用于合成孔径激光成像雷达的光折变全息并行成像处理研究

This project aims at the development of the principle and technology of optical imaging processing for synthetic aperture imaging laser radar (SAIL), and it includes the studies of a one-step focused-imaging parallel processing algorithm theory for SAIL in the spatial domain, a lithium-niobate non-volatile photorefractive holographic device for astigmatic Fourier transformation, a 3-D wavefront recording and diffraction theory of spatially-localized volume hologram with changing grating basic-vectors and different recording and reconstruction wavelengths, and an optical processor design as well as its experimental demonstration. The suggested investigations have apparent creativities, and the feasibility as proven by our previous work. This project will result in a new 2-D systematic algorithm for SAIL imaging, a new recording and diffraction theory of localized volume hologram with changing basic-vectors and different wavelengths, an integrated photorefractive holographic device with manifold optical functions, and an optical imaging processor which provides inherent parallel processing capabilities and will show its essential features of lightweight, compact construction, fast and real-time computing capabilities, low power consumption, and suitability for space-based or airborne applications. It is also seen that the processor can be modified to use for microwave-SAR image processing. Furthermore, such a research can lay the foundation for exploring an all-optical SAIL in which the acquirement of target information and the processing for imaging utilizes both optical means.

本申请旨在发展合成孔径激光成像雷达（SAIL）的光学成像处理原理和技术，研究内容包括空间域一步并行处理聚焦成像算法理论，像散傅立叶变换铌酸锂非挥发光折变全息，变基矢变波长空间局域性光折变体全息的三维波面记录和衍射理论，光学处理器结构设计及其实验演示。本研究具有创新性和前期工作证明的可行性，能够产生新的二维聚焦成像算法体系，建立新的变基矢和变波长局域性光折变体全息的记录和衍射理论，形成多性能一体化集成的光折变体全息光学器件，所建设的光学处理器发挥光学内在并行处理特性并将充分显示其轻量化，结构紧凑，高速和实时处理能力，功耗低，适合航天航空环境应用等优点。本研究结果也可以推广到微波SAR的图像处理应用，同时也为探索全光学实现目标信息获取和成像处理的全光合成孔径激光成像雷达奠定基础。

合成孔径激光成像雷达的研究已经发展出了充分体现光学特性的新体系结构，其基于光学波面变换原理而不再能够用微波实现。合成孔径激光成像雷达获取的目标信号比微波SAR更数学解析化，更加容易转化为空间域的二维并行处理算法。因此我们旨在发展合成孔径激光成像雷达（SAIL）的光学成像处理原理和技术。针对本项目的光学成像处理系统，建立了一种空间域二维聚焦成像算法体系，给出了算法的基本流程及其物理描述。结合侧视SAIL和直视SAIL单一点目标统一回波收集方程对成像过程进行了数学描述，并对SAIL光学处理器的时域，空域处理能力进行了分析。对现有的不同掺杂浓度、不同厚度的Fe:LiNbO3晶体进行了性能对比及检测试验，完成最大衍射效率的铌酸锂的掺杂体系调整和固定方案优化。根据合成孔径激光成像雷达的像散傅立叶变换一步并行成像处理系统的总体设计方案，完成柱面透镜的波前变换系统记录到Fe:LiNbO3和LiNbO3:Ce:Cu晶体，实现一体化像散傅立叶变换透镜的铌酸锂非挥发光折变全息元件的制备。建立用于合成孔径激光成像雷达的光折变全息一步并行成像处理系统，利用该处理系统实现对SAIL大口径实验室验证装置所得目标回波数据的光学像重建实验演示。基于一体化光折变体全息光学器件方案，实现多散射情况下的生物组织成像实验。本项目先后发表标注引用成果30项，包括SCI论文11篇，发表SPIE会议论文（EI收录）4篇，发表国内核心期刊论文（EI收录）6篇，授权发明专利8项，申请还未授权专利1项。培养研究生三名，其中博士生两名，硕士生一名。