Abstract: Methods and systems of sensing conditions in a fiber includes launching a light beam into a fiber. A first branch of scattered light is set to a mode other than a fundamental mode. A second branch of scattered light is optically filtered to remove unscattered input light. Brillouin scattered light is coherently detected on the first branch to produce a combined temperature/strain profile of the fiber. Raman scattered light on the second branch is directly detected to produce a temperature profile of the fiber. A strain profile of the fiber is determined, using a processor, based on the combined temperature/strain profile and the temperature profile.

Abstract: The present invention relates to an apparatus for measuring concentration of hemoglobin in blood using a photothermal effect, the apparatus including: a reference light source unit for radiating a reference beam; a photothermal light source unit for radiating a photothermal beam from which the photothermal effect is generated; a cuvette unit for accommodating a collected blood sample thereinto and having first and second reflection layers; and a concentration operation unit for calculating the concentration of hemoglobin by using the phase changes of interference signals generated from the incidence of the reference beam radiated from the reference light source unit onto the first and second reflection layers of the cuvette unit as the photothermal beam radiated from the photothermal light source unit is incident onto the cuvette unit and absorbed by hemoglobin to generate the photothermal effect through the emission of heat.

Abstract: A method of evaluating an image blur of an optical film includes displaying a test pattern by driving an organic light-emitting display apparatus including the optical film, obtaining an image by capturing the test pattern using a digital camera, obtaining a spatial luminance distribution from the image, transforming the spatial luminance distribution into a sensation curve, and estimating a blur width from the sensation curve, where the blur width is a distance between peaks having negative minimum values, from among a plurality of peaks of the sensation curve.

Abstract: A method for reconstructing optical properties of a diffracting object immersed in a liquid medium using a reconstruction system that comprises a spatially coherent light source and a matrix photodetector, wherein the liquid medium and the matrix photodetector are separated by a distance along a vertical direction. The method comprises illuminating the liquid medium, measuring (with the matrix photodetector) an intensity of a diffraction pattern transmitted by the illuminated medium along a vertical direction, and reconstructing the optical properties of the diffracting object at a reconstruction height according to a reconstruction algorithm from the measured intensity, wherein the reconstruction height has a value less than that of the distance between the medium and the matrix photodetector along the vertical direction.

Abstract: A ring laser gyroscope (RLG) includes moveable mirrors and a Micro-Electro-Mechanical Systems (MEMS) actuator coupled to the moveable mirrors to cause a respective displacement thereof that induces a phase modulation on counter-propagating light beams relative to one another. The induced phase modulation creates an optical path difference between the counter-propagating light beams corresponding to a virtual rotation that reduces the lock-in of the RLG.

Abstract: A system comprising a fiber optic gyroscope and a mixed signal application specific integrated circuit (ASIC) connected to the gyroscope is provided. The mixed signal ASIC comprises a digital logic unit, a relative intensity noise (RIN) analog-to-digital converter (ADC) coupled to the digital logic unit and configurable to receive a signal from a RIN detector, and a rate ADC coupled to the digital logic unit and configurable to receive a signal from a rate detector. The mixed signal ASIC also includes a light source digital-to-analog converter (DAC) coupled to the digital logic unit, and a thermo-electric cooler DAC coupled to the digital logic unit, both of which are configurable to send control signals to a light source of the gyroscope. The mixed signal ASIC further includes an integrated optical chip DAC, an eigen-frequency servo DAC, and a heater servo DAC, all of which are coupled to the digital logic unit.

Abstract: The present invention relates to a method for controlling a spectrometer for analyzing a product, the spectrometer including a light source including several light-emitting diodes having respective emission spectra covering in combination an analysis wavelength band, the method including steps of: supplying at least one of the light-emitting diodes with a supply current to switch it on, measuring a light intensity emitted by the light source by measuring a current at a terminal of at least another of the light-emitting diodes maintained off, determining, according to each light intensity measurement, a setpoint value of the supply current of each diode that is on, and regulating the supply current of each diode that is on so that it corresponds to the setpoint value.

