Abstract

We report on 3.2-µm pulse post-compression via spectral broadening in a hollow core capillary filled with noble gas. The mid-IR input pulses are generated in a femtosecond OPA based on KTA crystals, which delivers 6 mJ, 80 fs, 3.2 µm CEP-stable idler pulses. The mid-IR pulses are coupled into a 40-cm-long fused quartz capillary with the core diameter of 400 µm with a throughput of up to 60% and exhibit, at Argon pressure of 3 bar, maximum spectral broadening corresponding to a Fourier limited pulse duration below 20 fs. At 1.6 bar, partial two-fold pulse compression is obtained after passing the spectrally broadened pulse through 6 mm of CaF₂

© 2016 Optical Society of America