Patent ID: 7715730
Filing Date: 2010-05-11
Classification: G02B,H04J

Abstract:
1. A method for optical transmission of a polarization division multiplexed signal having two orthogonal polarized optical data signals whose first carrier signal and second orthogonal carrier signal respectively have the same wavelengths and are modulated by data signals, comprising: shifting the phase of the first carrier signal and the second carrier orthogonal signal so that the first carrier signal and second orthogonal carrier signal of said two orthogonal polarized optical data signals are phase shifted 90° relative to one another, wherein the phase difference between the carrier signals is controlled, and wherein that to obtain a phase control criterion the circular polarization component of the polarization division multiplexed signal is measured to provide a control signal; tapping off a measurement signal from the polarization division multiplexed signal; and splitting the tapped measurement signal into two identical signal components, one of which is converted directly into a first electrical sub-signal, the other is first fed via a λ/14 plate tuned to the wavelength of the carrier signals and a polarization filter and then converted into a second electrical sub-signal, wherein the two signal components are compared with one another to obtain a control signal, and wherein the phase between the carrier signals is varied so that electrical sub-signals have the same values.