"Predictions." . . "Gratings(spectra)" . . "Distribution." . . "Frequency." . . "Near infrared radiation." . . . . . . . . . "Fast Acting Optical Beam Deflection System"@en . . . . . . . . . . . . . . . . . . "This report describes the results of a study of the nature of optical deflection in the wave length range of 300-1000 nm, using transmission gratings of two different surface relief profiles, i.e., blazed saw-toothed and phase sinusoidal types. The experimental results confirm the theoretical predictions and provide a quantitative comparison of the performances of the two profiles. An analysis of results leads to the recommendation of the sinusoidal profile in preference to the blazed (saw-toothed) gratings. A broad-band high attenuation across the optical to near infrared frequencies may be achieved by the use of 'cross grating' structure with sinusoidal profile of judicious groove depth. Of the four usable sinusoidal gratings provided by the Cambridge Consultants Ltd., the quality of the two photoresist grating materials was found to be superior to that of synthetic fused silica (hard etched). (rrh)."@en . . . . . . . . . . . . . "The primary objective of the present investigation is to seek an effective and practical method to detect and suitably deflect a coherent optical radiation from its initial direction of incidence and thus avoid the occurrence of serious biological damages which may be caused by such harmful radiations in the wavelength range of 0.4 - 1 micrometer. In the research proposal a possible effective method of simultaneous detection and deflection method using a blazed diffraction grating has been discussed. A diffraction grating is an optical surface with many straight, parallel and equally spaced grooves which provide an optical diffraction due to the mutual interference of the light beams. The distribution of light into various orders of a grating depends upon the microscopic shape of the grooves of the grating. By ruling the grating with and controlling the angles of the grooves it is possible to concentrate the spectral energy in any desired angular region. This is called BLAZING a grating, and the groove-face angle psi is called the blaze angle. (jhd)."@en . "Depth." . . "Angles." . . "UNIVERSITY COLL OF NORTH WALES BANGOR SCHOOL OF ELECTRONIC ENGINEERING SCIENC E." . . "Optical properties." . . "Beams(radiation)" . . "Interference." . . "Quick reaction." . . "Fused silica." . . "Comparison." . . "Broadband." . . "Damage." . . "Optical materials." . . "Light." . . "Theory." . . . . "Transmittance." . . "Deflection." . . "Spectral energy distribution." . . "Diffraction." . . "Deflectors." . . "Attenuation." . . "Optics." . . "Surfaces." . . "Photoresistors." . . "Profiles." . . "Grooving." . . "Protective Equipment." . . "Coherent optical radiation." . .