Abstract: Various embodiments are disclosed relating to fabrication of an optical wedge. For example, one embodiment provides a method for manufacturing an optical wedge comprising inserting a wedge blank into a vacuum molding tool and applying a vacuum to the vacuum molding tool to temporarily hold the wedge blank against a molding surface of the vacuum molding tool. The method further comprises removing a layer from a top surface of the wedge blank to expose a machined surface of the wedge blank, and casting a finish layer on the machined surface to form a finish layer of a finished optical wedge.

Abstract: Embodiments of optical collimators are disclosed. For example, one disclosed embodiment comprises an optical waveguide having a first end, a second end opposing the first end, a viewing surface extending at least partially between the first end and the second end, and a back surface opposing the viewing surface. The viewing surface comprises a first critical angle of internal reflection, and the back surface is configured to be reflective at the first critical angle of internal reflection. Further, a collimating end reflector comprising a faceted lens structure having a plurality of facets is disposed at the second end of the optical waveguide.

Abstract: A light collector is provided to converge light from a light source down to a range of acceptance angles of an illumination optic, and to couple the converged light into the illumination optic, where the range of acceptance angles of the illumination optic is less than a range of emission angles of the light source.

Abstract: An integrated vision and display system comprises a display-image forming layer configured to transmit a display image for viewing through a display surface; an imaging detector configured to image infrared light of a narrow range of angles relative to the display surface normal and including a reflection from one or more objects on or near the display surface; a vision-system emitter configured to emit the infrared light for illuminating the objects; a visible- and infrared-transmissive light guide having opposing upper and/or lower face, configured to receive the infrared light from the vision-system emitter, to conduct the infrared light via TIR from the upper and lower faces, and to project the infrared light onto the objects outside of the narrow range of angles relative to the display surface normal.

Abstract: Various embodiments are disclosed that relate to scanning the direction of light emitted from optical collimators. For example, one disclosed embodiment provides a system for scanning collimated light, the system comprising an optical wedge, a light injection system, and a controller. The optical wedge comprises a thin end, a thick end opposite the thin end, a viewing surface extending at least partially between the thick end and the thin end, and a back surface opposite the viewing surface. The thick end of the optical wedge further comprises an end reflector comprising a faceted lens structure. The light injection system is configured to inject light into the thin end of the optical wedge, and the controller is configured to control the location along the thin end of the optical wedge at which the light injection system injects light.

Abstract: Embodiments of optical collimators are disclosed. For example, one disclosed embodiment comprises an optical waveguide having a first end, a second end opposing the first end, a viewing surface extending at least partially between the first end and the second end, and a back surface opposing the viewing surface. The viewing surface comprises a first critical angle of internal reflection, and the back surface is configured to be reflective at the first critical angle of internal reflection. Further, an end reflector is disposed at the second end of the optical waveguide, and includes a faceted lens structure to cause a majority of the viewing surface to be uniformly illuminated when uniform light is injected into the first end and also to cause a majority of the injected light to exit the viewing surface.

Abstract: Embodiments of optical collimators are disclosed. For example, one disclosed embodiment comprises an optical waveguide having a first end, a second end opposing the first end, a viewing surface extending at least partially between the first end and the second end, and a back surface opposing the viewing surface. The viewing surface comprises a first critical angle of internal reflection, and the back surface is configured to be reflective at the first critical angle of internal reflection. Further, a collimating end reflector comprising a faceted lens structure having a plurality of facets is disposed at the second end of the optical waveguide.

Abstract: A light collector is provided to converge light from a light source down to a range of acceptance angles of an illumination optic, and to couple the converged light into the illumination optic, where the range of acceptance angles of the illumination optic is less than a range of emission angles of the light source.

Abstract: A dynamic projected user interface includes a light source for generating a light beam and a spatial light modulator for receiving and dynamically modulating the light beam to create a plurality of display images that are respectively projected onto a plurality of keys in a keyboard. An optical arrangement is disposed in an optical path between the light source and the spatial light modulator for conveying the light beam from the light source to the spatial light modulator.

Abstract: A light guide of the tapered-waveguide type includes an input slab (30) for expanding a projected image between an input end and an output end, and an output slab (10) arranged to receive rays from the said output end, and to emit them at a point on its face that corresponds to the angle at which the ray is received. The input slab and output waveguide are matched so that all rays injected into the input end undergo the same number of reflections before leaving the output surface. With the invention the input slab (30) is itself tapered slightly towards the output waveguide. This means that input and output waveguides can be made the same length, in the direction of ray travel, and can therefore be folded over each other with no wasted space.

