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  • 1.
    Alcusa-Sáez, E. P.
    et al.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Díez, Antonio
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Rivera-Pérez, E.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Margulis, Walter
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Norin, L.
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Andrés, M. V.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Acousto-optic interaction in polyimide coated optical fibers with flexural waves2017Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 25, nr 15, s. 17167-17173Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.

  • 2.
    Brunetti, Anna Chiara
    et al.
    DTU Technical University of Denmark, Denmark.
    Margulis, Walter
    RISE., Swedish ICT, Acreo.
    Rottwitt, Karsten
    DTU Technical University of Denmark, Denmark.
    Raman probes based on optically-poled double-clad fiber and coupler2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 27, s. 28563-28572Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two fiber Raman probes are presented, one based on an optically-poled double-clad fiber and the second based on an opticallypoled double-clad fiber coupler respectively. Optical poling of the core of the fiber allows for the generation of enough 532nm light to perform Raman spectroscopy of a sample of dimethyl sulfoxide (DMSO), when illuminating the waveguide with 1064nm laser light. The Raman signal is collected in the inner cladding, from which it is retrieved with either a bulk dichroic mirror or a double-clad fiber coupler. The coupler allows for a substantial reduction of the fiber spectral background signal conveyed to the spectrometer.

  • 3.
    Camara, A.
    et al.
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. Pontifícia Universidade Católica do Rio de Janeiro,Brazil.
    Tarasenko, O.
    RISE., Swedish ICT, Acreo.
    Margulis, W.
    RISE., Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Study of thermally poled fibers with a two-dimensional model2014Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 22, s. 17700-15Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A two-dimensional (2D) numerical model is implemented to describe the movement of ions under thermal poling for the specific case of optical fibers. Three types of cations are considered (representing Na+, Li + and H3O+) of different mobility values. A cross-sectional map of the carrier concentration is obtained as a function of time. The role of the various cations is investigated. The assumptions of the model are validated by comparing the predictions to experimental data of the time evolution of the nonlinearity induced. A variational analysis of poling parameters including temperature, poling voltage, sign of the bias potential and initial ionic concentrations is performed for a particular fiber geometry. The analysis allows identifying the impact of these parameters on the induced secondorder nonlinearity in poled fibers.

  • 4.
    Camara, Alexandre R.
    et al.
    Rio de Janeiro State University, Brazil; Pontifical Catholic University of Rio de Janeiro, Brazil.
    Pereira, Joao
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Tarasenko, Oleksandr
    RISE., Swedish ICT, Acreo, Fiber Optics.
    Margulis, Walter
    RISE., Swedish ICT, Acreo, Fiber Optics. KTH Royal Institute of Technology, Sweden.
    Carvalho, Isabel C. S.
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Optical creation and erasure of the linear electrooptical effect in silica fiber2015Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 23, nr 14, s. 18060-18069Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We study the creation and erasure of the linear electrooptical effect in silicate fibers by optical poling. Carriers are released by exposure to green light and displaced with simultaneous application of an internal dc field. The second order nonlinear coefficient induced grows with poling bias. The field recorded (~108 V/m) is comparable to that obtained through classical thermal poling of fibers. In the regime studied here, the second-order nonlinearity induced (~0.06 pm/V) is limited by the field applied during poling (1.2 × 108 V/m). Optical erasure with high-power green light alone is very efficient. The dynamics of the writing and erasing process is discussed, and the two dimensional (2D) field distribution across the fiber is simulated.

  • 5. Candiani, A
    et al.
    Konstantaki, M
    Margulis, W
    RISE., Swedish ICT, Acreo.
     Pissadakis, S
    A spectrally tunable microstructured optical fibre Bragg grating utilizing an infiltrated ferrofluid2010Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 18, nr 24, s. 24654-Artikkel i tidsskrift (Fagfellevurdert)
  • 6. Chughtai, M. N.
    et al.
    Forzati, M.
    RISE., Swedish ICT, Acreo.
    Mårtensson, Jonas
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Rafique, D.
    Influence of polarization state, baud rate PMD on non-linear impairments in WDM systems with mixed PM (D)QPSK OOK channels2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 7, s. 8155-60Artikkel i tidsskrift (Fagfellevurdert)
  • 7.
    Coppel, L.G.
    et al.
    RISE., Innventia.
    Neuman, M.
    Edström, P.
    Lateral light scattering in paper: MTF simulation and measurement2011Inngår i: Optics Express, E-ISSN 1094-4087, nr 25, s. 25181-25187Artikkel i tidsskrift (Fagfellevurdert)
  • 8.
    Coronel, Edvin
    et al.
    Universidade Federal de Pernambuco, Brazil.
    Das, Avishek
    Universidade Federal de Pernambuco, Brazil.
    Gonzalez, Ivan
    RISE Research Institutes of Sweden.
    Gomes, Anderson
    KTH Royal Institute of Technology, Sweden.
    Margulis, Walter
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Von Der Weid, JP
    Universidade Federal de Pernambuco, Brazil.
    Raposo, Ernesto
    Universidade Federal de Pernambuco, Brazil.
    Evaluation of Pearson correlation coefficient and Parisi parameter of replica symmetry breaking in a hybrid electronically addressable random fiber laser2021Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 29, nr 15, s. 24422-24433Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The hybrid electronically addressable random (HEAR) laser is a novel type of random fiber laser that presents the remarkable property of selection of the fiber section with lasing emission. Here we present a joint analysis of the correlations between intensity fluctuations at distinct wavelengths and replica symmetry breaking (RSB) behavior of the HEAR laser. We introduce a modified Pearson coefficient that simultaneously comprises both the Parisi overlap parameter and standard Pearson correlation coefficient. Our results highlight the contrast between the correlations and presence or not of RSB phenomenon in the spontaneous emission behavior well below threshold, replica-symmetric ASE regime slightly below threshold, and RSB phase with random lasing emission above threshold. In particular, in the latter we find that the onset of RSB behavior is accompanied by a stochastic dynamics of the lasing modes, leading to competition for gain intertwined with correlation and anti-correlation between modes in this complex photonic phase. 

