Patent ID: 8064767
Filing Date: 2011-11-22
Classification: G02B,H04B,H04J

Abstract:
1. An optical receiver, comprising: a polarization beam splitter for receiving a polarization multiplexed optical beam with data encoded using orthogonal frequency division multiplexed (OFDM) format and splitting it into a first and a second beam; a first optical hybrid for receiving the first beam and a first local oscillator beam; a first set of photodetectors receiving output beams from the first optical hybrid and producing electrical signals; a digital signal processing unit receiving the electrical signals, converting them into digital signals, transforming the digital signals into frequency domain, forming a set of spectral subcarriers each having its own digital frequency, recovering the polarization state of each spectral subcarrier, demodulating the encoded data, and outputting an information encoded in the optical beam with data; wherein recovering the polarization of each spectral subcarrier comprises estimating the Jones Matrix for each sub-carrier frequency when the link starts operation and periodically during the receiver operation, and comparing the received signals with the ones expected with a current Jones Matrix and updating the Jones Matrix during receiver operation so to result in mitigation of PMD and improved system performance.