Abstract: A method of forming an integrated chip optical device as a protective layer formed over part of the face of the chip on which at least one optical waveguide is formed, and the protective coating is selectively removed leaving the coating over an edge region 18 and the edge of the device is polished to provide high edge quality against which offchip optical fibers may be abutted.

Abstract: A method of fabricating an integrated optical component on a silicon-on insulator chip comprising a silicon layer (1) separated from a substrate (2) by an insulating layer (3), the component having a first set of features, eg a rib waveguide (5) at a first level in the silicon layer (1) adjacent the insulating layer (3) and a second set of features, eg a triangular section (5B) at a second level in the silicon layer (1) further from the insulating layer (3), the method comprising the steps of: selecting a silicon-on-insulator chip having a silicon layer (1) of sufficient thickness for the first set of features; fabricating the first set of features in the silicon layer (1) at a first level in the silicon layer; increasing the thickness of the silicon layer (1) in selected areas to form a second level of the silicon layer (1) over part of the first level; and then fabricating the second set of features at the second level in the silicon layer (1).

Abstract: A rib waveguide structure comprising a layer (4) of light conductive material defined between two planar faces with a rib (9) formed on one of the faces and an optical components e.g. a tapered waveguide (6) optically coupled to the other face. An inverted rib waveguide comprising a light conductive layer (11) and a rib (10) that projects from the light conductive layer (11) into a substrate (4, 8) is also described as well as other optical devices comprising a light conductive layer separated from a substrate by a non-planar layer (3) of light confining material and optical devices comprising two or more layers (2, 3; 18, 19, 20) of light confining material buried within a rib with a light conducting component (10; 17; 22) at least a part of which is formed between planes defined by the two layers of light confining material. A method of forming such devices is also described.

Abstract: An infra-red dryer utilizes high velocity air jets which scrub and break up the moist air layer which clings to the surface of a freshly printed and/or coated sheet. The high velocity air jets are directed through multiple air flow apertures across an array of infra-red lamps onto the freshly printed and/or coated sheets. An extractor exhausts the moisture-laden air from an exposure zone while short wave infra-red radiation heats the ink and/or protective coating. The effective exposure to pressurized air is increased by the air jets which produce a balanced pressure air blanket along the sheet travel path. The moist air layer is displaced from the printed and/or coated sheet and is extracted from the press as the sheet moves through the exposure zone.

Abstract: A process for treating a waveguide structure which comprises a silicon substrate with an integrally formed rib waveguide is described. The waveguide has an end portion with a facet, the end portion overhanging the silicon substrate and having an oxide layer on its underside protruding from the facet of the waveguide. A nitride layer extends over the upper surface of the waveguide and the facet. The treatment process involves etching the oxide layer from the underside, growing a new oxide layer, etching the nitride layer and then depositing a new nitride layer.

Abstract: An apparatus is provided for coupling an optical fibre to a waveguide on an optical chip, the apparatus comprises a recess in the chip for receiving the optical fiber, the recess comprising a V-groove the side faces of which locate the position of the fiber in directions perpendicular to the optical axis of the fiber so as to position the fibre in alignment with the waveguide, and an end face adjacent the end of the waveguide, the end face of the recess being substantially flat and substantially perpendicular to the plane of the chip with its normal inclined to the optical axis of the waveguide so an optical fiber having an inclined end face can be brought into a close, abutting relationship with the end of the waveguide and brought into rotational alignment therewith about its optical axis by positioning the fiber so its inclined end face lies in planar contact with the end face of the recess.

Abstract: A process for making a silicon rib wavegide structure is described comporising the following steps:(i) forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface;(ii) depositing a buffer layer at least over said exposed surface;(iii) carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and(iv) forming a layer of cladding at least on side walls of the silicon rib.

Abstract: An apparatus and method for setting a sensitivity level of an optical encoding circuit in an input device includes an adjuster for adjusting the sensitivity level, a threshold locator for detecting a sensitivity threshold of the occurrence of a prescribed output from a light detector circuit, and a motion encoder for encoding motion from the output of the light detector circuit. The threshold locator locates a sensitivity threshold by setting the sensitivity level to one extreme, then repeatedly sampling the light detector circuit output for a prescribed state most likely at the one extreme, while incrementally changing the sensitivity level each time the prescribed state is detected. The sensitivity level used by the threshold locator thus approaches the sensitivity threshold of the prescribed state. A sensitivity level for motion encoding is set based on the sensitivity level for threshold location.

Abstract: A connection between an integrated optical waveguide and an optical fibre has a layer of silicon in which a rib waveguide is formed separated from a substrate by a layer of silicon dioxide. A V-groove is formed in the substrate for receiving an optical fibre, and the V-groove is arranged to align the optical fibre at a predetermined angle with respect to the waveguide. The rib waveguide and the underlying layer of silicon dioxide are formed to overhang the end of the V-groove so that the end of the waveguide is in close proximity with the end of an optical fibre positioned in the V-groove. A method of forming a connection, in which the V-groove is etched using a material which etches the substrate material as opposed to the layer of silicon dioxide, is also disclosed. Finally, a method of connecting an integrated optical waveguide to an optical fibre using a connection as described above is disclosed.