Generation of 3 mJ, 44 fs, 2.5 micrometer pulses from a single-stage Cr2+:ZnSe amplifier

TL;DR

This paper presents a highly efficient single-stage Cr2+:ZnSe laser amplifier producing 3 mJ, 44 fs pulses at 2.5 micrometers, achieving record peak power for this wavelength, with potential applications in attosecond X-ray pulse generation.

Contribution

It introduces a novel single-stage chirped pulse amplification system using Cr2+:ZnSe, achieving record energy and peak power at 2.5 micrometers with a simplified setup.

Findings

Produced 3 mJ, 44 fs pulses at 2.5 micrometers

Achieved 68 GW peak power, highest at this wavelength

System built in nitrogen for optimal pulse compression

Abstract

Lasers capable of generating attosecond X-ray pulses in the water window (282 to 533 eV) through high-order harmonic generation are normally based on inefficient, multi-stage optical parametric amplifiers or optical parametric chirped pulse amplifiers pumped by femtosecond or picosecond lasers. Here we report a very efficient single amplification stage laser based on traditional chirped pulse amplification capable of producing 3 mJ, near-transform limited 44 fs (<6 cycles), 1 kHz pulses centered at 2.5 micrometer. The 68 GW peak power is the highest value ever reached at this wavelength. In order to fully compress the laser pulses our system is built in a nitrogen box. Our system utilizes water cooled chromium doped zinc selenide (Cr2+:ZnSe) as the gain medium and is pumped by a commercial nanosecond holmium doped yttrium-aluminum-garnet (Ho:YAG) laser.