Abstract: A lenticular device is disclosed having a lens array with one or more lenticular convex ridges joined by cusped or concave valleys forming lens elements on one of its surfaces. In addition, the lenticular array is uniformly separated from a message transmitting surface by an air space directly related to a field of view of no more than 30.degree. determined by the converging light rays at the focal point. The carrier sheet or message is a plurality of messages resolved from a series of linear segments in the form of binary lineations placed in focus relative to the lens array. By establishing a proportional relationship between lens aperture and focal length, the rate of message change is predetermined for any prescribed viewing situation. Surface interference caused by reflection, chromatic diffraction, and other light loss is controlled by the relationship of optical design, and optical quality, coupled with other structural elements.

Abstract: A method consisting in that the holographic image of an object is recorded on a substrate, a two-dimensional image of the same or any other object of interest is formed on a separate substrate, and the substrate with the holographic image is then so arranged with respect to that with the two-dimensional image that both images are oriented to produce the desired effect. The images are reconstructed through illumination by a light beam of varying intensity and spatial coherence.

Abstract: An authenticating device comprises a transparent material, such as a plastic, having a thickness no greater than 100 micrometers embossed on one side with a lenticular array of lenslets having focal lengths substantially equal to this thickness, and embossed on the other side with a reflective relief pattern forming a periodic structure periods smaller than 100 micrometers, which periods are of a width that at least approximates that of the lenslets. The reflective relief structure of the authenticating device is secured to a viewable surface of the authenticated item sheet material and each period of the relief structure is comprised of a set of juxtaposed elements having significantly different reflective characteristics from one another.

Abstract: A beam splitter or combiner suitable for use with high-power laser beams employs matched dispersive elements to correct for dispersion of a separated beam.

Abstract: Surface relief patterns of predetermined configuration are fabricated by a process which involves exposing a photosensitive material at a first position to a laser interference pattern, rotating said material about an axis perpendicular to its surface to a second position, exposing said material at said second position to a laser interference pattern, wherein at least one and preferably both of said exposures is individually below the effective threshold for linear response of said material, the points of intersection of the two fringe patterns being exposed above said threshold as a result of the combined exposures, and developing said material. The method provides a facile technique for the manufacture of surface relief patterns and is particularly useful when the pattern is of submicrometer size and difficult to manufacture by mechanical means.

Abstract: A method is provided for pattern masking objects preparatory to subsequent working of the objects. The invention also includes those objects prepared in accordance with the method. The method is especially suited to the pattern-masking of relatively large and/or complexly shaped optical elements preparatory to the production of diffraction gratings thereat for use with laser radiation.The object to be worked, such as a mirror, is coated with a semiconductive masking material. Electrolytic etchant is placed on the masking material. Electromagnetic radiation of suitable wavelength and patterned in accordance with the desired pattern of the mask is projected through the etchant and onto the masking material. The radiation effects photoelectrochemical etching of the semiconductive masking material in the desired pattern to a desired depth. An etch-stop layer may be interposed between the object and the masking material to limit the etching action.

Abstract: An original information carrier is disclosed which comprises a recording layer applied to a carrier material. The recording layer contains information in the form of a relief image which is made of relief part-images which border on one another without overlapping. The recording layer further comprises a relief grating of different grating depths superimposed over the areas of said relief part-images.A process for producing an information carrier is disclosed which comprises exposing a recording layer through separate color separation originals, exposing the layer to a grating pattern, and developing the exposed recording layer.A process for forming a matrix containing the information stored on an information carrier is disclosed which comprises forming a layer of material on the original information carrier and then separating the layer from the carrier.

Abstract: Disclosed is an apparatus for and a method of establishing the domain walls within a stripe-domain supporting magnetizable film in a radially directed orientation, the separation of which is proportional to the distance from the center of the diffraction grating. The apparatus includes means for coupling to the stripe-domain supporting magnetizable film an orienting field that is directed orthogonal to the plane of the film but whose intensity from the center of the field source is inversely proportional to the distance from the center of the field source and further including means for coupling to said film an AC tickle field of significant to decreasing to zero amplitude for overcoming the hysteresis of the film.

Abstract: A device for dividing a laser beam, e.g. into parallel equidistant beams includes a glass plate with two opposing planer, parallel surfaces. A transmission grating is arranged on one glass surface. A reflecting layer is applied over the grating, and an opening is arranged in the layer at half the length of the plate, for taking the beam, which is to be divided, to and through the grating. The laser wavelength and the grating line density are selected to give total reflection at the free surface of the glass for a beam diffracted at the opening of the grating. By altering the angle of incidence of the beam, the distance between the subdivided beams can be continuously varied within given limits. The device is also utilizable for combining a plurality of separate beams into a single beam. (FIG. 3).