Abstract: Provided is a swim bladder bionic amphibious optical fiber ocean acoustic sensor, belonging to the field of optical fiber ocean sensors, consisting of a sound sensitive diaphragm, a diaphragm supporting shell, a section of coated optical fiber, a single-hole optical fiber sleeve and a single-mode optical fiber. An upper surface of the supporting shell is provided with two symmetrical overflow holes, and a structure includes a back cavity communicated with the overflow holes. A medium in the back cavity of the sensor may be replaced by inflating, deflating and filling water through the overflow holes, to achieve impedance matching with external environments. When the back cavity is inflated, the sensor serves as a fiber-optic microphone, and when the back cavity is deflated and filled with water, the sensor serves as a fiber-optic hydrophone. The working states could be switched flexibly to achieve a working mode like a swim bladder.

Abstract: A miniaturized PPKTP crystal-based entanglement source system using multi-mode reception is provided, which includes a pump light source, a pump light transmission module, an entanglement device, a first collection device, and a second collection device. In the entanglement source system, entangled lights are received by using multi-mode optical fibers, and an entangled light processing scheme of combining a temporal filtering technology and a spatial filtering technology is applied into a collecting device at one side of the entanglement source system, to form asymmetric device structures in the entanglement source system, to enable multi-mode reception.

Abstract: Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

Abstract: A system and method are provided for optical homodyne detection in an optical fiber interferometer. A detection signal is obtained by interfering an optical data signal with a phase-modulated optical reference signal. The modulator for the optical reference signal is phase-locked to an oscillatory modulation waveform. In embodiments, the modulator includes a piezoelectric element. In more specific embodiments, the modulator is a piezoelectric optical fiber-stretcher.

Abstract: A sensor and method for use in measuring a physical characteristic of a fluid in a microfluidic system is provided. A microfluidic chip has a thin deformable membrane that separates a microfluidic channel from a microwave resonator sensor. The membrane is deformable in response to loading from interaction of the membrane with the fluid. Loading may be fluid pressure in the channel, or shear stress or surface stress resulting from interaction of the membrane with the fluid. The deformation of the membrane changes the permittivity in the region proximate the sensor. A change in permittivity causes a change in the electrical parameters of the sensor, thereby allowing for a characteristic of the fluid, such as flow rate, or a biological or chemical characteristic, to be measured. Also, a microwave sensor with improved sensitivity for characterizing a fluid in a microfluidic channel is provided.

Abstract: The present disclosure relates to systems and methods suitable to measure trace amounts of specific ions in fluid samples. An example system includes a resonator having an input coupler and an output coupler. The example system also includes an ion-selective membrane (ISM) optically coupled to at least a portion of the resonator. The system additionally includes a light source configured to illuminate the resonator by way of the input coupler. Furthermore, the system includes a detector configured to receive output light by way of the output coupler and provide information indicative a concentration of a specific ion proximate to tire ISM.

Abstract: The present invention relates to an optoelectronic device (1) for detection of a target substance dispersed in a fluid (50). The optoelectronic device comprises:—a light source (2) adapted to emit a light radiation (LE) having an adjustable wavelength ?S;—an integrated electronic circuit (100) comprising a photonic circuit (10) operatively coupled to said light source;—a control unit (9) operatively coupled to said light source and to said photonic circuit.

Abstract: A fiber-optic salinity and temperature measurement includes a first Fabry-Perot interferometer and a second Fabry-Perot interferometer. Each of the Fabry-Perot interferometers includes a first optical fiber fusion spliced to a second optical fiber such that a relatively large cavity is formed between the fibers. The relatively large cavity forms the measurement chamber for each Fabry-Perot interferometer. The input port on each of the Fabry-Perot interferometers is coupled to an optical splitter such that a single optical signal input is provided to each Fabry-Perot interferometer. The output port on each of the Fabry-Perot interferometers is coupled to an optical combiner that combines the interference signal received from each of the Fabry-Perot interferometers. An optical signal analyzer coupled to an output port of the optical combiner determines the salinity and temperature of a sample material in the large cavity of the second Fabry-Perot interferometer.

