Mach - Zehnder Interferometer Transient Interference Fringe Collection Technology And Its Application In Laser Plasma Test

Laser plasma has broad application prospects and therefore the research on laser plasma has important significance. The main purpose of this paper is to develop transient fringe acquisition technique based on Mach-Zehnder interferometer, obtain high-quality interference fringes of laser plasma, and reconstruct wave-front of transient interference fringes.This paper describes and compares the various diagnostic methods. Quantitative three-dimensional distribution of laser plasma parameters can be obtained only through three-dimensional reconstruction method in interference which is the best laser plasma diagnostic method. However, since the beginning of the process of development of laser plasma expansion speed is very fast, to get clear interference fringes of laser plasma is a critical problem using short pulse laser.This paper develops interference fringes acquisition technique based on the Mach-Zehnder interference system. The adjustment method by equal optical paths of Mach Zehnder interferometer is proposed. White light is used to verify the extent of short coherence. Then the principle to acquire transient interference fringes by CCD is analyzed, meanwhile, a software-based control of the CCD acquisition method of transient interference fringes is proposed. It is proved that high-quality interference fringes are obtained in experiment through software-based CCD.Compared the interference fringes of laser plasma obtained by the established Mach-Zehnder interferometer with those obtained by traditional Mach-Zehnder interferometer, it is proved that the experimental equipment is reliable.Finally, FFT method is applied to reconstruct wave front of the interference fringes of laser plasma. Compare the effects using two different FFT methods and analyze the reasons why they affect the quality of interference fringes of laser plasma on the reconstruction results. Program is used to process different interference images and the quality of interference fringes has effect on the reconstruction results. This illustrates transient acquisition technique based on strictly equal optical path of two arms of Mach-Zehnder interferometer can greatly improve interference fringes and wave front reconstruction results.The high quality interference fringes obtained in this paper will lay a solid foundation for the follow-up work (process of interference fringe, acquisition of laser plasma parameters, etc.)...