Optical apparatus using polarized orthogonal control

An optical apparatus, comprising:

• a plurality of converting units converting a plurality of electrical signals into a plurality of signal lights, wavelength of the plurality of signal lights being different from each other;
• a plurality of polarization control units controlling polarizing states of the plurality of signal lights and outputting a plurality of polarization controlled lights respectively;
• an optical multiplexer multiplexing the plurality of polarization controlled lights into a multiplexed light;
• an optical branching unit branching the multiplexed light and outputting a branched light;
• a polarizing unit extracting only a signal light of the specified polarizing state from the branched light and outputting an extracted light;
• and
• a control unit detecting intensity of the extracted light and controlling the plurality of polarization control units on the basis of the detection result, wherein;
• the polarization direction of the plurality of polarization control units are modulated by a plurality of pilot signals respectively and the detection of the control unit is based on the plurality of pilot signals.

A method comprising:

• converting a plurality of electrical signals modulated by a plurality of pilot signals respectively to a plurality of signal lights;
• multiplexing the plurality of signal lights into a multiplexed signal light;
• extracting signal lights having a specific polarizing state from the multiplexed signal light and detecting the plurality of pilot signals, and;
• controlling the polarization direction of the plurality of signal lights based on the detected power of the the plurality of pilot signals.

A method comprising:

• generating a plurality of signal lights;
• controlling the polarization state of the plurality of signal lights and modulating the plurality of signal lights with a plurality of pilot signals respectively and outputting a plurality of polarization controlled lights;
• multiplexing the plurality of polarization controlled lights into a multiplexed signal light;
• extracting signal lights having a specific polarizing state from the multiplexed signal light and detecting the plurality of pilot signals, wherein;
• controlling of the polarization direction of the plurality of signal lights are processed based on the detected power of the the plurality of pilot signals.