Contrast degradation in a chirped-pulse amplifier due to generation of prepulses by postpulses.
Experiment and modeling show that the refractive index nonlinearity can significantly degrade the contrast of a chirped-pulse amplifier seeded with a pulse and a single postpulse. Multiple powerful non-equidistant pre- and postpulses are generated. For a Gaussian pulse and a hat-top beam, an incident postpulse of energy W results in a prepulse of energy 0.58B(2)W, where B is the nonlinear phase (B-integral) of the main pulse. Calculations show that level of satellites due to gain saturation is negligibly small. Experimental results for Ti:Sapphire regenerative and multipass amplifiers and prepulse generation in fused silica agree well with the theory.
Avesta Project Ltd., Solnechnaya 12, 142190, Troitsk, Moscow region, Russia.
N V
NV
Didenko
A V
AV
Konyashchenko
A P
AP
Lutsenko
S Yu
SY
Tenyakov
D000669:Amplifiers, Electronic; D016477:Artifacts; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D008962:Models, Theoretical; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*