Abstract: A very small high-reflectivity mirror surrounded by a low-reflectivity region is fabricated in a self-aligned manner directly on one of the output faces of a stripe-geometry solid-state laser. The phenomenon known as filamentation is thereby effectively controlled.

Abstract: A rear projection viewing screen combining high efficiency and uniformity of illumination with predetermined scattering characteristics is constructed through interference techniques. The viewing screen functions as a combination lens and appropriate diffuser.

Abstract: The invention provides a method for making a relief mask used for pattern neration in planar thin film overlays, which relief mask is structurally formed to produce intimate contact between a photoresist surface and a masking pattern during exposure of the photoresist surface. The present method comprises the steps of:1. depositing gold on a blank mask substrate;2. coating the gold-covered substrate with a photosensitive material;3. forming a relief pedestal on the blank mask substrate by exposure of the photoresist and etching of the gold; and,4. forming a masking pattern on the relief pedestal.

Abstract: A method for producing a photomask by exposing and development-processing a photographic light-sensitive material including a transparent support having thereon a masking layer and a silver halide emulsion layer to thereby form silver image areas, etch-bleaching the silver halide emulsion layer to thereby remove the silver image areas to uncover the masking layer thereunder, subjecting the coated support to etching to etch the uncovered masking layer with a mixed solution containing hydrofluoric acid and ammonium fluoride to thereby uncover the transparent support thereunder, and then removing the non-silver image areas to thereby reveal the masking layer.

Abstract: A method of precisely aligning a pattern on one side of an opaque substrate with a pattern on the opposite side thereof through the use of pattern-defining masks, wherein at least certain pattern areas previously not formed on the substrate, as defined selectively through the masks, are formed while the masks are aligned. The first mask is releasably secured to a first side of the substrate so as to define a particular orientation of a desired pattern therethrough, and is dimensioned such that at least one, but preferably several spaced peripheral areas thereof extend beyond adjacent peripheral edge portions of the wafer, with the extended mask areas including alignment indicia. A second mask is then positioned against a second side of the substrate, and is constructed with one or more outwardly extending peripheral areas and respectively associated alignment indicia corresponding in number, and spatial relationship, with those in the first mask.

Abstract: A method for producing a photomask, by exposing and development-processing a photographic material including a transparent support having thereon a masking layer and a silver halide emulsion layer to thereby form a silver image, etch-bleaching the silver halide emulsion layer to thereby remove the silver image areas, baking the remaining non-silver image areas to thereby decompose the binder contained therein, subjecting the coated support to etching to thereby remove the masking layer located at the areas corresponding to the silver image, and removing the decomposed binder to thereby uncover the masking layer at the areas corresponding to the non-silver image areas.

Abstract: A method for preparing a supplemental intensity-correction filter for an exposure lighthouse that is used to print viewing-screen structures for cathode-ray tubes. The method involves printing a screen structure without a supplemental filter, calculating how incremental areas of the light field must be modified at the surface of an optical element of the lighthouse to produce the desired screen structure, and then printing a supplemental filter on that surface having the transmission characteristics necessary to modify the light field as required.

Abstract: In a method of forming a Fresnel lens from a body of light-sensitive material of the type which undergoes changes in its optical path-length when exposed to light, the step of exposing each portion of such body of light-sensitive material to light to the extent necessary to impart to the respective portion the optical path-length requisite for the corresponding portion of the Fresnel lens to be formed.

Abstract: The photographic method of producing a printed circuit involves preparing a film negative from a graphic replica of the printed circuit and, through the film negative, exposing a photosensitive coating on a copper laminate board which is then developed and etched. This method is improved using Herschel-effect film in two successive steps, first producing a film image of the graphic printed-circuit replica and then producing the required film negative from the first film image. One of the film images is a film positive and the other is a film negative.

Abstract: Pulse width modulated surface relief phase holograms are produced on a substrate by developing a holographic interference pattern recorded on a photoresist deposited on the surface of said substrate as an amplitude modulated sinusoidal surface relief pattern so as to expose the surface of said substrate as a function of the intensity of said interference pattern, uniformly etching said substrate and removing said photoresist leaving a pulse width modulated, substantially two-level rectangular wave diffraction grating. Focused image holograms produced by this method on hard durable substrates may be used as masters for replicating said holograms in a suitable recording medium.

Abstract: A surface relief pattern, e.g. a surface relief hologram, is substantially linearly transferred to a hard durable substrate, capable of being used as a medium for permanent storage of the pattern or as a master for replicating the hologram, from a photoresist coated on the substrate, by exposing the photoresist and the substrate to a photoresist developer bath and a chemical bath capable of etching the substrate at a rate substantially proportional to the development rate of the photoresist. This technique allows the transfer of surface relief patterns with dimensions on the order of one micron or less, and is applicable to the formation of surface relief holographic patterns in permanent media for archival storage and to making master surface relief holograms.

Abstract: A method for forming micropatterns comprising, superposing a transparent raised image formed on a transparent substrate on a photosensitive layer of a photographic material or forming a transparent raised image on the photosensitive layer of the photographic material, uniformly exposing the photosensitive layer through the transparent raised image to light to which the photosensitive layer is sensitive so that the light intensity at edges of the transparent image is non-uniform, and developing the photosensitive layer to form a micropattern corresponding to the outlines of the transparent raised image.

Abstract: A method is disclosed for preparing masks for photo etch purposes. Preselected circuit combinations are scribed in an opaque film supported by a translucent film. Beginning with the most simple circuit combination, the scribed opaque film is peeled away and the resultant circuit is photographed. The next most simple circuit combination of scribed film is peeled away and the new circuit is photographed. This stripping and photographing process is continued until all circuit combinations are photographed from a single art work.

Abstract: There is provided a simple method and means for recording in any single-emulsion photographic film or plate an optical transparency which independently controls both the amplitude and the phase of the transmitted light at each transverse coordinate of the transparency according to predetermined spatial patterns. The phase and amplitude information are recorded at separate levels within the emulsion.

Abstract: In contact type photolithographic masking processes for fabricating planar structures, a photoresist is applied to a wafer and a mask is placed over the photoresist. Illumination through the mask, which has a pattern of opaque areas, produces a photochemical reaction in the photoresist which upon developing creates a duplicate of the mask pattern. However, the photoresist is conventionally applied by a spinning process and the rotation produces a build-up of the photoresist around the edges of the wafer. This build-up prevents the pattern portion of the mask from making good physical contact with the photoresist with a resultant decrease in reproducibility and accuracy of the fabricated pattern. A modified mask is formed with a channel corresponding to the peripheral build-up. The channel accepts the build-up so that good contact may be maintained between the photoresist and the patterned portion of the mask.

Abstract: Photolithographic techniques are employed to fabricate hemispherical or semicylindrical microlenses on the end surfaces of optical fibers. The power coupling efficiency between junction lasers and fibers is thereby significantly increased.

Abstract: a method for semiconductor device manufacture comprising the steps of, (a) repetitively aligning photomasks over a surface of a semiconductor substrate, said substrate having a layer of opaque material on said surface, said opaque material being adapted to receive and retain a photographic pattern; and (b) at least one of said steps employing a photomask of a particular construction, said particularly constructed photomask being placed in physical contact with said opaque material, said particularly constructed photomask essentially consisting of a planar glass substrate having a thickness of approximately 0.25 inches, one surface of said glass substrate having a thin film of chrome thereon, said thin film of chrome having a thickness of approximately 0.1 microns, said thin film of chrome having a photographic pattern formed therein, a layer of SiO.sub.2 fully covering said thin film of chrome and said surface of said glass substrate, said SiO.sub.