Abstract: The phase conjugation device includes at least one non-linear medium and an optical focussing system producing at least two focal points within the non-linear medium and capable of focussing light at these two points.

Abstract: A stereoviewer for observing a stereo pair of photographs three-dimensionally through binocular lenses is shown and described. The stereoviewer comprises a box-shaped main body case having a space for accommodating stereoscopic photographs; a lid for covering the main body case; holder portions provided on one side surface of the box-shaped main body case so as to position and hold the stereoscopic photographs in a non-perpendicular standing state; and binocular lenses provided thereon are inclined in such a manner that the binocular lenses face the vertical center portion of the stereoscopic photographs. This stereoviewer also serves as a package and has a simple structure. The thickness of the binocular lenses are varied so that the focal distance is different between the upper portion and the lower portion of said binocular lenses and the binocular lenses are decentered outwardly in the horizontal direction.

Abstract: A two lens stand magnifier having variable degrees of magnification of an object at a constant distance from an observer is disclosed. A permanently mounted plus lens and a movably mounted minus lens are arranged on a stand such that the plus lens is a constant distance away from the object to be magnified. As the minus lens is moved relative to the positive lens, magnification of an object located on the opposite side of the plus lens from the minus lens varies while the image stays substantially in focus at the constant distance from the observer. Defocus of the image during movement is avoided by the choice of the lens powers as well as the spacing of the range of movement of the minus lens relative to the plus lens.

Abstract: Disclosed is a variable lens assembly having a water chamber defined with a front lens holder between two flexible, transparent diaphragms and filled with a fluid, and a syringe connected to the front lens holder and controlled to vary the volume of the water chamber. The diaphragms are stretched to curve outwards and form into a biconvex lens as the plunger of the syringe is pushed forwards in compressing the fluid; the diaphragms are induced to curve inwards and form into a biconcave lens as the plunger of the syringe is pulled backwards in releasing the fluid.

Abstract: A stereoviewer for observing a stereo pair of photographs three-dimensionally through binocular lenses is shown and described. The stereoviewer comprises a box-shaped main body case having a space for accommodating stereoscopic photographs; a lid for covering the main body case; holder portions provided on one side surface of the box-shaped main body case so as to position and hold the stereoscopic photographs in a non-perpendicular standing state; and binocular lenses provided thereon are inclined in such a manner that the binocular lenses face the vertical center portion of the stereoscopic photographs. This stereoviewer also serves as a package and has a simple structure. The thickness of the binocular lenses are varied so that the focal distance is different between the upper portion and the lower portion of said binocular lenses and the binocular lenses are decentered outwardly in the horizontal direction.

Abstract: A sliced transform lens is used to combine and focus the optical output signals of a planar M by N laser diode array onto M detector elements in a linear detector by displacing lens slices. A sliced transform lens is used to separate the composite image of the laser diode array on the detector plane into ten spots (400 emitters per spot) by displacing the lens slices relative to each other collimated He-Ne laser beam was used to examine the sliced transform lens and the linear detector array was used to measure the image sizes and the crosstalks between the images. The results show the minimum separation is approximately five detector spacings apart. The lens elements are cut from a bulk material (BK-7) and ground to desired thickness and parallelism. Then the elements are "glued" together with standard optical wax compound and ground to the prescribed focal length. THe lens slices are cut before grinding, hence the composite lens is symmetric and zero-curf configuration is preserved.

Abstract: A night vision apparatus 10 includes a first focusing refracting lens 28 which focuses light rays 29 from distant scene 14 onto a light intensifier 30. The kinoform 40 or bifringent lens 78 are disposed in the light path to allow light rays 35 from near scene 18, 20, 22 and 24 to be focused onto light intensifier 30 to form a multi-focus night vision apparatus with increased depth of focus.

Abstract: A diffraction bifocal lens or lens system, comprising two profiled surfaces or interfaces or a linear combination thereof, wherein one profile provides for the bifocality of the lens and the other profile compensates for chromatic aberration. These lenses or lens systems exhibit two focal points, one which exhibits positive chromatic aberration and the other which exhibits negative chromatic aberration.

Abstract: A multifocal lens useful as a contact lens or implantable as an intraocular lens which comprises at least 3 zones, the first zone comprising a polymer of a specified refractive index, the second zone comprising a polymer having the same repeating units as the polymer comprising the first zone and having a specified refractive index differing from the refractive index of the polymer comprising the first zone by not more than 0.1 units and by not less than 0.01 units and the third zone between the first and second zones comprising a polymer having the same repeating units as the polymers comprising the first and second zones and having a refractive index continuously variable between that of the polymer comprising the first zone and that of the polymer comprising the second zone, the at least three zones being transparent and having no discontinuities visible to the human eye between the zones.

Abstract: A bar code scanner is disclosed employing a laser source and scan mirror for generating a light beam for scanning a bar code symbol or the like. The working range for distance between the scanner and the symbol is extended by placing an optical element in the path between the laser source and the scan mirror. This optical element may be a figure of rotation such as an axicon. A slit may be positioned downstream of the axicon to block the characteristic concentric rings produced in the beam in areas perpendicular to the scan line.

Abstract: A beam steering arrangement for a plurality of beams of electromagnetic radiation from a like plurality of sources arrayed with a preselected source-to-source spacing includes a first lens array. The period of the lenses corresponds to that of the sources. The lenses of the first array may be converging or diverging lenses, but when illuminated by the sources, each produces a beam of light including at least a diverging portion. A second lens array is cascaded with the first lens array, with the lenses of the second array illuminated by the diverging beam portions. The second lens array collimates the diverging beam portions. The second lens array is translated in a direction approximately transverse to the undeflected beam direction in order to scan or deflect the collimated beams. This may result in overfilling of the input apertures of the lenses of the output lens array, with consequent reduction in the amplitude of the main beam, and with generation of beams of lower intensity in other directions.