square 16QAM exhibits irretrievable (above the FEC limit) error floor.

  • 48.
    Navarro, Jaime Rodrigo
    et al.
    RISE, Swedish ICT, Acreo.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Kakkar, Aditya
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    RISE, Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Adaptive Boundaries Scheme for Cycle-Slip Mitigation in C-mQAM Coherent Systems2015In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 27, no 20, p. 2154-2157Article in journal (Refereed)
    Abstract [en]

    We propose a method for cycle-slip mitigation in circular multilevel quadrature amplitude modulation (C-mQAM) coherent optical systems, with constellation rotational asymmetry, based on an adaptive boundaries approach. The impact of cycle-slips in C-mQAM coming from Viterbi-Viterbi algorithm limits the phase noise tolerance. By introducing adaptive boundaries and a differential coding scheme, the ambiguity of asymmetrical rotation of constellation can be effectively removed. Performance of the proposed method is evaluated for a C-16QAM and C-64QAM for various laser linewidths. Results show a noticeable improvement in linewidth symbol duration product (Δν · TS) tolerance compared with the previous studies on C-mQAM and mQAM constellations. The Δν · TS tolerance reaches 4 × 10 -4 and 1.1 × 10 -4 for C-16QAM and C-64QAM, respectively, for 1 dB penalty at a symbol error rate of 10 -3.

  • 49.
    Olmedo, Miguel Iglesias
    et al.
    KTH Royal Institute of Technology, Sweden; VPI Photonics GmBH, Germany.
    Pang, Xiaodan
    RISE, Swedish ICT, Acreo.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE, Swedish ICT, Acreo.
    Louchet, Hadrien
    VPI Photonics GmBH, Germany.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Jacobsen, Gunnar
    RISE, Swedish ICT, Acreo.
    Monroy, Idelfonso Tafur
    DTU Technical University of Denmark, Denmark.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Effective linewidth of semiconductor lasers for coherent optical data links2016In: Photonics, ISSN 2304-6732, Vol. 3, no 2, article id 39Article in journal (Refereed)
    Abstract [en]

    We discuss the implications of using monolithically integrated semiconductor lasers in high capacity optical coherent links suitable for metro applications, where the integration capabilities of semiconductor lasers make them an attractive candidate to reduce transceiver cost. By investigating semiconductor laser frequency noise profiles we show that carrier induced frequency noise plays an important role in system performance. We point out that, when such lasers are employed, the commonly used laser linewidth fails to estimate systemperformance, and we propose an alternative figure of merit that we name "Effective Linewidth". We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28 Gbaud DP-16QAM over an optical link. Our investigations cover the use of semiconductor lasers both in the transmitter side and as a local oscillator at the receiver. The obtained results show that our proposed "effective linewidth" is easy to measure and accounts for frequency noise more accurately, and hence the penalties associated to phase noise in the received signal.

  • 50.
    Osorio, Camilo
    et al.
    University of Campinas, Brazil.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Barreto, Andre
    University of Campinas, Brazil.
    Monti, Paolo
    University of Campinas, Brazil.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Mello, Darli
    University of Campinas, Brazil.
    Dual-Mode Distance-Adaptive Transceiver Architecture for 5G Optical Fiber Fronthaul2018Conference paper (Refereed)
    Abstract [en]

    We propose a transceiver architecture for 5G fronthaul that adapts the modulation format according to the channel quality. The proposed solution operates in dual-mode using digital signal processing (DSP)-assisted analog radio-over-fiber (A-RoF) and digital radio-over-fiber (D-RoF) with multiple modulation orders. The system performance is assessed through Monte-Carlo simulations of the optical fiber link conveying wireless waveforms that utilize the filter bank multicarrier (FBMC) and orthogonal frequency-division multiplexing (OFDM) formats. The simulation results highlight the benefits of having both digital and DSP-assisted analog transmission capabilities to optimize the reach versus spectral efficiency trade-off in optical fronthaul.

12 1 - 50 of 93
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.7