Study On Light-control Array Based On Dual-mode Liquid Crystal Microlens Arrays

Traditional imaging detection technique utilizes imaging objectives or lenses to converge target lightwave onto the focal plane of the imaging system so as to form a specific lightfield distribution for next photoelectronic transformation,and thus convert the lightwave signals into electronic signals by the photoelectronic sensors utilized,and finally acquire required image information through electronic signal reprocessing.In particularly imaging circumstance such as complicated flowfield,strong light disturbance,or bad weather,the formed target images are often overshadowed because of scene blurring,strong background light illuminating,target features being small or weak or target rapid movement.In this case,it is difficult to improve the resolvability and detectability of targets according to common image information acquisition and processing methods.In this situation,some main measures including adjusting focal length or decreasing incident light intensity or increasing contrast,should be utilized to quickly process the target lightwave and then adjust the lightfield distribution over the focal plane,so as to achieve objective of remarkably enhancing target detection and recognition efficiency.Different from traditional imaging objective or lens,a light-control array(LCA)based on a new type of dual-mode electrically controlling liquid-crystal(LC)microlens array is presented.Firstly,the basic physical properties and fundamental theory of electrically controlled liquid-crystal microstructures are presented,and then simulations of controlling light function of electrically controlled LC microlens are carried out,and further the production flows of the LCAs are discussed carefully,and finally the key performances of the devices including the lightwave convergence and divergence efficiency,and the relationship between the focal length and the driving voltage,and the anti-glare-interference effect.At the same time,the LCA technology is further employed to switch on and off the optical fibers for arrayed lasers interconnection and the optical encryption and decryption of chaotic signals.The main works of the dissertation are as follows:1?Use differential iteration method to simulate the LC molecular director distribution,and then obtain the point spread function of the light fields over the output plane by the angular spectrum diffraction theory for overcoming the shortcomings of traditional geometric optics simulation process,for instance,complicated computation,slow convergence,and relatively large deviation.2?Optimizing the production process and device microstructure and thus proposing a technique to effectively reduce the thickness between the electrode layer and the LC layer and also reduce the driving voltage,so as to improve the adjustment performances of incident beams through fabricating aluminum films and polyimide electrode layers on both sides of the glass substrate,respectively.3?Innovatively presenting a method for controlling the switching interconnection properties of transportation lasers through the LCA constructed by a dual-mode liquid crystal microlens array,and thus developing an arrayed switching device architecture for strong laser transportation fibers and the encryption and decryption device architecture for chaotic light signal transportation.4?Innovatively presenting a technique of using a dual-mode liquid crystal microlens array as a core component of the LCA to adjust and generate needed lightfield distribution over the imaging plane,so as to demonstrate several advantages,for instance,being more flexible and reliable,defocused blur and strong light interference to detected targets being effectively eliminated.