关于红外探测器灵敏度理论限的分析

Analysis of the Theoretical Limitation on an Infrared Detector Sensitivity

本文参考有关文献对红外探测器灵敏度理论限,进行了系统的叙述。推导出探测器背景光子噪声限D~#_(BLIP)的表达式,分析了探测器达到背景噪声限的条件及光伏器件R_oA_d的重要性。进一步说明背景光子噪声并不是探测器灵敏度的最后极限。在相干探测中,信号光子噪声将是限制灵敏度的主要因素。信号光子噪声限的灵敏度较背景光子噪声限的灵敏度要高出几个数量级。在长波长的情况下,热噪声将是探测器灵敏度的主要限制。

A brief review of the theoretical limitation on an infrared detector sensitivity was presented systematically. The DBLIP expression of the background fluctuation limit of a detector was derived and the condition approaching to the background fluctuation limit of the detector and the importance of a photovoltaic device parameter R_oA_d were analysised. It was further explained that the background fluctuation limit was not the final limit of the detector sensitivity. In optical heterodyne detection, the signal photon noise is a dominant factor reducing sensitivity. The sensifivity of signal photon noise limit can be higher by several orders of magnitude than that of the background photon noise limit. Under the condition of the long-wavelength the thermal noise is the dominant limitation of the detector sensitivity.