The measurement system of high energy laser beam quality factor β is mainly used for state debugging and comprehensive performance parameters diagnosis of laser system,while these parameters can evaluate the laser output performance and the far-field spot focusing ability of the laser system.Aiming at the defect that the beam quality factor β close to the diffraction limit occupying too few pixels in the area array detectors,a measurement method was proposed based on microscopic magnification with high-precision scanning slit,and the relevant scheme was analyzed and calculated.In addition,a verification scheme of measurement results using the combination of fixed aberration elements and collimator light sources was designed to analyze the uncertainty of measuring device of developed high energy laser beam quality factor β,and the measurement uncertainty was better than 10%.

In order to measure the reflectivity of large-aperture and high-reflectivity optical elements in high energy laser transmission system, a precision measurement system for two-dimensional scanning of largeaperture optical elements was designed. The structure and working principle of the system were introduced, the factors affecting the measurement accuracy of the system were analyzed, and the influence of systematic error of the scanning system on the measurement accuracy was theoretically analyzed. The results show that the measurement error is 10-6 magnitude when the horizontal deviation is 0.29 mm perpendicular to the beam propagation direction. When the variation of cavity length is small, the rotation axis deviation can be compensated and the system can be fine adjusted by adjusting the ring-down cavity mirror. By fitting the data of light intensity and time, the corresponding first-order exponential function fitting curve was obtained, and the ring-down time as well as the reflectivity was obtained by calculation. Through contrast analysis, this kind of error analysis method can more effectively measure the reflectivity of cavity mirrors and can reduce the error brought by the experimental data itself.

In the evaluation and analysis of high-power laser system, the beam quality of laser is the decisive factor of the system beam quality and also an important index of acceptance and appraisal of laser, among which the beam divergence angle is an important parameter to identify the laser beam quality. The range of laser wavelength tested in this system is relatively wide, generally between 0.532 μm～10.6 μm, and no suitable detector can cover the whole band. Therefore, a new method was adopted to solve the measurement problem of wide-band beam divergence angle. The method of combining charge coupled device（CCD） imaging and scanning slit was used to measure the wide-band beam divergence angle. The CCD method was used to measure the laser beam divergence angle in visible and near-infrared band（0.532 μm～1.2 μm）, and the scanning slit method was used to measure the laser beam divergence angle in mid-infrared band（1.2 μm～10.6 μm）. The combination of the two methods can accurately measure the laser beam divergence angle in different wavebands.

The cavity ring-down method is currently the only method for measuring ultra-high reflectivity（reflectivity is greater than 99.9%） of optical elements. An optimal extraction method for the relationship between laser signal intensity and time in cavity ring-down method was introduced, and a test system for ultra-high reflection ratio of optical elements based on cavity ring-down method was designed. The data of cavity ring-down curve were divided into five sections by piecewise exponential fitting, the R~2（R-square） and rootmean-square error（RMSE） values corresponding to the index fitting results of each section were compared and analyzed, and the ring-down time of each index fitting was calculated. The experimental results show that the results obtained from 40%～60% of the cavity ring-down curve data are closest to the real value, and the reflectivity of the corresponding cavity mirror is 99.988 977%. Finally, by comparing with the reflectance of the cavity mirror, it is shown that this data fitting method can effectively measure the reflectivity of the cavity mirror and reduce the error caused by the experimental data.

大功率激光功率测量常用量热法,但溯源复杂.介绍了具有较高测量精度的基于光压原理的大功率激光功率测量方法,设计了利用1/105精度天平大功率激光测量实验,测试了基于GaAs半导体材料制作的反射镜的反射率及损伤阈值,确定了基于GaAs半导体材料反射镜的相关性能.得到了普通实验室条件下的功率测量重复性及线性,验证了1/105精度天平用于大功率激光测量的可行性.通过实验结果结合理论计算,得出利用1/105精度天平的光压测量功率的测量上限可以达到3×104?W以上.

测量高能激光远场辐照度分布是评估激光武器系统性能指标的一个有效方法.对国内外现有的几种高能激光远场辐照度分布测量方法进行了比较和归纳,对各种技术的优点和缺点作了深入的分析,并对靶面抗损伤技术、取样衰减技术和功率密度定标技术3项关键技术研究进展进行了介绍,在该基础上阐述了高能激光能量远场辐照度分布直接测量技术的发展趋势.

