All-solid-state generation of 100-kHz tunable mid-infrared 50-fs pulses in type I and type II AgGaS_2

We report the operation of an all-solid-state system for the generation of tunable mid-infrared sub-50-fs pulses. A Ti:sapphire regenerative amplifier, pumped by 10 W of power from 532-nm, diode-pumped, frequency-doubled $\mathrm{Nd}:{\mathrm{YVO}}_4$ lasers, produced $4‐\mathit{\mu }\mathrm{J}$ energy, sub-50-fs pulses at 800 nm with a 100-kHz repetition rate. This output was used to drive a $\beta ‐{\mathrm{BaB}}_2{\mathrm{O}}_4$ optical parametric amplifier followed by a difference-frequency generator based on a ${\mathrm{AgGaS}}_2$ crystal. Continuous tuning of ultrafast pulses from $2.4 \mathit{\mu }\mathrm{m}$ to longer than $12 \mathit{\mu }\mathrm{m}$ was obtained. A performance comparison of difference-frequency generation in type I and type II phase-matched ${\mathrm{AgGaS}}_2$ is reported.