基于参量放大的中红外辐亮度定标技术研究

介绍了基于参量放大方法定标中红外辐射源辐亮度的原理和实验装置，推导了不同偏振态的辐射源的辐亮度和单位模式光子数关系式。实验采用大功率连续532 nm激光泵浦非线性LiNbO3晶体，产生632.8 nm和3.34 μm波长的下转换光子，利用这对可见-红外下转换相关光子对在时间、空间上的高度相关性，在红外下转换光子方向注入待测中温黑体辐射源，通过测量632.8 nm下的转换光子信号的光子计数，实现黑体辐射源在3.34 μm波段光谱辐亮度的绝对定标，报道了1.53%的定标不确定度。

Investigation of Mid-infrared Radiance Calibration Based on Parametric Amplification

The principle、the method and the experimental system of mid-infrared radiance calibration based on parametric amplification technique were introduced. The equation between different polarization source and its photons per mode was deduced. A high power CW laser stabilized at 532 nm was used to pump a LiNbO3 nonlinear crystal, producing two correlated-photons whose wavelengths were 632.8 nm and 3.34 μm, respectively. The under-calibrated blackbody at 3.34 μm was injected along the direction of the infrared down-converted photons. With the high relativity of the VIS-IR photon pairs, through the measurement of the visible down-converted photons at 632.8 nm, the radiance of the blackbody source at 3.34 μm can be calibrated and 1.53% relative standard uncertainty was reported.