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Multilayer porous silicon diffraction gratings operating in the infrared
Date Issued
01-01-2012
Author(s)
Lai, Meifang
Sridharan, Gayathri M.
Liu, Yinong
Parish, Giacinta
Bhattacharya, Shanti
Keating, Adrian
Abstract
Transmission diffraction gratings operating at 1,565 nm based on multilayer porous silicon films are modeled, fabricated, and tested. Features down to 2 μm have been patterned into submicron-thick mesoporous films using standard photolithographic and dry etching techniques. After patterning of the top porous film, a second anodization can be performed, allowing an under-layer of highly uniform porosity and thickness to be achieved. High transmission greater than 40% is measured, and modeling results suggest that a change in diffraction efficiency of 1 dB for a 1% change in normalized refractive index can be achieved. Preliminary measurement of solvent vapor shows a large signal change from the grating sensor in agreement with models. © 2012 Lai et al.
Volume
7