Theoretical And Experimental Analysis Of Beam Steering Technology

Beam steering is indispensable in many optical and photonic applications.Electro-optic deflectors based on liquid crystal have attracted widespread attention because of their advantages,such as small size,low driving voltage,high electro-optic coefficient,low power consumption and so on.Especially the liquid crystal blazed grating,which combines liquid crystal and a blazed grating,has great potential in the fields of laser lidar,adaptive optics system and projection display and so on,owing to its simple fabrication process and convenient operation.Firstly,this dissertation made a theoretical and experimental study on the beam steering technology based on liquid crystal blazed grating.Through theoretical analysis and numerical simulation of the working principle and deflection characteristics,a reflection-type liquid crystal blazed grating with a discrete deflection angle of 20.9° was designed.On this basis,a reflection-type liquid crystal blazed grating was fabricated experimentally,and its deflection characteristics under different incident wavelengths,polarization states and incident angles were measured.According to the experimental results,a scheme was proposed which are using dual-frequency liquid crystal to fabricate liquid crystal blazed grating.The simulation results show that the scheme is beneficial to obtain a larger deflection angle.In addition,this dissertation also made a theoretical study on the beam steering technology based on silicon-based optical waveguide.With the development of silicon photonic integrated technology,the method using optical waveguide arrays on silicon-on-insulator to achieve beam steering has become a new research topic.In order to realize the large-angle steering,a novel wavelength-tuning silicon-based beam steerer technique was proposed.We analyzed the factors affecting its deflection characteristics from the structure design and working principle's point of view.And its deflection characteristics were simulated and calculated.The results show that a fast scanning of 57.60° can be achieved just using a tunable laser source with 30nm.