  • 9.
    Dely, H.
    et al.
    CNRS, France.
    Joharifar, M.
    KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE Research Institutes of Sweden, Digitala system, Industriella system. KTH Royal Institute of Technology, Sweden.
    Gacemi, D.
    CNRS, France.
    Salgals, T.
    Riga Technical University, Latvia.
    Schatz, R.
    KTH Royal Institute of Technology, Sweden.
    Sun, Y. -T
    KTH Royal Institute of Technology, Sweden.
    Bonazzi, T.
    CNRS, France.
    Rodriguez, E.
    CNRS, France.
    Todorov, Y.
    CNRS, France.
    Vasanelli, A.
    CNRS, France.
    Udalcovs, Aleksejs
    RISE Research Institutes of Sweden.
    Spolitis, S.
    Riga Technical University, Latvia.
    Bobrovs, V.
    Riga Technical University, Latvia.
    Ozolins, Oskars
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Sirtori, C.
    CNRS, France.
    High bitrate data transmission in the 8-14 µm atmospheric window using an external Stark-effect modulator with digital equalization2023Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 31, nr 5, s. 7259-7264Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High bitrate mid-infrared links using simple (NRZ) and multi-level (PAM-4) data coding schemes have been realized in the 8 µm to 14 µm atmospheric transparency window. The free space optics system is composed of unipolar quantum optoelectronic devices, namely a continuous wave quantum cascade laser, an external Stark-effect modulator and a quantum cascade detector, all operating at room-temperature. Pre- and post-processing are implemented to get enhanced bitrates, especially for PAM-4 where inter-symbol interference and noise are particularly detrimental to symbol demodulation. By exploiting these equalization procedures, our system, with a full frequency cutoff of 2 GHz, has reached transmission bitrates of 12 Gbit/s NRZ and 11 Gbit/s PAM-4 fulfilling the 6.25 % overhead hard-decision forward error correction threshold, limited only by the low signal-to-noise ratio of our detector. 

  • 10.
    Deniel, L.
    et al.
    CNRS Univ Paris-Sud, France.
    Gay, M.
    CNSR Univ Rennes, France.
    Pérez Galacho, D.
    CNRS Univ Paris-Sud, France; Universitat Politècnica de València, Spain.
    Baudot, C.
    ST Microelectronics, France.
    Bramerie, L.
    CNSR Univ Rennes, France.
    Ozolins, Oskars
    KTH Royal Institute of Technology, Sweden.
    Boeuf, F.
    ST Microelectronics, France.
    Vivien, L.
    CNRS Univ Paris-Sud, France.
    Peucheret, C.
    CNSR Univ Rennes, France.
    Marris-Morini, D.
    CNRS Univ Paris-Sud, France.
    DAC-less PAM-4 generation in the O-band using a silicon Mach-Zehnder modulator2019Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 27, nr 7, s. 9740-9748Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate 20-Gb/s 4-level pulse amplitude modulation (PAM-4) signal generation using a silicon Mach-Zehnder modulator (MZM) in the O-band. The modulator is driven by two independent binary streams, and the PAM-4 signal is thus generated directly on the chip, avoiding the use of power-hungry digital-to-analog converters (DACs). With optimized amplitude levels of the binary signals applied to the two arms of the MZM, a pre-forward error correction (FEC) bit-error rate (BER) as low as 7.6 × 10 −7 is obtained. In comparison with a commercially available LiNbO 3 modulator, the penalty is only 2 dB at the KP4 FEC threshold of 2.2 × 10 −4

  • 11. Deschout, H.
    et al.
    Hagman, Joel
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SIK – Institutet för livsmedel och bioteknik.
    Fransson, S.
    Jonasson, J.
    Rudemo, M.
    Loren, Niklas
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SIK – Institutet för livsmedel och bioteknik.
    Straightforward FRAP for quantitative diffusion measurements with a laser scanning microscope2010Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 18, nr 22, s. 22886-22905Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Confocal or multi-photon laser scanning microscopes are convenient tools to perform FRAP diffusion measurements. Despite its popularity, accurate FRAP remains often challenging since current methods are either limited to relatively large bleach regions or can be complicated for non-specialists. In order to bring reliable quantitative FRAP measurements to the broad community of laser scanning microscopy users, here we have revised FRAP theory and present a new pixel based FRAP method relying on the photo bleaching of rectangular regions of any size and aspect ratio. The method allows for fast and straightforward quantitative diffusion measurements due to a closed-form expression for the recovery process utilizing all available spatial and temporal data. After a detailed validation, its versatility is demonstrated by diffusion studies in heterogeneous biopolymer mixtures. © 2010 Optical Society of America.

