光参量啁啾脉冲放大系统非线性晶体长度确定及调谐方法研究

首先介绍了模拟光参量啁啾脉冲放大（OPCPA）过程的多种计算模型，在此基础上提出了三步走逐步逼近算法，以确定OPCPA过程中最稳输出时所需的非线性晶体长度.这种算法综合利用了上述计算模型，随着计算模型越来越精确，非线性晶体长度的计算范围越来越小.因而利用这种算法能高效、精确地确定最佳非线性晶体长度.最后提出在OPCPA过程引入一定的相位失配量，来调谐最稳输出时所需晶体长度，从而能突破晶体加工精度不够的局限，在实际OPCPA过程中获得稳定输出.

Methods for determining and detuning the length of nonlinear crystal in optical pulse chirped amplifier

Three kinds of simulating models for optical pulse chirped amplifier (OPCPA) are introduced at first. Then the three-step way to determine the length of the nonlinear crystal for most stable output is put forward. In this method, all the there models are used. As the more complex models are used, the ranging length for simulation becomes shorter. So it is efficient and accurate to useing this method to determine the optimized nonlinear crystal length. Then the way is also studied to introduce some phase mismatching in OPCPA to detune the nonlinear crystal length for most stable output. Simulating results show that as the mismatching angles increases, the nonlinear crystal length for most stable output becomes longer. So it is suggested that the nonlinear crystal be manufactured longer than designed. Most stable output can be obtained by introducing some phase mismatching in the experiments.