Optical communications with polarization dependent loss compensation

An optical communication system for data transmitting from a transmitter to a receiver over fiber using dual polarization light, comprising:

• a first data controller at the transmitter side;
• the first controller performs a first polarization mixing transformation on a data for a first polarized beam and a data for a second polarized beam;
• the second polarized beam being orthogonal to the first polarized beam;
• a second data controller at the receiver side;
• the second controller performs a second mixing transformation on a received data transmitted in the first polarized beam and a received data transmitted in the second polarized beam;
• this second transformation is performed in an opposite direction to a transmitter transformation with exactly same sequence as in the transmitter part, wherein the data is transmitted in orthogonal frequency division multiplexed (OFDM) format, further comprising a forward error correction (FEC) encoder unit for data encoding at the transmitter side;
• a FEC decoder unit at the receiver side;
• and wherein FEC block is longer than polarization correlation time;
• further comprising an interleaver at the transmitter side;
• and a de-inverleaver at the receiver side;
• and wherein for the signal at rate R bit/sec, FEC block length of N bit and interleaving depth of M, the polarization correlation time T is T<=2*N*M/R.