标准激光光源近场空域测量精度研究

Study on Spatial Measurement Accuracy of Standard Laser Source Near-Field Parameters

为了研究标准激光光源近场空域测量精度,在理论方面建立了标准激光光源近场强度分布的理论模型,在实验方面提出了科学级CCD面响应非均匀性校正方案和激光近场计算算法。利用非均匀性校正后的科学级CCD和二维扫描装置,在1053nm标准激光光源软边光阑50mm×50mm口径内S形扫描,通过子孔径拼接得到标准激光光源近场图像。近场分布测试结果与理论值一致,差异主要是因为离轴抛物面镜表面粗糙度与科学级CCD随机噪声产生了高频分量。对近场参数测试结果进行分析,调制度扩展不确定度为0.08(k=2),对比度扩展不确定度为0.01(k=2)。研究结果提高了国家大科学工程激光参数测量系统近场空域测试置信度。

In order to study on the spatial measurement accuracy of standard laser source near-field parameters, the theoretical model of near-field intensity distribution of standard laser source is established. The surface response non- uniformity correction program of the scientific grade CCD and calculation algorithm of laser near field is proposed. Using corrected scientific grade CCD and two-dimensional scanning device, the 50 mm × 50 mm soft-stop images of 1053 nm standard laser source are obtained by S-shaped scanning and capturing. The near-field image of standard laser source is got by the sub-aperture image mosaic. The test results of near-field intensity distribution are accordance with the theoretical results. The main difference between them is the high frequency components mainly caused by the roughness of off-axis parabolic mirror and random noise of the scientific grade CCD . The analysis of near-field parameters test results is that the uncertainty of modulation is 0.08 （κ = 2）, and the uncertainty of contrast is 0.01 （κ= 2）. The near-field measurement confidence of laser measurement system of National Science and Engineering is improved by the study results.