Patent classifications
G01C19/722
Resonant fiber optical gyroscope using antiresonant nodeless fiber
An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.
Apparatus and method for diminished bias error due to polarization mismatch
Bias error in a resonant fiber optic gyroscope (RFOG) is diminished by reducing polarization mismatch between a polarization Eigenstate of optical signals propagating inside of a resonator of the RFOG and the polarization of optical signals being injected into the resonator of the RFOG. The polarization mismatch is reduced by filtering the optical signals circulating in the resonator and the optical signals injected into the resonator with common polarizers.
Rotation sensor, rotation sensing method, and applications
A chip-scale ultrasensitive ring laser gyroscope that utilizes the physics of exceptional points. By exploiting the properties of such non-Hermitian degeneracies, the rotation-induced frequency splitting becomes proportional to the square root of the gyration speed (.sup.1/2), thus enhancing the sensitivity to low angular rotations by orders of magnitudes. At its maximum sensitivity limit, the measurable spectral splitting is independent of the radius of the cavity rings involved. Binary and ternary systems and associated methods are described.
Systems and methods for reducing polarization-related bias errors in RFOGS
Systems and methods for reducing polarization-related bias errors in RFOGS are described herein. In certain implementations, an RFOG system includes a fiber optic resonator, one or more laser sources, wherein light from the laser sources launches first and second optical beams into the fiber optic resonator in opposite directions, and an electro-optically tunable devices in the resonator path configured to modulate the phase difference between polarization components in the first and second optical beams as the optical beams propagate within the fiber optic resonator. The system further includes at least one photodetector, wherein the polarization components of the first and second optical beams are incident on the photodetector, wherein the at least one photodetector provides an electrical signal, and at least one processing unit configured to receive the electrical signal and calculate a rotation rate for the RFOG and provide a drive signal for the electro-optically tunable device.
MICROELECTROMECHANICAL SYSTEM (MEMS) DEVICE READOUT WITH OPTICAL DIRECTIONAL COUPLER
A microelectromechanical systems (MEMS) device comprises an optical directional coupler comprising: a first waveguide having a first and a second end, wherein a light beam is introduced into the first end; a second waveguide having a third and a fourth end, wherein the light beam is evanescently coupled between the two waveguides in the central region; a first photodetector to detect first optical power in the light beam at the second end; and a second photodetector to detect second optical power in the light beam at the fourth end; a vibrating proof mass adjacent to the coupler in a first direction from the coupler, wherein when inertial forces are applied to the MEMS device in a second direction, the proof mass moves in the first direction; a processor to determine the displacement of the proof mass from the coupler as a function of the first and the second optical power.
APPARATUS AND METHOD FOR DIMINISHED BIAS ERROR DUE TO POLARIZATION MISMATCH
Bias error in a resonant fiber optic gyroscope (RFOG) is diminished by reducing polarization mismatch between a polarization Eigenstate of optical signals propagating inside of a resonator of the RFOG and the polarization of optical signals being injected into the resonator of the RFOG. The polarization mismatch is reduced by filtering the optical signals circulating in the resonator and the optical signals injected into the resonator with common polarizers.
HOLLOW CORE RESONANT FIBER OPTICAL GYROSCOPE
An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.
Etchless acoustic waveguiding in integrated acousto-optic waveguides
An acousto-optic waveguide device comprises a substrate comprising a first material having a first refractive index and a first acoustic velocity; a cladding layer over the substrate, the cladding layer comprising a second material having a second refractive index that is distinct from the first refractive index, the second material having a second acoustic velocity that is distinct from the first acoustic velocity; and an optical core surrounded by the cladding layer, the optical core comprising a third material having a third refractive index that is higher that the first refractive index and the second refractive index, the third material having a third acoustic velocity that is distinct from the first acoustic velocity and the second acoustic velocity. The cladding layer that surrounds the optical core has a thickness configured to substantially confine acoustic waves to the cladding layer when an optical signal propagates through the optical core.
FLANGE-BONDED LOOPBACK FOR FIBER-OPTIC GYROSCOPE (FOG)
One example includes fiber optic gyroscope (FOG) assembly. The FOG assembly includes a spool comprising a flange. The FOG assembly also includes an optical fiber comprising an optical fiber coil portion that is counter-wound in a first orientation and a second orientation opposite the first orientation. The optical fiber portion can be coupled to the flange. The optical fiber further includes a loopback portion with respect to the first orientation that is secured to the flange.
Hollow core fiber pigtail system and method
An interface for a hollow core fiber is provided that facilitates the direct pigtailing of the hollow core fiber to a port on an electro-optic device. The interface includes an angled face that attaches to the electronic device at an angle that minimizes optical power loss as light propagates from the electronic device to the hollow core fiber.