简述了高能高功率激光技术的发展现状及其计量测试需求,介绍了近年来开展的高能高功率激光参数计量测试研究取得的进展,给出激光功率能量、时域参数和空域参数等测量原理和方法.指出了高能高功率激光参数测量面临的主要问题及需要突破的关键技术,包括大动态范围功率能量"无畸变"衰减技术、激光功率能量现场测量技术和功率能量计溯源及后向散射补偿方法等.

钛宝石飞秒激光放大系统具有重复频率低、脉冲波形复杂等特点,为准确测量其峰值功率,提出对单次脉冲波形和脉冲宽度测量的需求。介绍了单脉冲飞秒激光时域波形和脉冲宽度的测量原理和测量方法,设计了基于频率分辨光学开关法的单脉冲飞秒激光时域参数测量装置。讨论了单脉冲飞秒激光时域参数测量校准面临的问题及解决方法。

跟瞄精度是空间激光通信系统捕获、跟踪和瞄准(acquisition,tracking and pointing,ATP)分系统的重要指标参数之一,其准确测量是评估空间激光通信系统远距离通信性能的关键.介绍了空间激光通信系统ATP分系统跟瞄精度的测试方法,设计了一种基于平行光管法的空间激光通信系统动态瞄参数测量装置,分析和讨论了影响动态跟瞄精度测量不确定度的因素.试验表明,该测量装置在100 Hz振动频率条件下,ATP分系统稳定精度测量不确定度达到1.9μrad(k=2),可用于空间激光通信系统ATP分系统跟瞄参数检测以及远距离激光通信性能评估.

功率和能量是微弱激光的两个基本参数,激光功率和能量测量一直是微弱激光参数计量中最基础的研究工作.文章总结了美国标准技术研究院(NIST)、英国国家物理实验室(NPL)以及中国国家计量院(NIM)在微弱激光功率能量计量方面的技术现状,重点介绍了国防科技工业光学计量一级站在微弱激光功率能量计量方面已具备的条件,详细说明了所采用的测量原理以及所达到的测量范围和测量不确定度等技术指标.提出了微弱激光功率和能量计量的发展趋势和发展方向.

考虑惯性约束聚变系统中的磷酸二氢钾/磷酸二氘钾(KDP\ DKDP)的吸收系数直接影响系统的转换效率及最终输出能量,本文研究了KDP\DKDP倍频晶体吸收系数的测量方法.提出了新的基于朗伯定律的倍频晶体吸收系数斜入射测量法.建立了斜入射状态下入射光偏振态与晶体o光和e光的关系模型,推导了小角度入射下晶体e光折射率的迭代计算方法.采用该方法计算了晶体的e光折射率,通过测量得到的数据间接计算出了KDP\DKDP倍频晶体吸收系数.详细分析了该方法在测量过程中的各项误差来源,得出该方法测量误差优于0.000 2 cm-1.最后,对一块40mm×40 mm× 60 mm的开关晶体元件进行测试并与分光光度法比对以验证提出方法的可行性,结果显示两种测量方法的偏差小于0.000 2 cm-1,表明该方法可用于惯性约束聚变系统中倍频晶体吸收系数的测量.

Laser Rayleigh-Brillouin scattering is an effective non-intrusive method for measurement of density, temperature and pressure in gas flows. In theory, the power of Rayleigh-Brillouin scattered laser light is proportional to the gas density, the full width at half maximum (FWHM) and the Brillouin shift of the Rayleigh-Brillouin scattering spectrum is related to the gas temperature and pressure, respectively. In this paper, a measurement device based on Fabry-Perot interferometer (FPI) is designed to measure the Rayleigh-Brillouin spectrum of nitrogen gas. The experimental data is obtained at different pressures under room temperature conditions. The L3 model is used to fit the experimental data to obtain the FWHMs and Brillouin shifts of the Rayleigh-Brillouin profiles. The composite Rayleigh-Brillouin profiles which consist of Rayleigh peak, stokes peak and anti-stokes peak are represented by three distinct peaks of Lorentz functions. Fitting results show that the error of FWHMs and Brillouin shifts obtained by L3 model is less than 10% compare with the Tenti S6 model. Some factors that affect the measurement accuracy of the Rayleigh-Brillouin parameters are also analyzed and discussed.

