Work

Efficient spectral broadening from 850 nm to 1150 nm in the low-peak-power regime using a single-stage bulk multipass cell

Year: 2026

Type: article

Abstract: Multipass-cell (MPC) based spectral broadening is a robust approach for ultrashort pulse compression; however, its extension to oscillator-level pulse energies remains challenging due to insufficient nonlinear phase accumulation at low peak power. Here, we demonstrate a single-stage MPC system driven directly by a 500 nJ, 5 W, 120 fs, 10 MHz oscillator, achieving efficient spectral broadening with 69% overall optical efficiency through dispersion engineering. The pulse duration was compressed down to 10.1 fs, corresponding to a relative peak power of 67% with respect to the Fourier-transform-limited (FTL) pulse. Good beam quality and homogeneous spectral broadening are maintained throughout the nonlinear propagation, indicating stable operation without beam collapse. To our knowledge, this is the first demonstration of spectral broadening spanning 850 nm-1150 nm in a single-stage bulk MPC directly driven by an oscillator in the sub-µJ regime. This compact, high-repetition-rate source is promising for applications such as multiphoton microscopy and coherent Raman imaging.

Source: Optics Express

DOI: 10.1364/oe.617943

Authors: Zeyang Hu, Kilian Fritsch, Oleg Pronin

Institution: Helmut Schmidt University

Language: English

Topic: Laser-Matter Interactions and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funder: Deutsche Forschungsgemeinschaft