  • 12.
    Etcheverry, Sebastian
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Russom, A.
    KTH Royal Institute of Technology, Sweden.
    Laurell, F.
    KTH Royal Institute of Technology, Sweden.
    Margulis, Walter
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Fluidic trapping and optical detection of microparticles with a functional optical fiber2017Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 25, nr 26, s. 33657-33663Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A fiber probe is presented that traps single micro-sized particles and allows detection of their optical properties. The trapping mechanism used is based on fluid suction with a micro-structured optical fiber that has five holes along its cladding. Proof-of-principle experiments with a diluted solution of fluorescently labeled particles are performed. The fiber probe presented here may find various applications in life-science and environmental monitoring. ©

  • 13.
    Gustafsson, Oscar
    et al.
    KTH Royal Institute of Technology, Sweden.
    Karim, Amir
    RISE., Swedish ICT, Acreo.
    Berggren, Jesper
    KTH Royal Institute of Technology, Sweden.
    Wang, Qin
    RISE., Swedish ICT, Acreo.
    Reuterskiöld-Hedlund, Carl
    KTH Royal Institute of Technology, Sweden.
    Ernerheim-Jokumsen, Christopher
    KTH Royal Institute of Technology, Sweden.
    Soldemo, Markus A.
    KTH Royal Institute of Technology, Sweden.
    Weissenrieder, Jonas
    KTH Royal Institute of Technology, Sweden.
    Persson, Sirpa
    RISE., Swedish ICT, Acreo.
    Almqvist, Susanne
    RISE., Swedish ICT, Acreo.
    Ekenberg, Ulf A.
    KTH Royal Institute of Technology, Sweden.
    Noharet, Bertrand
    RISE., Swedish ICT, Acreo.
    Asplund, Carl
    IRnova AB, Sweden.
    Göthelid, Mats
    KTH Royal Institute of Technology, Sweden.
    Andersson, Jan Y.
    RISE., Swedish ICT, Viktoria.
    Hammar, Mattias
    KTH Royal Institute of Technology, Sweden.
    Photoluminescence photoresponse from InSb/InAs-based quantum dot structures2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 19, s. 21264-71Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    InSb-based quantum dots grown by metal-organic vapor-phase epitaxy (MOVPE) on InAs substrates are studied for use as the active material in interband photon detectors. Long-wavelength infrared (LWIR) photoluminescence is demonstrated with peak emission at 8.5 μm and photoresponse, interpreted to originate from type-II interband transitions in a p-i-n photodiode, was measured up to 6 μm, both at 80 K. The possibilities and benefits of operation in the LWIR range (8-12 μm) are discussed and the results suggest that InSb-based quantum dot structures can be suitable candidates for photon detection in the LWIR regime.

  • 14.
    Han, M.
    et al.
    Beijing Jiaotong University, China.
    Wang, M.
    Beijing Jiaotong University, China.
    Fan, Yuchuan
    RISE Research Institutes of Sweden, Digitala system, Industriella system. KTH Royal Institute of Technology, Sweden.
    Cai, S.
    Beijing Jiaotong University, China.
    Guo, Y.
    Beijing Jiaotong University, China.
    Zhang, N.
    Beijing Jiaotong University, China.
    Schatz, Rickard
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE Research Institutes of Sweden, Digitala system, Industriella system. KTH Royal Institute of Technology, Sweden.
    Pang, Xiaodan
    RISE Research Institutes of Sweden, Digitala system, Industriella system. KTH Royal Institute of Technology, Sweden.
    Simultaneous modulation format identification and OSNR monitoring based on optoelectronic reservoir computing2022Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 30, nr 26, s. 47515-47527Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An approach for simultaneous modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring in digital coherent optical communications is proposed based on optoelectronic reservoir computing (RC) and the signal’s amplitude histograms (AHs) obtained after the adaptive post-equalization. The optoelectronic RC is implemented using a Mach-Zehnder modulator and optoelectronic delay feedback loop. We investigate the performance of the proposed model with the number of symbols, bins of AHs and the hyperparameters of optoelectronic RC. The results show that 100% MFI accuracy can be achieved simultaneously with accurate OSNR estimation for different modulation formats under study. The lowest achievable OSNR estimation mean absolute errors for the dual-polarization (DP)-quadrature phase-shift keying signal, the DP-16-ary quadrature amplitude modulation (16QAM) signal, and the DP-64QAM signal are 0.2 dB, 0.32 dB and 0.53 dB, respectively. The robustness of the proposed scheme is also evaluated when the optoelectronic RC is in presence of additive white Gaussian noises. Then, a proof of concept experiment is demonstrated to further verify our proposed method. The proposed approach offers a potential solution for next-generation intelligent optical performance monitoring in the physical layer.

