Disclosed herein are configurations and methods to produce very low loss waveguide structures, which can be single-layer or multi-layer. These waveguide structures can be used as a sensing component of a small-footprint integrated optical gyroscope. By using pure fused silica substrates as both top and bottom cladding around a SiN waveguide core, the propagation loss can be well below 0.1 db/meter. Low-loss waveguide-based gyro coils may be patterned in the shape of a spiral (circular or rectangular or any other shape), that may be distributed among one or more of vertical planes to increase the length of the optical path while avoiding the increased loss caused by intersecting waveguides in the state-of-the-art designs. Low-loss adiabatic tapers may be used for a coil formed in a single layer where an output waveguide crosses the turns of the spiraling coil.

Disclosed herein are configurations and methods to produce very low loss waveguide structures, which can be single-layer or multi-layer. These waveguide structures can be used as a sensing component of a small-footprint integrated optical gyroscope. By using pure fused silica substrates as both top and bottom cladding around a SiN waveguide core, the propagation loss can be well below 0.1 db/meter. Low-loss waveguide-based gyro coils may be patterned in the shape of a spiral (circular or rectangular or any other shape), that may be distributed among one or more of vertical planes to increase the length of the optical path while avoiding the increased loss caused by intersecting waveguides in the state-of-the-art designs. Low-loss adiabatic tapers may be used for a coil formed in a single layer where an output waveguide crosses the turns of the spiraling coil.

A gyroscope and method for navigating using the gyroscope can include a substrate that can define a cavity. The cavity can be placed under a vacuum, and a birefringent microrotor can be located in the cavity. A light source can direct light through the substrate and into the cavity to establish an optical spring effect, which act on the microrotor to establish an initial reference position, as well as to establish rotational and translational motion of said microrotor. A receiver can detect light that has passed through said cavity. Changes in light patterns that can be detected at the receiver can be indicative of a change in position of the microrotor. The change and rate of change in position of the microrotor can be used for inertial navigation.

A gyroscope and method for navigating using the gyroscope can include a substrate that can define a cavity. The cavity can be placed under a vacuum, and a birefringent microrotor can be located in the cavity. A light source can direct light through the substrate and into the cavity to establish an optical spring effect, which act on the microrotor to establish an initial reference position, as well as to establish rotational and translational motion of said microrotor. A receiver can detect light that has passed through said cavity. Changes in light patterns that can be detected at the receiver can be indicative of a change in position of the microrotor. The change and rate of change in position of the microrotor can be used for inertial navigation.

A spherical resolver system includes a spherical body, an outer body, a first sensor coil, a second sensor coil, a third sensor coil, a first primary coil, and a circuit. The spherical body has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The circuit is coupled to the first primary coil and is operable to supply a first alternating current (AC) reference signal (V.sub.r1) to the first primary coil, whereby a first sensor signal (V.sub.x) is selectively induced in the first sensor coil, second sensor signal (V.sub.y) is selectively induced in the second sensor coil, and a third sensor signal (V.sub.z) is selectively induced in the third sensor coil, and supplies one or more signals representative of the sensor position.

A spherical resolver system includes a spherical body, an outer body, a first sensor coil, a second sensor coil, a third sensor coil, a first primary coil, and a circuit. The spherical body has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The circuit is coupled to the first primary coil and is operable to supply a first alternating current (AC) reference signal (V.sub.r1) to the first primary coil, whereby a first sensor signal (V.sub.x) is selectively induced in the first sensor coil, second sensor signal (V.sub.y) is selectively induced in the second sensor coil, and a third sensor signal (V.sub.z) is selectively induced in the third sensor coil, and supplies one or more signals representative of the sensor position.

A spherical resolver system includes a spherical body, an outer body, a first sensor coil, a second sensor coil, a third sensor coil, a first primary coil, and a circuit. The spherical body has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The circuit is coupled to the first primary coil and is operable to supply a first alternating current (AC) reference signal (V.sub.r1) to the first primary coil, whereby a first sensor signal (V.sub.x) is selectively induced in the first sensor coil, second sensor signal (V.sub.y) is selectively induced in the second sensor coil, and a third sensor signal (V.sub.z) is selectively induced in the third sensor coil, and supplies one or more signals representative of the sensor position.

A spherical resolver system includes a spherical body, an outer body, a first sensor coil, a second sensor coil, a third sensor coil, a first primary coil, and a circuit. The spherical body has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The circuit is coupled to the first primary coil and is operable to supply a first alternating current (AC) reference signal (V.sub.r1) to the first primary coil, whereby a first sensor signal (V.sub.x) is selectively induced in the first sensor coil, second sensor signal (V.sub.y) is selectively induced in the second sensor coil, and a third sensor signal (V.sub.z) is selectively induced in the third sensor coil, and supplies one or more signals representative of the sensor position.

An inertial measurement unit includes a sensor and a heat preservation system. The heat preservation system includes a heat preservation body and a heat source. The sensor is positioned on the heat preservation body. The heat source is configured to generate heat. The heat preservation body is configured to transfer the heat from the heat source to the sensor to maintain a preset temperature in a space surrounding the sensor.

An inertial measurement unit includes a sensor and a heat preservation system. The heat preservation system includes a heat preservation body and a heat source. The sensor is positioned on the heat preservation body. The heat source is configured to generate heat. The heat preservation body is configured to transfer the heat from the heat source to the sensor to maintain a preset temperature in a space surrounding the sensor.