Patent ID: 6968132
Filing Date: 2005-11-22
Classification: H04J

Abstract:
1. A method comprising: modulating a first optical signal with a first data stream to produce a first modulated spectrum; applying a propagation delay to each wavelength component of the first modulated spectrum to produce a processed first modulated spectrum having a total signal amplitude that is substantially constant over time, the propagation delay substantially linearly related to wavelength by a first slope; modulating a second optical signal with a second data stream to produce a second modulated spectrum; applying a propagation delay to each wavelength component of the second modulated spectrum to produce a processed second modulated spectrum having a total signal amplitude that is substantially constant over time, the propagation delay substantially linearly related to wavelength by a second slope; combining the processed first modulated spectrum with the processed second modulated spectrum to produce a combined signal; dividing the combined signal into a first portion and a second portion; applying a propagation delay to each wavelength component of the first portion of the combined signal, the propagation delay substantially linearly related to wavelength by a slope that is an inverse of the first slope, to produce a first output signal substantially comprising the first modulated spectrum and a substantially constant offset; and applying a propagation delay to each wavelength component of the second portion of the combined signal, the propagation delay substantially linearly related to wavelength by a slope that is an inverse of the second slope, to produce to produce a second output signal substantially comprising the second modulated spectrum and a substantially constant offset.