  • 15.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, T
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    EEPN CD study for coherent optical nPSK nQAM systems with RF pilot based phase noise compensation2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 8, s. 8862-70Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, T
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    Receiver implemented RF pilot tone phase noise mitigation in coherent optical nPSK nQAM systems2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 15, s. 14487-94Artikkel i tidsskrift (Fagfellevurdert)
  • 17.
    Jacobsen, Gunnar
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, Tianhua
    RISE., Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Popov, Sergei Yu
    KTH Royal Institute of Technology, Sweden.
    Sergeyev, Sergey V.
    Aston University, United Kingdom.
    Study of EEPN mitigation using modified RF pilot and Viterbi-Viterbi based phase noise compensation2013Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 21, nr 10, s. 12351-12362Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We propose - as a modification of the optical (RF) pilot scheme -a balanced phase modulation between two polarizations of the optical signal in order to generate correlated equalization enhanced phase noise (EEPN) contributions in the two polarizations. The method is applicable for n-level PSK system. The EEPN can be compensated, the carrier phase extracted and the nPSK signal regenerated by complex conjugation and multiplication in the receiver. The method is tested by system simulations in a single channel QPSK system at 56 Gb/s system rate. It is found that the conjugation and multiplication scheme in the Rx can mitigate the EEPN to within 1/2 orders of magnitude. Results are compared to using the Viterbi-Viterbi algorithm to mitigate the EEPN. The latter method improves the sensitivity more than two orders of magnitude. Important novel insight into the statistical properties of EEPN is identified and discussed in the paper.

  • 18. Johansson, S
    et al.
    Bjurshagen, S
    Canalias, C
    Pasiskevicius, V
    Laurell, F
     Koch, R
    RISE., Swedish ICT, Acreo.
    An all solid-state UV source based on a frequency quadrupled, passively Q-switched 946 nm laser2007Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 15, nr 2, s. 449-58Artikkel i tidsskrift (Fagfellevurdert)
  • 19. Junique, S
    et al.
    Wang, Q
    Almqvist, S
    Noharet, B
    Andersson, JY    
    RISE., Swedish ICT, Viktoria.
    Large-area, three-state, binary amplitude binary phase vertical-cavity multiple quantum well electroabsorption modulator2007Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 15, nr 14, s. 8566-75Artikkel i tidsskrift (Fagfellevurdert)
  • 20.
    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 compensation2015Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 23, nr 9, s. 11221-11226Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 21.
    Lin, Rui
    et al.
    Huazhong University of Science and Technology, China; KTH Royal Institute of Technology, Sweden.
    Kerrebrouck, Joris
    Ghent University, Belgium.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Verplaetse, Michiel
    Ghent University, Belgium.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Zhang, Lu
    KTH Royal Institute of Technology, Sweden; Shanghai Jiao Tong Universit, China.
    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
    fYangtze Optical fiber and Cable Joint Stock Limited Company, China.
    Keulenaer, Timothy
    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/λ/core NRZ and EDB IM/DD transmission over multicore fiber for intra-datacenter communication networks2018Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 26, nr 8, s. 10519-10526Artikkel i tidsskrift (Fagfellevurdert)
    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/λ/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 × 100 Gbps/λ/core transmission of both non-return-to-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..

  • 22.
    Lindberg, Robert
    et al.
    KTH Royal Institute of Technology, Sweden.
    Laurell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Fröjdh, Krister
    Proximion AB, Sweden.
    Margulis, Walter
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. KTH Royal Institute of Technology, Sweden.
    C-cavity fiber laser employing a chirped fiber Bragg grating for electrically gated wavelength tuning2020Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 28, nr 7, s. 9208-9215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a novel C-cavity concept for tunable lasers. The laser is based on a semiconductor optical amplifier (SOA), serving both as a gain medium as well as a modulator, and a chirped fiber Bragg grating (C-FBG) which acts as the end mirrors on both cavity ends. Driving the SOA with a pulse pair with variable delay enables wavelength tuning by targeting different regions in the C-FBG with the circulating pulse. The cavity design allows for wide tuning while maintaining a constant repetition rate, we show a tuning range of 35 nm -limited by the C-FBG's reflection bandwidth. Time-multiplexed operation with four different wavelengths is also demonstrated. Furthermore, the laser performance and dynamics under different operating conditions are analyzed and discussed.

