[en] This invention relates to an improved wide-range radiation gage having a controlled-gain photodetector for determining a material property. Hereinafter, the invention is described with reference to accurately measuring a wide range of steel plate thicknesses, or steel strip thicknesses, in a hot steel rolling mill which normally produces a steel product under variable operating conditions. However, it will become apparent that the invention is equally applicable to gaging other materials, and other properties such as weight per unit area or density, and to other industrial installations as well as to a variety of laboratory apparatus

[en] Some theoretical considerations and practical results regarding the utilization of the ROL 50 photovoltaic cell in a leveling control system and glass quality control equipment are presented. (authors)

[en] Two measurement techniques are investigated to characterize photodetector linearity. A model for the two-tone and three-tone photodetector systems is developed to thoroughly investigate the influences of setup components on the measurement results. We demonstrate that small bias shifts from the quadrature point of the modulator will induce deviation into measurement results of the two-tone system, and the simulation results correspond well to experimental and calculation results. (authors)

[en] Here, in this review article we discuss new updates on PID techniques, other than the Cherenkov method. In particular, we discuss recent efforts to develop high resolution timing, placing an emphasis on small scale test results.

[en] The importance of laser radiation sources in photodetector calibration processes is considered and shown. As an example of that, a recently made work comparing the spectral radiant flux measurement uncertainty of several absolute radiometers is described

No abstract available

[en] The method proposed is a modification of the additive method. It is suitable for photodetectors with differences from linearity less than 10 %. The photodetector nonlinearity can be measured in a simple way in a range of 4 decades. That is quite enough for the most industrial applications

[en] We report on the design and testing of novel mixed analog and digital front end ASICs custom made for the single photon detectors considered for the BTeV RICH system. The key features are reviewed, as well as results achieved using electronics bench tests and beam studies

[en] We wish to report a recent experimental observation of anticorrelation from first-order and second-order incoherent thermal fields in the joint photodetection of two independent photodetectors. In the view of classical theory, the nontrivial second-order correlation of thermal light is caused by the statistical correlation of intensity fluctuations, which can be observed only from first-order coherent thermal radiations. What is the physical cause of this observed anticorrelation, then?

[en] A simple negative feedback model based on Miller's formula is used to investigate the properties of Avalanche Photodetectors (APDs). The proposed method can be applied to study classical APD as well as new type of devices, which are operating in the Internal Negative Feedback (INF) regime. The method shows a good sensitivity to technological APD parameters making it possible to use it as a tool to analyse various APD parameters. It also allows better understanding of the APD operation conditions. The simulations and experimental data analysis for different types of APDs are presented.