Contrast limitation due to pump noise in an optical parametric chirped pulse amplification system

The contrast ratio of the recompressed output pulses in an optical parametric chirped pulse amplification system can be limited by temporal noise on the pump pulse. We present a simple analysis which can be used to estimate both the contrast ratio of this background noise and the duration of its pedestal. The estimated values compare well quantitatively with values derived using a more accurate computer simulation code. (C) 2007 Elsevier B.V. All rights reserved.