Enhancement of optical parametric chirped pulse amplification by controlling idler laser pulse

We present a novel method for optical parametric chirped pulse amplification to enhance the spectral bandwidth of amplified signal pulses by suppressing reconversion in a collinear degenerate geometry using a sequence of crystal pairs. The scheme consists of a conventional crystal pair used for achieving saturated amplification at the peak portion of the seed laser pulse, and a number of additional crystal pairs for optimizing the amplified seed laser pulse, especially in its spectral range and output stability. Numerical results showed that the proposed scheme can be used to produce a stable amplified seed laser pulse with a broader spectral bandwidth than the input spectrum under ordinary conditions.