Patent ID: 8090270
Filing Date: 2012-01-03
Classification: H04B,H04J

Abstract:
1. An apparatus comprising: a driver configured to receive a data signal having an original data rate of 2R Gb/s, and separate said data signal into first and second data signals, each of said first and second data signals having a data rate of R Gb/s; a first differential phase shift keying (DPSK) modulator for modulating said first data signal on a first optical signal with a DPSK data modulation to provide a first optical data signal, said first optical signal having a first carrier frequency; a second DPSK modulator for modulating said second data signal on a second optical signal with a DPSK data modulation to provide a second optical data signal, said second optical signal having a second carrier frequency, the absolute value of the difference between the first carrier frequency and the second carrier frequency being approximately an odd number of one-quarter of R GHz; a variable delay element coupled to said second DPSK demodulator configured for imparting a variable delay to said second optical data signal compared to first optical data signal; and a combiner coupled to an output of said first DPSK modulator and an output of said second DPSK modulator and configured for combining said first optical data signal and said second optical data signal into an aggregate signal for coupling to an optical information channel, said first optical data signal being relatively orthogonally polarized relative to said second optical data signal.