提出了一种可用于干涉条纹傅里叶变换分析的空间载波频率估计方法.通过干涉条纹的加窗切趾处理及旁瓣质心坐标的计算,得到空间载波频率的高准确度估计.基于傅里叶变换的位移定理,用估计的空间载波频率实现了载频的移除.模拟和实验结果表明此方法可以有效地抑制传统干涉条纹傅里叶变换分析中的载频移除误差和频谱泄漏误差.

Using the angular spectrum theory of scalar diffraction ,the phase retrieval algorithm with two intensity patterns was carried out ,and was used to test the optical surfaces and wave‐fronts .The wavefronts of the spherical wave surfaces were retrieved by the algorithm in exper‐iment .The algorithm of wavefront fitting based on the Zernike polynomials was realized with computer programmer by calculating generalized inverse matrix of Zernike coefficients .

水下激光主动成像系统的探测能力不仅与探测系统自身参数有关,还与水质等环境因素有关.为评估水质对水下激光成像系统探测能力的影响,根据圆盘透明度成像模型,研究了吸收系数、散射系数、漫射衰减系数等水体水质参数与圆盘透明度的关系,给出了圆盘透明度与水下激光主动成像系统最大探测深度的表达式.实验表明,ICCD距离选通水下激光主动成像系统最大探测深度值与理论计算值相对误差小于20％.基于成像理论的圃盘透明度模型反映了水下激光成像系统探测能力与水体水质参数的关系,可用圆盘透明深度来评估水下激光成像系统的探测能力.

A scanning measurement system is constructed to measure the transmissivity of each site in large aperture optic components. This system enlarges the beam diameter of light source, and uses a computer-controlled scanning system to measure the transmissivity of optics. The experiments show that the testing accuracy and repeatability of this system both are better than ±0.1%.

High energy laser (HEL) meter by means of calorimetric method is used to measure continuous wave (CW) laser with energy more than 50 kJ .The photoelectricity calibration is usually made by CW laser illumination with known power for more than 20 minutes ,and be-cause of the heat loss ,the uncertainty is up to 12% .The influence of heat radiation and heat convection on energy measurements of CW high energy laser was analyzed theoretically based on the model of calorimetric plane absorbing HEL energy meter .The cooling down model for laser energy meter with plane absorbing chamber was deduced accurately which made it possi-ble to compensate for heat loss of energy meter .The experiments apparatus was established to verify the correctness of the model .With this model ,the measurement uncertainty of photoe-lectricity calibration decreases to 1% above .

Laser Rayleigh-Brillouin scattering is a powerful diagnostic tool for the study of gas flow properties. It provides an effective method for non-intrusive measurement of density, temperature and velocity in the gas flow. The received scattered laser light power is proportional to the gas density, the linewidth of the Rayleigh-Brillouin scattering spectrum is related to the gas temperature, and the Doppler frequency shift of the peak of the Rayleigh-Brillouin scattering spectrum is related to the gas velocity. The Rayleigh-Brillouin scattering spectrum can be measured by a Fabry-Perot interferometer operated in the imaging mode where an intensified CCD camera is frequently used to record the interference patterns of the Fabry-Perot interferometer. The Rayleigh-Brillouin scattering spectrum is then reconstructed from the measured data deconvolved with the Fabry-Perot instrument function. In this paper, the analysis and design of an imaging Fabry-Perot interferometer for the measurement of the Rayleigh-Brillouin scattering spectrum in the gas flow is presented. Some factors that limit the performance of the imaging Fabry-Perot interferometer are analyzed and discussed.

A chopper was used to change continuous laser into microsecond repetition-rate pulse width laser,then a single pulse chooser was used to make a single pulse laser from the repetition-rate laser.A trap detector was used to measure the output power of the continuous laser.Besides,the high-speed APD probe and high-gain PIN probe were used to detect the waveform of the pulse laser waveform,and the oscilloscope was used to measure the width of the pulse laser.Based on the measured power and waveform,the pulse laser's energy could be obtained.Using this method,the 0.2 pJ micro energy laser measurement and calibration could be realized.Through analysis,the measurement uncertainty of the device reached 0.42%.