Research On Suppression Effect Of Grating Lobe By Structural Parameters Of Optical Phased Array Device

Laser scanning technology is widely used in free-space optical communications,aerospace,laser radar,and laser imaging.Optical phased array scanning technology is a promising new scanning technology that can complete accurate and rapid laser beam forming without moving the laser scanning system.However,due to the limitation of the current process technology,the wavelength of the working light is generally smaller than the element element spacing of the optical phased array,which causes the scanning beam to inevitably generate grating lobes,which greatly reduces the scanning accuracy and scanning speed.Therefore,the research on the optimization of grating lobes in optical phased arrays is of great significance in practical engineering applications.This paper mainly studies the effect of structural parameters of optical phased array devices on grating lobe suppression.The developments at home and abroad are introduced,and the theory of optical phased array beamforming and deflection is introduced in detail.The principle of grating lobe suppression is discussed,different structural parameters are simulated,the suppression effect of grating lobe is studied,and improved particle swarm algorithm is applied The element distribution of the non-uniform optical phased array was optimized to achieve the best grating lobe suppression,and the effect of the cascade structure on the grating lobe was further studied.Finally,a dual-structure grating device and a liquid crystal for optical scanning were designed.Optical switch structure.Specifically,there are three aspects to carry out research work:1.Discussed three kinds of grating lobes suppression methods.Using density weighting method,the effect of grating lobes suppression on linear phase change,curve change and random range change of optical phased array were studied.The swarm algorithm optimizes the unequal spacing and obtains the optimal array elements with ultra-low grid lobes.2.The cascade theory of the optical phased array is described,the cascaded composite structure and the cascaded coarse/fine structure are discussed,and the irregular optical phased array cascade structure is optimized to satisfy the phase matching and obtain a good grid.The effect of flap suppression.3.The effects of the number of optical phased array elements and the wavelength of incident light on the suppression of grating lobes are discussed.A dual-structure grating device for beam scanning and a liquid crystal optical switch for beam scanning are designed.The quality of the structure makes it possible to apply it to actual engineering in the future.