The Miniaturization Of Large-diameter Laser Intensity Spatial And Temporal Distribution Characteristics Of The Measurement System

Laser intensity space-time distribution means laser intensity space distribution vs. time, It is particularly important to trace and detect target, diagnose laser beam quality, measure laser transmission from atmosphere, and it is widespread used in these fields such as laser distance-measuring, laser communication, etc.CCD imaging method has notable advantage of high resolution in laser intensity distribution, especially with the development of CCD technology, CCD's measurement dynamic range becomes increasingly larger, its techniques of noise handling is getting better, so CCD imaging method has wide prospect in laser parameter measurement. CCD imaging method is divided into diffuse reflect and diffused transmission. There are some reports on diffuse reflect home and abroad, but the properties of diffuse reflect is surface scattering, which requires extremely high requirements of surface of the diffusion screen and misfits integration, so diffuse reflect imaging is yet not convenient in many occasions. At present, There is not any report on measuring laser parameter by diffused transmission imaging method.CCD diffused transmission imaging method is used for measuring laser intensity distribution in the measurement system of"Small-sized heavy caliber laser intensity space-time characteristic". The measurement principle of the system is presented. The scattering properties of the diffusion screen is researched through theory and experiments, There is a detailed introduction on the design of optical system. The field of view, light path, reflector, focal length and aperture of camera lens, depth of field of CCD cameral are respectively introduced. The reasons of geometrical distortion and intensity distortion of laser spot are analyzed, a grid-method for rectifying distortion based on uniting pixels is given and is validated by experiments. The data processing software and computational method of laser beam parameter are introduced. The system's mechanical structure has been finished. After being calibrated and debugged, the system is used for measuring 532 nm laser spot, which validate diffused transmission imaging method's correctness. Finally, the uncertainty of measurement of the system are analyzed, some further research on the system is discussed. The system provides a new way to measure laser parameter, Which implements large laser spot intensity distribution and power measurement at the same time in small space, it has the advantage of high resolution for intensity distribution measurement and of high accuracy for power measurement, which is of great significance for practical engineering issues. The measurement system has been applied to import scientific research tests,and achieved a lot of valuable experimental data.