Nortel Networks Corporation

James Watts

Ian A Abraham

Christopher G Tanner

Kenneth Snowdon

Alan Fisher

Andrew Waterhouse

Andrew Liu

Optical assemblies of the type supported on an optical bench and comprising a one or more components such as lasers, lenses, filters, isolators and waveguides, are sensitive to movement variation. One of the causes of movement is temperature tracking. Previously, thermo-electric coolers have been used to maintain the top-surface temperature of an optical bench within a certain range. However, although thermo-electric coolers are operable to maintain optical bench temperature they are themselves still sensitive to temperature tracking and can deform. Because an optical bench is typically supported on the top surface of a thermo-electric cooler this leads to deformation of the optical bench itself and as a result performance of the optical assembly is affected. An improved design of thermo-electric cooler is described where the top surface of the cooler is divided into separate regions, each having a neutral region in which deformation is minimal. A thermally conductive sheet is placed over each of these regions such that only one temperature monitor is required. Optical components are then supported over the thermally conductive sheet in the neutral regions.

Thermo-electric cooler for use in an optical assembly

A coding scheme to identify the connections an optical fiber is to form in an optical assembly is provided. The coding scheme consists of a series of colors, typically four, provided along the fiber length. The combination of colors identifies the connection the fiber is to form. Colors are transferred to the optical fiber by sublimation of the dye at a relatively low temperature. The sublimed dye then diffuses into the outer coating of the optical fiber.

Optical fiber coating and coding scheme

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Chelmsford, United Kingdom

James Watts