Far infra-red applications of pyroelectric retina tv tubes

A pyroelectric video tube which transforms a thermal image into a CRO display is useful in a number of experiments. A few applications in usually difficult areas have been selected as examples. Text-book demonstrations in either optics or thermodynamics are often easier to do in the infra-red than in the visible. Applications include recording mode patterns of lasers with cw powers as low as 1 mW. The tubes are also useful in controlling the thickness and parallelism of infra-red flats which are apaque in the visible but transparent in parts of the infra-red spectrum.