Optimization design of stable and high quality optical parametric chriped pulse amplification system

This paper proposes that in order to realize high-quality and stable output from an optical parametric chirped pulse amplification(OPCPA) system, the two nonlinear courses included in an OPCPA system must be optimized at the same time. These two nonlinear courses are the optical parametric amplifying (OPA) course and the second harmonic generation(SHG) course of the pump. In order to optimize the parametric amplifier, several kinds of physical models are set up and they will be used to solve different kinds of problems. The analyzing method is set up to get symmetrical output signal in x and y from an optical parametric amplifier. The method of making certain the length of the nonlinear crystal is also set up to get the most stable OPA output. In the study of the second harmonic generation course, mismatched SHG is put forward to get stable second harmonic pump. The study shows that mismatched SHG can not only improve the stability of the pump, but also decrease the modulation in near field and pulse waveform, thus improve the beam quality of the pump.