Abstract: A thermal solution for an electronic device, which is positioned between a heat source and an external surface of the electronic device and/or another component of the electronic device, where the thermal solution facilitates heat dissipation from the heat source while shielding the external surface and/or second component from the heat generated by the heat source.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor. These devices are particularly suitable for incorporation in optical and opto-electronic intergrated circuits as they permit the fabrication of waveguides having right-angle bends with a radius of the order of 2 ?m.

Abstract: A liquid crystal device such as a display comprises a twisted liquid crystal layer whose surface director orientation at a first surface is oriented in a first direction and whose surface director orientation at a second surface is oriented in a second different non-perpendicular direction. The layer is disposed, for instance, between a linear polarizer and a reflector. A retarder is disposed between the layer and the polarizer and compensates for residual retardation of the layer at a first voltage across the layer. For instance, the retarder has a retardation substantially equal to the residual retardation and an optic axis perpendicular to the bisectrix of the orientations.

Abstract: There is provided a non-linear optical device for enhancing the bandwidth accessible in the nonlinear generation of an optical signal. The device comprises a planar optical waveguide, the planar optical waveguide being operative to generate an optical output from an optical input having an input bandwidth by means of a non-linear optical process, the optical output having a wavelength within an accessible bandwidth, wherein the planar optical waveguide is operative to enhance the accessible bandwidth such that the ratio of the accessible bandwidth to the input bandwidth is at least 4. The device is particularly applicable to broad optical continuum generation, but may also be used in a parametric oscillator or amplifier arrangement with broad tuning range.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor. These devices are particularly suitable for incorporation in optical and opto-electronic integrated circuits as they permit the fabrication of waveguides having right-angle bends with a radius of the order of 2 &mgr;m.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor.

Abstract: A method and apparatus for providing an automatically upgradeable software application includes targeted advertising based upon demographics and user interaction with the computer. The software application includes a display region used for banner advertising that is downloaded over a network such as the Internet. The software application is accessible from a server via the network and demographic information on the user is acquired by the server and used for determining what advertising will be sent to the user. The software application further targets the advertisements in response to normal user interaction with the computer. Data associated with each advertisement is used by the software application in determining when a particular advertisement is to be displayed. This includes the specification of certain programs that the user may have so that, when the user runs the program (e.g., a spreadsheet program), a relevant advertisement will be displayed (e.g., an advertisement for a stock brokerage).

Abstract: A reflective liquid crystal device comprises in sequence a linear polarizer, a retarder arrangement comprising two retarders, and a reflector. A first of the retarders provides a retardation of m&lgr;/2 and a second of the retarders provides a retardation of n&lgr;/4, where m is an integer and n is an odd integer, and wherein at least one of the first and second retarders comprises a Bistable Twisted Nematic (BTN) liquid crystal. This BTN retarder is switchable between a first state in which the retarder provides a retardation of m&lgr;/2 or n&lgr;/4 and a second state in which the retardation is zero.

Abstract: A broadband optical retardation device, such as may be used for polarisation encoding of display information or in diffractive optical systems, includes a patterned uniform half wave plate retarder in combination with a non-patterned uniform quarter wave plate retarder having an optic axis oriented at 90° to the xz plane. The patterned retarder consists of alternating first and second regions having first and second optic axes at different orientations to a reference axis, for example at +22.5° and −22.5° to the xz plane. Considering light of wavelength &lgr;° incident on the retarder and linearly polarised in the xy plane, such light is differently polarised by the regions, and the light output by the device includes regions in which the light is right circularly polarised and regions in which the light is left circularly polarised.

Abstract: A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates; and means for applying a voltage across the liquid crystal layer. A first region of the liquid crystal layer is an active region for display and a second region of the liquid crystal layer is a nucleation region for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p)A in the first region of the liquid crystal layer and has a second value (d/p)N different from the first value in the second region of the liquid crystal layer.

Abstract: A polarisation rotator is provided for rotating the polarisation direction of linearly polarised light by any arbitrary angle other than 90°. The device comprises a layer of liquid crystal material disposed between alignment surfaces. In one mode, a 90° twist is induced in the liquid crystal director. An expression is provided for relating the retardation of the layer to the amount of polarisation rotation and the angle between the polarisation direction of incident light and the alignment direction at the input side of the liquid crystal layer.

Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electroptical system. The electroptical system comprises a PDLC film comprising a liquid crystal mixture forming micro-droplets in an optically isotropic, transparent polymer matrix between 2 electrode layers. The liquid crystal mixture comprises one or more compounds of the formula I wherein R, A1, A2, Z1, Z2, X1, X2, Q, Y and n are as defined herein.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor. These devices are particularly suitable for incorporation in optical and opto-electronic integrated circuits as they permit the fabrication of waveguides having right-angle bends with a radius of the order of 2 &mgr;m.

Abstract: A method and apparatus for providing an automatically upgradeable software application that includes targeted advertising based upon demographics and user interaction with the computer. The software application is a graphical user interface that includes a display region used for banner advertising that is downloaded from time to time over a network such as the Internet. The software application is accessible from a server via the Internet and demographic information on the user is acquired by the server and used for determining what banner advertising will be sent to the user. The software application further targets the advertisements in response to normal user interaction, or use, of the computer. Associated with each banner advertisement is a set of data that is used by the software application in determining when a particular banner is to be displayed.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor.

Abstract: A device (6) for attachment to a pipe (7) to be installed in the ground has load cells (17) for detecting a pulling force applied to the pipe (7), as the latter is pulled through the ground, an inclinometer (18), for detecting the inclination of the device (6), and a pressure transducer (20) for detecting the pressure surrounding the device. Data representative of the pulling force, inclination and pressure is stored in the device (6) and protected against unauthorised access by a security code or procedure, so that a verifiable record of the pipe installation process is available.

Abstract: A solid-state, surface-emitting, optical device such as a light emitting diode (LED) or vertical cavity surface emitting laser (VCSEL) has a body of optical gain medium overlying a high reflectivity distributed BRAGG reflector (DBR) mirror which is carried on part of an underlayer. The gain layer is part of an epitaxial layered structure extending from the underlayer and over the mirror.

Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electrooptical system. The electrooptical system comprises a PDLC film comprising a liquid crystal mixture forming micro- droplets in an optically isotropic, transparent polymer matrix between 2 electrode layers. The reactive liquid crystalline compounds are of formula II, R′—G′—R″, wherein R′, G′ and R″ are as defined herein. The liquid crystal mixture comprises one or more compounds of the formula I wherein R, A1, A2, Z1, Z2, X1, X2, Q, Y and n are as defined herein.

Abstract: A method for controlling the fuelling rate for an internal combustion engine including: a) controlling the fuelling rate in a fuel led control mode whereby the fuelling rate is controlled as a function of the operator demand on the engine during at least a portion of low engine load operation; b) controlling the fuel rate in an air led control mode whereby the fuelling rate is controlled as a function of the air flow rate to the engine during at least a portion of medium-to-high engine load operation; and c) providing a point of transition between the two control modes wherein each control mode provides substantially the same predetermined fuelling rate.

Abstract: A reflective liquid crystal device comprises a polarizer and a mirror between which are disposed several retarder. At least one of the retarders is a variable liquid crystal element whose optic axis is switchable so as to switch the device between a reflective state and a non-reflective state. In the non-reflective state, the total retardance of the retarders between the polariser and the mirror is equal to an odd number of quarter wavelengths for a wavelength at or adjacent the middle of the visible spectrum.