Abstract: A method is provided for fabricating a passive optical sensor on a tip of an optical fiber. The method includes perpendicularly cleaving a tip of an optical fiber and mounting the tip of the optical fiber in a specimen holder of a photosensitive polymer three-dimensional micromachining machine. The method includes forming a three-dimensional microscopic optical structure within the photosensitive polymer that comprises a two cavity Fabry-Perot Interferometer (FPI) having a hinged optical layer that is pivotally coupled to a suspended structure. The method includes removing an uncured portion of the photosensitive polymer using a solvent. The method includes depositing a reflective layer on a mirror surface of the hinged optical layer. The method includes positioning the pivotally hinged optical layer to a closed position with the suspended structure, aligning the mirror surface with the cleaved tip of the optical fiber.

Abstract: A generator, in particular of a wind power installation, for generating electric current, comprising a rotor and a stator having stator teeth and grooves arranged between said stator teeth for receiving at least one stator winding, wherein a measuring device is provided to determine the deflection of at least one stator tooth of the stator in connection with the generator, wherein the measuring device is connected to at least one measuring unit, which is embodied as a strain gauge.

Abstract: A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Abstract: A photonic aerosol particle sensor includes a plurality of photonic waveguide resonators each having a photonic waveguide disposed along a separate waveguide resonator path and each photonic waveguide having a lateral waveguide width different than the waveguide width of other photonic waveguide resonators in the plurality. All waveguides in the plurality of photonic waveguide resonators have a common vertical thickness and are formed of a common photonic waveguide material. An optical input connection couples light into the waveguide resonators. A particle input conveys aerosol particles toward the waveguide resonators and an aerosol particle output conveys aerosol particles away from the waveguide resonators. At least one optical output connection is optically connected to accept light out of the plurality of photonic waveguide resonators to provide a signal indicative of at least one characteristic of the aerosol particles to be analyzed.

Abstract: A method of making passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes forming a three-dimensional microscopic optical structure on a cleaved tip of an optical fiber that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Abstract: A system for measuring pressure, temperature or both includes a diaphragm that responds to a change in temperature or pressure, and a base connected to the diaphragm that has a sapphire element. Between the diaphragm and the base is a cavity. An optical fiber that conducts light reflected off of a surface of the diaphragm is adjacent the cavity. An interrogator is used for detecting a deflection of the diaphragm based on at least two reflected light signals having similar wavelengths and coherence lengths. A quadrature phase detection unit demodulates signals received by the interrogator.

Abstract: Optical detectors and methods of forming them are provided. The detector includes: a controller, pump and probe laser generators that generate modulated pump laser and probe lasers, respectively, a microring cavity that receives the lasers, a microbridge, and a photodetector. The microring cavity includes covered and exposed portions. The microbridge is suspended above the exposed portion and interacts with an evanescent optical field. The wavelength and modulated power of the pump laser are controlled to generate the evanescent optical field that excites the microbridge to resonance. The microbridge absorbs optical radiation which changes the resonance frequency proportionately. The probe laser is modulated in proportion to a vibration amplitude of the microbridge to form a modulated probe laser which is provided to the photodetector.

Abstract: An optical module includes a wavelength variable interference filter having a fixed reflective film, a movable reflective film which faces the fixed reflective film with a gap between reflective films interposed therebetween, and an electrostatic actuator that changes the gap between reflective films, and a gap control unit that controls the electrostatic actuator. The gap control unit controls the electrostatic actuator on the basis of an order which is set in accordance with a wavelength to be measured, and changes the gap between the reflective films.

Abstract: A passive microscopic Fabry-Pérot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Abstract: A power analysis apparatus includes antenna circuitry gathers readings of electromagnetic waves that emanate from a power delivery network of a circuit to be analysed. Spectral analysis circuitry analyses the readings to determine a resonance frequency from said electromagnetic waves and processing circuitry performs one or more actions based on the resonance frequency.

Abstract: An in-line fiber-optic sensing element, a system, and methods for detecting strain using a fiber optic sensor are described that include using at least two chirped grating structures. In an implementation, an in-line fiber-optic sensing element that employs example techniques in accordance with the present disclosure includes an optically transmissive fiber including a core and an outer layer; a Fabry-Perot cavity defined by a portion of the optically transmissive fiber and two chirped fiber-Bragg grating structures, where the two chirped grating structures are separated and are configured to reflect light.

Abstract: Inspecting a multilayer sample. In one example embodiment, a method may receiving, at a beam splitter, light and splitting the light into first and second portions; combining, at the beam splitter, the first portion of the light after being reflected from a multilayer sample and the second portion of the light after being reflected from a reflector; receiving, at a computer-controlled system for analyzing Fabry-Perot fringes, the combined light and spectrally analyzing the combined light to determine a value of a total power impinging a slit of the system for analyzing Fabry-Perot fringes; determining an optical path difference (OPD); recording an interferogram that plots the value versus the OPD for the OPD; performing the previous acts of the method one or more additional times with a different OPD; and using the interferogram for each of the different OPDs to determine the thicknesses and order of the layers of the multilayer sample.

