Optical gyroscopes and methods of manufacturing of optical gyroscopes

A method for fabricating a photonic integrated circuit for a ring resonator optical gyroscope, the method comprising:

• depositing a first dielectric layer to form a bottom waveguide cladding on a substrate;
• depositing a first waveguide material on portions of the first dielectric layer to form a first waveguide core layer, the first waveguide core layer forming:
• a ring resonator, and
• a plurality of lower reflector portions;
• depositing a second dielectric layer over the first waveguide core layer and portions of the first dielectric layer, the second dielectric layer forming a first top cladding for the first waveguide core layer;
• depositing a second waveguide material on portions of the second dielectric layer to form a second waveguide core layer, the second waveguide core layer forming:
• a plurality of vertical Bragg grating couplers, each one of the plurality of vertical Bragg grating couplers being disposed over a corresponding one of the plurality of lower reflector portions, and
• a chip waveguide optically coupling the ring resonator to the plurality of vertical Bragg grating couplers,
• depositing a magneto-optic material on portions of the second waveguide core layer, the magneto-optic material configured to form a permanent magnet generating a magnetic field through at least the second waveguide core layer, a combination of the magneto-optic material and portions of the second waveguide core layer forming at least one optical circulator optically coupled to the chip waveguide;
• and
• depositing a third dielectric layer over the second waveguide core layer, the magneto-optical material, and portions of the second dielectric layer, the third dielectric layer forming a second top cladding layer for the second waveguide core layer.