Patent ID: 7277645
Filing Date: 2007-10-02
Classification: G02B,G02F,H04B

Abstract:
1. An apparatus for generating an optical carrier signal for a long-haul fiber optic transmission system, said apparatus comprising: a pulse generator including a phase modulator having a driving electrode, an input optical port and an output optical port, said output port optically coupled to an input optical port of a delay interferometer; a radio frequency electrical drive signal applied to the driving electrode for phase modulating a continuous wave (CW) input light applied to the input port of the phase modulator; the input port of the delay interferometer optically coupled to a first and a second light path, such that a time delay exhibited between the light paths is substantially ⅔ of the bit period of a data stream to be transmitted by the system, the light paths being optically coupled to an output port of the delay interferometer; and wherein a 90-degree AP optical carrier signal is produced at the output port of the delay interferometer and each output pulse of the carrier signal has an optical phase difference of substantially 90 degrees relative to an adjacent pulse.