Time-Resolved FDTD and Experimental FTIR Study of Gold Micropatch Arrays for Wavelength-Selective Mid-Infrared Optical Coupling Show others and affiliations
2021 (English) In: Sensors, E-ISSN 1424-8220, Vol. 21, no 15, article id 5203Article in journal (Refereed) Published
Abstract [en]
Infrared radiation reflection and transmission of a single layer of gold micropatch two-dimensional arrays, of patch length ∼1.0μm and width ∼0.2μm, have been carefully studied by a finite-difference time-domain (FDTD) method, and Fourier-transform infrared spectroscopy (FTIR). Through precision design of the micropatch array structure geometry, we achieve a significantly enhanced reflectance (85%), a substantial diffraction (10%), and a much reduced transmittance (5%) for an array of only 15% surface metal coverage. This results in an efficient far-field optical coupling with promising practical implications for efficient mid-infrared photodetectors. Most importantly we find that the propagating electromagnetic fields are transiently concentrated around the gold micropatch array in a time duration of tens of ns, providing us with a novel efficient near-field optical coupling.
Place, publisher, year, edition, pages MDPI, 2021. Vol. 21, no 15, article id 5203
Keywords [en]
FDTD, FTIR, metal micropatch arrays, near field optics, far field optics, nano fabrication, electron beam lithography, infrared sensing
National Category
Atom and Molecular Physics and Optics
Identifiers URN: urn:nbn:se:ri:diva-55658 DOI: 10.3390/s21155203 OAI: oai:DiVA.org:ri-55658 DiVA, id: diva2:1583093
2021-08-052021-08-052022-02-10 Bibliographically approved