Abstract: An optical ring resonator-based gyroscope includes a photonic integrated circuit (PIC) chip including a plurality of optical elements, the plurality of optical elements including a resonator ring; and a printed circuit board including a plurality of electrical components, the photonic integrated circuit being mounted on a surface of the printed circuit board, the photonic integrated circuit and the printed circuit board being electrically connected. A photonic integrated circuit (PIC) chip including a substrate; a dielectric layer; a first waveguide layer forming at least: a ring resonator and reflector portions; a second waveguide layer forming at least: vertical Bragg grating couplers disposed over one of the plurality of reflector portions, a chip waveguide; a magneto-optic layer encapsulated in the dielectric layer; and a metal layer forming a plurality of metal connection pads and a plurality of wire traces for electrically connecting the PIC chip to electronic components.

Abstract: Low loss photonic waveguides and ring resonators are necessary for highly accurate gyroscope functionality. For fabrication of these low loss waveguides and ring resonators, an improved and cost-effective fabrication method has been proposed wherein for silicon nitride waveguides, a minimum of 2 ?m thin bottom oxide cladding above etched trenches (cavities) in silicon facilitates both lower losses and higher Q values ring resonators as compared to the conventional 8 ?m thick bottom oxide cladding without etched trenches in silicon. The trenches below the thin bottom oxide cladding are created through xenon difluoride (XeF2) gas etching in selective areas of silicon substrate through vias (openings). After etching the trenches, these vias are filled by the addition of a final top oxide cladding layer. The proposed method provides about three times improvement both in propagation losses as well as in quality factor for side coupled ring resonators.

Abstract: An optical waveguide structure for an optical gyroscope, the structure including a substrate; at least a first silicon nitride waveguide loop and a second silicon nitride waveguide loop connected to the substrate, the first silicon nitride waveguide loop and the second silicon nitride waveguide being disposed at different vertical distances from the substrate; at least one vertical coupler optically coupling the first silicon nitride waveguide loop to the second silicon nitride waveguide; and a plurality of air cavities defined in material below the first and second silicon nitride waveguide loops, no air cavities being defined in regions immediately below a coupling region defined around the at least one vertical coupler.

Abstract: The disclosed structures and methods are directed to a chip for an optical gyroscope and methods of manufacturing the chip for the optical gyroscope. The chip comprises a substrate, a waveguide having a first waveguide cladding layer and a waveguide core; and a ring resonator having a first ring cladding layer and a ring resonator core attached to the first ring cladding layer. A side wall of the ring resonator core forms an obtuse angle with an upper surface of the substrate. The method comprises etching a ring groove and a waveguide groove; placing the optical fiber ring into the ring groove and the optical fiber waveguide into the waveguide groove. The method further comprising splicing two ends of an optical fiber; annealing the ring junction of the optical fiber ring; and attaching the optical fiber waveguide to the waveguide groove and the optical fiber ring into the ring groove.

Abstract: The disclosed structures and methods are directed to a chip for an optical gyroscope and methods of manufacturing of the chip for the optical gyroscope. The chip comprises a substrate, a waveguide having a first waveguide cladding layer and a waveguide core; and a ring resonator having a first ring cladding layer and a ring resonator core attached to the first ring cladding layer. A side wall of the ring resonator core forms an obtuse angle with an upper surface of the substrate. The method comprises depositing a first cladding layer on an upper surface of a silicon substrate; depositing a core layer; depositing a resist mask pattern to define a form of a ring resonator core and a form of a waveguide core; etching the core layer outside of the resist mask pattern; and stripping the resist mask pattern off.