FLEET光学系统参数优化  

Parameters optimization of FLEET optical system

作　　者：王建新 陈爽[3] 陈力[3] 杨文斌 邱荣[1,2] 白福忠 李同洪[5] Wang Jianxin;Chen Shuang;Chen Li;Yang Wenbin;Qiu Rong;Bai Fuzhong;Li Tonghong(Joint Laboratory for Extreme Conditions Matter Properties,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;Sichuan Civil-military Integration Institute,Mianyang,Sichuan 621010,China;Facility Design and Instrumentation Institute,China Aerodynamic Research and Development Center,Mianyang,Sichuan 621000,China;School of Mechanical Engineering,Inner Mongolia University of Technology,Huhhot,Inner Mongolia 010051,China;National Center of Quality Inspection and Testing on Diamond Tools,Ezhou,Hubei 436000,China)

机构地区：[1]西南科技大学极端条件物质特性联合实验室,四川绵阳621010 [2]四川省军民融合研究院,四川绵阳621010 [3]中国空气动力研究与发展中心,设备设计与测试技术研究所,四川绵阳621000 [4]内蒙古工业大学机械工程学院,内蒙古呼和浩特010051 [5]国家金刚石工具质量检验检测中心,湖北鄂州436000

出　　处：《光电工程》2022年第4期39-46,共8页Opto-Electronic Engineering

基　　金：国家自然科学基金青年基金资助项目(11902277);国家自然科学基金面上项目(62165011,51765054)。

摘　　要：FLEET流场测速时,荧光丝的形态和特征影响流场速度测量的精度和覆盖范围,而这些参数又取决于FLEET光学系统参数,有必要对FLEET光学系统参数对荧光丝的影响规律进行研究。本文研究了光学系统的主要参数飞秒激光脉冲能量和聚焦透镜焦距对荧光丝长度、光丝峰值强度、功率密度、信噪比的影响,并在最优实验参数条件下,对不同压强下空气飞秒荧光丝的寿命进行探测。实验表明,飞秒荧光丝的激发存在功率密度阈值,本实验中大致在2×10^(13)W/cm^(2),光学系统参数优化应以飞秒荧光丝信噪比高且光丝强度分布均匀为基准。飞秒荧光丝的寿命约为几微秒,因此,两次测速采样的时间间隔应小于微秒量级。本文研究结果可以为FLEET光学系统主要参数确定提供依据。Using FLEET to measure flow field velocity,the shape and feature of fluorescent filament impact on the accuracy and range of the velocity measurement,and are determined by the parameters of the FLEET optical system.Therefore,it is necessary to study the influence of FLEET optical system parameters on fluorescent filament.In this paper,the influences of main parameters for optical system,namely pulse energy of femtosecond laser and focal length of the focusing lens,on the length of filament,peak intensity,energy density of filament and signal to noise ratio are investigated by experiment.The lifetime of air fluorescent filament under different pressures are measured with the optimum experiment parameters.Experiments show that there is a power density threshold for femtosecond fluorescent filaments excitation,which is about 2×10^(13)W/cm^(2)in this experiment.The optimization of optical system parameters should be based on the high signal-to-noise ratio and uniform intensity distribution of filament.The lifetime of femtosecond fluorescent filaments is about several microseconds.Therefore,the time interval between two velocity measurement samples should be less than microseconds.The results are useful for determining the main parameters of FLEET optical system.

关 键 词：FLEET 流速测量 荧光寿命 图像处理 

分 类 号：O439[机械工程—光学工程]