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.

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。

According to the special requirements of high-power diode pumped laser(DPL) for high-power driving power,we put forward a particular discharge and driving control circuit based on large current and constant power.We designed a suit of laser diode(LD) array driving power supply by combining the existing charging circuit with the over-current protection circuit,and applied it to DPL system which was based on high-power LD array.Through electrical properties and relevant experiment,it is proved that this power can provide a more than 200A driving current with the pulse width of 230μs and the frequency of 20Hz for DPL.It has important value for kinds of DPL-based laser weapon systems in practice.

The numerical model of the light field distribution in the side-pumped laser medium of LD was established.An analytical solution for the pumping light refraction in the rod-shaped gain medium was simplified with ray tracing.The normalized distribution of pumping light in the medium was simulated numerically with Matlab.The selection principle to acquire the parameters of high-quality and high-energy laser output is proposed.The influence of the structural parameters on the distribution of pumping light is analyzed.The experiment result shows that the gain distribution of pumping light in the laser medium is satisfactory when the radius of the beam waist is 1μm,the number of LD is 40,the radius of the medium is 1.5 mm, the pumping distance between the luminous surface and the medium is 0.5 mm and the absorption coefficient of the medium is 2 cm~(-1)～6 cm~(-1).

The LD side-pumping structure was designed to meet the requirement of miniaturization and spot uniformity of the laser system for weapon systems.The compact laser resonator was designed.In this design,the thermal effect is compensated by the total reflection concave mirror.The laser output,whose average single pulse energy is 96 mJ(energy fluctuation 6%),pulse width is 10 ns and divergence angle is 3 mrad was obtained as the current is 60 A and the frequency is 20 Hz.The laser system can still work stably when the temperature rise to 50℃.

The character of the pumping light distribution in Nd∶YAG rod gain medium direct side-pumped by diode bars with half-ring form are studied in this paper.An analytical solution to the radical distribution of the pump light in the rod gain medium is provided based on the different parameters.Through the method of ray trace the simulated numerical calculation and the variation laws are made with the software Matlab,the influence to the distribution of pumping light is analyzed with the parameters of the pumping-structure and shows the laws of the influence,then analyses the reason why the difference occurs,and in the end the principle about how to take those parameters have been suggested.The theory can offer reference to design the solid state laser rods side-pumped by laser diode.