Patent application number | Description | Published |
20080204726 | APPARATUS FOR CHARACTERIZING FIBER BRAGG GRATINGS - An apparatus characterizes at least one fiber Bragg grating. The apparatus includes a laser pulse source, an optical spectrum analyzer, and multiple optical paths. A first optical path includes a pulse stretcher and an attenuator. A second optical path optically coupled to the first optical path includes a mirror. A third optical path optically coupled to the first optical path includes a first fiber Bragg grating. A fourth optical path is optically coupled to the second optical path, the third optical path, and the optical spectrum analyzer. A fifth optical path optically coupled to the laser pulse source and the optical spectrum analyzer includes a delay line. | 08-28-2008 |
20080226217 | PHOTONIC CRYSTAL STRUCTURE SENSOR - An acoustic sensor and a method of fabricating an acoustic sensor are provided. The acoustic sensor includes at least one photonic crystal structure and an optical fiber having an end optically coupled to the at least one photonic crystal structure. The acoustic sensor further includes a structural portion mechanically coupled to the at least one photonic crystal structure and to the optical fiber. The at least one photonic crystal structure, the optical fiber, and the structural portion substantially bound a region having a volume such that a frequency response of the acoustic sensor is generally flat in a range of acoustic frequencies. | 09-18-2008 |
20090052829 | OPTICAL DEVICE USING A HOLLOW-CORE PHOTONIC BANDGAP FIBER - An optical device includes a hollow-core photonic-bandgap fiber, wherein at least a portion of the hollow-core photonic-bandgap fiber has a longitudinal axis and is twisted about the longitudinal axis. | 02-26-2009 |
20090059238 | SYSTEM AND METHOD FOR USING SLOW LIGHT IN OPTICAL SENSORS - An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by perturbations to at least a portion of the optical sensor. | 03-05-2009 |
20090175584 | OPTICAL FIBER WITH A CORE RING - An optical fiber includes a cladding with a material having a first refractive index and a pattern of regions formed therein. Each of the regions has a second refractive index lower than the first refractive index. The optical fiber further includes a core region and a core ring having an inner perimeter, an outer perimeter, and a thickness between the inner perimeter and the outer perimeter. The thickness is sized to reduce the number of ring surface modes supported by the core ring. | 07-09-2009 |
20090192769 | METHOD AND APPARATUS FOR MODELING THE MODAL PROPERTIES OF OPTICAL WAVEGUIDES - A method and apparatus models one or more electromagnetic field modes of a waveguide. The method includes calculating a first matrix having a plurality of elements and having a first bandwidth using a refractive index profile of the waveguide. The plurality of elements of the first matrix represents an action of Maxwell's equations on a transverse magnetic field within the waveguide. The method further includes rearranging the plurality of elements of the first matrix to form a second matrix having a second bandwidth smaller than the first bandwidth. The method further includes shifting the second matrix and inverting the shifted second matrix to form a third matrix. The method further includes calculating one or more eigenvalues or eigenvectors of the third matrix corresponding to one or more modes of the waveguide. | 07-30-2009 |
20090195785 | LOW-NOISE FIBER OPTIC SENSOR UTILIZING A LASER SOURCE - A fiber-optic sensor includes an optical fiber coil and a laser source optically coupled to the coil. Light from the source is transmitted to the coil as a first signal propagating along the coil in a first direction and a second signal propagating along the coil in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the coil to generate a third signal. The laser source is frequency-modulated or can have a coherence length longer than a length of the coil. | 08-06-2009 |
20090207401 | APPARATUS FOR CHARACTERIZING FIBER BRAGG GRATINGS - An apparatus characterizes at least one fiber Bragg grating. The apparatus includes a laser pulse source, an optical spectrum analyzer, and multiple optical paths. A first optical path includes a pulse stretcher and an attenuator. A second optical path optically coupled to the first optical path includes a mirror. A third optical path optically coupled to the first optical path includes a first fiber Bragg grating. A fourth optical path is optically coupled to the second optical path, the third optical path, and the optical spectrum analyzer. A fifth optical path optically coupled to the laser pulse source and the optical spectrum analyzer includes a delay line. | 08-20-2009 |
20090207414 | APPARATUS AND METHOD FOR OPTICAL COHERENCE TOMOGRAPHY - An apparatus is provided for measuring a frequency-domain optical coherence tomography power spectrum from a sample. The apparatus includes a broadband light source, an optical spectrum analyzer, and a partially reflective element optically coupled to the light source, to the optical spectrum analyzer, and to the sample. A first portion of light from the light source is reflected by the partially reflective element and propagates to the optical spectrum analyzer. A second portion of light from the light source propagating through the partially reflective element, impinging the sample, reflecting from the sample, and propagating to the optical spectrum analyzer. | 08-20-2009 |
