Patent ID: 6634808
Filing Date: 2003-10-21
Classification: H04B,H04J

Abstract:
A method for transmitting at least one first and one second data signal in polarization division multiplex in an optical transmission system, the method comprising the steps of:generating a first modulated signal at a transmitting end by modulating a first carrier signal with the first data signal; generating a second modulated signal by modulating a second carrier signal, which differs from the first carrier signal by a differential frequency, with the second data signal; polarizing the first and second modulated signals orthogonally with respect to one another; combining the polarized signals to form an optical multiplex signal; transmitting the optical multiplex signal; conducting the optical multiplex signal at a receiving end, via a polarization control element to a polarization splitter; splitting the optical multiplex signal, via the polarization splitter, into the first and second modulated signals; converting the first modulated signal into a first electrical signal; converting the second modulated signal into a second electrical signal; determining a spectral component of at least one of the first and the second electrical signals at the differential frequency; and deriving from the spectral component at least one control signal for controlling the polarization control element.