宽波段高精度激光能量计设计

Design of wide-band and high-precision laser energy meter

针对宽波段、高精度、大能量范围的激光能量测量需求,设计了激光能量计。利用快速响应的热电堆作为传感器,在热电堆探测面涂覆高吸收率碳纳米烯材料,实现了宽光谱吸收。采用大小2个热电堆探测器布置于能量计正反两面的方法,使能量计具有1 mJ~40 J超宽能量范围,并且具有较高的测量精度。利用有限元仿真软件建立了吸收腔热路结构的三维有限元模型,并对不同类型的激光脉冲做了加热模型模拟仿真。根据仿真结果,对探测器的线性进行了修正,从而减小了由于传感器的输出电信号与被测光信号之间的非线性所导致的测量误差。用激光能量计标准装置对能量计进行了标定实验,测量结果表明,经修正后激光能量计的测量重复性优于0.6%,线性度优于1.1%。将激光能量计溯源到国家激光能量基准,测量相对扩展不确定度达到2.5%(k=2)的优异水平。

A laser energy meter was designed to meet the requirements of laser energy measurement with wide band,high precision and large energy range.The fast-responding thermopile was used as the sensor,and the high-absorptivity carbon nanolene material was coated on the detection surface of thermopile,which realized the wide spectrum absorption.The energy meter had an ultra-wide energy range of 1 mJ~40 J and the high measurement accuracy by using two thermopile detectors arranged on the both sides of the energy meter.The three-dimensional finite element model of the thermal path structure of absorption cavity was established by using the finite element simulation software,and the heating model of different types of laser pulse were simulated.According to the simulation results,the linearity of the detector was corrected,thus the measurement error caused by the nonlinearity between the output electrical signal of the sensor and the measured optical signal was reduced.The calibration experiment of the energy meter was carried out with the standard device of laser energy meter.The measurement results show that the repeatability of the modified laser energy meter is 0.6%,and the linearity is better than 1.1%.The laser energy meter is traceable to the national laser energy benchmark,and the relative extended uncertainty of measurement reaches an excellent level of 2.5%(k=2).