Fast Acting Optical Beam Detection and Deflection System.

The final report gives an account of progress made in the time period of January 1983 - December 1987 on Fast Acting Optical Beam Detection and Deflection System. It has been divided into two parts, each section being self-contained. Part 1 deals with the investigation of optical detection of coherent radiations of helium-neon laser of wavelength 0.6328 micrometers with corona poled polyvinylidene fluoride PVDF film using its pyroelectric property. The results show that a detection time of 0.56 microsec may be achieved with PVDF pyroelectric detectors. Part 2 reports the results of acousto-optic deflection of coherent He-Ne laser radiations using a water-cell which was energized by well-poled PVDF film in the frequency range of 10 MHz-70MHz 100 deflection efficiency of the primary beam energy has been achieved with this technique at a deflection angle of 1 deg. The water cell was then replaced with a Tellurium dioxide cell which provided 84 deflection efficiency at an angle of 3 deg. Finally, the report discusses a possible effective method of simultaneous deflection and deflection of coherent laser radiations with very high efficiency using blazed diffraction grating in the wavelength range of 0.4 - 1 micrometer at angles 18 deg or more. Keywords Optical detectors.