Northern Telecom Limited

William D Westwood

Paolo Cielo

Herman W Willemsen

Frank Reginald Shepherd

Richard Prescott Skillen

David R Baraff

Richard W Streater

Nur M Serinken

Steven Kos

John S Wei

Robert J Boynton

Carla J Miner

Blair K MacLaurin

Robert Gordon Poulsen

Gerald M Smith

Michel I Gallant

Shmuel Maniv

An edge emitting optoelectronic source is integrally formed on a surface of a semiconductor substrate. An optical waveguide is integrally formed on the same surface of the substrate adjacent to the source. The waveguide is aligned with the source for optical coupling of the source to the waveguide. The waveguide comprises an optical diverter for diverting at least a portion of any light propagating along the waveguide toward the source through a surface of the waveguide. An optoelectronic detector is secured to that surface of the waveguide through which light is diverted for receiving light diverted through that surface. The resulting optoelectronic apparatus is suitable for launching and detecting optical signals in large volume bidirectional optical fiber transmission systems.

Optoelectronic apparatus and method for its fabrication

The end point in plasma etching is detected by monitoring the optical emission from the plasma, selecting a particular optical emission line and detecting a substantial variation in the intensity of the emission. This indicates a change in material being etched and thus the completion of etching of one material, or the beginning of etching of another material. It is also applicable to removing, or etching, photoresist material.

End point control in plasma etching

A thin film transistor has a semiconductor layer, an insulating layer and source, drain and gate electrodes. The improvement comprises creating an enhanced conductivity layer in the semiconductor by ion implantation or diffusion on phased deposition. The benefits of the enhanced conductivity layer are that transistor action is obtained without the conventional annealing step and DC stability is much improved.

Thin film transistors

A thin film transistor has a semiconductor layer, an insulating layer and source, drain and gate electrodes. The improvement comprises creating an enhanced conductivity layer in the semiconductor by ion implantation or diffusion on phased deposition. The benefits of the enhanced conductivity layer are that transistor action is obtained without the conventional annealing step and D.C. stability is much improved.

A matrix multiplexed field effect display has switch devices at matrix crosspoints to provide a turn-on threshold for the field effect material. The switch devices are thin film metal-insulator-metal (MIM) switches. The display is operated at low current so that the MIM switches, which may be deposited on glass, do not degrade rapidly in use.

Displays controlled by MIM switches of small capacitance

Using a sputter deposition system to reactively deposit a material such as an oxide, it is relatively easy to achieve either an oxygen-doped film with appreciable metallic content or an oxide film. However it is difficult with known systems to obtain an intermediate film having an accurately controlled resistivity, transparency, and composition, such films being of much use in semiconductor applications, in displays and in photovoltaic cells. It is now proposed that an apertured barrier be used to accurately fix the flow rate of target material to the substrate and in addition, that reactive gas flow be regulated and directed only to the immediate vicinity of the substrate. In this way the composition of the film can be accurately fixed. By establishing an r.f. field at the substrate, increased dissociation of the reactive gas can be achieved to render the gas more reactive and so enhance certain film properties such as transparency.

Reactive deposition method and apparatus

A terminal has a reciprocating print head bearing a series of linearly arranged, individually-magnetizable styli for printing on magnetic particle oriented paper. The terminal may be used as a printer, or as a display by combining the printer with an erasing head comprising a series of linearly arranged magnets which create a rotating magnetic field to erase the magnetic particle oriented paper when the erasing head is reciprocated. The print and erase heads are mounted on a common carriage. The terminal is cheap to manufacture and, if used as a printer, has the advantage of reusable paper. If used as a display, it required no refresh.

Read/write arrangement for a magnetic terminal

A thermally activated liquid ink printing head has a plurality of orifices in a wall of an ink reservoir, the ink retained in the orifices by surface tension. Electrical heating elements heat the ink in the orifices, the ink being caused to pass across to a paper sheet positioned adjacent to the orifices. The orifices may extend in a line across the head or may be in other predetermined patterns, such as for printing alpha-numerics a character at a time. The ink may be completely or partly vaporized. The heating current may flow through the ink.

Thermally activated liquid ink printing

An electrostatic ink ejection printing head uses an ink reservoir having small holes in its wall, the ink retained within the holes by surface tension. An electrostatic field is produced at each hole, as required, to overcome the surface tension and cause the ink to move into contact with a paper sheet to produce a dot. The holes can be in any desired predetermined formation. An electrode can be positioned opposite each hole, the paper between electrode and hole, or an electrode can be formed around or on either side of each hole. The electrodes are pulsed as necessary.

Electrostatic ink ejection printing head

In a liquid ink printing system, ink is supplied to a reservoir at a constant pressure, and viscosity of ink in orifices in the reservoir wall is decreased by electrically heating the ink in the orifices. By this means the amount of ink deposited on a paper sheet moving past the orifices can be varied.

Printing by modulation of ink viscosity

A liquid ink printer uses electrostatic control of ink flow along paths defined by strips of hydrophilic material. The strips may be discontinuous, with a narrow gap across which ink is urged to flow by application of a voltage to an electrode, or a gate member may be pulled down onto a strip to prevent ink flow. In a further arrangement drops of ink are extracted from the ends of the strips and accelerated towards a printing position by an electrode pattern.

Printer with electrostatic ink control

An optical imaging device divides a long thin object, such as a line of print, into several sections and arranges the sections into an overlapping image, of area form as compared to the original linear form of the object. A plurality of lenses are used, each lens associated with a particular section of the object. Each lens is tilted relative to the other lenses so that the plane of the lens is perpendicular to the line connecting the center of the related image section and object section, and also displaced in a direction normal to the extent of the line of lenses so that the center of each lens is on the line connecting the center of the related image section and object section. The lenses can extend in a curve to reduce magnification variations from lens to lens, and conveniently the lenses are rectangular and molded as a single unit.

Multiple lens system for an optical imaging device

An optical system for a scanning apparatus uses a folded optical path with certain mirrors moving, the movement of the mirrors such that the length of the optical path, and thus the magnification, is maintained constant. Either a fixed or movable lens system can be provided. With a fixed lens system there is differential movement of mirrors. With a moving lens system, the lens system and image receiver move in fixed relationship with the scanning mirror.

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Nepean, Canada

William D Westwood