Abstract

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.

Fundamental sensitivity limit imposed by dark 1/f noise in the low optical signal detection regime

Emily J. McDowell, Jian Ren, and Changhuei Yang
Opt. Express 16(10) 6822-6832 (2008)

Johnson Noise Limited Operation of Photovoltaic InSb Detectors

Donald N. B. Hall, Richard S. Aikens, Richard Joyce, and Thomas W. McCurnin
Appl. Opt. 14(2) 450-453 (1975)

Integration of MEMS IR detectors with MIR waveguides for sensing applications

Mahmut Sami Yazici, Bowei Dong, Dihan Hasan, Fujun Sun, and Chengkuo Lee
Opt. Express 28(8) 11524-11537 (2020)

Proposal of the Detectivity D** for Detectors Limited by Radiation Noise†

R. Clark Jones
J. Opt. Soc. Am. 50(11) 1058-1059 (1960)

Efficient waveguide-integrated tunnel junction detectors at 1.6 µm

Philip C. D. Hobbs, Robert B. Laibowitz, Frank R Libsch, Nancy C. LaBianca, and Punit P. Chiniwalla
Opt. Express 15(25) 16376-16389 (2007)