  • 23.
    Lu, Yang
    et al.
    Hangzhou Dianzi University, China.
    Agrell, Erik
    Chalmers University of Technology, Sweden.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden (2017-2019), 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 (2017-2019), ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Chen, Jiajia
    KTH Royal Institute of Technology, Sweden ; South China Normal University, China .
    Multi-channel collision-free reception for optical interconnects2018Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 26, nr 10, s. 13214-13222Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 24.
    Magalhaes, Regina
    et al.
    University of Alcala, Spain.
    Garcia-Ruiz, Andres
    University of Alcala, Spain.
    Martins, Hugo
    University of Alcala, Spain.
    Pereira, Joao
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Margulis, Walter
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Martin-Lopez, Sonia
    University of Alcala, Spain.
    Gonzalez-Herraez, Miguel
    University of Alcala, Spain.
    Fiber-based distributed bolometry2019Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 27, nr 4, s. 4317-4328Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optical fibers are inherently designed to allow no interaction between the guided light and the surrounding optical radiation. Thus, very few optical fiber-based technologies exist in the field of optical radiation sensing. Accomplishing fully-distributed optical radiation sensing appears then as even more challenging since, on top of the lack of sensitivity explained above, we should add the need of addressing thousands of measurement points in a single, continuous optical cable. Nevertheless, it is clear that there exist a number of applications which could benefit from such a distributed sensing scheme, particularly if the sensitivity was sufficiently high to be able to measure correctly variations in optical radiation levels compatible with the earth surface. Distributed optical radiation sensing over large distances could be employed in applications such as Dynamic Line Rating (DLR), where it is known that solar radiation can be an important limiting factor in energy transmission through overhead power cables, and also in other applications such as thermo-solar energy. In this work, we present the proof-of-concept of the first distributed bolometer based on optical fiber technology and capable of detecting absolute changes of irradiance. The core idea of the system is the use of a special fiber coating with high emissivity (e.g., carbon coating or black paint). The high absorption of these coatings translates into a temperature change that can be read with sufficiently high sensitivity using phase-sensitive reflectometry. To demonstrate the concept, we interrogate distinct black-coated optical fibers using a chirped-pulse ÖOTDR, and we readily demonstrate the detection of light with resolutions in the order of 1% of the reference solar irradiance, offering a high-potential technology for integration in the aforementioned applications.

  • 25. Malmström, M
    et al.
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Tarasenko, O
    RISE., Swedish ICT, Acreo.
    Pasiskevicius, V
    Laurell, F
    Soliton generation from an actively mode-locked fiber laser incorporating an electro-optic fiber modulator2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 3, s. 2905-Artikkel i tidsskrift (Fagfellevurdert)
  • 26. Malmström, M
    et al.
    Tarasenko, O
    RISE., Swedish ICT, Acreo.
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Pulse selection at 1 MHz with electrooptic fiber switch2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 9, s. 9465-70Artikkel i tidsskrift (Fagfellevurdert)
  • 27. Malmström, M
    et al.
    Yu, Z
    RISE., Swedish ICT, Acreo.
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Tarasenko, O
    RISE., Swedish ICT, Acreo.
    Laurell, F
    All-fiber cavity dumping2009Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 17, nr 20, s. 17596-602Artikkel i tidsskrift (Fagfellevurdert)
  • 28.
    Margulis, Walter
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. KTH Royal Institute of Technology, Sweden.
    Das, Avishek
    Universidade Federal de Pernambuco, Brazil.
    von der Weid, JP
    University of Rio de Janeiro, Brazil.
    Gomes, Anderson
    Universidade Federal de Pernambuco, Brazil.
    Hybrid electronically addressable random fiber laser2020Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 28, nr 16, s. 23388-23396Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report here a novel architecture for a random fiber laser exploiting the combination of a semiconductor optical amplifier (SOA) and an erbium doped fiber (EDF). The EDF was optically biased by a continuous wave pump laser, whereas the SOA was arranged in a fiber loop-mirror and driven by nanosecond duration current pulses. Laser pulses were obtained by synchronizing the SOA driver to the returning amplified Rayleigh back-scattered light from a selected short section of the EDF. By tuning the SOA pulse rate, random lasing was achieved by addressing selected meter-long sections of the 81-m long EDF, which was open-ended. Laser oscillation can be potentially obtained with SOA modulation frequencies from several kHz to the MHz regime. We discuss the mechanism leading to the hybrid random laser emission, connecting with phase sensitive optical time domain reflectometry and envision potential applications of this electronically addressable random laser.

  • 29.
    Margulis, Walter
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. KTH Royal Institute of Techology, Sweden.
    Lindberg, Robert
    KTH Royal Institute of Techology, Sweden.
    Laurell, Fredrik
    KTH Royal Institute of Techology, Sweden.
    Hedin, Gunnar
    Proximion AB, Sweden.
    Intracavity interrogation of an array of fiber Bragg gratings2021Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 29, nr 1, s. 111-118Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, we explore the interrogation of an array of fiber Bragg gratings as part of a laser cavity. A semiconductor optical amplifier in a sigma-shaped fiber cavity provides gain and is gated periodically at a rate that matches the roundtrip time associated with each grating of the array. The interrogator exhibits clear laser properties such as a threshold and linewidth narrowing. Besides improving the signal-to-noise ratio and enabling the re-use of wavelengths, it is found that this interrogation scheme enables monitoring of weak gratings spaced by less than 1 cm. Intracavity grating interrogation studied here is found to be a simple and powerful way to increase the number of sensor points for industrial applications. 

