Inventors:
Joseph M. Kahn - Red Bank NJ
Bryon L. Kasper - Allentown PA
Assignee:
AT&T Bell Laboratories - Murray Hill NJ
International Classification:
H04B 1006
Abstract:
An optical homodyne receiver is realized by employing two separate signal amplification paths in a balanced receiver configuration. Specifically, the relative phase difference between a received optical signal and a local oscillator signal is extracted from nodes which, from the point of view of an amplifier extracting a data component signal, are at ac ground. This approach permits a phase detector amplifier, which extracts the relative phase component, to be dc coupled in addition to having a higher transimpedance for lower thermal noise, and thus higher sensitivity. Additionally, by extracting the data and phase component signals at different points in a balanced receiver configuration, the data and phase amplifiers can be separately engineered for optimum performance.
