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Dynamic measurement of beam divergence angle of different fields of view of scanning lidar
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The laser beam divergence angle is one of the important parameters to evaluate the quality of the laser beam.It can not only accurately indicate the nature of the beam divergence when the laser beam is transmitted over a long distance,but also objectively evaluate the performance of the laser system.At present,lidar has received a lot of attention as a core component of environment awareness technology.Micro-electromechanical system(MEMS)micromirror has become the first choice for three-dimensional imaging lidar because of its small size and fast scanning speed.However,due to the small size of the MEMS micromirror,the lidar scanning system has a small field of view(FOV).In order to achieve a wide range of scanning imaging,collimating optical system and wide-angle optical system are generally added to the system.However,due to the inherent properties of the optical lens,it is impossible to perfect the imaging,so the effects of collimating and expanding the beam will be different at different angles.This article aims to propose a measurement system that dynamically measures the divergence angles of MEMS scanning lidar beams in different fields of view to objectively evaluate the performances of scanning lidar systems. 相似文献
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Numerical investigation of multi-beam laser heterodyne measurement with ultra-precision for linear expansion coefficient of metal based on oscillating mirror modulation
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This paper proposes a novel method of multi-beam laser heterodyne measurement for metal linear expansion coefficient. Based on the Doppler effect and heterodyne technology, the information is loaded of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by temperature variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain the value of linear expansion coefficient of metal by the calculation. This novel method is used to simulate measurement for linear expansion coefficient of metal rod under different temperatures by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.4%. 相似文献
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基于闪光光解-磁旋转光谱(LFP-FRS)装置,以烷烃为例,研究了OH自由基(·OH)的反应动力学。通过266 nm的脉冲激光光解臭氧产生·OH,利用2.8μm中红外磁旋转吸收光谱直接测量反应腔中·OH浓度的衰减,在准一级近似反应条件下,获得了5 kPa压力下的甲烷与·OH反应的速率常数为6.59×10-15 cm3/(molecule·s),并对比了不同压力条件下,甲烷、乙烷和丙烷与·OH反应的速率常数的变化。利用化学模型,对其化学过程中存在的多个反应通道进行了模拟,为·OH相关的重要大气化学机制及反应过程研究奠定了基础。 相似文献
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提出了一种多光束激光外差测微小角度的新方法. 基于激光外差技术和Doppler效应, 通过做简谐振动的Doppler振镜对不同时刻入射光的正弦调制, 把待测角度信息加载到外差信号的频率差中, 经信号解调后可以得到待测角度参数值, 经加权平均处理可以提高待测角度的测量精度. 利用这种新方法, 通过Matlab仿真了平面标准镜不同入射角的模拟结果, 表明该仿真结果的最大相对误差小于0.789677%.
关键词:
角度测量
多光束激光外差
激光Doppler技术
Fourier分析 相似文献
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