  • 30.
    Montiel I Ponsoda, Joan J.
    et al.
    Aalto University, Finland.
    Norin, Lars
    RISE., Swedish ICT, Acreo.
    Ye, Changgeng
    NLIGHT Corporation, Finland.
    Bosund, Markus
    Beneq Oy, Finland.
    Söderlund, Mikko J.
    Beneq Oy, Finland.
    Tervonen, Ari
    Aalto University, Finland.
    Honkanen, Seppo K.
    University of Eastern Finland, Finland.
    Ytterbium-doped fibers fabricated with atomic layer deposition method2012Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 20, nr 22, s. 25085-95Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a new fabrication method of producing ytterbium doped fibers by atomic layer deposition (ALD) in combination with the conventional modified chemical vapor deposition (MCVD) technique. An MCVD soot-preform with a porous layer of SiO2 is coated with layers of Yb2O3 and Al2O3 prior to sintering, using the gas-phase ALD method. An SEM/EDS material analysis study shows that the dopants successfully penetrate the full thickness of 320 μm of the soot layer. An Yb-doped fiber fabricated by this technique shows a background attenuation of 20 dB/km, a uniform longitudinal Yb-doping profile, and good laser characteristics with a slope efficiency of 80%. Furthermore, we present a comparison in terms of photodarkening between the MCVD-ALD fiber and a solution doped fiber, fabricated with the same MCVD recipe. The new MCVD-ALD fiber appears to be more photodarkening resistant.

  • 31.
    Murnieks, Rihards
    et al.
    Riga Technical University, Latvia.
    Salgals, Toms
    Riga Technical University, Latvia.
    Alnis, Janis
    University of Latvia, Latvia.
    Ostrovskis, Armands
    Riga Technical University, Latvia.
    Ozolins, Oskars
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Riga Technical University, Latvia; KTH Royal Institute of Technology, Sweden.
    Brice, Inga
    University of Latvia, Latvia.
    Sedulis, Arvids
    Riga Technical University, Latvia; University of Latvia, Latvia.
    Draguns, Kristians
    University of Latvia, Latvia.
    Lyashuk, Ilya
    Riga Technical University, Latvia.
    Berkis, Roberts
    University of Latvia, Latvia; University of Innsbruck, Austria.
    Udalcovs, Aleksejs
    RISE Research Institutes of Sweden.
    Bi, Toby
    Max Planck Institute, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany.
    Pang, Xiaodan
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Riga Technical University, Latvia; KTH Royal Institute of Technology, Sweden.
    Porins, Jurgis
    Riga Technical University, Latvia.
    Spolitis, Sandis
    Riga Technical University, Latvia.
    Del' Haye, Pascal
    Max Planck Institute, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany.
    Bobrovs, Vjaceslavs
    Riga Technical University, Latvia.
    Silica micro-rod resonator-based Kerr frequency comb for high-speed short-reach optical interconnects.2023Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 31, nr 12, s. 20306-20320Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Conventional data center interconnects rely on power-hungry arrays of discrete wavelength laser sources. However, growing bandwidth demand severely challenges ensuring the power and spectral efficiency toward which data center interconnects tend to strive. Kerr frequency combs based on silica microresonators can replace multiple laser arrays, easing the pressure on data center interconnect infrastructure. Therefore, we experimentally demonstrate a bit rate of up to 100 Gbps/λ employing 4-level pulse amplitude modulated signal transmission over a 2 km long short-reach optical interconnect that can be considered a record using any Kerr frequency comb light source, specifically based on a silica micro-rod. In addition, data transmission using the non-return to zero on-off keying modulation format is demonstrated to achieve 60 Gbps/λ. The silica micro-rod resonator-based Kerr frequency comb light source generates an optical frequency comb in the optical C-band with 90 GHz spacing between optical carriers. Data transmission is supported by frequency domain pre-equalization techniques to compensate amplitude–frequency distortions and limited bandwidths of electrical system components. Additionally, achievable results are enhanced with offline digital signal processing, implementing post-equalization using feed-forward and feedback taps.

