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UV Technology Overview

Ultraviolet (UV) image sensors have been and are actively being developed for a variety of space-borne astronomy missions. There is a large range in the maturity of UV detectors. Some systems have already flown numerous times and still continue to undergo refinements. At the other extreme, there are potentially breakthrough novel devices that require the development of several fundamental technologies before a sensor can become viable. The detector, which historically is one of the most problematic parts of any astronomical spacecraft, represents only a few percent of the total costs but plays a critical role in the overall capability of the instrument. For a telescope of a given aperture, it is the detector that determines the feasibility of various science projects. Although several types of image sensors are expected to make significant performance improvements, no existing nor future detector system will ever be ideal for all ultraviolet applications, not even the newest, most highly innovative devices. Each detector system has its own unique set of advantages and inherent limitations. This review presents an overview of UV technologies including those that are currently available as well as those that are in their early stages of development. Special attention is given to those devices not covered extensively in other reviews in this volume. In addition, special attention is given to the physical processes responsible for the inherent capabilities of a few important existing and future UV detectors. This research was supported in part by grant NAG5-7148 from the National Aeronautics and Space Administration