Author: Refael Whyte, Lee Streeter, Michael Cree, Adrian Dorrington
Affiliation: University of Waikato, New Zealand
Abstract: Time-of-Flight (ToF) range cameras measure distance for each pixel by illuminating the entire scene with amplitude modulated light and measuring the change in phase between the emitted light and reflected light. One of the most significant causes of distance accuracy errors is multi-path interference, where multiple propagation paths exist from the light source to the same pixel. These multiple propagation paths can be caused by inter-reflections, subsurface scattering, edge effects and volumetric scattering. Several techniques have been proposed to mitigate multi-path interference. In this paper a review of current techniques for resolving measurement errors due to multi-path interference is presented, as currently there is no quantitative comparison between techniques and evaluation of technique parameters. The results will help with the selection of a multi-path interference restoration method for specific time-of-flight camera applications.
Author: Mohammad Habib, Farhan Quaiyum, Syed Islam, Nicole McFarlane
Affiliation: University of Tennessee, Knoxville, United States
Abstract: Perimeter-gated single photon avalanche diodes (PGSPAD) in standard CMOS processes have increased breakdown voltages and improved dark count rates. These devices use a polysilicon gate to reduce the premature breakdown of the device. When coupled with a scintillation material, these devices could be instrumental in radiation detection. This work characterizes the variation in PGSPAD noise (dark count rate) and breakdown voltage as a function of applied gate voltages for varying device shape, size, and junction type.
Author: Min-Woong Seo, Taishi Takasawa, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito
Affiliation: Shizuoka University, Japan
Abstract: A low-noise high-sensitivity CMOS image sensor for scientific use is developed and evaluated. The prototype sensor contains 1024(H) × 1024(V) pixels with high performance column-parallel ADCs. The measured maximum quantum efficiency (QE) is 69 % at 660 nm and long-wavelength sensitivity is also enhanced with a large sensing area and the optimized process. In addition, dark current is 0.96 pA/cm2 at 292 K, temporal random noise in a readout circuitry is 1.17 electrons RMS, and the conversion gain is 124 uV/e-. The implemented CMOS imager using 0.11-um CIS technology has a very high sensitivity of 87 V/lx*sec that is suitable for scientific and industrial applications such as medical imaging, bioimaging, surveillance cameras and so on.
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