Abstract: A system and method for determining the position of objects in a radiation room for radiation therapy comprises several room lasers arranged in the radiation room, each of which is designed for patient positioning to project at least one laser line onto the surface of a patient located on a patient table in the radiation room. At least one camera detects at least one laser line projected onto the surface of the patient by at least one of the room lasers, and an evaluation and control apparatus determines the coordinate points along the laser line projected onto the surface of patient during a radiation procedure based on measurement values detected by the camera through a real-time triangulation process and compares them with target coordinate points. The coordinate points determined during the radiation procedure may be saved for documentation of the radiation procedure.

Abstract: A gas sensor is proposed, which can detect a gas by a novel configuration while reduction in size is achieved. The gas sensor (1) does not need a light absorption path as in a prior art so that the size can be reduced correspondingly. Further, in the gas sensor (1), a gas is absorbed in an ionic liquid (IL), and a dielectric constant of the ionic liquid (IL) that changes by absorbing the gas can be measured according to a change in light intensity that occurs by a surface plasmon resonance phenomenon in a metal layer (7). Thus, the gas sensor (1) including the novel configuration that can detect a gas based on the change in the light intensity can be realized.

Abstract: A cable for distributed fiber optic sensing comprising a flexible tape, an optical fiber suitable for Brillouin scattering measurement forming at least two lengths, and at least one free end of at least one length being connectable to a reading unit, wherein at least a section of the longitudinal length of the flexible tape is situated between at least a section of the two lengths such that the two lengths are in close proximity such that a temperature gradient between the two lengths is minimized, and wherein the section of the tape and the section of lengths can flex together.

Abstract: A monitoring system (2) for monitoring the number and/or concentration of particles and/or micro organisms (12, 22) in a fluid (10). The monitoring system (2) generates an alarm if a predefined criterion is met. The monitoring system (2) includes a micro processer (6) which executes programmed instructions in order to identify and classify particles (12), a storage member (8), and an optical sensor member (40) having a 2-D optical sensor (4) and a light source (36). The optical sensor member (40) records an image of a part of the fluid (10) and the monitoring system (2) determines the number and/or concentration of particles (12) in the fluid (10) on the basis of the optical response of single particles (12) in a sample zone (38) in the fluid (10). The fluid (10) in the sample zone (38) is kept stationary relative to the optical sensor member (40) during the image recording.

Abstract: A spectrometer is provided. In one implementation, for example, a spectrometer comprises an excitation source, a focusing lens, a movable mirror, and an actuator assembly. The focusing lens is adapted to focus an incident beam from the excitation source. The actuator assembly is adapted to control the movable mirror to move a focused incident beam across a surface of the sample.

Abstract: The invention concerns an electronic method for extracting the amplitude ES and the phase ?S of an electrical signal in a synchronous detector, the signal containing a modulated part Imod of the form Imod ? ES f(t)*cos(?S??R(t)), where ?R(t) and f(t) are two known temporal modulation functions. The method comprises the following steps: multiplying the signal by two reference signals C(t) and S(t) constructed from ?R(t) and f(t); integrating the resulting signals over a time tint; determining the amplitude and phase of said signal from the quantities X and Y resulting from the previous integrations. The method is characterised in that: said electrical signal is multiplied by C(t) and S(t) that can be decomposed on the same set of frequencies as those present in Imod. The invention also concerns the application of the above method in interferometric circuits and the use and execution of the above method.

Abstract: A method and system for transmitting source light to a plurality of Sagnac interferometers includes a first directional coupler that splits the source light into a second light beam and a third light beam. The second light beam supplies light to a first Sagnac interferometer and the second light beam supplies light to a second directional coupler, and the first directional coupler also delivers light returning from the first Sagnac interferometer to a first detector that is used to indicate rotation of the first Sagnac interferometer. The second directional coupler splits the third light beam into a fourth light beam and a fifth light beam, and the fourth light beam supplies light to a second Sagnac interferometer. The second directional coupler delivers light returning from the second Sagnac interferometer to a second detector, and the second detector provides a signal indicative of rotation of the second Sagnac interferometer.