20090208163 | HIGH-SENSITIVITY FIBER-COMPATIBLE OPTICAL ACOUSTIC SENSOR - An acoustic sensor includes at least one photonic crystal structure having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing mechanically coupled to the at least one photonic crystal structure. At least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the housing. | 08-20-2009 |
20090244544 | UNIDIRECTIONAL CROW GYROSCOPE - An optical waveguide gyroscope includes at least one optical coupler configured to receive a first optical signal at a first port, to transmit a second optical signal to a second port, and to transmit a third optical signal to a third port. The optical waveguide gyroscope further includes a plurality of resonant waveguides optically coupled to the second port and the third port. The resonant waveguides are generally adjacent to one another and optically coupled to one another. At least a portion of the second optical signal propagates from the second port to the third port by propagating through the plurality of resonant waveguides, and at least a portion of the third optical signal propagates from the third port to the second port by propagating through the plurality of resonant waveguides. The at least a portion of the second optical signal propagates through each resonant waveguide of the plurality of resonant waveguides in a clockwise direction and the at least a portion of the third optical signal propagates through each resonant waveguide of the plurality of resonant waveguides in a counterclockwise direction. | 10-01-2009 |
20090263090 | MULTIPLE-CORE OPTICAL FIBER WITH COUPLING BETWEEN THE CORES - An optical fiber includes a cladding, a first core, and a second core. At least one of the first core and the second core is hollow and is substantially surrounded by the cladding. At least a portion of the first core is generally parallel to and spaced from at least a portion of the second core. The optical fiber includes a defect substantially surrounded by the cladding, the defect increasing a coupling coefficient between the first core and the second core. | 10-22-2009 |
20100021115 | OPTICAL DEVICE USING A HOLLOW-CORE PHOTONIC-BANDGAP FIBER - An optical device includes a hollow-core photonic-bandgap fiber, wherein at least a portion of the hollow-core photonic-bandgap fiber is adjustably axially twisted. | 01-28-2010 |
20100039649 | OPTICAL SENSOR UTILIZING HOLLOW-CORE PHOTONIC BANDGAP FIBER WITH LOW PHASE THERMAL CONSTANT - An optical sensor includes an optical coupler. The optical sensor further includes a photonic bandgap fiber having a hollow core and an inner cladding generally surrounding the core. The photonic bandgap fiber is in optical communication with the optical coupler. Light signals counterpropagate through the photonic bandgap fiber and return to the optical coupler. The photonic bandgap fiber has a phase thermal constant S less than 8 parts-per-million per degree Celsius. | 02-18-2010 |
20100067827 | OPTICAL IMAGE PROCESSING USING MINIMUM PHASE FUNCTIONS - A method utilizes an optical image processing system. The method includes providing a measured magnitude of the Fourier transform of a complex transmission function of an object or optical image. The method further includes providing an estimated phase term of the Fourier transform of the complex transmission function. The method further includes multiplying the measured magnitude and the estimated phase term to generate an estimated Fourier transform of the complex transmission function. The method further includes calculating an inverse Fourier transform of the estimated Fourier transform, wherein the inverse Fourier transform is a spatial function. The method further includes calculating an estimated complex transmission function by applying at least one constraint to the inverse Fourier transform. | 03-18-2010 |
20100092125 | Optical structure on an optical fiber and method of fabrication - An optical structure on an optical fiber and a method of fabrication is provided. The optical structure includes an end of an optical fiber and a layer formed on the end of the optical fiber. The layer comprises one or more first portions having a first optical pathlength in a direction perpendicular to the layer and one or more second portions having a second optical pathlength in the direction perpendicular to the layer, the second optical pathlength different from the first optical pathlength. | 04-15-2010 |
20100142887 | METHOD OF FABRICATING AN OPTICAL SWITCH - Aa method fabricates an optical switch comprising a microsphere coated with silicon nanocrystals. The method includes providing a silica optical fiber. The method further includes melting at least a portion of the fiber to form at least one silica microsphere. The method further includes coating the microsphere with a silica layer. The method further includes precipitating silicon nanocrystals within the silica layer by annealing the microsphere. The method further includes passivating the nanocrystals by annealing the microsphere in a hydrogen-containing atmosphere. | 06-10-2010 |
