Ultra-short pulse focusing algorithm for optical parametric chirp pulse amplification numerical simulation platform

The development of optical parametric chirp pulse amplification (OPCPA) numerical simulation platform involves physical models such as broadening and compression pulse, focusing output. In the platform, Fresnel far-field diffraction equation is usually used to simulate characteristics ultrashort focusing. Firstly, we need calculate field distribution different wavelength components in then use inverse Fourier transform obtain temporal spatial pulse. However, for components, sizes focused grids obtained by algorithm are not equal, subsequent resampling required, which will increase amount calculation. addition, due limitation calculation range light compression, there also a problem poor resolution field. this work, mathematical expression that can adjust output fast fourier derived. main mechanism follows. Based on equation, sampled independently discrete process meet requirements adjustable After identity transformation, results be calculated algorithm. Furthermore, sampling conditions satisfied when using further analyzed discussed. It solves how improve keep computational grid size each component consistent traditional far process, provides convenience direct time-frequency transformation. reveal dark ring region shows strong spatiotemporal coupling characteristics. This has been successfully applied OPCPA expected play an important role optimizing design laser device.