Devices to mitigate polarization mode dispersion

A device comprising:

• an input coupler having a first differential group delay value;
• a first optical waveguide coupled to the input coupler, the first optical waveguide having a second differential group delay value;
• a rotating component coupled to the first optical waveguide, the rotating component configured to:
• rotate a first polarization mode to a second polarization mode perpendicular to the first polarization mode;
• and rotate the second polarization mode to the first polarization mode;
• the rotating component having a third differential group delay value;
• a second optical waveguide coupled to the rotating component, the second optical waveguide having a fourth differential group delay value;
• and
• one or more of an output and an optical detector coupled to the second optical waveguide,
• the second differential group delay value and the fourth differential group delay value dependent on respective lengths of the first optical waveguide and the second optical waveguide, the respective lengths selected such that a total differential group delay value of the input coupler, the first optical waveguide, the rotating component and the second optical waveguide is one or more of about zero and a given value.

A device comprising:

• an input coupler;
• one or more of an output and an optical detector;
• a first polarization splitter rotator (PSR) in optical communication with the input coupler;
• a second PSR in optical communication with one or more of the output and the optical detector;
• and
• a pair of intermediate optical waveguides that optically couple the first PSR and the second PSR, the pair of intermediate optical waveguides being of different lengths,
• the first PSR configured to:
• split an optical signal from the input coupler into a first portion having a first polarization mode and a second portion having a second polarization mode, perpendicular to the first polarization mode;
• rotate the second polarization mode to the first polarization mode such that both the first portion and the second portion are in the first polarization mode;
• and convey the first portion and the second portion to respective optical waveguides of the pair of intermediate optical waveguides, the different lengths between the pair of intermediate optical waveguides adjusting a differential group delay between the first portion and the second portion,
• the second PSR configured to:
• rotate the first polarization mode of the first portion to the second polarization mode such that the first portion is in the second polarization mode and the second portion is in the first polarization mode;
• combine the first portion and the second portion;
• and output the first portion and the second portion towards one or more of the output and the optical detector.