20100220332 | FIBER OPTIC SENSOR USING A BRAGG FIBER - An optical sensor includes an optical coupler configured to receive a first optical signal and to split the first optical signal into a second optical signal and a third optical signal. The optical sensor further includes a Bragg fiber in optical communication with the optical coupler. The second optical signal and the third optical signal counterpropagate through the Bragg fiber and return to the third port and the second port, respectively. | 09-02-2010 |
20100220387 | SUPERFLUORESCENT FIBER SOURCE WITH ENHANCED MEAN WAVELENGTH STABILITY - A doped superfluorescent fiber source (SFS) has an enhanced mean wavelength stability. A method stabilizes the mean wavelength of a SFS. The method includes pumping the SFS with pump light from a pump source having a wavelength dependent on the temperature of the pump source and dependent on the power of the pump light. The length of the fiber is selected to compromise between reduction of the dependence of the mean wavelength on the pump light power and reduction of the contribution of the forward amplified spantaneous emission light produced by the fiber to the output light. | 09-02-2010 |
20100296093 | APPARATUS AND METHODS USING HOLLOW-CORE FIBER TAPERS - An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter. | 11-25-2010 |
20100302548 | LASER-DRIVEN OPTICAL GYROSCOPE HAVING A NON-NEGLIGIBLE SOURCE COHERENCE LENGTH - A fiber-optic sensor, a method of configuring a fiber-optic sensor, and a method of using a fiber-optic sensor are provided. The fiber-optic sensor includes an optical fiber coil having a length and a laser source optically coupled to the coil. The laser source has a coherence length. Light from the source is transmitted to the coil as a first signal propagating along the coil in a first direction and a second signal propagating along the coil in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the coil to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters. | 12-02-2010 |
20100309474 | GYROSCOPE UTILIZING MEMS AND OPTICAL SENSING - A gyroscope and a method of detecting rotation are provided. The gyroscope includes a structure configured to be driven to move about a drive axis. The structure is further configured to move about a sense axis in response to a Coriolis force generated by rotation of the structure about a rotational axis while moving about the drive axis. The gyroscope further includes an optical sensor system configured to optically measure movement of the structure about the sense axis. In certain embodiments, the gyroscope is a microelectromechanical system (MEMS) gyroscope. | 12-09-2010 |
20110001981 | FIBER BRAGG GRATING DEVICES UTILIZING SLOW LIGHT - In certain embodiments, an optical device and a method of use is provided. The optical device includes a fiber Bragg grating having a substantially periodic refractive index modulation along a length of the fiber Bragg grating. The fiber Bragg grating has a power transmission spectrum with a plurality of local transmission minima, wherein each pair of neighboring local transmission minima has a local transmission maximum therebetween. The local transmission maximum has a maximum power at a transmission peak wavelength. The optical device further includes a narrowband optical source in optical communication with a first optical path and a second optical path. The narrowband optical source is configured to generate light having a wavelength at or in the vicinity of a local transmission maximum or at or in the vicinity of a wavelength at which the power transmission spectrum has a maximum slope between a local transmission maximum and either one of two local transmission minima neighboring the local transmission maximum. | 01-06-2011 |
20110041616 | ACOUSTIC SENSOR WITH AT LEAST ONE PHOTONIC CRYSTAL SLAB - An acoustic sensor includes at least one structure including at least one photonic crystal slab and an optical fiber optically coupled to the at least one photonic crystal slab, and having at least one optical resonance with a resonance frequency and a resonance lineshape. The acoustic sensor further includes a housing mechanically coupled to the at least one structure. At least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the housing. | 02-24-2011 |
20110088470 | METHOD USING ASYMMETRIC OPTICAL RESONANCES - A method utilizes an optical resonator that includes a reflective element and a spatial mode filter positioned relative to the reflective element such that light emitted from the spatial mode filter is reflected by the reflective element. The optical resonator has an optical resonance with a resonance lineshape that is asymmetric as a function of wavelength. | 04-21-2011 |
20110134432 | SYSTEM AND METHOD FOR USING SLOW LIGHT IN OPTICAL SENSORS - An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by relative movement between the optical waveguide and the at least one optical coupler. | 06-09-2011 |
