British Telecommunications Public Limited Company

British Telecommunications Corporation

The Post Office

David B Payne

David B Mortimore

Alan M Hill

Peter Healey

Benjamin J Ainslie

Michael H Reeve

Andrew David Wallace

David John McCartney

Russell P Davey

Roy Andrew Lobbett

Yu R Zhou

Sandrew Robert John Cook

Giles R Chamberlin

Kevin J Blyth

Colin A Millar

The present invention relates to communication, in particular to communication involving analogue-like signals that are multiplexed together. There is provided a method of communicating with a plurality of devices, each of which of which provides a signal whose amplitude varies in an analogue fashion, the method including the steps of: temporally interleaving the signals from the devices so as to form a multiplexed signal having a plurality of sequential pulses, which pulses can, in an analogue fashion, each have an amplitude within a continuous range, each pulse originating from a respective device, and each pulse having a plurality of temporal portions; and, forming a synchronisation signal within the multiplexed signal for demultiplexing the multiplexed signal, the synchronisation signal being formed by reducing the amplitude within a temporal portion of at least some of the pulses.

Framing of analog communication

A gated optical amplifier for a PON includes an input for receiving an optical signal to be amplified, an output for outputting and amplified optical signal, an optical amplifier device for amplifying an optical input thereto, a detector, and an optical switch for allowing the amplified optical signal to leave the output upon the detector detecting the presence of an optical signal of a predetermined magnitude.

Optical network

Tunable optical filters

Communications network with switching distributed among a central

Optical star couplers

Optical two-way transmission system with loop reflector modulator

Optical filters

Technique for reducing fibre joint loss

Optical resonating device

A pair of optical fibres which are to be joined are located with their end portions in coupling elements one of which is transparent to light. The coupling elements are located such that the ends of the fibres are in approximate alignment. Light is transmitted along one fibre so that it is received by the fibre in the transparent coupling element. Light which is not coupled into the core of the fibre is sensed by a sensor and the relative position of the fibres is adjusted until the level of sensed light is a minimum. The sensing of the light is carried out at positions spaced angularly about the waveguide so that an indication of the direction of any misalignment is obtained. The coupling elements are then secured in this position. The adjustment of the fibres can be carried out using a linear translation stage and a microprocessor which controls the stage in accordance with signals from the sensor.

Coupling of dielectric optical waveguides

Growing community of inventors

Wickham Market, United Kingdom

David B Payne