Multioctave infrared supercontinuum generation in large-core As2S3 fibers.

Optics letters

PubMedID: 25490497

Théberge F, Thiré N, Daigle JF, Mathieu P, Schmidt BE, Messaddeq Y, Vallée R, Légaré F. Multioctave infrared supercontinuum generation in large-core As2S3 fibers. Opt Lett. 2014;39(22):6474-6477.
We report on infrared supercontinuum (SC) generation through laser filamentation and subsequent nonlinear propagation in a step-index As2S3 fiber. The 100 µm core and high-purity As2S3 fiber used exhibit zero-dispersion wavelength around 4.5 µm, a mid-infrared background loss of 0.2??dB/m, and a maximum loss of only 0.55??dB/m at the S-H absorption peak around 4.05 µm. When pumping with ultrashort laser pulses slightly above the S-H absorption band, broadband infrared supercontinua were generated with a 20 dB spectral flatness spanning from 1.5 up to 7 µm. The efficiency and spectral shape of the SC produced by ultrashort pulses in large-core As2S3 fiber are mainly determined by its dispersion, the S-H contaminant absorption, and the mid-infrared nonlinear absorption.