高精度宽光谱低温绝对辐射计研制

Development of High-Precision Wide-Spectrum Absolute Cryogenic Radiometer

研制了一种可用于高精度光辐射功率测量以及光电探测器的光谱响应率校准的低温绝对辐射计,其核心探测器采用壁厚为50μm、内表面具有高分散性碳纳米管黑色镜面涂层的高纯铜腔。经实验分析得到该核心探测器腔体对0.25~16μm波段光的吸收率大于0.9999,对0.5~16μm波段光的吸收率大于0.99995。低温绝对辐射计工作在5.2K时,等效噪声功率在纳瓦(nW)量级。经考察分析评定,低温绝对辐射计对0.25~16μm波段100μW水平的光辐射功率进行测量的相对标准不确定度为0.041%,对0.5~16μm波段1mW水平的光辐射功率进行测量的相对标准不确定度为0.015%。

An absolute cryogenic radiometer(ACR)with a detachable optical window was designed and built for high accuracy optical radiant power measurement and photodetector spectral responsivity calibration.The ACR receiver is an electroplated pure copper cavity with a 50-μm-thick wall and inner surface coated with a specular black polymer material mixed with highly dispersible carbon nanotubes.The absorptivity of the cavity receivers was evaluated to be≥0.9999 in the 0.25~16μm wavelength range and≥0.99995 in 0.5~16μm.When the ACR works at the temperature of~5.2K,the noise-equivalent power is in the order of nanowatts(NW).The relative standard uncertainty is 0.041%for the measurement of~100μW optical radiant power in the 0.25~16μm wavelength and 0.015%for~1mW in the 0.5~16μm wavelength.