| In recent years,with the development of laser technology,the transmission characteristics of laser gradually become a research focus.The measurement technology of spatial distribution of laser intensity is developing to a more accurate and faster direction.How to quickly and accurately obtain the intensity distribution of laser beam is the key to solve the measurement.At present,it is an effective way to obtain the spatial distribution of light intensity by using the complex amplitude transmission of laser.However,the diffraction transmission calculation process is not suitable for both near and far field.In this paper,the complex amplitude reconstruction and diffraction transmission required to solve the distribution of light intensity are studied,and the method based on matrix product Angle spectrum is emphasized to accurately and quickly measure the spatial distribution of laser light intensity.Firstly,the reconstruction method of complex amplitude based on axial light intensity is studied,including the three-plane double gradient iterative method with double gradient factor,and the transport of intensity equation method.Secondly,the matrix product angular spectral method is studied,realizing free sampling in frequency domain and space domain and is suitable for near field and far field.Combined with the three-plane double gradient method,the difference between beam width and actual measurement of the corresponding position is less than 2.0%.The M~2 factor errors were less than 2.8%compared with the beam quality measuring instrument.Finally,the synchronous acquisition of axial two light intensity was realized through the transverse splitting prism.Combined with the light intensity transmission equation method and the matrix product of angular spectrum method,the spatial distribution of light intensity measurement without lens was realized.The experimental verification platform was built and the visual interface was designed.The error is less than 2.4%compared with that measured by beam quality measuring instrument.The repeatability error is less than 1.2%.In addition,the systematic error and random error of the experimental process are analyzed. |
