Study On The Realization Method Of Large Aperture Liquid Crystal Optical Phased Array

Liquid crystal optical phased array(LCOPA)is an integrated device that uses liquid crystal molecules as a phase shifting material,which has a large number of electrode arrays with dense structures,and performs wave-front phase modulation on the incident light beam under the action of an electric field.Liquid crystal optical phased arrays generally employ low-voltage drive methods based on electrode addressaddressed scanning,with advantages such as high accuracy,low inertia,agile scanning,and low SWaP(size,weight,and power consumption).In order to adapt to the trend of miniaturization,simple operation,and light weight of the space optical communication system,making the space optical communication terminal has the ability of full-duplex,multi-user instant communication;in order to reduce the laser emission divergence angle,improve the laser The radar's angular resolution increases the radar detection distance and improves the radar target search capability;also improves the control precision and directional energy density of laser weapons,the paper has studied the realization method of large-aperture liquid crystal optical phased arrays,proposed an improved large-aperture phased array theoretical model,and creatively designed a large-port liquid crystal optical phased array device structure,then theoretically simulated the far-field characteristics of the device and analysis in depth.last but not least,made in-depth research and unique design of the wave controller system.The specific research content is as follows:(1)Analyze the theoretical model of improved large-aperture liquid crystal optical phased array far field characteristics.The model adopts the sub-aperture coherence principle and COM electrode division control for phase modulate and phase compensate separately to realizes continuous phase distribution of adjacent sub-apertures.An improved large-aperture liquid crystal optical phased array device structure is designed.The upper substrate ITO is engraved with a periodically distributed grating electrode,and the lower substrate ITO reference electrode is physically divided according to the size of the sub-aperture area so that the voltages of the reference electrodes in each area are independently controlled.then the paper has proposed a corresponding reference electrode voltage driving method to achieve large-aperture liquid crystal optical phased beam control on a single phased array antenna.(2)Study the far field characteristics of the modified large-caliber liquid crystal optical phased array.Combining the principle of microwave phased array radar,the Fraunhofer diffraction model of large-aperture liquid crystal phased array is studied.The phase modulation and phase compensation of the sub-aperture near-field of a large-aperture liquid crystal optical phased array is performed.Aperture near-field fast Fourier transform was performed and numerical simulation was performed.The simulation results show that the near-field phase distribution of the outgoing light of the LC phased array antenna is continuous;when the pointing angle is in the range of 0 to±6 degree,the numerical relationship between the far field diffraction efficiency and the directional angle shows a smooth and monotonic decrease,and the diffraction efficiency is greater than 48%;When the pointing angle is in the range of 0 to 3 degree,the diffraction efficiency is greater than 80%,indicating that the design and implementation of improved large-aperture liquid crystal optical phased array devices are theoretically feasible.(3)Realize the design of large aperture liquid crystal optical phased array wave controller.Study the overall system design of the liquid crystal phased array wave controller,first the power module of the wave controller,followed by the development of the wave controller management system and the communication interface system.Then study the arithmetic components of the wave controller,which is mainly responsible for wave-control algorithm of the control matrix Realization of the large-aperture liquid crystal optical phase array and finally the realization of the driver of the wave controller.The phased array wave controller supports communication interfaces such as USB and SPI,and adopts the MIPI interface for high-speed wave control data transmission.The maximum operating frame rate or frequency supported is up to 150 KHz.