Method and system for a polarization mode dispersion tolerant optical homodyne detection system with optimized transmission modulation

  • US 7,599,627 B2
  • Filed: 05/31/2001
  • Issued: 10/06/2009
  • Est. Priority Date: 05/31/2001
  • Status: Expired due to Fees
First Claim
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1. A method of optical communication in an optical communication system, comprising the steps of:

  • providing a quadrature modulated optical data signal by a transmitter, the optical data signal including two data bands separated in frequency, each data band having in-phase and quadrature components;

    during transitional states of the quadrature modulated optical data signal in which data symbols change in value, reducing, by the transmitter, the power to zero such that transmitted power decreases to zero at approximately a mid point of the transitional states;

    combining the optical data signal with a side carrier at a single frequency between the two data bands of the optical data signal;

    transmitting, by the transmitter, the combined optical data signal;

    receiving, by a receiver, the combined optical data signal;

    separating, at the receiver, the side carrier from the two data bands of the combined optical data signal;

    increasing an amplitude of the side carrier;

    modulating the side carrier into two shifted side carriers, one of the two shifted carriers being shifted in frequency to the middle of each of the respective two data bands; and

    correcting, at the receiver, for polarization mode dispersion on the combined signal by adjusting a polarization state of each of the two shifted side carriers to match a polarization state of the one of the two data bands at which the respective shifted side carrier is centered.

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