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: An integrated optical circuit for use in a fibre optic gyroscope which senses rotation rates by determining a phase shift due to the Sagnac Effect between light beams travelling around an optical fibre sensing loop (4) in opposite directions, the circuit being provided on a silicon-on-insulator chip comprising a layer of silicon separated from a substrate by an insulating layer, the circuit comprising: rib waveguides (11) formed in the silicon layer for receiving light from a light source (2) and transmitting light to a light detector (3), fibre optic connectors (9) in the form of grooves etched in the silicon layer for receiving the respective ends of the optical fibre sensing loop (4); rib waveguides (11) formed in the silicon layer for transmitting light to and from said fibre optic connectors (9) so as to direct light beams in opposite directions around the sensing loop (4) and receive light beams returning therefrom, phase determining means and (13,17,31) integrated in silicon layer for determining a pha

Abstract: An optoelectronic device is mounted on a planar substrate in electrical connection with solder bumps adjacent an edge of the substrate and connection to a lead frame is made by loading the edge of the substrate on a lead frame support with lead frame conductors in engagement with the solder bumps and applying heat to melt the solder.

Abstract: The device is formed on a silicon-on-insulator chip (which comprises a layer of silicon (1) separated from a substrate (3) by an insulator layer (2)) and comprises an integrated waveguide (4) formed in the silicon layer (1) and a reflective facet (6) formed in a recess in the silicon layer (1). The facet (6) is positioned to redirect light in a desired direction. The waveguide (4) and facet (6) are both formed in the silicon layer (1) so their positions can be defined by the same lithographic steps so they are automatically aligned with each other.

Abstract: External Cavity Laser An external cavity laser comprising first and second feedback means with an optical gain medium (2) therebetween, one of the feedback means is provided by a grating (4) formed in a silicon waveguide and the other feedback means is provided by a reflective back facet (2B) of the optical gain medium (2). The output wavelength of the laser, at a given temperature, can thus be determined during its manufacture and the laser can be made by mass production techniques. The grating (4) may be thermally isolated to obviate the need for temperature control means (6) to control the temperature of the grating (4). An array of lasers may be provided on a single chip.

Abstract: An optical device for splitting up a multi-wavelength light beam into a plurality of individual beams, each comprising light of a different wavelength or a narrow beam of wavelengths. The optical device includes an optical grating and an optical system for directing the incident beam onto the optical grating. The incident beam is divided into two portions, and one portion is directed onto the grating in one direction, while the other portion is directed onto the grating along an opposite direction. Preferably the grating is formed in two parts and one beam portion is directed through the two grating parts in succession in one direction while the other beam portion is directed through the two grating parts in succession along an opposite direction. A common mirror may be used to direct light towards the grating and to receive light returning from the grating. The device may also be used as a multiplexer by reversing the direction of light transmitted through the device.

Abstract: Attachment of an optical fibre (22) to a planar substrate (17) having a major face and an edge surface (14) perpendicular to the major face, the optical fibre (22) being positioned in a groove (18) provided in the major face of the substrate (17) and extending over the edge of the substrate, a mechanical restraint (24) such as a transparent apertured disc being affixed to the edge surface (19) of the substrate, e.g. by a light-cured adhesive (17) to resist movement of the optical fibre (22) in a direction substantially perpendicular to the major face.