# Pulses from a mid-infrared quantum cascade laser frequency comb using an external compressor

## TL;DR

This paper demonstrates pulse compression of a mid-infrared quantum cascade laser frequency comb using an external stretcher-compressor, achieving shorter pulses and detailed phase noise characterization.

## Contribution

It introduces a method to compress QCL frequency combs in the mid-infrared using a Martinez-type stretcher-compressor, improving pulse duration and phase noise analysis.

## Key findings

- Compressed pulses from 134 ps to 12 ps duration.
- Achieved peak to average power ratio of 40.7.
- Measured timing jitter of 335 fs and pulse-to-pulse jitter of 2.0 fs.

## Abstract

A Martinez-type stretcher-compressor is used to modify the spectral phases of a high-power (~1 W) QCL comb emitted at 8.2 {\mu}m with more than 100 cm-1 spectral bandwidth. Using this scheme, we demonstrate a compression of the QCL output from a 134 ps continuous wave waveform, to a train of pulses of width 12 ps, and a power with peak to average ratio of 40.7. An evaluation of the phase noise of the free-running device yields an integrated timing jitter of 335 fs over the frequency range 20 kHz - 100 MHz, and a pulse-to-pulse jitter of 2.0 fs.