Low-loss waveguides in ultrafast laser-deposited As2S3 chalcogenide films

Ultrafast pulsed laser deposition was used to successfully deposit atomically smooth 5-mum-thick As(2)SA(3) films. The as-deposited,films,were photosensitive at wavelengths close to the band edge (approximate to520 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, n(2,As2S3), was measured using both four-wave mixing and the Z-scan technique and varied with wavelength from 100 to 200 times fused silica (n(2,silica) approximate to 3 x 10(-16) cm(2)/W) between 1500 nm and 1100 nm with low nonlinear absorption. (C) 2003 Optical Society of America.