The propagation of the basic mode Guassian beam in the optical system with square aperture stop is discussed. In a coaxial optical system, regardless of the transformation and diffraction of the components before the aperture of grating, considering the transformation and diffraction of the aperture of grating and the components behind it, according to the Collins formula, the amplitude distribution of output light field of imaging system is given by way of stationary phase method, the amplitude distribution of output light field of non-imaging system is given following the imaging-relaying pr...
