Patent ID: 8412047
Filing Date: 2013-04-02
Classification: H04B,H04J

Abstract:
1. A polarization multiplexed light transmitter which transmits a polarization multiplexed light containing a first optical signal and a second optical signal of which polarization states are mutually orthogonal, comprising: a delay regulating unit configured to regulate relative delay times of the first and second optical signals; a delay control unit configured to make orthogonal polarization components contained in a monitor light obtained by taking out a part of the polarization multiplexed light to interfere with each other, to generate a polarization interfering light, and configured to judge a delay time between the first and second optical signals based on a change in a state of an electric signal obtained by photo-electrically converting the polarization interfering light, and configured to control a regulation amount in the delay regulating unit so that the judged delay time reaches a predetermined value; a polarization separating section that separates an output light from a light source section into two lights having polarization states which are mutually orthogonal; a first optical modulating section that modulates one of the lights separated by the polarization separating section to generate the first optical signal; a first modulation driving section that generates a first modulation signal for driving the first optical modulating section; a second optical modulating section that modulates the other light separated by the polarization separating section to generate the second optical signal; a second modulation driving section that generates a second modulation signal for driving the second optical modulating section; and a polarization combining section that combines the first and second optical signals generated by the first and second optical modulating section into one light, wherein the delay regulating unit makes relative delay times of the first and second modulation signals output from the first and second modulation driving sections to be variable, and the delay control unit comprises: