title: Multilayer porous silicon diffraction gratings operating in the infrared.
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.
authors.affiliation: School of Mechanical and Chemical Engineering, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, 6009, Australia. adrian.keating@uwa.edu.au.
authors.forename: Meifang
authors.initials: M
authors.lastname: Lai
authors.forename: Gayathri M
authors.initials: GM
authors.lastname: Sridharan
authors.forename: Giacinta
authors.initials: G
authors.lastname: Parish
authors.forename: Shanti
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Adrian
authors.initials: A
authors.lastname: Keating