Abstract

A chirped-pulse amplification table-top terawatt (T³) Ti:sapphire laser systems allowing to access to extremely high optical field strengths are widely used in the high intensity physics [1] In the last years the second harmonic pulses of such systems were started to use in some experiments. It allowed to perform experiments in new spectral range and additionally to increase contrast of pulses. For practical use in the high intensity physics important is to design frequency doublers, with high conversion efficiency and small lengthening of the generated femtosecond pulses. Conversion efficiency of the frequency doubler is very sensitive to the spatial beam profile and contrast of the femtosecond pulses and in many cases it limits the conversion efficiency at numbers that are much lower than ones caused by group velocity mismatch of the fundamental and second harmonic pulses.

© 1996 IEEE