British Telecommunications Public Limited Company

British Telecommunications Corporation

Bt&d Technologies Limited

Michael J Adams

Michael J Robertson

Michael A Fisher

Leslie D Westbrook

Paul Rodgers

Ian Douglas Henning

Simon Ritchie

David Mace

Jaspal Singh

David A Mace

Optically resonant structure

Selective optical signal switch and/or combiner

Semiconductor laser structures

Optical signal processing device

Optical power limiter

Optical switch

An opto-electronic device, comprising an optical waveguide and means for imposing an electrical field in a direction transverse to the waveguide, is designed such that the spatial spread of the electrical field is very small. The electrical field overlies the region of peak amplitude of the profile of optical radiation in the waveguide. Constructed principally out of semiconductor materials made from elements selected from the III and V groups of the Periodic Table, the device lends itself to monolithic integration in optical communications systems.

Electro-optic devices with waveguide and having small spatial spread of

An optical waveguide device, suitable for coupling to optical fibers, provides a combination of narrow optical confinement and small changes in refractive index along a first axis, with broad optical confinement and large changes in refractive index along a second, perpendicular axis. A rib waveguide in which a single transverse mode beam can propagate, comprises a thin guiding layer 2 sandwiched between a pair of relatively thick confining layers 1, 3 of refractive index only slightly less than that of the guiding layer 2. The rib is etched through both the upper confining layer 3 and the guiding layer 2 and is exposed at its sides and top to air.

Single mode optical waveguides of rectangular cross-section

Growing community of inventors

Suffolk, United Kingdom

Michael J Adams