Abstract: A flat panel lens system as a tapered light guide that has minimal or no margin for fan out. The tapered light guide includes a thin end, and a thick end of which is a bevelled mirror or an optical equivalent. Light is injected into the thin end and the mirror is such that rays injected through a point at the thin end emerge collimated from one of the light guide surfaces, and that collimated rays injected at an appropriate angle through one of the light guide surfaces emerge from a point at the thin end. Bragg gratings can be utilized for color implementations as well. The tapered light guide can be fabricated as a single piece, by extrusion, injection molding, or the combination/variation of extrusion and injection molding, as well as other commonly known techniques.

Abstract: A flat panel lens system as a tapered light guide that has minimal or no margin for fan out. The tapered light guide includes a thin end, and a thick end of which is a bevelled mirror or an optical equivalent. Light is injected into the thin end and the mirror is such that rays injected through a point at the thin end emerge collimated from one of the light guide surfaces, and that collimated rays injected at an appropriate angle through one of the light guide surfaces emerge from a point at the thin end. Bragg gratings can be utilized for color implementations as well. The tapered light guide can be fabricated as a single piece, by extrusion, injection molding, or the combination/variation of extrusion and injection molding, as well as other commonly known techniques.

Abstract: A fluid displacement mechanism is disclosed. In an embodiment, first and second cavities are separated by a flexible membrane. The first cavity contains a non-conductive fluid and the second cavity contains a conductive fluid. First and second electrodes are positioned in the first and second cavities respectively such that the application of a voltage between the electrodes causes movement of the membrane by the build up of an electrostatic charge between the membrane and first electrode.

Abstract: The transmission properties of the signal carrier wavelengths in a wavelength division multiplexed optical transmission system are equalised with reference to their signal to noise ratios at a receiver. Each wavelength transmitter transmits a bit sequence as a modulation on the respective wavelength. At the receivers each wavelength modulated with the bit sequence is converted into a corresponding electrical signal. From a spectrum of that electrical signal, an electrical signal to noise ratio is determined. The measurements for the wavelengths are used to control adjustment of the individual wavelength transmitters such that the signal to noise ratios of the wavelengths are substantially equal.

Abstract: An electrophoretic display has a matrix addressing structure which includes a first support structure 10 on one side of the display and a second support structure 20, substantially parallel to the said first support structure, on the other side of the display. On the inner surface 12 of the first support structure 10 there is a first set of parallel electrodes 11 and on the facing the inner surface 23 of the second support structure 20 there are second 22 and third 21 sets of parallel electrodes arranged substantially orthogonal to the first set of electrodes 11. The electrodes 21,22 of the second and third sets are interspersed with one another.

Abstract: A tuneable optical filter having a variable wavelength transmittance. The filter comprises a pre-polariser, a post-polariser and a birefringent plate positioned between the pre-polariser and the post-polariser. A twisted nematic liquid crystal cell (TN LCD) is positioned between the pre-polariser and the post-polariser, the TN LCD being controlled, in use, to tune the filter. A quarter wave plate is positioned adjacent the birefringent plate.

Abstract: A method of operating Raman amplification pump lasers, especially in telecommunication systems, is described and claimed, in which the Raman pump laser output powers are modulated in characteristic fashions. Parameters of these characteristic modulations may be detected at remote locations (i.e. locations along the communications fibres) even in the presence of large amounts of noise. Thus, by detecting losses of signals indicative of the characteristic modulations, breaks in the communication fibres can be detected more reliably. The disappearance of these signals can then be used to shut down the typically high power Raman pump lasers, thereby reducing the possibility of high laser powers escaping from the broken fibres. The specification also described an improved method of detecting the disappearance of a data signal at an amplifier unit, using a periodic filter to split the incoming signal into two streams, the first stream comprising data and noise, and the second comprising noise only.

Abstract: A laser drilling process capable of producing a plurality of holes in a pharmaceutical dosage form, at high speed, is presented. The process utilizes a high power CO.sub.2 laser steered by an acousto-optic deflector together with various mirrors and optical components to achieve the correct beam path geometry, in order to produce an unlimited number of holes through the surface or coating of a dosage form, at rates up to 100,000 units or more per hour.

Abstract: A transmitted (TX) signal received from the remote location is mixed in a polarization resolving beam splitter (10) with a local oscillator (LO) signal from a laser (15). The LO and TX signal components emerging from the beam splitter (10) are orthogonally polarized, but their polarization states are brought into alignment by passage through two birefringent elements (19, 20) before falling on two photodetectors (17, 18). Adjustment of a polarization controller (16) ensures that approximately equal LO power falls on each photodetector.

Abstract: A planar coil of single mode fiber has opposed ends twisted into orthogonal planes to form a non-planar coil 20 exhibiting circular birefringence. The amount of birefringence exhibited is modulated by means of an electromechanical transducer 34 which controls the distance separating two diametrically opposed portions of the coil. Two or more such controllers may be formed in tandem with intervening additional coils 50 providing quarter-wave linear birefringence.