Spectral broadening of 112  mJ, 1.3  ps pulses at 5  kHz in a LG₁₀ multipass cell with compressibility to 37  fs

Abstract

The first-order helical Laguerre–Gaussian mode (also called donut mode) is used to improve the energy throughput of nonlinear spectral broadening in gas-filled multipass cells. The method proposed in this Letter enables, for the first time to the best of our knowledge, the nonlinear spectral broadening of pulses with energies beyond 100 mJ and is suitable for an average power of more than 500 W while conserving an excellent spatio-spectral homogeneity of ∼ 98 % and a Gaussian-like focus profile. Additionally compressibility from 1.3 ps to 37 fs is demonstrated.

Ultrafast MHz‐Rate Burst‐Mode Pump–Probe Laser for the FLASH FEL Facility Based on Nonlinear Compression of ps‐Level Pulses from an Yb‐Amplifier Chain

“…Its scalability to kW average power and pulse energy levels exceeding 100 mJ has just recently been demonstrated. [ 45,46 ]…”

“…Its scalability to kW average power and pulse energy levels exceeding 100 mJ has just recently been demonstrated. [37,38] The about 30 fs rms timing jitter may be further reduced with a recently developed nonlinear amplifying loop mirror (NALM) laser oscillator. [39] The jitter refers to the locking of the optical laser to the main laser oscillator.…”

Temporal quality of post-compressed pulses at large compression factors

“…Industrygrade, high-power picosecond ytterbium (Yb)-based lasers can thus be directly converted into femtosecond sources, making it possible to extend their high repetition rate, power-scalability and reliability to ultrafast strong field physics [4,5,6]. Compressing the input pulse to less than a tenth of its original duration in a single compression stage has been demonstrated multiple times [5,6,7,8,9,10,11,12,13,14,15], with a recent record approaching a compression factor of 40 in a single compression stage [5].…”

Multipass cell for high-power few-cycle compression

“…An alternative could be nonlinear compression in multipass cells [14][15][16], which recently has been demonstrated at 112 mJ pulse energy [17] and at 1 kW average output power [18]. These cells feature an excellent transmission of up to 96% [18] and a high resilience to beam quality imperfections and pointing instabilities due to their extended free aperture, which allows for straightforward power scaling.…”