Soliton-effect self-compressed single-cycle 9.6-W mid-IR pulses from a 21-W OPCPA at 3.25 {\mu}m and 160 kHz

TL;DR

This paper demonstrates a high-power, CEP-stable mid-IR OPCPA producing near-single-cycle pulses at 3.25 μm with excellent stability, achieved through soliton self-compression in a gas-filled photonic crystal fibre, enabling advanced applications in extreme photonics.

Contribution

It introduces a 21-W mid-IR OPCPA with self-compression to sub-9-cycle pulses without additional devices, advancing high-power ultrafast laser technology.

Findings

Achieved 97 fs pulse duration at 3.25 μm

Generated 14.5 fs pulses with 9.6 W average power

Maintained 0.33% rms CEP stability over 288 million pulses

Abstract

We report a 21-W mid-IR OPCPA that generates 131-{\mu}J and 97 fs (sub-9-cycle) pulses at 160 kHz repetition rate and at a centre wavelength of 3.25 {\mu}m. Pulse-to-pulse stability of the CEP-stable output is excellent with 0.33% rms over 288 million pulses (30 min) and compression close to a single optical cycle was achieved through soliton self- compression inside a gas-filled mid-IR anti-resonant-guiding photonic crystal fibre. Without any additional compression device, stable generation of 14.5 fs (1.35-optical-cycle) pulses was achieved at an average power of 9.6 W. The resulting peak power of 3.9 GW in combination with the near-single-cycle duration and intrinsic CEP stability, make our OPCPA a key-enabling technology for the next generation of extreme photonics, strong-field attosecond research and coherent X-ray science.