The pump-induced degradation of the temporal contrast of laser pulses amplified by optical parametric chirped-pulse amplification (OPCPA) is studied analytically. In OPCPA systems, the temporal fluctuations of the pump pulse are coupled to the spectrum of the chirped signal by the instantaneous parametric gain and lead to a reduction in the temporal contrast of the recompressed amplified signal. The intensity and shape of the induced temporal pedestal depend on the pump fluctuations and the parametric amplifier operating regime. General equations describing the contrast degradation are derived and applied to the case of sinusoidal pump-intensity modulation and pump amplified spontaneous emission. The reduction of the contrast in the amplified pulse is quantified analytically and via simulations for an OPCPA system.
© 2007 Optical Society of America
Lasers and Laser Optics
Original Manuscript: July 5, 2007
Revised Manuscript: October 12, 2007
Manuscript Accepted: October 12, 2007
Published: November 30, 2007
C. Dorrer, "Analysis of pump-induced temporal contrast degradation in optical parametric chirped-pulse amplification," J. Opt. Soc. Am. B 24, 3048-3057 (2007)