  • 32. Myren, N
    et al.
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Time evolution of frozen in-field during thermal poling of fused silica optical fibers with internal alloy electrodes2005Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 13, nr 9, s. 3438-Artikkel i tidsskrift (Fagfellevurdert)
  • 33. Myren, N
    et al.
    Olsson, H
    RISE., Swedish ICT, Acreo.
    Norin, L
    RISE., Swedish ICT, Acreo.
    Sjödin, N
    Helander, P
    RISE., Swedish ICT, Acreo.
    Svennebrink, J
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Wide wedge-shaped depletion region in thermally poled fiber with alloy electrodes2004Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 12, nr 25, s. 6093-Artikkel i tidsskrift (Fagfellevurdert)
  • 34. Neuman, M.
    et al.
    Coppel, L.G.
    RISE., Innventia.
    Edström, P.
    Point spreading in turbid media with anisotropic single scattering2011Inngår i: Optics Express, E-ISSN 1094-4087, nr 3, s. 1915-1920Artikkel i tidsskrift (Fagfellevurdert)
  • 35. Olsson, B-E
    et al.
    Djupsjöbacka, Anders
    RISE., Swedish ICT, Acreo.
    Mårtensson, Jonas
    RISE., Swedish ICT, Acreo.
    Alping, A.
    112-Gbit/s RF-assisted dual carrier DP-16-QAM transmitter using optical phase modulator2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 26, s. 784-789Artikkel i tidsskrift (Fagfellevurdert)
  • 36.
    Pereira, Joao
    et al.
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Camara, Alexandre
    Universidade do Estado do Rio de Janeiro, Brazil.
    Laurell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Tarasenko, Oleksander
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo.
    Margulis, Walter
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Linear electro-optical effect in silica fibers poled with ultraviolet lamp2019Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 27, nr 10, s. 14893-14902Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A second-order nonlinearity was induced in silica fibers poled by exposure to ultraviolet (UV) radiation and simultaneous high voltage applied to internal electrodes. The UV light source was a tubular lamp with spectral peak at 254 nm. The highest second-order nonlinear coefficient measured through the linear electro-optic effect was 0.062 pm/V. The erasure of the recorded voltage with UV excitation was studied, and the stability of the poled fiber at a temperature exceeding ~400 K was investigated. By eliminating the use of a focused laser beam as excitation source, the technique enables poling many pieces of fiber in parallel.

  • 37.
    Pereira, Joao
    et al.
    KTH Royal Institute of Technology, Sweden.
    Grüner-Nielsen, Lars
    DTU Technical University of Denmark, Denmark.
    Rottwitt, Karsten
    DTU Technical University of Denmark, Denmark.
    Town, Graham
    Macquarie University, Australia.
    Laurell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Margulis, Walter
    KTH Royal Institute of Technology, Sweden; Fiberactivity Ltda, Brazil.
    Electrooptic control of the modal distribution in a silicate fiber2022Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 30, nr 8, s. 12474-12483Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate the use of the electrooptic effect to control the propagation constant of the guided modes in silicate few mode fibers with internal electrodes. The electrooptic effect induces a perturbation of the fiber's refractive index profile that controls intermodal interference. To increase the electrooptic effect the silicate fibers are poled. The response time is in the nanosecond range. 

  • 38.
    Pereira, Joao
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. KTH Royal Institute of Technology, Sweden.
    Tarasenko, Oleksander
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Claesson, Åsa
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Laurell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Margulis, Walter
    KTH Royal Institute of Technology, Sweden; Fiberactivity Ltda, Brazil.
    Optical poling by means of electrical corona discharge2022Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 30, nr 12, s. 20605-20613Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrical corona discharge is employed in this work to deposit ions on the surface of an optical fiber, creating a strong electric field that is used for poling. Green laser light propagating in the core frees photocarriers that are displaced by the poling field. The technique presented can induce a higher optical nonlinearity than previously obtained in traditional optical poling with internal metal electrodes. To date, a maximum second order nonlinearity 0.13 pm/V has been achieved for a 15 kV corona discharge bias. 

  • 39. Rafique, D.
    et al.
    Mussolin, M.
    Forzati, M.
    RISE., Swedish ICT, Acreo.
    Mårtensson, Jonas
    RISE., Swedish ICT, Acreo.
    Chugtai, M. N.
    Ellis, A. D.
    Compensation of intra-channel nonlinear fibre impairments using simplified digital back-propagation algorithm2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 10, s. 9453-60Artikkel i tidsskrift (Fagfellevurdert)
  • 40. Rafique, D.
    et al.
    Mussolin, M.
    Mårtensson, Jonas
    RISE., Swedish ICT, Acreo.
    Forzati, M.
    RISE., Swedish ICT, Acreo.
    Fischer, J. K.
    Molle, L.
    Nölle, M.
    Schubert, C.
    Ellis, A. D.
    Polarization multiplexed 16QAM transmission employing modified digital back-propagation2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 26, s. b805-10Artikkel i tidsskrift (Fagfellevurdert)
  • 41.
    Rebolledo-Salgado, Israel
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Chalmers University of Technology, Sweden.
    Ye, Zhichao
    Chalmers University of Technology, Sweden.
    Christensen, Simon
    DTU Technical University of Denmark, Denmark.
    Lei, Fuchuan
    Chalmers University of Technology, Sweden.
    Twayana, Krishna
    Chalmers University of Technology, Sweden.
    Schröder, Jochen
    Chalmers University of Technology, Sweden.
    Zelan, Martin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Torres-Company, Victor
    Chalmers University of Technology, Sweden.
    Coherent supercontinuum generation in all-normal dispersion Si3N4 waveguides2022Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 30, nr 6, s. 8641-8651Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spectral broadening of optical frequency combs with high repetition rate is of significant interest in optical communications, radio-frequency photonics and spectroscopy. Silicon nitride waveguides (Si3N4) in the anomalous dispersion region have shown efficient supercontinuum generation spanning an octave-bandwidth. However, the broadening mechanism in this regime is usually attained with femtosecond pulses in order to maintain the coherence. Supercontinuum generation in the normal dispersion regime is more prone to longer (ps) pulses, but the implementation in normal dispersion silicon nitride waveguides is challenging as it possesses strong requirements in propagation length and losses. Here, we experimentally demonstrate the use of a Si3N4 waveguide to perform coherent spectral broadening using pulses in the picosecond regime with high repetition rate. Moreover, our work explores the formation of optical wave breaking using a higher energy pulse which enables the generation of a coherent octave spanning spectrum. These results offer a new prospect for coherent broadening using long duration pulses and replacing bulky optical components.

