A 10-mJ-level compact CPA system based on Yb:KGW for ultrafast optical parametric amplifier pumping

A compact diode-pumped Yb:KGW regenerative amplifier producing 10 Hz, 10-mJ-level picosecond pulses at 1,040 nm is demonstrated. The system is used at the new front end of the PHELIX petawatt laser system to pump an ultrafast optical parametric amplifier for temporal contrast enhancement. Before frequency doubling, a pulse length of ∼1 ps is obtained by using a stretcher/compressor system based on a single large-aperture chirped volume Bragg grating.