Lucent Technologies Inc.

At&t Bell Laboratories

James J Royer

Sungho Jin

Thomas H Tiefel

Kalpendu Ranjitrai Shastri

A novel non-mechanical optical fiber switch contains a magneto-optic element and a tubular magnet. The magneto-optic element is disposed within the field of the magnet but outside of the magnet bore. The beam of radiation from the switch input to the switch output passes through the axial bore of the magnet. The magnet contains magnetically anisotropic material, preferably a deformation-aged alloy having Fe, Cr and Co as major constituents. The switch is advantageously used in optical fiber communication systems.

Article comprising a non-mechanical optical fiber switch

A laser driver includes a reference circuit, which may be a bandgap reference, mounted in thermal contact with the laser. The reference produces a current component Iptat that is proportional to the absolute temperature. The modulation current is proportional to Iptat, which slowly with temperature, up to a certain junction temperature (e.g., 65 to 70 degrees C.). Above that temperature, the modulation current increases more rapidly by adding an additional current component Icomp. This provides for the required increase in modulation current to compensate for temperature variations in the laser output. This technique allows the laser to be operated without cooling (as by a thermoelectric cooler) in many applications. The laser driver may optionally include circuitry to provide a bias current, which may be controlled by a backface monitor or threshold detector.

Growing community of inventors

Hanover Township, Northampton County, PA, United States of America

James J Royer