Abstract: A laser beam pointing and positioning system includes first and second rotatable diffraction gratings. Each grating deviates a laser beam by a predetermined angle of deviation. The relative rotational position of the gratings is controlled to change the beam steering angle and direction of a laser beam. A maximum beam steering angle of twice the angle of deviation may be achieved in any direction. The diffraction gratings may be etched on transmissive substrates of optical glass, sapphire, silicon (Si), Zinc Selenide (ZnSe), Zinc Sulfide (ZnS), or Germanium (Ge). The substrates may be positioned within rotary elements coupled respectively to electromechanical positional control elements to rotate the gratings.

Abstract: A laser beam pointing and positioning system includes first and second rotatable diffraction gratings. Each grating deviates a laser beam by a predetermined angle of deviation. The relative rotational position of the gratings is controlled to change the beam steering angle and direction of a laser beam. A maximum beam steering angle of twice the angle of deviation may be achieved in any direction. The diffraction gratings may be etched on transmissive substrates of optical glass, sapphire, silicon (Si), Zinc Selenide (ZnSe), Zinc Sulfide (ZnS), or Germanium (Ge). The substrates may be positioned within rotary elements coupled respectively to electromechanical positional control elements to rotate the gratings.

Abstract: A reflector and method for fabricating diffraction gratings in reflectors comprises the steps of placing one or more layers (38, 56-64) of a dielectric reflective enhancing material on a reflective surface (34, 54), and forming grooves (40, 66) only in the top layer (38, 64) of the dielectric material to form the gratings. Precise control of the efficiency is obtained by decreasing the thickness (b', b") of the grooved layer and adjusting the ratio (b'/b") of the material under the grooves and adjacent to the grooves.

Abstract: There is disclosed an integrated optical design of head-up displays suitable for use in aircraft cockpits and the like. The display system is comprised of a holographic optical element used as the combiner for presenting a direct view of the exterior on which are superimposed image signals generated by a source device such as a cathode ray tube and transmitted to the combiner through an optical system including a relay lens containing tilted and decentered optical elements to compensate for the aberration present in the holographic optical element. There are further disclosed four relay lens design forms particularly suited for use in the design of such holographic head-up displays. The disclosure includes integrated designs in which (a) the holographic element may or may not be constructed with aberrated wavefront and (b) a beam splitter is incorporated for insertion of a stand-by sight, possibly also being tilted for the correction of aberrations.

Abstract: This invention is applicable to display systems, such as in a helmet mounted display or a head-up display, utilizing a holographic lens operating at a relatively large off-axis angle in order to perform the dual function of a combiner glass and an eyepiece. The holographic lens is used in conjunction with more conventional optical elements (lenses, mirrors and prisms) to present a high quality collimated virtual image of an object, such as the face of a cathode ray tube, to an observer. The aberrations inherent in a holographic lens constructed to operate at a large off-axis angle and with a large field of view are corrected both by constructing the holographic lens with aberrated wavefronts and by the optical elements used in conjunction with the holographic lens during playback. Some arrangements of the playback systems of the invention include a relay lens having cylindrical surfaces and tilted and/or decentered elements used to compensate for the axial astigmatism and axial coma in the holographic lens.