Femtosecond infrared supercontinuum generation in 6H-SiC crystal

We report on supercontinuum generation in silicon carbide (6H-SiC), pumped by tunable femtosecond pulses in the wavelength range of 1.3 - 2.4 μm, which cover the regions of normal, zero, and anomalous group velocity dispersion of the material. More than an octave spanning infrared supercontinuum spectra were measured, demonstrating almost constant blue cut-offs around 0.9 μm. Low energy thresholds for supercontinuum generation (depending on the pump wavelengths, but generally below 200 nJ) were demonstrated due to large nonlinear refractive index of the material (n2 = 97 ± 19 × 10−16 cm2/W), which was experimentally evaluated by measurement of the nonlinear transmission at 2.0 μm.