Polarization multiplexing optical transmission system, polarization multiplexing optical receiver and polarization multiplexing optical transmission method

A polarization multiplexing optical receiver, comprising:

• a polarization splitting unit
• receiving a polarization multiplexed light obtained by multiplexing a first polarized transmission light and a second polarized transmission light which are modulated according to a first input signal and a second input signal including respective identifier to differentiate between the first input signal and the second input signal, and
• splitting the polarization multiplexed light into a first polarized received light and a second polarized received light;
• a pair of photoelectric conversion units converting the first polarized received light and the second polarized received light into respective electric signals and outputting a first received signal and a second received signal;
• a demodulation unit performing symbol recognition about the first received signal and the second received signal, and outputting a first demodulated signal and a second demodulated signal;
• an identifier detecting unit detecting the identifiers from the first demodulated signal and the second demodulated signal;
• and
• a delay compensation unit calculating a delay difference between the first demodulated signal and the second demodulated signal based on the identifiers, and inserting delay time corresponding to the delay difference into the first demodulated signal or the second demodulated signal.

A polarization multiplexing optical transmission method, comprising the steps of:

• adding identifiers to a first input signal and a second input signal, respectively, so as to differentiate between the first input signal and the second input signal;
• modulating a first polarization light according to the first input signal, and outputting a first polarized transmission light;
• modulating a second polarization light according to the second input signal, and outputting a second polarized transmission light;
• multiplexing the first polarized transmission light and the second polarized transmission light to obtain a polarization multiplexed light;
• splitting the polarization multiplexed light into a first polarized received light and a second polarized received light;
• converting the first polarized received light and the second polarized received light into respective electric signals and outputting a first received signal and a second received signal;
• performing symbol recognition about the first received signal and the second received signal, and forming a first demodulated signal and a second demodulated signal;
• detecting the identifiers from the first demodulated signal and the second demodulated signal;
• and
• calculating a delay difference between the first demodulated signal and the second demodulated signal based on the identifiers, and inserting delay time corresponding to the delay difference into the first demodulated signal or the second demodulated signal.