绝对吸收式激光能量计高准确度校准技术研究

High-accuracy optical calibration technology for absolute-absorbing laser energy meter

采用量热法的高能激光能量计用于测量能量大于50kJ的连续波高能激光能量,通常用已知功率的连续激光开展激光能量计的光电校准需要激光照射时间超过20min,而由于热损失等原因,进行长时间激光能量校准时,校准不确定度高达12%。以量热式平面吸收高能激光能量计为模型,从理论上分析了热辐射、热对流对连续波高能激光能量测量结果的影响,得到了较准确的平面吸收腔激光能量计冷却数学模型,实现了能量计热损失补偿,并通过建立相应的实验装置验证了该模型,用其对装置的测量结果加以修正,可使光电校准的测量不确定度减小到1%以下。

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 .