Abstract: To provide a wavelength tunable light source which can both ensure operation speed and reduce a drive voltage. A wavelength tunable light source according to the present invention includes a pair of reflectors at least one of which is a movable reflector, an active layer provided between the pair of reflectors, and a beam on part of which the movable reflector is formed and which is supported by a support member. The beam includes a blade part projecting between the support member and the movable reflector in a direction intersecting a stretching direction of the beam, and a center of gravity of the beam in the stretching direction is located at a distance less than half a length of the beam in the stretching direction.

Abstract: Disclosed is a method and apparatus for the non-invasive selection of high-quality seeds, based on optical coherence tomography, by which pathogen-infected and pathogen-free seeds can be discriminated in a non-invasive manner. The apparatus is operated by the processes of scanning a seed of diagnostic interest in a non-invasive manner using an optical coherence tomographic unit; processing interference signals of the scanned tomographic images to produce tomographic image data of the seed of diagnostic interest; analyzing the tomographic image data; comparing the analyzed tomographic image data with preset reference tomographic image data; diagnosing the seed of diagnostic interest as a pathogen-infected or pathogen-free seed according to the comparison data; and selecting high-quality seeds according to the diagnosis data. It can screen high-quality seeds with rapidity, convenience, and accuracy at a low cost and is industrially applicable, making a great contribution to agricultural quarantine inspection.

Abstract: Optical-based apparatus and method for sensing parameters in connection with an asset, such as a pipeline, are provided. At least two sites in an optical fiber may include a respective fiber grating arranged to have a respective optical response in a wavelength spectrum having a distinguishing feature indicative of a value of a respective local parameter at a respective grating site. The two fiber gratings may be further arranged to form, in combination with a respective portion of the optical fiber which extends between the two sites, respective optical backscatter portions that when combined with one another are effective to sense an optical change in the fiber portion between the sites indicative of a value of a distributed parameter. This is a parameter modality different from a parameter modality of the respective local parameters at the respective grating sites.

Abstract: A mobile device which senses particulate matter is provided. The mobile device includes a housing having an air flow path through which air flows when the mobile device is shaken; an inertia sensor that detects acceleration of the mobile device; a light-scattering type sensor that irradiates the air flow path with light and detects particulate matter in air flowing through the air flow path; and a controller that includes a counter for counting the particulate matter detected by the light-scattering type sensor, and a flow rate calculator for detecting an air flow rate of the air flow path based on a detection signal of the inertia sensor.

Abstract: A system and method for obtaining multispectral images of fresh meat at predetermined wavelength bands at a first time, subjecting the images to analysis in an image analysis system comprising a computer programmed to perform such analysis, and outputting a forecast of meat tenderness at a later point in time. Predetermined key wavelength bands are precorrelated with a high degree of prediction of meat tenderness and/or other properties of meat and are used in the multispectral system and method. A system and method for determining the key wavelengths is also disclosed. The multispectral imaging system and method is suitable for use in an industrial setting, such as a meat processing plant. The system and method is useful in a method for determining quality and yield grades at or near the time of imaging in lieu of visual inspection with the unaided human eye, increasing efficiency and objectivity.

Abstract: An apparatus for measuring information indicative of electromobility in a sample includes a light source for generating coherent light, a modulator that modulates the optical path length, particularly a reciprocatable modulator arranged for modulating a first part of the generated light, a sample cell for accommodating the measured sample for applying an electric field to the sample and for receiving a second part of the generated light for interaction with the sample in the electric field, a modulator monitor for monitoring the modulator by detecting interference between a first part of the light coming from the modulator and an unmodulated third part of the generated light, and a light detector arranged separately from the modulator monitor for detecting interference between a second part of light coming from the modulator and light received from the sample cell. The detected signal includes the information indicative of electromobility in the sample.