Open AccessNear-field effect in the infrared range through periodic Germanium subwavelength arrays
Author(s) -
Wei Dong,
Toru Hirohata,
Kazutoshi Nakajima,
Xiaoping Wang
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.026677
Subject(s) - optics , germanium , infrared , materials science , surface plasmon , electric field , diffraction , field (mathematics) , optoelectronics , plasmon , physics , silicon , mathematics , quantum mechanics , pure mathematics
Using finite-difference-time-domain simulation, we have studied the near-field effect of Germanium (Ge) subwavelength arrays designed in-plane with a normal incidence. Spectra of vertical electric field component normal to the surface show pronounced resonance peaks in an infrared range, which can be applied in a quantum well infrared photodetector. Unlike the near-field optics in metallic systems that are commonly related to surface plasmons, the intense vertical field along the surface of the Ge film can be interpreted as a combination of diffraction and waveguide theory. The existence of the enhanced field is confirmed by measuring the Fourier transform infrared spectra of fabricated samples. The positions of the resonant peaks obtained in experiment are in good agreement with our simulations.