2.6mJ/100Hz CEP stable near-single-cycle 4{\mu}m laser based on OPCPA and hollow-core-fiber compression

TL;DR

This paper demonstrates a stable, near-single-cycle 4μm laser system with high energy and efficiency, achieved through OPCPA and hollow-core-fiber compression, suitable for advanced mid-infrared applications.

Contribution

It introduces a novel 4μm laser system combining OPCPA and hollow-core-fiber compression with passive CEP stabilization, achieving high energy, efficiency, and near-single-cycle pulse duration.

Findings

11.8 mJ pulse energy at 100 Hz achieved

Pulse compressed to ~21.5 fs with 2.6 mJ energy

CEP stability of ~370 mrad demonstrated

Abstract

A carrier envelope phase stable near-single cycle mid-infrared laser based on optical parametric chirped pulse amplification and hollow-core-fiber compression is demonstrated. 4 {\mu}m laser pulses with 11.8 mJ energy are delivered from a KTA based OPCPA with 100 Hz repetition rate, and compressed to be ~105 fs by a two-grating compressor with efficiency over 50%. Subsequently, the pulse spectrum is broadened by employing a krypton gas-filled hollow-core-fiber (HCF). Then, the pulse duration is further compressed to 21.5 fs through a CaF2 bulk material with energy of 2.6 mJ and stability of 0.9% RMS, which is about 1.6 cycle for 4 {\mu}m laser pulse. The near-single cycle 4 {\mu}m laser pulse CEP is passively stabilized with ~370 mrad based on a CEP stable 4 {\mu}m OPA injection.