Frequency separation stabilization method for optical heterodyne or optical homodyne communication

摘要

A system for stabilizing a frequency separation between two coherent light sources includes first and second current sources driving first and second semiconductor laser devices (1, 2) with first and second frequencies (f1, f2), respectively. Light from the semiconductor laser devices (1, 2) is combined in a multiplexer (5), and a portion (7) of the combined light is diverted to an optical-to-electrical transducer (8). The output current (10) from the transducer (8) is combined with an output (12) of a local oscillator (11) driven at a selected frequency. A combined signal is then filtered by a filter (14) and used to form a control signal of one of the semiconductor laser devices (2).