《外文翻译红外辐射探测器的激光诊断》.doc

an infrared radiation detector for laser diagnostics Abstract 　A liquid biased, liquid crystal, infrared radiation detector has been devised for the purpose of determining the time integrated output spectrum and power spatial distribution of infrared radiation. The device has been specifically used to measure the spectrum and spatial power distribution of the output of a quasi-cw carbon monoxide gas laser.The detector recording medium is composed of thin mylaroated with temperature sensitive, encapsulated,cholesteric, liquid crystals and energy absorbing black paint.A uniform spatial color distribution of the liquid crystals is established and maintained by immersion in a controlled temperature liquid bath.The resulting uniform color distribution is modified, at various spatial points, by the addition of laser energy obtained either indirectly from the laser output coupler to yield the spatial dependence of the near or far field laser output or from a spectrometer output to yield the spectrum of the laser output. The addition of less than 15 mJ /cm2 of incident energy is adequate to modify the color distribution. The uniformity and precise control of the liquid crystal temperature and hence color, by the use of a liquid bath, makes it possible to compare colors, and hence laser output powers, at various spatial points.This permits the mapping of the laser near field output spatial distribution and the distribution of the laser spectrum with greater sensitivity than has been possible with more conventional techniques.Results showing the near field energy distribution and output spectrum of a supersonic flow,electric discharge CO laser obtained using the detection technique will be presented. Introduction 　　A supersonic flow quasi -cw carbon monoxide gas laser has recently been constructed. (1) Among the relevant data necessary for characterizing lasers of this type are the temporal, spatial, and spectral energy distribution of the infrared laser output. Temporal beh