Time-resolved FDTD and experimental FTIR study of gold micropatch arrays for wavelength-selective mid-infrared optical couplingShow 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 similar to 1.0 mu m and width similar to 0.2 mu m, 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. © 2021 by the authors.
Place, publisher, year, edition, pages
Basel: 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
Physical Sciences
Identifiers
URN: urn:nbn:se:hh:diva-45376DOI: 10.3390/s21155203ISI: 000682177800001PubMedID: 34372439Scopus ID: 2-s2.0-85111465509OAI: oai:DiVA.org:hh-45376DiVA, id: diva2:1583845
Funder
Vinnova, 2020-00797EU, Horizon 2020, 739508European Commission, 1.1.1.2/VIAA/4/20/7402021-08-102021-08-102022-02-10Bibliographically approved