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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
20120330157 | CONFOCAL MICROSCOPE, SYSTEM AND METHOD THEREFOR - Aspects of the present invention are directed to apparatuses, arrangements, systems and methods for collecting information using one or more modalities. As consistent with one or more embodiments, an apparatus includes first and second scanning mirror arrangements having different scanning axes and respectively facing different directions. The first scanning mirror arrangement directs source light and image light in two paths, and the second scanning mirror arrangement directs image light from a target to the first scanning mirror arrangement. The first and second scanning mirror arrangements cooperatively scan source light from the first scanning mirror and via the second scanning mirror to target locations with at least two degrees of freedom, and direct image light from the target locations. | 12-27-2012 |
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 |
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 |
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 |