Abstract: A sensor is provided. The sensor includes at least one optical waveguide and an optical reflector. The optical reflector is optically coupled to the at least one optical waveguide and includes a first portion and a second portion. The first portion is configured to reflect a first portion of light back to the at least one optical waveguide. The second portion is configured to reflect a second portion of light back to the at least one optical waveguide. The reflected second portion of the light differs in phase from the reflected first portion of the light by a phase difference that is not substantially equal to an integer multiple of ? when the second portion of the optical reflector is in an equilibrium position in absence of the perturbation.

Abstract: Examples are provided for measuring force applied to a device, such as a stylus tip. An example stylus includes a stylus body, a stylus tip, and the stylus tip including a light emitting device and a compressible light reflecting optic, the light emitting device comprising a light emitter and a light detector, and the compressible light reflecting optic comprising a first reflective layer configured to (i) allow a first portion of light from the light emitting device to pass and (ii) to reflect a second portion of light from the light emitting device, and a second reflective layer, more reflective than the first reflective layer, configured to reflect light from the light emitting device, the first layer being spaced from the second layer by a light-transmissive material. A force exerted on the stylus tip is measurable based at least on a parameter of light received at the light detector.

Abstract: A method, system, and apparatus are disclosed for a ruggedized photonic crystal (PC) sensor packaging. In particular, the present disclosure teaches a ruggedized packaging for a photonic crystal sensor that includes of a hermetic-seal high-temperature jacket and a ferrule that eliminate the exposure of the optical fiber as well as the critical part of the photonic crystal sensor to harsh environments. The disclosed packaging methods enable photonic crystal based sensors to operate in challenging environments where adverse environmental conditions, such as electromagnetic interference (EMI), corrosive fluids, large temperature variations, and strong mechanical vibrations, currently exclude the use of traditional sensor technologies.

Abstract: A guided mode resonance (GMR) sensor assembly and system are provided. The GMR sensor includes a waveguide structure configured for operation at or near one or more leaky modes, a receiver for input light from a source of light onto the waveguide structure to cause one or more leaky TE and TM resonant modes and a detector for changes in one or more of the phase, waveshape and/or magnitude of each of a TE resonance and a TM resonance to permit distinguishing between first and second physical states of said waveguide structure or its immediate environment.

Abstract: Aspects are generally directed to receivers and methods for optically demodulating optical signals. In one example, a receiver includes an optical resonator to receive an optical signal, the optical resonator including an optical medium interposed between first and second semi-reflective surfaces, where the first and second semi-reflective surfaces are positioned to resonate optical signal energy, and the optical resonator is configured to disrupt the optical signal energy resonance responsive to a variation in the received optical signal. The receiver may further include a probe source positioned to provide an optical probe beam to the optical medium, the optical medium being configured to interrupt the optical probe beam during the optical signal energy resonance and to transmit at least a portion of the optical probe beam in response to the disruption of the optical signal energy resonance, and a detector to detect the transmitted portion of the optical probe beam.

Abstract: A system and method includes nano opto-mechanical-fluidic resonators (nano-resonators), e.g., for identification of particles, e.g., single viruses and/or cells.

Abstract: The present invention provides the sensor for measuring the relative sliding between two interfaces based on the principle of EFPI. The sensor comprises two optical fibers and two slopes arranged on the reflective slope. Each surface of the slope is disposed with reflecting surface; and the bottom of each optical fiber is arranged with reflecting end surface. The reflecting surfaces are perpendicular to each of an optical axis of the fiber, thus the Fabry-Perot cavity is formed between reflective end surface and emitting surface to measure the sliding of object B relative to object A in a plane. A fiber and a slope can also be further added to measure the sliding of object B relative to object A in a three dimensional space. The sensor does not affected by the temperature and electromagnetic interference; and has the advantages of high accuracy, strong resisting interference capability and durability.

Abstract: There is provided a device arranged to couple with an electromagnetic source. The device comprises an optical metamaterial arranged to increase the intensity of radiation at a predetermined optical wavelength. The optical metamaterial has a periodic reflective component having a dimension no greater than the predetermined wavelength.

Abstract: A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.

