High-power, mid-infrared, picosecond pulses generated by compression of a CO2 laser beat-wave in GaAs

TL;DR

This paper demonstrates a novel method to generate high-power, picosecond mid-infrared laser pulses using beat-wave compression in GaAs, achieving high repetition rates and exploring phase-mismatched difference frequency generation effects.

Contribution

It introduces a new technique combining CO2 laser beat-waves with GaAs and NaCl for efficient mid-IR pulse generation at high power and repetition rates.

Findings

Generated ~2 ps, 10 μm laser pulses with high power.

Showed the role of cascaded phase-mismatched difference frequency generation.

Achieved high repetition rate pulse generation using a 200 ps beat-wave.

Abstract

We report on the generation of a train of ~ 2 ps, 10 um laser pulses via multiple four-wave mixing and compression of an infrared laser beat-wave propagating in the negative group velocity dispersion region of bulk GaAs and a combination of GaAs and NaCl. The use of a 200 ps, 106 GHz beat-wave, produced by combining laser pulses amplified on the 10P(20) and 10P(16) transition of a CO2 laser, provides a novel method for generating high-power, picosecond, mid-IR laser pulses at a high repetition rate. By using 165 and 882 GHz beat-waves we show that cascaded phase-mismatched difference frequency generation plays a significant role in the four-wave mixing process in GaAs.