High-Power, Few-Cycle, Angular Dispersion Compensated Mid-Infrared Pulses From a Noncollinear Optical Parametric Amplifier

We demonstrate a scheme for correcting the angular dispersion of the 3.1-
$\mu$
m idler beam from a high repetition rate, KTiOAsO
$_4$
(KTA) based noncollinear optical parametric amplifier pumped at 1.03 
$\mu$
m and seeded by broadband signal pulses at 1.55 
$\mu$
m. Following angular dispersion correction, successful temporal chirp compensation was possible, and a close to transform-limited pulse duration of 70 fs and a pulse energy of 30 
$\mu$
J at a repetition rate of 100 kHz were obtained. The angular chirp compensated KTA-based scheme is scalable to higher pulse energies and average powers and has various advantages compared to periodically poled and angle-tuned LiNbO
$_3$
-based amplifiers, which exhibit low resistance to photorefractive damage.