Abstract: Disclosed is detecting changes in pressure in a medium, with an optical fiber having a core diameter at an immersion surface contact of the fiber of less than 10 ?m; a layer of material deposited on said end of the fiber, the material being of a thickness of from about 2 nm to about 10 nm. Also disclosed is detecting pressure waves in a medium comprising: contacting the medium with a fiber optic, the fiber integrated with a light source and a detector, the fiber optic having a diameter of less than 10 ?m at an immersion surface contact of the fiber; providing a thin layer of material on the immersion surface contact, wherein said thin layer of material is of a thickness in a range of from about 2 nm to about 10 nm; and detecting Fresnel back reflections from the immersion end of the fiber.

Abstract: Certain example implementations of the disclosed technology include an optical-interferometer sensor assembly for measuring pressure or acceleration. The sensor assembly includes a diaphragm configured to deflect responsive to an applied stimulus, a diaphragm support structure in communication with the diaphragm, a sensing optical interferometer having a first optical cavity in communication with at least a portion of the diaphragm and the diaphragm support structure, and a reference optical interferometer having a second optical cavity in communication with the diaphragm support structure. The sensor assembly can include a sensing optical fiber in communication with the sensing optical interferometer and a reference optical fiber in communication with the reference optical interferometer. The sensor assembly can include a housing in communication with the diaphragm and the diaphragm support structure, and configured to reduce a thermal expansion mismatch in the sensor assembly.

Abstract: An optical sensor is described for distinguishing between liquids of different refractive index, through strength of interference caused by an optical cavity having an exposed optical boundary in contact with such liquids. The sensor may be used, for example, to distinguish between water and aviation fuel in an aircraft fuel tank.

Abstract: Networks of semiconductor structures with fused insulator coatings and methods of fabricating networks of semiconductor structures with fused insulator coatings are described. In an example, a semiconductor structure includes an insulator network. A plurality of discrete semiconductor nanocrystals is disposed in the insulator network. Each of the plurality of discrete semiconductor nanocrystals is spaced apart from one another by the insulator network.

Abstract: An optical filter includes: a lower substrate; a lower mirror provided to the lower substrate; a lower electrode provided to the lower substrate; an upper substrate disposed so as to be opposed to the lower electrode; an upper mirror provided to the upper substrate, and opposed to the lower mirror; and an upper electrode provided to the upper substrate, and opposed to the lower electrode, wherein the upper substrate has a groove surrounding the upper mirror in a plan view, the groove includes a first side surface section, a second side surface section, a bottom surface section, a first end section located between the first side surface section and the bottom surface section, and a second end section located between the second side surface section and the bottom surface section, in a cross-sectional view, and the first end section and the second end section each have a curved surface.

Abstract: An optical sensor apparatus illuminates nested optical cavities by a broadband light source, such as a tunable laser. A composite interference signal is obtained from light reflected from the nested optical cavities, partial interference spectra are recovered from the composite interference signal, cavity depths are measured based on the partial interference spectra, and electrical signals are provided based on the final measured cavity depths.

Abstract: An electromagnetic waveguide assembly is disclosed, which includes a microresonator and a perturbative member. A gap is between the perturbative member and the nearest surface of the microresonator. The perturbative member is within a range for perturbing the electromagnetic wave supported by the microresonator.

Abstract: The present invention relates to a system for interoperating a full-duplex radio-over-fiber (RoF) network in a fiber-to-the-home (FTTH) network and to a method associated with the system. The system comprises, at the central station (100), a laser diode (105a), a first optical circulator (105b), an optical carrier generating unit (105c), and a second optical circulator (105d). The system comprises, at a base station (101), a third optical circulator (101a) a band pass filter (101b) coupled to the third optical circulator (101a) and configured to select only the optical signal having a corresponding pass band in which is used for converting an uplink signal as a remote local oscillator signal. The unselected optical signal is transmitted as downlink data.

Abstract: A movable substrate of a wavelength variable interference filter includes a movable portion and a groove which is provided outside of the movable portion, in a plan view when the movable substrate is seen from a substrate thickness direction, the groove includes a bottom surface having an even groove depth dimension and a side surface which is continued to the bottom surface, and the side surface is configured with arc-like first curved surface portion and second curved surface portion, in a cross-sectional view when the movable substrate is cut along the substrate thickness direction.

