Abstract: A surface relief structure consisting of a random distribution of surface features with varying feature profile and depth, is described. The texture serves to suppress the reflection of electromagnetic waves in the optical region of the spectrum without dispersing any portion of the spectrum by diffraction. Processes for fabricating the random distribution anti-reflecting textures in common materials are also described. The disclosed textures are particularly useful as anti-reflecting covers for displays, and as directly molded anti-reflecting surfaces in eyeglass lenses. Other applications such as covers for artwork, and improved solar cells are made practical by the invention.

Abstract: An interference lithography system is described that is capable of exposing high resolution patterns in photosensitive media and employing yield increasing active stabilization techniques needed in production environments. The inventive device utilizes a division-of-wavefront interference lithography configuration which divides a single large field size optical beam using one or more mirrors, and is actively stabilized with a subsystem employing; a phase modulator operating on each divided wavefront section; a novel feedback apparatus for observing the relative phase shifts between interfering wavefront sections; and a control system for holding the relative phase shifts constant.

Abstract: A microstructure-based chemical sensor that can be interrogated by a remote observer. The device acts as an electromagnetic wave filter in the optical region of the spectrum, filtering one or more wavelength bands where the band spectral notch location shifts in response to the accumulation of material on the surface of the microstructure sensor. The apparatus has a substrate having a surface relief structure containing dielectric bodies with one or more physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in an array covering at least a portion of the surface of the substrate. A retro-reflecting structure allows interrogation of the sensor over a wide field of view. The device is particularly useful as a water monitoring device in hard to reach locations, and as a chemical warfare or explosives detector that can be read from a safe distance.

Abstract: An apparatus for filtering electromagnetic waves, the apparatus comprising a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. Also disclosed is a material sensor utilizing this apparatus.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: An apparatus for filtering electromagnetic waves and sensing deposition of chemical species, the apparatus having a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. The apparatus may include one, two, or more such arrays, spaced from one another to create one or more cavities between the arrays.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: An apparatus for filtering electromagnetic waves, the apparatus comprising a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. Also disclosed is a material sensor utilizing this apparatus.

Abstract: An apparatus for filtering electromagnetic waves and sensing deposition of chemical species, the apparatus comprising a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. The apparatus may include one, two, or more such arrays, spaced from one another to create one or more cavities between the arrays.

Abstract: An interference lithography system is described that is capable of exposing high resolution patterns in photosensitive media and employing yield increasing active stabilization techniques needed in production environments. The inventive device utilizes a division-of-wavefront interference lithography configuration which divides a single large field size optical beam using one or more mirrors, and is actively stabilized with a subsystem employing; a phase modulator operating on each divided wavefront section; a novel feedback apparatus for observing the relative phase shifts between interfering wavefront sections; and a control system for holding the relative phase shifts constant.

Abstract: A high resolution, high-throughout, large field size, production environment, lithographic tool system and method includes an interferometric pattern generator utilizing three or four mutually coherent optical beams organized in a flexible beam expansion, filtering, aperturing, and delivery system, large area pattern uniformity is attained via optimized illumination beam positioning and shaping. A passive stabilization system achieves fully modulated interferometric patterns in high mechanical and acoustical vibration manufacturing environments.

Abstract: A double exposure process is disclosed whereby a first exposure produced by conventional photolithographic techniques generates a latent negative image in a photoresist etch mask layer (22), the image subsequently employed to modulate a second exposure generated by the multiple beam interferometric lithography technique. Periodic surface relief structures (80) patterned by the second exposure and formed after development of the exposed photoresist material, are restricted to regions (52) defined by the initial exposure, with the photoresist material (54) outside these regions remaining unmodulated, or devoid of the periodic structures (80), and suitable for use as a mask in a subsequent etching process.

Abstract: A holographic lithography tool (110) for generating a light interference pattern used to expose a photosensitive medium (119) employs a refracting prism (121) in the optical path between divergent illuminating beams (127a, 127b). The prism is optically coupled to the photosensitive medium via an index matching fluid (123). By increasing the incident beam angle and the index of refraction, the prism reduces the size of features recorded in the photosensitive material. The divergent illuminating beams are generated by a beam delivery system which preferably employs easily adjustable fiber optic cables (176, 184). Use of the prism coupling technique facilitates use of fiber-optic-compatible wavelengths in the blue region of the spectrum in a variety of applications, such a distributed feedback grating fabrication.

Abstract: A high resolution, high-throughout, large field size, production environment, lithographic tool system and method includes an interferometric pattern generator utilizing three or four mutually coherent optical beams organized in a flexible beam expansion, filtering, aperturing, and delivery system, large area pattern uniformity is attained via optimized illumination beam positioning and shaping. A passive stabilization system achieves fully modulated interferometric patterns in high mechanical and acoustical vibration manufacturing environments.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: Method of fabricating a coherently exposed multiple holographic lens including a first step of fabricating an incoherently exposed master multiple holographic lens with an array of overlapping holographic lens elements, each of said lens elements having an interference pattern substantially covering the entire area of the lens. The master multiple holographic lens is illuminated with a first beam of light from a coherent source to provide a plurality of light waves equal in number to the number of lens elements in the master lens. The plurality of light waves overlap in a region downstream of the master lens. A holographic recording medium is positioned in the region of overlap such that an area thereon is illuminated simultaneously by each of the plurality of light waves. A second beam of light from a coherent source is directed toward the area of the holographic recording medium illuminated by the plurality of light waves.

Abstract: An optical correlator system comprising a laser to generate a signal beam, a film to spatially modulate that beam, and a beam splitter to split the signal beam into two component beams. The first component beam is directed onto a first side of a multiple holographic lens, which generates from the component beam a first matrix of individually converging beams and a second matrix of individually diverging beams. The second component beam is directed onto a second side of the holographic lens, which generates from this component beam a third matrix of individually converging beams and a fourth matrix of individually diverging beams. The beams of the first and third matrices are focused by the holographic lens onto first and second matched filters, respectively, and correcting optical elements are used to focus the beams of the second and fourth matrices onto third and fourth matched filters, respectively.