Local Spectral Compression method for CPA lasers

The paper presents an experimental demonstration of a new phase-only measurement technique called local spectral compression (LSC) on a chirped pulse amplification (CPA) laser system by inserting an acousto-optic programmable dispersive filter (AOPDF) in front of the last three-pass amplifier and a nonlinear BBO crystal at the output. The second harmonic signal is recorded with a spectral detector. Results demonstrate that the LSC method performs adequately for both second and third order measurements. This paper shows the suitability of this method to optimize spectral phase on CPA femtosecond laser system.