利用液晶光楔实现超分辨率成像  

Super-Resolution Imaging Using Liquid Crystal Optical Wedge

作　　者：曹凡 周波 刘志强 叶茂 Cao Fan;Zhou Bo;Liu Zhiqiang;Ye Mao(School of Optoelectronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,Sichuan,China)

机构地区：[1]电子科技大学光电科学与工程学院,四川成都611731

出　　处：《光学学报》2024年第19期160-167,共8页Acta Optica Sinica

摘　　要：探究液晶光楔器件在超分辨率成像中的应用,利用液晶材料制备得到可电控调制光束偏转方向的液晶光楔器件,通过改变施加电压的幅值采集多帧亚像素位移的图像序列,结合插值方法合成得到高分辨率的图像,相对初始图像的极限分辨率提升约55.0%。相比于利用双光楔旋转、液晶透镜光轴移动获得多帧图像序列的方法,该设计具有图像畸变小、响应速度快、对系统光焦度无影响的优点。Objective The simplest way to achieve high-resolution imaging is by increasing the number of pixels per unit area of the image sensor.However,this can lead to smaller pixel sizes,which in turn increases scattering noise,ultimately degrading image quality and raising costs.Super-resolution(SR)imaging involves acquiring a sequence of images of the same scene with slight displacements and then synthesizing these to create a higher-resolution image.The multi-frame SR reconstruction technique primarily involves:1)sub-pixel shifted image acquisition of the same scene,2)alignment of the acquired images,and 3)the use of interpolation methods to obtain higher-resolution images.Conventional methods that involve using double optical wedge rotation and liquid crystal lens optical axis shift suffer from significant image distortion,complex control mechanisms,and slow response speeds.We propose a super-resolution imaging system utilizing a liquid crystal optical wedge device that electronically modulates beam deflection to acquire sub-pixel shifted images.By simply adjusting the amplitude of the applied voltage,the deflection angle and direction of the beam can be precisely controlled without mechanical movement.The liquid crystal optical wedge device can achieve a minimum thickness of just a few micrometers,resulting in fast response times.Methods In this study,we propose a super-resolution imaging system that incorporates a liquid crystal optical wedge device paired with a polarizer and a fixed focal length camera module.We first introduce the principle of electronically modulated beam deflection within the liquid crystal optical wedge and theoretically analyze the relationship between beam deflection and image displacement.A sequence of images of the same scene is captured at varying driving voltages,and the average displacement between images is measured using the Keren alignment method.Experimental results demonstrate that electronically modulated sub-pixel image shifts are achieved within acceptable error margins.The lim

关 键 词：成像系统 液晶光楔 光束偏转 亚像素位移 超分辨率成像 

分 类 号：TN141.9[电子电信—物理电子学]