Increase of SHG-FROG Calculation Speed by 'Second Initial Value'

摘要

The "second initial value" introduced to raise the retrieval speed of the chirped pulse for SHG-FROG means a random square pulse, with amplitude of random width and zero phase, is chosen as the initial value of retrieval, and after several iterative calculations the amplitude width resemble to the real value is gained. Then the second initial value is decided with amplitude of the gotten width and phase of random chirp-like distribution. Numerical calculation results show that "Second initial value" can expedite the SHG-FROG.