Ultrafast pulsed laser deposition was used to successfully deposit atomically smooth 5-μm-thick As2S3 films. The as-deposited films were photosensitive at wavelengths close to the band edge (≈520 nm), and waveguides could be directly patterned into them by photodarkening using an argon-ion or frequency-doubled Nd:YAG laser. The linear and nonlinear optical properties of the films were measured as well as the photosensitivity of the material. The optical losses in photodarkened waveguides were <0.2 dB/cm at wavelengths beyond 1200 nm and <0.1 dB/cm in as-deposited films. The third-order nonlinearity, n2, As2S3, was measured using both four-wave mixing and the Z-scan technique and varied with wavelength from 100 to 200 times fused silica (n2, Silica≈3×10−16 cm2/W) between 1500 nm and 1100 nm with low nonlinear absorption.
© 2003 Optical Society of America
(160.2750) Materials : Glass and other amorphous materials
(160.4330) Materials : Nonlinear optical materials
(230.7370) Optical devices : Waveguides
(310.1860) Thin films : Deposition and fabrication
A. Zakery, Y. Ruan, A. V. Rode, M. Samoc, and B. Luther-Davies, "Low-loss waveguides in ultrafast laser-deposited As2S3 chalcogenide films," J. Opt. Soc. Am. B 20, 1844-1852 (2003)