Abstract: A self-referencing composite Fabry-Pérot cavity sensor, including methods of use and manufacture. The cavity sensor comprises a substrate defining a first cavity portion juxtaposed to a second cavity portion. The first and second cavity portions are provided having a predetermined depth offset. A polymer or other dielectric material is disposed within the first and second cavity portions. An interference spectrum resulting from a light source of a known wavelength is reflected through the sensor and produces a first refractive index from the first cavity portion offset by a second refractive index from the second cavity portion. The difference in refractive indices can be used to determine various physical parameters. An optical sensor according to the present technology may be used with vapor sensing, pressure sensing, protein detection, photo-acoustic imaging, and the like.

Abstract: A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.

Abstract: A device and method include a broadband light source in communication with a waveguide to provide a light signal for interrogating each of a plurality for sensors within the waveguide. An analyzer modulates the light signal with a microwave signal and demodulates and evaluates light signals reflected by the sensors. An amplitude and a phase of each reflected signal from each sensor is distinguished in the time domain and the modulated signal is reconstructed in the frequency domain.

Abstract: The present invention is directed to an assembly for use in detecting an analyte in a sample based on thin-film spectral interference. The assembly comprises a waveguide, a monolithic substrate optically coupled to the waveguide, and a thin-film layer directly bonded to the sensing side of the monolithic substrate. The refractive index of the monolithic substrate is higher than the refractive index of the transparent material of the thin-film layer. A spectral interference between the light reflected into the waveguide from a first reflecting surface and a second reflecting surface varies as analyte molecules in a sample bind to the analyte binding molecules coated on the thin-film layer.

Abstract: An optical sensor including a MEMS structure, and a grating coupled resonating structure positioned adjacent to the MEMS structure, the grating coupled resonating structure comprising an interrogating grating coupler configured to direct light towards the MEMS structure. The interrogating grating coupler is two dimensional, and the interrogating grating coupler and the MEMS structure form an optical resonant cavity.

Abstract: 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.

Abstract: 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.

Abstract: A system for sensing downhole pressure in in a hydrocarbon well using a Fabry-Perot (F-P) sensor in series with a Fiber Bragg Grating and maintaining the back pressure on the sensor system with a surface sealing system and a surface pressure control system.

Abstract: An method and apparatus for measuring gravitational force are described where at least one first radiation can be provided to at least one optomechanical oscillator, the at least one optomechanical oscillator being structured to deform under the gravitational force to cause a shift in resonance associated with the at least one optomechanical oscillator. In addition, at least one second radiation is received from the at least one optomechanical oscillator, wherein the at least one second radiation is associated with the shift in the resonance, and the shift in the resonance can be determined based on the first and second radiations.

Abstract: A mass sensor system including multiple Fabry-Perot microcavities connected in parallel by multiple waveguides. Each of the mass sensors includes a microbridge having a fundamental resonance frequency, and a movable reflective mirror etched into the microbridge; a fixed reflective mirror etched in a substrate, the fixed reflective mirror being fixed to the substrate in a region spaced apart from the movable reflective mirror; and an optical waveguide etched in the substrate that connects the movable mirror and the fixed mirror forming the Fabry-Perot microcavity interferometer. The system includes a tunable continuous-wave laser operative to optically interrogate the Fabry-Perot microcavity of each of the plurality of mass sensors, and a receiver operative to receive sensor signals from each of the plurality of mass sensors, the sensor signals comprising reflective signals and transmitted signals.

Abstract: The invention relates to an optical sensor comprising an optical waveguide (1) and a light-sensitive element (4) for detecting light coupled out of the waveguide (1) and also various ring resonators (2), the ring resonators (2) being coupled optically to the mentioned waveguide (1) and, with the exception of at most one of the ring resonators (2), each having a means (5) for adjusting resonance frequencies of the respective ring resonator (2) and/or of the coupling between the ring resonator (2) and the waveguide (1) and at least two of the ring resonators (2) having different optical lengths in an initial state and being disposed for having their resonance frequencies influenced by means of different variables to be measured which are specific for each of these ring resonators (2). The invention refers furthermore to a method which can be implemented with a sensor of this type for detecting molecules of at least one substance.

Abstract: Device and method for acquiring position with a confocal Fabry-Perot interferometer. In a general aspect, the device for acquiring position may include an arrangement for acquiring position where the acquiring arrangement has a confocal Fabry-Perot interferometer. In another general aspect, a method for acquiring position may include generating an interference pattern dependent on a position of an object by a confocal Fabry-Perot interferometer; detecting the interference pattern to obtain a measuring signal; and evaluating the measuring signal.