  • 42.
    Rugeland, Patrik
    et al.
    RISE., Swedish ICT, Acreo, Fiber Optics.
    Sterner, Carola
    RISE., Swedish ICT, Acreo, Fiber Optics.
    Margulis, Walter
    RISE., Swedish ICT, Acreo, Fiber Optics.
    Visible light guidance in silica capillaries by antiresonant reflection2013Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 21, nr 24, s. 29217-29222Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hollow silica capillaries are examined as optical waveguides evaluating the antiresonant reflecting optical waveguide (ARROW) effect by sequentially reducing the wall thickness through etching and measuring the optical transmission. It is found that the periodicity of the transmission bands is proportional to the wall thickness and that the propagation loss is of the order of a few dB/m.

  • 43.
    Silander, Isak
    et al.
    Umeå University, Sweden.
    Zakrisson, Johan
    Umeå University, Sweden.
    Silva De Oliveira, Vinicius
    Umeå University, Sweden.
    Forssén, Clayton
    Umeå University, Sweden.
    Foltynowicz, Aleksandra
    Umeå University, Sweden.
    Rubin, Tom
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Zelan, Martin
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Axner, Ove
    Umeå University, Sweden.
    In situ determination of the penetration depth of mirrors in Fabry-Perot refractometers and its influence on assessment of refractivity and pressure2022Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 30, nr 14, s. 25891-25906Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A procedure is presented for in situ determination of the frequency penetration depth of coated mirrors in Fabry-Perot (FP) based refractometers and its influence on the assessment of refractivity and pressure. It is based on assessments of the absolute frequency of the laser and the free spectral range of the cavity. The procedure is demonstrated on an Invar-based FP cavity system with high-reflection mirrors working at 1.55 µm. The influence was assessed with such a low uncertainty that it does not significantly contribute to the uncertainties (k = 2) in the assessment of refractivity (&lt;8 × 10−13) or pressure of nitrogen (&lt;0.3 mPa).

  • 44. Sudirman, A
    et al.
     Björk, G
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Reflectometry, ablation fluid retrieval with an optical fiber2010Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 18, nr 1, s. 134-Artikkel i tidsskrift (Fagfellevurdert)
  • 45.
    Sudirman, Aziza
    et al.
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Etcheverry, Sebastian
    RISE - Research Institutes of Sweden (2017-2019), ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Stjernström, Mårten
    KTH Royal Institute of Technology, Sweden.
    Laurell, Frederik
    KTH Royal Institute of Technology, Sweden.
    Margulis, Walter
    RISE., Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    A fiber optic system for detection collection of micrometer-size particles2014Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 22, nr 19, s. 21480-21487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An optical fiber containing longitudinal holes adjacent to the core has been used to detect and collect fluorescent particles from a solution. Excitation light was launched through the fiber and fluorescence signal was guided back to a detector system. As a proof of principle, green and red fluorescent polystyrene beads were detected and selectively collected from a water solution containing a mixture of red and green fluorescent beads.

  • 46. Tipsuwannakul, E.
    et al.
    Chughtai, M. N.
    Forzati, M.
    RISE., Swedish ICT, Acreo.
    Mårtensson, Jonas
    RISE., Swedish ICT, Acreo.
    Andrekson, P.
    Karlsson, M.
    Influence of self-cross-phase modulation on 40 Gbaud dual polarization DQPSK/D8PSK signals in 10 Gbit/s OOK WDM systems2010Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 18, nr 23, s. 24178-88Artikkel i tidsskrift (Fagfellevurdert)
  • 47.
    Vanin, E
    RISE., Swedish ICT, Acreo.
    Performance evaluation of intensity modulated optical OFDM system with digital basebdistortion2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 5, s. 4280-93Artikkel i tidsskrift (Fagfellevurdert)
  • 48. Vanin, E
    et al.
    Jacobsen, G
    RISE., Swedish ICT, Acreo.
    Analytical estimation of laser phase noise induced BER floor in coherent receiver with digital signal processing2010Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 18, nr 5, s. 4246-59Artikkel i tidsskrift (Fagfellevurdert)
  • 49.
    Wang, Q
    et al.
    RISE., Swedish ICT, Acreo.
    Junique, S
    Agren, D
    Almqvist, S
    Noharet, B
    Arrays of vertical-cavity electroabsorption modulators for parallel signal processing",2005Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 13, nr 9, s. 3323-30Artikkel i tidsskrift (Fagfellevurdert)
  • 50. Xu, T
    et al.
    Jacobsen, G
    RISE., Swedish ICT, Acreo.
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    Analytical estimation of phase noise influence in coherent transmission system with digital dispersion equalization2011Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 19, nr 8, s. 7756-68Artikkel i tidsskrift (Fagfellevurdert)
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