GLS and GLSSe ultrafast laser inscribed waveguides for mid-IR supercontinuum generation

Abstract

Using the ultrafast laser inscription technique, buried channel waveguides have been fabricated in gallium lanthanum sulfide and gallium lanthanum sulfide selenide glasses to demonstrate the suitability of the materials for supercontinuum generation in the mid-IR. Supercontinuum generation was performed using 100 femtosecond pump pulses with micro-Joule pulse energies and a center wavelength of 4.6 µm, which is in the anomalous dispersion regime for these waveguides. Under such pump conditions, supercontinuum was obtained covering a 25-dB-bandwidth of up to 6.1 um with a long-wavelength edge of 8 µm. To our knowledge, this represents the broadest and the longest-wavelength IR supercontinuum generated from an ultrafast laser inscribed waveguide to date.