介绍了一种新型的基于参量下转换实现红外辐射源绝对辐亮度的定标方法。参量下转换过程产生0.631 ?滋m和3.39 ?滋m波段的一对相关光子, 通过测量自发参量下转换和受激参量下转换两个过程中在0.631 ?滋m波段光子的计数比值, 可以获取3.39 ?滋m的单位模式平均光子数, 并进一步导出红外光源的辐亮度。介绍了定标原理、实验装置, 分析了主要的测量不确定性因素, 定标结果表明OPO激光器光谱辐亮度的合成标准不确定优于1.18%。初步证实了通过探测可见波段光子计数实现红外辐射源的辐亮度定标的原理可行性。研究结果将有望应用于基于受激参量下转换的红外波段高精度定标以及红外OPO激光器等领域。

A new absolute calibration method based on the parametric down-conversion was introduced. In the parametric down-conversion process, two correlated-photons were produced whose wavelengths were 0.631 μm and 3.39 μm, the average photon countsper mode of the 3.39 μm were obtained by measuring the ratio of 0.631 μm photon counts in the two processes including the spontaneous parametric down-conversion and the stimulated parametric down-conversion, and further radiance of the infrared source could be calculated. In this paper, the calibration principle and experimental device were described and the uncertainty of this method was analyzed. The results show that relative combined uncertainties of a OPO laser was better than 1.18% and prove the feasibility of radiance calibration of the infrared radiation by detecting the photon counting in the visible band. The study results are expected to be used in the field of high precision calibration of infrared band based on stimulated parametric down-conversion and infrared OPO laser and other fields.