Excess Noise Factor in Avalanche Photodiodes with Dead Space Effect

This project aims to produce a graphical user interface (GUI) for MATLAB programs written byJ.S.Marsland as part of his research into the excess noise factor in avalanche photodiodes (APDs). TheGUI will be produced using the GUIDE package supplied with the MATLAB software combined withthe MATLAB programs. The GUI will then be used to compare this research work with the researchwork of others e.g. the Monte Carlo calculations made by the research group at the FrenchAerospace Laboratory (ONERA). Comparison with other research work will require the digitization ofsome graphs published in academic journals.

Investigation of the parameters of a single photon detector for quantum communication

Nowadays the best single photon detectors from a practical view are those based on InGaAs/InP avalanche photodiodes, operating at a wavelength of 1.55 μm. The dependence of quantum efficiency and noise levels on the temperature and bias voltage of avalanche photodiodes were carried out.

High-performance HgCdTe avalanche photodetector enabled with suppression of band-to-band tunneling effect in mid-wavelength infrared

HgCdTe avalanche photodiodes promise various fascinating applications due to the outstanding capability of detecting weak signals or even single photon. However, the underlying transport mechanisms of diverse dark current components are still unresolved at high reverse bias, thus limiting the development of high-performance devices. Here, we establish an accurate model to demonstrate the competitive mechanism between band-to-band and avalanche dark currents in positive-intrinsic-negative structures. Based on the high consistency between the simulated and measured results, we find that both components jointly dominate overall dark current but with a larger avalanche current. This breaks the conventional cognition that band-to-band dark current contributes the majority. With the guidance, we reconstruct an optimized device and achieve gain 1876 (6153) and dark current 10−10 (10−9) A at bias −10 (−10.5) V, respectively. Comparisons of dark current and gain with reported single-element devices further confirm the outstanding performance of our device.

Application features of micro-pixel avalanche photodetectors in the laser Doppler anemometers

The optical receiver is an essential part of any laser Doppler anemometer. Traditionally, vacuum photomultiplier tubes are used for reliable reception of weak optical radiation. However, this type of photodetector has its own drawbacks, which lead to a design complication and an increase in the cost of LDA. In this work, the characteristics of silicon micropixel avalanche photodiodes are investigated and the operation of a silicon photomultiplier as a photodetector in an LDA is tested when measuring the velocity on test benches. The possibility of using Si-PMT to receive optical signals of the laser Doppler anemometer is shown.