The noise power spectral density of a detector is essential for determining the frequency of operation and readout architecture that yields an optimal signal-to-noise ratio. In this work, we characterize a waveguide-integrated PbTe mid-infrared detector and report on its noise spectrum, highlighting the presence of a current-dependent 1/f term dominating at low frequency and/or high bias over the Johnson component typical of a photoconductor. This behaviour, together with the substantially flat frequency response in the range between 1 kHz to 1 MHz, guide towards a lock-in readout strategy, that allows one to operate in the region of minimum noise without penalties in the detection performance. Practical guidelines to optimize the readout resolution are provided and the limit of detection of a gas sensing system exploiting PbTe photoconductors is derived, as an example of how a careful co-design of sensors and electronics can dramatically improve the detection performance.

中文翻译：

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波导集成 PbTe MIR 探测器的 1/f 噪声特性及其对检测限的影响


探测器的噪声功率谱密度对于确定产生最佳信噪比的操作频率和读出架构至关重要。在这项工作中，我们描述了波导集成 PbTe 中红外探测器的特征，并报告了其噪声频谱，突出显示了电流相关 1/f 项在低频和/或高偏置下占主导地位的约翰逊组件（典型的约翰逊组件）的存在。光电导体。这种行为与 1 kHz 至 1 MHz 范围内基本平坦的频率响应一起，指导锁定读出策略，该策略允许在最小噪声区域中工作，而不会影响检测性能。提供了优化读出分辨率的实用指南，并得出了利用 PbTe 光电导体的气体传感系统的检测极限，作为传感器和电子器件的仔细协同设计如何显着提高检测性能的示例。