Supercontinuum generation in single-crystal YAG fibers pumped around the zero-dispersion wavelength

Yttrium aluminum garnet (YAG) is a common host material for both bulk and single-crystal fiber lasers. With increasing interest in developing optical technologies in the short-wave infrared and mid-infrared wavelength range, YAG may be a potential supercontinuum medium for these applications. Here, we characterize femtosecond laser pumped supercontinuum generation with 1200-2000 nm pump wavelengths (lambda(p)) for undoped, single-crystal YAG fibers, which are representative of the normal, zero, and anomalous-dispersion regimes. Supercontinuum was observed over the spectral region of about 0.2 to 1.6 lambda(p). Z-scan measurements were also performed of bulk YAG, which revealed little dispersion of the nonlinear index of refraction (n(2)) in the region of interest. The measured values of n(2) (similar to 1 x 10(-6) cm(2)/GW) indicate a regime in which the nonlinear length, L-NL, is less than the dispersion length, L-D, (L-NL << L-D). We report intensity clamping of the generated filament in the normal group velocity dispersion (GVD) regime and an isolated anti-Stokes peak in the anomalous GVD regime, suggesting further consideration is needed to optimize supercontinuum generation in this fiber medium. (C) 2021 Optical Society of America

Automated summary

Yttrium aluminum garnet (YAG) is a potential supercontinuum medium for developing optical technologies in the short-wave infrared and mid-infrared wavelength range. Experimental results show that supercontinuum generation in undoped YAG fibers can cover a spectral region from 0.2 to 1.6 times the pump wavelength. Z-scan measurements also reveal little dispersion of the nonlinear index of refraction in YAG.