The Study Of Beam Shaping Properties Of The Noval Binary Optical Elements

Laser micro-machining technique and spectral analysis technique based on diffraction grating are potential for the development in the application field. In this paper, several commonly used homogenizer and their design methods are understood, so as some means for suppress high-order diffraction. For the beam characteristics and practical use in the laboratory, we designed an array Photon Sieve(APS) homogenizer for improving the uniformity of the wavefront of laser and designed a quasi-sinusoidal reflection type single-order diffraction grating(QSRG) for suppressing high-order diffraction to improve the spectroscopy system’s signal-to-noise ratio(SNR) and precision by using the binary optical theory and employing the microelectronic processing techniques.In this paper, we first studied the function of binary optical element(BOE) for shaping the wave and some algorithmic method used for implementing the design of BOE. And then, designed two new type BOEs:APS homogenizer and QSRG. The processes of design homogenizer is first compute the parameter of a single PS, then simulate with MATLAB and finally acquire layout structure use LEDIT software. The procedure of design single diffraction grating is to acquire the grating’s period according to wavelength and then make the masks using LEDIT software. The basic unit of APS homogenizer is photon sieve(PS), APS homogenizer use the PS as the base element to construct array, and to acquire the uniform intensity distribution of the355nm laser in the laboratory. The designed element’s size is50.9mm×50.9mm, and the number array is300x300. The outer-most ring width of base element is2.318um, and has a focus of1mm. Quasi-sinusoid single diffraction elements cut the single grating line to many square areas, and distribute these areas in sine function. The total area of the grating is8mm x8mm, and is constructed by many40umx40um square which has20um minimal size.To experiment prove the property of diffraction elements. We first look the structure under high-resolve microscope and then test them. The results show the PS array homogenizer can effective improve the uniformity of laser’s wavefront and the Quasi-sinusoid single-order diffraction grating can suppression high-order diffraction effective.