Dammann 光栅的等光强分束特性被广泛应用于线阵激光雷达发射机中。本论文在调研了大量文献资料后，对一维 Dammann 光栅在线阵激光雷达发射机中的应用做了相关研究。

本论文首先介绍了激光雷达的基本原理和实现方式，给出了基于 Dammann 光栅的一 维线阵激光雷达发射机结构。然后以单缝衍射及普通光栅衍射理论为基础，解释了 Dammann 光栅的分束原理。并基于遗传算法设计出了 13 元的 Dammann 光栅方案。为检 验设计方案的优劣，用 Matlab 程序仿真菲涅尔衍射过程对分光效果进行了检验，发现在 近场处分束均匀性很差，而在远场处分束均匀。之后分析了光栅制作过程中可能产生的两 种误差对分束均匀性及衍射效率的影响，发现两种误差都会使分束均匀性变差，但纵向误 差会明显的使衍射效率提高。最后对成品 Dammann 光栅的分束特性进行了验证实验，实 验显示现有光栅的零级衍射较强，光束间隔角较大，用于发射机时需要加准直扩束系统。77269

毕业论文关键词 Dammann 光栅 一维线阵激光雷达发射机 Matlab 仿真 遗传算法 表面误差

Title The Application of One-Dimensional Dammann Grating in Linear Lidar Transmitter

Abstract The Dammann grating, which can split a beam of light into uniform beams, is widely employed in linear lidar transmitter。 On the basis of researching lots of literatures and meterials, the application of one-dimensional Dammann grating on line array laser radar transmitter is studied in this paper。

First, the basic principle and realization of the lidar is introduced in this paper, and the structure of the linear lidar transmitter based on the Dammann grating is gaven。 Then the Dammann grating’s beams splitting phenomenon is explained using the single slit diffraction and ordinary grating diffraction theory。 After illustrating the principle of how to design a Dammann grating, the method of 13-beam Dammann grating designing is given using the genetic algorithm。 In order to test the beam splitting results of the design solution, the grating’s Fresnel diffraction process is simulated using Matlab software。 It was found that the splitting uniformity is bad in near-filed diffraction, but it is pretty uniform in far-field diffraction。 Then the effects of two surface errors generated in grating making on beams uniformity and diffraction efficiency are analyzed。 It was seen that both of the two errors make splitting uniformity to be terrible, but the vertical error make the diffraction efficiency larger obviously at the same time。 At the last of the paper, the beam splitting properties of a finished Dammann grating are verified。 It is shown that the finished Dammann grating we have has a strong zero-diffraction, and angle between two nearest beam is large than operating requirements, so a collimating and beam expanding system is needed。

Keywords Dammann grating Linear lidar transmitter Matlab simulation Genetic algorithm Surface error

本科毕业设计说明书 第 I 页

目 次

1 绪论 1

1。1 研究背景 1

1。2 国内外研究进展 1

1。3 论文的研究内容 3

2 激光雷达线阵发射机的实现方式