High temporal contrast 1053 nm femtosecond pulses via spectral broadening and filtering in an air-filled multi-pass cell using a Yb:CALGO amplifier

Seed laser sources that offer high temporal contrast are essential for enhancing overall temporal contrast. In this study, we demonstrate the generation of a high temporal contrast seed laser by spectral broadening and filtering of a Yb: CALGO femtosecond amplifier in an air-filled multi-pass cell.

The temporal contrast exceeds 109 within 100 ps prior to the main pulse, with a pulse energy of 227 µJ and a duration of 118 fs. Given its excellent beam quality and stability, this laser source is well-suited as a high-quality seed for Nd: glass-based ultra intense laser facilities. This work achieves a remarkable internal efficiency of over 70% in generating a clean seed pulse for ultra intense lasers.