Integrated High-Extinction Ratio Unbalanced Mach Zehnder Interferometers and Integrated Mach Zehnder Interferometers Incroporating Coil Resonators

A photonic integrated circuit forming part of a Mach Zehnder interferometer, the photonic integrated circuit comprising:

• a resonator;
• a first waveguide comprising an optical input at a first port and a delay arm;
• a second waveguide, the second waveguide coupled to the resonator at a first position;
• a first coupler that optically couples the first waveguide to the second waveguide at a second position;
• and
• a second coupler that optically couples the first waveguide to the second waveguide at a third position,
• wherein the waveguide delay arm is positioned between the first coupler and the second coupler.

A photonic integrated circuit forming part of a Mach Zehnder interferometer, the photonic integrated circuit comprising:

• a first waveguide with an optical input at a first port and a delay arm;
• a second waveguide;
• a first coupler that optically couples the first waveguide to the second waveguide at a first position;
• a waveguide coil resonator;
• and
• a second coupler that optically couples the first waveguide to the second waveguide at a second position, the second position different from the first position.