Efficient Spectral Broadening in the 100-W Average Power Regime Using Gas Filled Kagome HC-PCF and Pulse Compression

TL;DR

This paper demonstrates efficient spectral broadening and pulse compression of high-power laser pulses using a gas-filled Kagome HC-PCF, achieving sub-100 fs pulses with over 100 MW peak power at high average power levels.

Contribution

It introduces a simple, high-power pulse compression method using gas-filled Kagome HC-PCF, enabling high peak power and ultrashort pulses at megahertz repetition rates.

Findings

Spectral broadening factor of 16 achieved in the fiber.

Pulse compression to 88 fs from 740 fs at high power.

Over 100 W of compressed average power with >100 MW peak power.

Abstract

We present nonlinear pulse compression of a high-power SESAM-modelocked thin-disk laser (TDL) using an Ar-filled hypocycloid-core Kagome Hollow-Core Photonic Crystal Fiber (HC-PCF). The output of the modelocked Yb:YAG TDL with 127 W average power, a pulse repetition rate of 7 MHz, and a pulse duration of 740 fs was spectrally broadened 16-fold while propagating in a Kagome HC-PCF containing 13 bar of static Argon gas. Subsequent compression tests performed using 8.4% of the full available power resulted in a pulse duration as short as 88 fs using the spectrally broadened output from the fiber. Compressing the full transmitted power through the fiber (118 W) could lead to a compressed output of >100 W of average power and >100 MW of peak power with an average power compression efficiency of 88%. This simple laser system with only one ultrafast laser oscillator and a simple single-pass fiber pulse compressor, generating both high peak power >100 MW and sub-100-fs pulses at megahertz repetition rate, is very interesting for many applications such as high harmonic generation and attosecond science with improved signal-to-noise performance.