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Non-mechanical laser beam steering has been reported previously in liquid crystal array devices. To be one of the most promising candidates to be practical non-mechanical laser deflector, its laser induced effect still has few theoretical model. In this paper, we propose a theoretical model to analyze this laser induced effect of LC-OPA to evaluate the deterioration on phased beam steering. The model has three parts: laser induced thermal distribution; temperature dependence of material parameters and beam steering deterioration. After these three steps, the far field of laser beam is obtained to demonstrate the steering performance with the respect to the incident laser beam power and beam waist.

To improve the steering precision and angular resolution of liquid-crystal optical phased array, in this paper, we proposed a modified periodic phase controlled method to realize a continuous scanning with a constant angular resolution of less than 20 μ rad, meanwhile, its precision is less than 5 μ rad (rms). Also, another method we proposed is called subaperture coherence that can realize even better angular resolution less than 5 μ rad, which is the limitation of our measurement instrument.

This paper reviews the research progress of liquid crystal optical phased array (LCOPA) devices in space laser communication applications. According to the constraints of space applications and system requirements, in the design and key technologies of array devices, the research progresses on the implementation methods such as wide-point range, large-aperture optical aperture, short response time, and space environment adaptability are emphatically introduced. In introducing the wide beam pointing range, the beam control method and the digital concatenation scheme are mainly described. In the study of large aperture, the area filling module and the area selection module are separately analyzed. And comparatively expounded the realization of sub-millisecond order rapid response of liquid crystal materials, and finally gave the United States Air Force laboratory's research on the liquid crystal optical phased array device irradiation environment adaptability research results.

Ship target detection is increasingly important to the current war today. Space-based Detection is an important way for getting the remote-sensing image included the ship target. Ship target characteristics analysis is the key of infrared image reorganization. It includes the thermal radiation of the target and background, Atmospheric transmission characteristics, imaging characteristics of detector and target characteristics. In order to get the simulation image in the infrared long-waveband, it analyses the characteristics of the infrared ship target and background. The target characteristics are known clearly, it could make the extraction process of target more effective and accurate. The target characteristics analysis is more conducive to the detection and recognition of the target.

High deflection efficiency is one of the urgent requirements for practical liquid crystal optical phased array (LC-OPA). In this paper, we demonstrate that high order grating lobes induced from fringe effect are the most important issue to reduce occupation of main lobe. A novel theoretical model is developed to analyze the feature of grating lobes when the device of LC-OPA is working on the scheme of variable period grating (VPG) or variable blazing grating (VBG). Subsequently, our experiments present the relevant results showing a good agreement with the theoretical analysis.

We present a scheme of nonmechanical laser beam steering using ZnS/InP quantum dots doping nematic liquid crystal as the optical recording film. Because of its internal electric field generated by blue laser-induced charge carrier distribution, liquid crystal molecules are reoriented to form a phase grating which make the incident angle steer to the angle as we desire. Being a nonmechanical programmable laser beam steering, the anisotropy of the relative permittivity tensor and blue laser-induced electric carriers play a significant effect in determining the reorientable liquid crystal molecule and reconfigurable phase modulation of the gratings, that determines the steering angle and steering efficiency.

Joint Transform Correlator (JTC) is a more advanced optical pattern recognizer. Compared with computer correlation matched method, it has many advantages, such as parallel processing, high speed and more sampling points. The bottleneck technique of JTC is how to recognize the distorted targets in cluttered scene. The Maximum Average Correlation Height (MACH) algorithm applied in JTC is presented. The MACH algorithm has powerful capability of recognition for distorted targets (rotation and scale etc.). Through optimizing MACH frequency domain filter and projecting it to space domain, the MACH reference image can be obtained. This MACH reference image clearly records various distortions of a target. Based on the basic principle of JTC, the distorted targets in cluttered scene can be detected. Optical experiments with JTC show that the edge features of detected image should be extracted, the correlation calculation of MACH reference image and detected target can be performed accurately and the bright correlation peaks can be obtained. In the process of optical correlation recognition, the performance of MACH reference image is used sufficiently. The energy of correlation peaks is greatly enhanced, the cluttered scene can be suppressed effectively and the MACH reference image has high distortion tolerance. To demonstrate the feasibility of MACH reference image, the scale distorted car in cluttered scene is successfully detected.