Integrated polarimeter in an optical line system

A method of operating a polarimeter comprising:

• receiving input light at a Polarization Maintaining (PM) coupler and splitting the input light to a first output and a second output;
• receiving the first output at a first polarization device coupled to a first PM fiber which is coupled to the PM coupler;
• receiving the second output at a second polarization device coupled to a second PM fiber which is coupled to the PM coupler;
• detecting light with a plurality of detectors coupled to the first polarization device and the second polarization device;
• and
• determining outputs i1, i2, i3, i4 based on outputs of the plurality of detectors, the outputs i1 , i2, i3, i4 are linear projections of corresponding Stokes Parameters of the input light.

A polarimeter comprising:

• a Polarization Maintaining (PM) coupler with an input configured to receive input light and split the input light to a first output and a second output;
• a detector prior to the PM coupled configured to detect total power of the input light;
• a first PM fiber coupled to the first output;
• a second PM fiber coupled to the second output;
• a first polarizer coupled to the first PM fiber;
• a second polarizer coupled to the second PM fiber;
• and
• a first detector coupled to the first polarizer and a second detector coupled to the second polarizer,
• wherein outputs i1, i2, i3, i4 are determined based on outputs of the first detector, the second detector, and the total power, the outputs i1, i2, i3, i4 are linear projections of corresponding Stokes Parameters of the input light.