A5035437641- Advanced Optical Sensing Technologies
- Advanced Semiconductor Detectors and Materials
- Semiconductor Quantum Structures and Devices
- Advanced X-ray and CT Imaging
- Optical Imaging and Spectroscopy Techniques
- Photoacoustic and Ultrasonic Imaging
- Photocathodes and Microchannel Plates
- Analytical Chemistry and Sensors
University of Sheffield
2023-2025
An extremely low noise Separate Absorption and Multiplication Avalanche Photodiode (SAM-APD), consisting of a GaAs0.52Sb0.48 absorption region an Al0.85Ga0.15As0.56Sb0.44 avalanche region, is reported. The device incorporated appropriate doping profile to suppress tunneling current from the achieving large gain, ∼130 at room temperature. It exhibits excess factors 1.52 2.48 gain 10 20, respectively. At our measured factor more than three times lower that in commercial InGaAs/InP SAM-APD....
Electron-only avalanche multiplication and low excess noise has previously been established in InAs photodiodes (APDs). However, there is currently a lack of experimental investigations into the photon detection capability planar APDs. Here, equivalent power (NEP) APDs operating with low-noise transimpedance amplifier investigated for first time. Our devices have responsivity 0.7 A/W excellent linearity at wavelength 1550 nm. Using these APDs, very NEP <inline-formula...
Avalanche photodiodes (APD) can improve the signal to noise ratio in applications such as LIDAR, range finding and optical time domain reflectometry. However, APDs operating at eye-safe wavelengths around 1550 nm currently limit sensitivity because APDs' impact ionization coefficients avalanche layers are too similar, leading poor excess performance. The material AlGaAsSb has highly dissimilar (with electrons dominating gain) so is an excellent for wavelength APDs. We previously reported a...
It is well known that avalanche photodiode can enhance the signal to noise ratio of a detection system, when excess low. The factor, F which characterizes an APD be calculated using established theory from R. McIntyre. When hole electron ionization coefficients, k = 0, ~2 achieved at high gain. This means gain, M, increased without penalty factor. In this work, we will present progress in APDs incorporating InAs and AlGaAsSb as regions. Both show ~0 therefore F~2. former used for low photon...
There is an increased demand for low noise avalanche photodiodes (APDs) infrared wavelengths at 1550 nm long range Light Detection and Ranging applications. Here we present two classes of APD that produce high gain but with extremely excess factors, <i>F ~ 2</i>. InAs APDs show < 2</i> offer detection wavelength up to 3500 nm, although this drops ~3000 when cooled. For reducing effects scattering in atmosphere, could be attractive option. In addition are based on a simple homojunction...
Sensing of weak photon fluxes in the short to mid-wave infrared is important for a variety applications such as optical communication systems, light detection and ranging (LiDAR) remote gas sensing. For most demanding applications, avalanche photodiodes (APDs) are regularly employed due enhanced sensitivity afforded by their internal gain. Indium Arsenide (InAs) material which exhibits near ideal multiplication properties capable detecting radiation up 3 μm at 77 K. Due exclusive electrons,...