Abstract

Chirped pulse amplification (CPA) with a Ti:sapphire regenerative amplifier has produced femtosecond pulses with millijoule energies at kHz repetition rates [1]. The performance of these laser systems has been limited primarily by the inability to compensate the spectral pulse phase to all orders in the compressor after the pulse has been stretched and amplified by making typically twenty roundtrips in a regenerative amplifier. Several authors have used dispersive ray tracing calculations to modify the design of the pulse stretcher and / or compressor in order to reduce the residual phase distortions which cause pulse broadening in a CPA system [2]. In order to further shorten the pulses from CPA systems, it would be extremely useful to measure directly the actual intensity and phase of the amplified pulses under different conditions. This information would then provide a means for checking the dispersive ray tracing models of the stretcher / compressor as well as providing information on precisely what sort of phase compensation is needed.

© 1994 Optical Society of America