ABSTRACT
GeSbS ridge waveguides have recently been demonstrated as a promising mid - infrared platform for integrated waveguide - based chemical sensing and photodetection. To date, their nonlinear optical properties remain relatively unexplored. In this paper, we characterize the nonlinear optical properties of GeSbS glasses, and show negligible nonlinear losses at 1.55 µm. Using self - phase modulation experiments, we characterize a waveguide nonlinear parameter of 7 W-1/m and nonlinear refractive index of 3.71 × 10-18 m2/W. GeSbS waveguides are used to generate supercontinuum from 1280 nm to 2120 nm at the -30 dB level. The spectrum expands along the red shifted side of the spectrum faster than on the blue shifted side, facilitated by cascaded stimulated Raman scattering arising from the large Raman gain of chalcogenides. Fourier transform infrared spectroscopic measurements show that these glasses are optically transparent up to 25 µm, making them useful for short - wave to long - wave infrared applications in both linear and nonlinear optics.
ABSTRACT
In this paper we explore the TeO(2)-Bi(2)O(3)-BaO glass family with varied TeO(2) concentration for Raman gain applications, and we report, for the first time, the peak Raman gain coefficients of glasses within this glass family extrapolated from non-resonant absolute Raman cross-section measurements at 785 nm. Estimated Raman gain coefficients show peak values of up to 40 times higher than silica for the main TeO(2) bands. Other optical properties, including index dispersion from the visible to the long wave Infrared (LWIR) are also summarized in this paper.
