Towards direct nonlinear compression of energetic sub-nanosecond pulses to the ultrafast regime

TL;DR

This paper introduces a novel multi-mirror multi-pass cell technique for directly compressing high-energy sub-nanosecond laser pulses into ultrashort femtosecond pulses, enabling scalable ultrafast laser sources.

Contribution

It proposes a compact, cost-effective method for spectral broadening and pulse compression of high-energy pulses using multi-pass cells, demonstrated through simulations and a proof-of-concept setup.

Findings

Spectral broadening factor of 15 achieved in air with 260 MW peak power.

Simulation of compressing 300-ps pulses to sub-ps Fourier transform limit.

Proof-of-concept multi-mirror cell setup demonstrated feasibility.

Abstract

Applications of terawatt-class lasers can enormously benefit from pulse trains with kHz repetition rates. The associated unprecedented combinations of peak and average powers require the development of new concepts for scalable ultrashort pulse generation. We propose using multi-mirror multi-pass cells as a compact and cost-efficient solution for the direct post-compression of sub-nanosecond pulses into the femtosecond regime. We simulate spectral broadening of 100-mJ, 300-ps pulses to a sub-ps Fourier transform-limit in a 1-m diameter multi-pass cell. Furthermore, an 11-mirror cell for about 300 passes was set-up for proof-of-concept. To reach a spectral broadening factor of 15 in air, only 260 MW of peak power were required. The proposed scheme can efficiently transform industrially mature high-power, high-energy lasers into unique ultrafast sources.