"Single Photon Detection: Basics, Challenges, and Probability Distribution Corrections in Avalanche Photodiodes"

by Nicole Menkart

Friday, October 21, 2022 -- 12:00 p.m.
Large Conference Room, 1207 Energy Research Facility

Advisor:  Professors Thomas Murphy and Rajarshi Roy

Single photon detection has become increasingly important in the last decade to study the quantum properties of light and its interactions with atoms and molecules. It has laid the foundation of coherent states emitted by laser sources and has been an indispensable technique in many quantum information applications. However, all single photon detectors have dark counts which can be comparable to that of the photon counts when weak light sources, such as novel lasers or single-photon emitters, are used. In these cases, a characterization of the statistical properties of the dark counts is necessary. It is often assumed that dark counts follow a Poisson process, but we find that in InGaAs avalanche photodiodes, the measured distributions differ significantly from Poisson due to the presence of dead time and afterpulsing. In order to correct the distributions, we extend the dead time to remove afterpulsing effects and then apply an iterative algorithm to remove dead time effects from the probability distributions. This work is supported by the Office of Naval Research (N00142012139).

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