Multi-GW Peak Power Scaling in a Multi-pass Cell by Divided Pulse Scheme

Abstract

Multi-pass cells, known for their efficient spectral broadening, currently face a challenge in their peak power scalability. To address this, we implemented a strategy where the input pulse was split into 8 replicas, resulting in an increased pulse energy following nonlinear compression. The used laser delivered 208 fs pulses at 1030 nm, with pulse energies reaching up to 140μJ. Using 3 calcite crystals, the input pulse was divided and passed through the MPC, achieving a spectral broadening down to a 40 fs bandwidth limit. Subsequently, the replicas were recombined using an identical set of crystals and compressed via chirped mirrors. FROG measurements revealed a duration of 43 fs. The recombination losses amounted to less than 5 % of the output energy. This method is particularly attractive and cost-effective for spectral broadening of ultrafast lasers with adjustable repetition rate.