高效率复合探测激光雷达光学系统性能的研究

发布时间：2018-07-25 08:59

【摘要】：影响复合探测激光雷达系统性能的因素主要有三个：激光器、探测器和光学系统，在激光器、探测器确定的情况下研究光学系统对提升系统性能具有重要意义。传统的复合探测激光雷达光学系统结构一般选择折反射式，这样会存在中心遮挡，效率低下；传统的分光镜分光效率一般为70%—80%，具有较大的提升空间。本文将在此基础上完成高效率复合探测激光雷达光学系统的性能研究，并进一步提出在探测器象元数少于阵列光束数目时的激光高效率接收方法。本文对分光系统效率的提高进行了研究。首先分析复合探测分光系统的工作原理，其次，针对激光、红外视场角小及系统透过率低下提出改进方法，使得激光视场角由原来的3.5°提高至7°，红外波段的视场角由原来的6.9°提高至10.4°。分光系统激光的理论上的透过率由原来的85.3%提高至99%以上，系统的红外波段理论上的透过率由原来的85.9%提高至99%以上。本文还讨论了高效率激光阵列接收系统的设计。首先，完成激光阵列接收系统的分析。然后，对激光接收系统进行设计，主要包括光纤阵列的设计以及薄膜结构的设计。最后，分析接收系统中激光、微透镜和光纤的耦合效率。当纵向偏移、横向偏移、角度偏移量在一定范围内，激光接收系统整体耦合效率理论在93%以上。本文分析了复合探测光学系统的主体结构，针对中心遮挡，提出折射式复合探测共口径结构，并分别针对红外光学系统、激光光学系统完成高效率设计。复合探测光学系统的9.7μm红外波段透过率由原来的61.1%提高到66.3%，系统1.064μm的激光的透过率由原来的62.9%提高到72.7%，，且折射式系统不会对中心优质光束进行遮挡。经模拟，激光光学系统、红外光学系统的弥散斑直径分别为17μm、22μm，均小于阵列探测器的面元尺寸，有助于消除串扰，提高整体效率。
[Abstract]:There are three main factors that affect the performance of compound detection lidar system: laser, detector and optical system. It is very important to study the optical system in the case of laser and detector to improve the performance of the system. The traditional optical system of compound detection lidar generally chooses the refractive type, which will have center occlusion and low efficiency, and the traditional spectroscope is generally 70-80, which has a large lifting space. On this basis, the performance of high efficiency composite detection lidar optical system will be studied, and a high efficiency laser receiving method when the number of detector pixels is less than the number of array beams is proposed. In this paper, the improvement of the efficiency of the spectroscopic system is studied. Firstly, the working principle of the compound detecting and splitting system is analyzed. Secondly, an improved method is proposed to improve the laser, infrared field of view angle and the low transmittance of the system. The laser field angle is increased from 3.5 掳to 7 掳, and that of infrared band is increased from 6.9 掳to 10.4 掳. The theoretical transmittance of the system is increased from 85.3% to more than 99%, and the theoretical transmittance of the infrared band of the system is increased from 85.9% to more than 99%. The design of high efficiency laser array receiving system is also discussed in this paper. Firstly, the laser array receiving system is analyzed. Then, the laser receiving system is designed, including fiber array design and thin film structure design. Finally, the coupling efficiency of laser, microlens and fiber is analyzed. The overall coupling efficiency of the laser receiving system is over 93% when the longitudinal, lateral and angle offsets are in a certain range. In this paper, the main structure of the compound detection optical system is analyzed. For the center occlusion, the refraction compound detection common aperture structure is proposed, and the high efficiency design of the laser optical system is completed respectively for the infrared optical system and the laser optical system. The transmittance of the complex detection optical system in the infrared band of 9.7 渭 m is increased from 61.1% to 66.3%, the transmittance of the laser at 1.064 渭 m is increased from 62.9% to 72.7%, and the refraction system does not block the central high quality beam. By simulation, the diffusing spot diameters of laser optical system and infrared optical system are respectively 17 渭 m or 22 渭 m, which are smaller than that of array detector, which is helpful to eliminate crosstalk and improve overall efficiency.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN958.98

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