20110142397 | MULTIPLE-CORE OPTICAL FIBER WITH COUPLINGS BETWEEN THE CORES - An optical fiber includes a cladding, a first core, and a second core. At least one of the first core and the second core is hollow and is substantially surrounded by the cladding. At least a portion of the first core is generally parallel to and spaced from at least a portion of the second core. The optical fiber includes a defect substantially surrounded by the cladding, the defect increasing a coupling coefficient between the first core and the second core. | 06-16-2011 |
20110176140 | LOW-NOISE FIBER-OPTIC SENSOR UTILIZING A LASER SOURCE - A fiber-optic sensor includes an optical fiber coil and a laser source optically coupled to the coil. Light from the source is transmitted to the coil as a first optical signal and a second optical signal counter-propagating through the coil. The optical paths of the first optical signal and the second optical signal are substantially reciprocal with one another and the first optical signal and the second optical signal are combined together after counter-propagating through the coil to generate a third optical signal. The laser source is frequency-modulated or can have a coherence length longer than a length of the coil. | 07-21-2011 |
20110268384 | OPTICAL-FIBER-COMPATIBLE ACOUSTIC SENSOR - An acoustic sensor includes a diaphragm having a reflective element. The sensor has an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element. A first end of the optical fiber and the reflective element form an optical cavity therebetween. The acoustic sensor further includes a structural element mechanically coupled to the diaphragm and the optical fiber. The structural element includes a material having a coefficient of thermal expansion substantially similar to the coefficient of thermal expansion of the optical fiber. For example, the material can be silica. | 11-03-2011 |
20110273712 | APPARATUS AND METHODS USING HOLLOW-CORE FIBER TAPERS - An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter. | 11-10-2011 |
20110317167 | APPARATUS FOR MEASURING A FREQUENCY-DOMAIN OPTICAL COHERENCE TOMOGRAPHY POWER SPECTRUM FROM A SAMPLE - An apparatus is provided for measuring a frequency-domain optical coherence tomography power spectrum from a sample. The apparatus includes a partially reflective element configured to be optically coupled to a light source and to the sample. A first portion of light from the light source is configured to be reflected by the partially reflective element. A second portion of light from the light source is configured to propagate through the partially reflective element, to impinge the sample, and to reflect from the sample. The apparatus is configured to receive the first and second portions of light and to measure the frequency-domain optical coherence tomography power spectrum in response to the first portion of light and the second portion of light. | 12-29-2011 |
20120062902 | FIBER OPTIC SENSOR USING A HOLLOW CORE FIBER - An optical sensor includes at least a portion of an optical waveguide having a hollow core generally surrounded by a cladding. The cladding substantially confines a first optical signal and a second optical signal within the hollow core as the first optical signal and the second optical signal counterpropagate through the optical waveguide. Interference between the first optical signal and the second optical signal is responsive to perturbation of the at least a portion of the optical waveguide. | 03-15-2012 |
20120069346 | METHOD OF USING A UNIDIRECTIONAL CROW GYROSCOPE - A method for detecting rotation includes providing a plurality of resonant waveguides generally adjacent to one another and optically coupled to one another. Each resonant waveguide of the plurality of resonant waveguides is configured to allow light to propagate along the resonant waveguide in a planar path. The method further includes propagating light along each path in a clockwise direction or along each path in a counterclockwise direction. | 03-22-2012 |
20120086934 | SLOW-LIGHT FIBER BRAGG GRATING SENSOR - In certain embodiments, an optical device and a method of use is provided. The optical device can include a fiber Bragg grating and a narrowband optical source. The narrowband optical source can be configured to generate light. A first portion of light can be transmitted along a first optical path extending along and through the length of the fiber Bragg grating at a group velocity. The light can have a wavelength at or in the vicinity of a wavelength at which one or more of the following quantities is at a maximum value: (a) the product of the group index spectrum and a square root of the power transmission spectrum, (b) the slope of a product of the group index spectrum and one minus the power transmission spectrum, and (c) the slope of a product of the group index spectrum and the power transmission spectrum. | 04-12-2012 |
20120099803 | OPTICAL IMAGE PROCESSING USING MAXIMUM OR MINIMUM PHASE FUNCTIONS - A method utilizes an optical image processing system. The method includes calculating a product of (i) a measured magnitude of a Fourier transform of a complex transmission function of an object or optical image and (ii) an estimated phase term of the Fourier transform of the complex transmission function. The method further includes calculating an inverse Fourier transform of the product, wherein the inverse Fourier transform is a spatial function. The method further includes calculating an estimated complex transmission function by applying at least one constraint to the inverse Fourier transform. | 04-26-2012 |
