Abstract: A beam shaping system for an astigmatic light source utilizes two lenses, both having diffractive power. A first lens shapes the beam in a first dimension and a second lens shapes the beam in a second dimension perpendicular to the first.

Abstract: A cylindrical lens and a binary optical element for collimating with low optical aberrations an asymmetrically diverging input wavefront. The binary optical element is formed on a planar substrate on which a binary optical diffraction pattern is etched on the front surface thereof. The binary optical diffraction pattern is designed such that each ray of light from the diverging input light source will travel the same optical path length or vary from that optical path length by an integer multiple of the wavelength of the light in travelling from its source to its exit from the front surface of the binary optical element. A beam angle alignment element is also provided, to be utilized in conjunction with a cylindrical lens and the binary optical element, for correcting angular misalignments of diode lasers whose output wavefront has an optical axis which is either above or below the plane in which the active region is formed.

Abstract: A wobble correction lens for a raster output scanner combines a positive cross-scan plano-cylindrical lens, which provides most of the optical power for focusing the light beam to a scan line, with a diffractive surface, which corrects the cross-scan field curvature of the cross-scan plano-cylindrical lens. The diffractive surface will have a multi-level structure (binary diffractive optical surface) which possesses a diffractive phase function that will flatten the cross-scan field curvature of the plano-cylindrical lens.

Abstract: A three-color laser scanner using a holographically-generated plane linear grating disk (hologon). The disk includes peripherally-arranged facets having identical multiplexed diffraction gratings. Each multiplexed grating is formed from plural superimposed interference patterns accumulated by multiple exposures to light from a single monochromatic laser beam source. The multiplexed grating is optimized to diffract certain light wavelengths in a single, multichromatic (plural wavelength) input laser beam. The diffracted output beam comprises respective wavelength beam components that simultaneously scan in collinear fashion. Modulation of the plural wavelength components in the incident beam allows the output beam to scan expose a multicolor image at the image plane.

Abstract: An image reading apparatus including a diffraction grating element including a transparent plate shaped in the form of consecutive steps to separate a light reflected from a document into a zero order light, -1 order light, and +1 order light. The transparent plate is arranged so that the zero order light has a wavelength in a blue region and +1 order light and -1 order light have wavelengths either in green and red regions, respectively or in red and green regions, respectively.

Abstract: A phase type focusing screen has a plurality of minute patterns of a given shape formed by protrudent and/or recessed parts and allocated on a surface of an optically transparent base plate. Assuming that a stepped level difference between a top face of the protrudent part or a bottom face of the recessed part and the surface of the base plate is d, a refractive index of a material of the base plate is n and the shortest wave length within a working wave length region is .lambda., the following condition is satisfied:d.gtoreq.1.5.lambda.

Abstract: A multifocal optical device is provided for focusing light traveling parallel to an optical axis of the device. The multifocal optical device comprises a multifocal phase zone plate including at least two annular zones disposed substantially concentrically about the optical axis and spaced in a radial dimension from the optical axis in proportion to the square root of q, where q is an integer zone number; and an absorbing material disposed on a portion of ones of the annular zones for absorbing a portion of the light.

Abstract: An apparatus comprising a circular ruling engine having a supporting means oscillatable in a controlled manner with a substrate section on said supporting means and means for lifting and lowering a ruling means to rule said substrate section to generate a grating pattern from a number of grating patterns to produce an off-axis grating section. Also disclosed is a method for forming off-axis grating sections.

Abstract: A diffraction grating comprises the plurality of grating rings provided at positions such that their radii r are selected so that a function .phi.(r) of r satisfies the following differential equation and initial conditions, ##EQU1## where .lambda. is the wavelength of a scanning light beam, f is the focal length of the diffraction grating, r is the radius from the center of diffraction grating, M is the distance from the diffraction grating to a scanning surface expressed as a multiple of the focal length f, and moreover the relation.phi.(r)=n+.phi.(0)n=0, 1, 2, . . .(n is a non-negative integer)is satisfied.

Abstract: Substrate-supported optical device structures such as, e.g. quantum-well infrared detectors/detector arrays are provided with a grating for optical coupling. A binary, reflection grating is designed so that nh is approximately equal to .lambda./4 where n is the refractive index of the grating, h is the thickness of the grating, and .lambda. is a wavelength of interest.