ABSTRACT
Optoelectronic sensors detect electromagnetic radiations such as x-rays, ultraviolet (UV), visible, and infrared (IR) light, ranging from short to long wavelengths. This chapter discusses the operating principles of optoelectronic sensors including the mechanisms for converting radiation to electrons and the spectral responses of sensors from UV to IR. It also discusses point sensors, multi-pixel/position-sensitive sensors, and image sensors, respectively, for the detection of UV –IR light. The chapter describes sensors with high gain of the order of 106 for low light level as well as those for high light level. It also describes x-ray sensors, and explains the need to take several factors into account such as spectral response, gain, and spatial and time resolutions for the selection of proper sensors. The conversion of photons to electrons is a key process in optoelectronic sensors. The conversion efficiency, which depends upon wavelength, is called a spectral response and expressed as quantum efficiency.