20120141081 | MULTIPLE-CORE OPTICAL FIBER WITH COUPLING BETWEEN THE CORES - An optical fiber includes a cladding, a first core, and a second core. At least one of the first core and the second core is hollow and is substantially surrounded by the cladding. At least a portion of the first core is generally parallel to and spaced from at least a portion of the second core. The optical fiber includes a defect substantially surrounded by the cladding, the defect increasing a coupling coefficient between the first core and the second core. | 06-07-2012 |
20120182557 | METHOD OF DETECTING A TOPOLOGY OF A REFLECTIVE SURFACE - A method detects a topology of a reflective surface. The method includes providing an optical fiber positioned such that light emitted from the optical fiber is reflected by at least a portion of the reflective surface. The optical fiber and the portion of the reflective surface form an optical resonator having an optical resonance with a resonance lineshape. The method further includes emitting light from the optical fiber while the optical fiber is at a plurality of positions along the reflective surface. The light emitted from the optical fiber irradiates a corresponding plurality of portions of the reflective surface. The method further includes measuring a change of the resonance lineshape due to the irradiation of the plurality of portions of the reflective surface. | 07-19-2012 |
20120186353 | ACOUSTIC SENSOR WITH AT LEAST ONE PHOTONIC CRYSTAL STRUCTURE - An acoustic sensor includes at least one photonic crystal structure and an optical fiber in optical communication with the at least one photonic crystal structure. The at least one photonic crystal structure has at least one optical resonance with a resonance frequency and a resonance lineshape, wherein at least one of the resonance frequency and the resonance lineshape is responsive to acoustic waves incident upon the acoustic sensor. The acoustic sensor further includes an optical fiber in optical communication with the at least one photonic crystal structure. The optical fiber is configured to transmit light which impinges the at least one photonic crystal structure and to receive at least a portion of the light which impinges the at least one photonic crystal structure. | 07-26-2012 |
20120213471 | MICRORESONATOR OPTICAL SWITCH HAVING NANOPARTICLES AND METHOD OF OPTICAL SWITCHING - An optical switch includes a microresonator comprising a plurality of silicon nanoparticles within a silicon-rich silicon oxide layer. The microresonator further includes an optical coupler optically coupled to the microresonator and configured to be optically coupled to a pump source and to a signal source. A method of optical switching includes providing an optical switch comprising an optical coupler and a microresonator having a plurality of nanoparticles and receiving an optical pulse by the optical switch, wherein at least a portion of the optical pulse is absorbed by the nanoparticles such that at least a portion of the microresonator undergoes an elevation of temperature and a corresponding refractive index change when the optical pulse has an optical power greater than a predetermined threshold level. | 08-23-2012 |
20120281225 | OPTICAL SENSOR HAVING A NON-NEGLIGIBLE SOURCE COHERENCE LENGTH - An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical waveguide having a length and a laser source optically coupled to the waveguide. The laser source has a coherence length. Light from the source is transmitted to the waveguide as a first signal propagating along the waveguide in a first direction and a second signal propagating along the waveguide in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the waveguide to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters. | 11-08-2012 |
20120281226 | OPTICAL SENSOR USING A HOLLOW CORE WAVEGUIDE - An optical sensor includes at least a portion of an optical waveguide having a hollow core. The optical waveguide substantially confines a first optical signal and a second optical signal within the hollow core as the first optical signal and the second optical signal counterpropagate through the optical waveguide. Interference between the first optical signal and the second optical signal is responsive to perturbation of the at least a portion of the optical waveguide. | 11-08-2012 |
20120281899 | APPARATUS AND METHOD FOR PROCESSING OPTICAL COHERENCE TOMOGRAPHY IMAGING DATA - An apparatus and method process optical coherence tomography (OCT) imaging data from a sample. The method includes using a magnitude spectrum and an estimated phase term of a complex spatial Fourier transform of a complex intermediate function to generate an estimated complex spatial Fourier transform. The method further includes calculating an inverse Fourier transform of the estimated complex spatial Fourier transform and calculating an estimated intermediate function by applying at least one constraint to the inverse Fourier transform. The apparatus includes a partially reflective element configured to reflect a first portion of light and to allow a second portion of light to propagate through the partially reflective element and to reflect from the sample. The apparatus further includes a detector that measures the OCT power spectrum in response to the first and second portions of light. | 11-08-2012 |
