菲涅耳望远镜全孔径合成成像激光雷达：原理

Fresnel Telescope Full-Aperture Synthesized Imaging Ladar:Principle

提出了一种菲涅耳望远镜全孔径合成成像激光雷达的概念,原理基于对目标进行同轴同心相位二次项偏振正交双光束扫描的光电数据收集以及光学和数字计算空间复相位解调的图像重构。具有两种工作模式即目标移动而光束一维扫描和目标静止而光束二维扫描,能够实现目标超光学分辨率极限的二维成像并具有三维成像能力。由于实施了空间对时间的传输信号转化并且采用了同轴光束相干探测和复数相位合成,提高了接收灵敏度和成像信噪比,大大降低了大气对于激光传输的影响,允许使用低质量的接收光学系统从而能大大增加接收光学口径而降低激光发射功率,由于使用了光桥接器使得整体光、电、机械结构更加简单。给出了详细原理叙述和数学分析。

An idea of Fresnel telescope full-aperture synthesized imaging ladar is proposed,which is based on the optoelectronic data collection from the relative scanning between target and two cocentric coaxial beams of polarization-orthogonal quadratic wavefronts,and the image reconstruction from the complex quadratic phase decoded with optics and digital processing.It has two operational modes with moving target by 1D beam scanning and statistic target by 2D scanning.The imaging resolution is higher than that from the diffraction limit and 3D imaging is also possible.Because of the transformation of spatial signal to temporary signal and the utilization of coherent detection of coaxial beams,both the imaging S/N ratio and the receiving sensitivity are improved,and particularly the atmospheric influence is decreased greatly,optical receiving system of low quality is allowed to use to increase optical receiving aperture and decrease laser transmitting power.The systematic optoelctronic and mechanical configuration is quite simple due to the use of an optical hybrid.The detailed description of principle and mathematical analysis is given.