Patent application number | Description | Published |
20100033729 | BIAS-INSTABILITY REDUCTION IN FIBER OPTIC GYROSCOPES - A computer-implementable method of reducing bias instability in a fiber optic gyroscope includes receiving, with a computer, a first data set enabling the computer to generate a model of the gyroscope, including a light source, a photodetector, and a plurality of optical components and fiber sections coupling the light source to the photodetector, and a light signal to be propagated from the light source to the photodetector. The light signal has an associated wavelength spectrum. For each wavelength of the spectrum, the relative lightwave intensity reaching the photodetector is calculated. A signal-wave intensity and a spurious-wave intensity are determined from the calculated relative lightwave intensities. A scale factor is determined from the signal-wave intensity. The spurious-wave intensity is integrated over the wavelength spectrum of the light source to obtain a total spurious-wave intensity. A rate bias error is determined based on the total spurious-wave intensity and the scale factor. | 02-11-2010 |
20100073681 | BIAS-REDUCED FIBER OPTIC GYROSCOPE - A fiber optic gyroscope includes a light source, a coupler coupled to the light source, a photodetector coupled to the coupler, an integrated optic circuit (IOC) coupled to the coupler by a first element, and a sensing loop coupled to the IOC by second and third elements. At least one of the first, second and third elements includes a polarizing element. | 03-25-2010 |
20100284018 | SYSTEMS AND METHODS FOR EFFECTIVE RELATIVE INTENSITY NOISE (RIN) SUBTRACTION IN DEPOLARIZED GYROS - Effective relative intensity noise (RIN) subtraction systems and methods for improving ARW performance of a depolarized gyros. This invention taps the RIN detector light in the sensing loop, after the light transmits through the depolarizer and the coil but before it combines with the counter propagating lightwave. The tapped RIN lightwaves are polarized with pass-axis orientated in the same direction as that of the IOC, so that the RIN detector receives lightwaves with spectrum substantially identical to that of the rate detector, leading to more effective RIN subtraction. | 11-11-2010 |
20100316332 | BIAS-INSTABILITY REDUCTION IN FIBER OPTIC GYROSCOPES - Apparatus for providing Bias-Instability reduction in Fiber Optic Gyroscopes are provided. In one embodiment, an optical circuit for a fiber optic gyroscope having a broadband light source and an optical fiber loop comprises: a PM fiber of length v; an IOC coupled to the PM fiber via a pigtail of length d | 12-16-2010 |
20110292951 | FIBER LIGHT SOURCE WITH HIGH MEAN WAVELENGTH STABILITY AND RELIABILITY - A broadband light source configured to emit a stable broadband optical beam is provided. The broadband light source includes at least one optical pump source, an optical system including a polarization beam combiner, and a solid state laser medium. The optical system is configured to receive at least one optical pump beam from a respective one of the at least one optical pump source. The solid state laser medium receives a substantially unpolarized pump beam from a first output of the optical system. Stable broadband amplified spontaneous emission is output from a second output of the optical system. | 12-01-2011 |
20120113432 | CONSTANT OPTICAL POWER SENSOR USING A LIGHT SOURCE CURRENT SERVO COMBINED WITH DIGITAL DEMODULATION INTENSITY SUPPRESSION FOR RADIATION AND VIBRATION INSENSITIVITY IN A FIBER OPTIC GYROSCOPE - Systems and methods for fiber-optic gyroscopes are provided. In one embodiment, a fiber-optic gyroscope comprises: a light source current servo coupled to a light source that transmits light through an optic path, wherein the light source current servo controls intensity of light through the optic path via a light source current drive that supplies current to power the light source; and an intensity control signal processor coupled to the optic path via a photo detector, wherein the intensity control signal processor outputs an intensity control signal to the light source current servo, wherein the intensity control signal is a function of intensity of light as received at the photo detector; wherein the light source current servo compares the intensity control signal against a stable analog voltage reference to adjust the light source current drive and drive optical power at the photo detector towards a constant level. | 05-10-2012 |
20120229811 | HIGH-LINEARITY SIGNAL-PROCESSING AMPLIFIER - A clamp-point active circuit is provided. The clamp-point active circuit includes a rate amplifier configured to receive an output from a device transitioning between at least two levels. The clamp-point active circuit has at least one switching device configured to receive an output from the rate amplifier. The at least one switching device is in at least one respective feedback loop of the rate amplifier. A switching of the at least one switching device causes the rate amplifier to amplify with high linearity in a desired operating range and to clamp outputs received from the transitioning device that are outside the desired operating range to a fixed level. | 09-13-2012 |
20130034329 | MODULAR OPTICAL ASSEMBLY - An assembly includes an optical device including an optical component and a plurality of supporting electrical components, a housing that is configured to house the optical component, a cap that is configured to substantially enclose the optical component in the housing, and a mounting member that is configured to removably electrically and mechanically connect the optical component to a printed board. In some examples, the housing does not house any electrical components of the optical device. The housing is physically separate from the mounting member and is configured to removably mechanically connect to the mounting member. The housing and mounting member define an electrically conductive pathway from the optical component to the printed board. When the cap is mechanically disconnected from the housing, the optical component may be exposed. The cap may also be configured to mechanically and optically connect an optical fiber assembly to the optical component. | 02-07-2013 |
20130044328 | SYSTEMS AND METHODS FOR ENVIRONMENTALLY INSENSITIVE HIGH-PERFORMANCE FIBER-OPTIC GYROSCOPES - Systems and methods for environmentally insensitive high-performance fiber-optic gyroscopes are provided. In one embodiment, a loop closure electronics apparatus for a fiber optic gyroscope having an optical phase modulator characterized by a transfer function that includes an error component of at least second order is provided. The apparatus comprises: a first digital circuit that generates a digital bias modulation signal; a second digital circuit that generates a digital feedback signal; at least one digital-to-analog converter that produces an electrical signal that drives the phase modulator from the digital bias modulation signal and the digital feedback signal; and a compensator that includes an analog filter of at least second order and a digital filter of at least second order, wherein the analog filter and the digital filter pre-filter the electrical signal to compensate for the error component. | 02-21-2013 |
20140168655 | BROADBAND FIBER LIGHT SOURCE WITH HIGH WAVELENGTH STABILITY UNDER RADIATION FOR IFOG APPLICATIONS - A rare-earth-doped-fiber light source with wavelength stability includes a rare-earth doped fiber and an undoped fiber placed in proximity to each other and having the same host material and the same cross-sectional structure, a coupler configured to direct a first portion of pump power from a pump laser to the undoped fiber so the first portion of pump power was twice passed through the coupler; and a wavelength division multiplexer configured to input a second portion of pump power from the pump laser to the rare-earth doped fiber. The rare-earth doped fiber is an active medium for the broadband light source and includes a fiber core doped with rare-earth ions. The undoped fiber includes a rare-earth-dopant-free fiber core. The length of the undoped fiber is one of the same as that of the doped fiber or optimized to match a radiation sensitivity of the doped fiber. | 06-19-2014 |
20140198317 | STABLIZED PUMP LASER WITH OUTPUT REFLECTOR ON POLARIZING OPTICAL FIBER - A laser apparatus comprises a pump laser device, and a polarizing optical fiber having a proximal end and a distal end, with the polarizing optical fiber coupled to the pump laser device at the proximal end. At least one output reflector is written on the polarizing optical fiber toward the distal end. Only one polarization mode is supported when a laser beam is transmitted through the polarizing optical fiber from the pump laser device. | 07-17-2014 |