20120300214 | GYROSCOPE UTILIZING TORSIONAL SPRINGS AND OPTICAL SENSING - A gyroscope and a method of detecting rotation are provided. The gyroscope includes a structure configured to be driven to move about a drive axis. The structure is further configured to move about a sense axis in response to a Coriolis force generated by rotation of the structure about a rotational axis while moving about the drive axis. The structure further includes at least one first torsional spring extending generally along the drive axis and at least one second torsional spring extending generally along the sense axis. The gyroscope further includes an optical sensor system configured to optically measure movement of the structure about the sense axis. | 11-29-2012 |
20130022307 | OPTICAL SYSTEM HAVING A PHOTONIC CRYSTAL STRUCTURE AND METHOD OF FABRICATION - An optical structure includes an optical waveguide and at least one photonic crystal structure. The optical structure also includes a structural portion mechanically coupled to the optical waveguide and the at least one photonic crystal structure such that a region substantially bounded by the structural portion, the optical waveguide, and the at least one photonic crystal structure has a specified volume. | 01-24-2013 |
20130141729 | METHOD OF DETECTING AN ACCELERATION - A method detects an acceleration. The method includes providing a spatial mode filter positioned such that light emitted from the spatial mode filter is reflected by at least a portion of a reflective surface. The spatial mode filter and the portion of the reflective surface form an optical resonator having an optical resonance with a resonance lineshape. The method further includes emitting light from the spatial mode filter and irradiating the portion of the reflective surface. The portion of the reflective surface is responsive to acceleration of the optical resonator by changing curvature. The method further includes measuring a change of the resonance lineshape due to the acceleration of the optical resonator. | 06-06-2013 |
20130193961 | SYSTEM AND METHOD FOR MEASURING PERTURBATIONS USING A SLOW-LIGHT FIBER BRAGG GRATING SENSOR - An optical device, a method of configuring an optical device, and a method of using a fiber Bragg grating is provided. The optical device includes a fiber Bragg grating, a narrowband optical source, and at least one optical detector. The fiber Bragg grating has a power transmission spectrum as a function of wavelength with one or more resonance peaks, each comprising a local maximum and two non-zero-slope regions with the local maximum therebetween. The light generated by the narrowband optical source has a wavelength at a non-zero-slope region of a resonance peak that is selected such that one or more of the following quantities, evaluated at the resonance peak, is at a maximum value: (a) the product of the group delay spectrum and the power transmission spectrum and (b) the product of the group delay spectrum and one minus the power reflection spectrum. | 08-01-2013 |
20130292555 | APPARATUS AND METHODS UTILIZING OPTICAL SENSORS OPERATING IN THE REFLECTION MODE - Optical apparatus and methods utilizing sensors operating in the reflection mode are provided. The apparatus includes at least one optical bus. The at least one optical bus is configured to be optically coupled to at least one source of input optical signals, to at least one optical detector, and to a plurality of reflective sensing elements. The at least one optical bus transmits an input optical signal from the at least one source to the plurality of reflective sensing elements. At least one reflective sensing element of the plurality of reflective sensing elements receives a portion of the input optical signal and reflects at least a portion of the received portion. The at least one optical bus transmits the reflected portion to the at least one optical detector. | 11-07-2013 |
20130340232 | METHOD OF FABRICATING AN OPTICAL-FIBER-COMPATIBLE SENSOR - A method for fabricating a sensor is provided, with the sensor including a reflective element and an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element and propagates in an optical cavity between the optical fiber and the reflective element. The method includes positioning an element within the optical cavity. The element has a coefficient of thermal expansion and a thickness that compensate a refractive index change with temperature of a medium within the optical cavity. | 12-26-2013 |
20140029011 | OPTICAL SENSOR HAVING A NON-NEGLIGIBLE SOURCE COHERENCE LENGTH - An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical loop having a length and a laser source optically coupled to the loop. The laser source has a coherence length. Light from the source is transmitted to the loop as a first signal and a second signal counterpropagating along the loop. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after counterpropagating through the loop to generate a third signal. A ratio of the coherence length to the length of the loop is greater than 1. | 01-30-2014 |
20140130597 | GYROSCOPE UTILIZING TORSIONAL SPRINGS AND OPTICAL SENSING - A gyroscope and a method of detecting rotation are provided. The gyroscope includes a structure configured to be driven to move about a drive axis. The structure is further configured to move about a sense axis in response to a Coriolis force generated by rotation of the structure about a rotational axis while moving about the drive axis. The structure further includes at least one first torsional spring extending generally along the drive axis and at least one second torsional spring extending generally along the sense axis. The gyroscope further includes an optical sensor system configured to optically measure movement of the structure about the sense axis. | 05-15-2014 |
20140217269 | COUPLED WAVEGUIDES FOR SLOW LIGHT SENSOR APPLICATIONS - An optical device includes at least one optical waveguide including a plurality of elongate portions. Light propagates sequentially and generally along the elongate portions. At least two elongate portions of the plurality of elongate portions are generally planar with one another and are adjacent and generally parallel to one another. The at least two elongate portions are optically coupled to one another such that the light is coupled between the at least two elongate portions in a direction generally perpendicular to the at least two elongate portions as the light propagates generally along the at least two elongate portions. | 08-07-2014 |
20140233884 | METHOD OF OPTICAL SELF-SWITCHING USING MICRORESONATOR OPTICAL SWITCH HAVING NANOPARTICLES - An optical switch includes a microresonator comprising a plurality of silicon nanoparticles within a silicon-rich silicon oxide layer. The microresonator further includes an optical coupler optically coupled to the microresonator and configured to be optically coupled to a signal source. A method of optical switching includes providing an optical switch comprising an optical coupler and a microresonator having a plurality of nanoparticles and receiving an optical pulse by the optical switch, wherein at least a portion of the optical pulse is absorbed by the nanoparticles such that at least a portion of the microresonator undergoes an elevation of temperature and a corresponding refractive index change when the optical pulse has an optical power greater than a predetermined threshold level. | 08-21-2014 |
20140340688 | SLOW-LIGHT SENSOR UTILIZING AN OPTICAL FILTER AND A NARROWBAND OPTICAL SOURCE - An optical device and a method of using an optical filter are provided. The optical device includes an optical filter and a narrowband optical source. The optical filter has a refractive index that varies along a length of the optical filter. The narrowband optical source is in optical communication with the optical filter and is configured to generate light having a wavelength at or in the vicinity of at least one of a wavelength corresponding to a local transmission maximum and a wavelength corresponding to a maximum slop of the group index spectrum of the optical filter. | 11-20-2014 |
20150022818 | LASER-DRIVEN OPTICAL GYROSCOPE WITH PUSH-PULL MODULATION - A system and method for reducing coherent backscattering-induced errors in an optical gyroscope is provided. A first time-dependent phase modulation is applied to a first laser signal and a second phase modulation is applied to a second laser signal. The phase-modulated first laser signal propagates in a first direction through a waveguide coil and the phase-modulated second laser signal propagates in a second direction opposite the first direction through the waveguide coil. The first time-dependent phase modulation is applied to the phase-modulated second laser signal after the phase-modulated second laser signal propagates through the waveguide coil to produce a twice-phase-modulated second laser signal. The second time-dependent phase modulation is applied to the phase-modulated first laser signal after the phase-modulated first laser signal propagates through the waveguide coil to produce a twice-phase-modulated first laser signal. The twice-phase-modulated first and second laser signals are transmitted to a detector. | 01-22-2015 |
20150023633 | SELF-SWITCHING MICRORESONATOR OPTICAL SWITCH - An optical switch includes a microresonator comprising a silicon-rich silicon oxide layer and a plurality of silicon nanoparticles within the silicon-rich silicon oxide layer. The microresonator further includes an optical coupler optically coupled to the microresonator and configured to be optically coupled to a signal source. The microresonator is configured to receive signal light having a signal wavelength, and at least a portion of the microresonator is responsive to the signal light by undergoing a refractive index change at the signal wavelength. The optical switch further includes an optical coupler optically coupled to the microresonator and configured to be optically coupled to a signal source. The optical coupler transmits the signal light from the signal source to the microresonator. | 01-22-2015 |