Abstract: A system for spectral reading includes a plurality of LEDs, an interface, and a processor. The plurality of LEDs are disposed in a physical array. Light from the plurality of LEDs is enabled to be collimated at a Fabry-Perot etalon. The interface is configured to receive a gap calibration table and power characteristics of a plurality of LEDs. The processor is configured to determine an LED switch table. The LED switch table indicates a set of the plurality of LEDs with power above a threshold at a plurality of wavelengths. The processor is further configured to cause measurement of a sample using the gap calibration table and the LED switch table for a set of gap values and determine measurement results.

Abstract: According to an aspect of one or more embodiments, a system for inspecting a slab of material may include a single mode optical fiber, a broadband light source configured to emit light over the optical fiber, a beam assembly configured to receive the light over the optical fiber and direct the light toward a slab of material, a computer-controlled etalon filter configured to receive the light over the optical fiber either before the light is directed toward the slab of material or after the light has been reflected from or transmitted through the slab of material, filter the light, and direct the light over the optical fiber, and a computer-controlled spectrometer configured to receive the light over the optical fiber after the light has been filtered by the etalon filter and after the light has been reflected from or transmitted through the slab of material and spectrally analyze the light.

Abstract: An image pickup apparatus is an image pickup apparatus capable of acquiring an image of an object in gas and in liquid, the image pickup apparatus including: an image pickup optical system; an image pickup device; a controlling portion configured to make an in-gas judgment if a vignetting portion is detected in an image signal and make an in-liquid judgment if a vignetting portion is not detected in the image signal; and a display data generating portion configured to generate certain display data corresponding to in-gas image pickup if the in-gas judgment is made and generate other display data corresponding to in-liquid image pickup if the in-liquid judgment is made.

Abstract: An interferometer system comprising an optical detector including a substrate and a two-dimensional array of pixels disposed on the substrate is provided. The interferometer system may further comprise an interferometer disposed proximate the optical detector without an optical element between the interferometer and the optical detector. The interferometer may include a first plate positioned proximate the substrate and extending over the two-dimensional array of pixels, a second plate spaced apart from the first plate, the first and second plates defining an optical gap between them, and at least one actuatable spacer positioned between the first plate and the second plate and configured to space apart the first and second plates from one another and to selectively alter a thickness of the optical gap.

Abstract: A metrology system includes an optical frequency separation apparatus in the path of the pulsed light beam and configured to interact with the pulsed light beam and output a plurality of spatial components that correspond to the spectral components of the pulsed light beam; a plurality of sensing regions that receive and sense the output spatial components; and a control system connected to an output of each sensing region. The control system is configured to: measure, for each sensing region output, a property of the output spatial components from the optical frequency separation apparatus for one or more pulses; analyze the measured properties including averaging the measured properties to calculate an estimate of the spectral feature of the pulsed light beam; and determine whether the estimated spectral feature of the pulsed light beam is within an acceptable range of values of spectral features.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.

Abstract: A spectrometer (10) for gas analysis is provided, the spectrometer comprising a measurement cell (28) having a gas to be investigated, a light source (12) for the transmission of light (14) into the measurement cell (28) on a light path (16), a filter arrangement (22) having a Fabry-Perot filter (24a-c) in the light path (16), in order to set frequency properties of the light (14) by means of a transmission spectrum of the filter arrangement (22), as well as a detector (36, 38) which measures the absorption of the light (14) by the gas (30) in the measurement cell (28). In this connection the filter arrangement (22) has a plurality of Fabry-Perot filters (24a-c) arranged behind one another in the light path (14) and a control unit (44) for the filter arrangement (22) is provided in order to change the transmission spectrum by setting at least one of the Fabry-Perot filters (24a-c).

Abstract: An etalon is provided with a fixed substrate and a movable substrate opposed to the fixed substrate. The fixed substrate is provided with a first bonding surface to be bonded to the movable substrate via a bonding film and a first electrode surface on which a part of the first electrode is formed. The movable substrate is provided with a second bonding surface to be bonded to the first bonding surface via the bonding film and a second electrode surface on which a part of the second electrode is formed. In the state in which the fixed substrate and the movable substrate are bonded to each other with the bonding film, the first electrode formed on the first electrode surface and the second electrode formed on the second electrode surface have contact with each other.

Abstract: A system for scanning light to define a range gated signal includes a pulsed coherent light source that directs light into the atmosphere, a light gathering instrument that receives the light modified by atmospheric backscatter and transfers the light onto an image plane, a scanner that scans collimated light from the image plane to form a range gated signal from the light modified by atmospheric backscatter, a control circuit that coordinates timing of a scan rate of the scanner and a pulse rate of the pulsed coherent light source so that the range gated signal is formed according to a desired range gate, an optical device onto which an image of the range gated signal is scanned, and an interferometer to which the image of the range gated signal is directed by the optical device. The interferometer is configured to modify the image according to a desired analysis.

Abstract: A spatial Fourier transform spectrometer is disclosed. The Fourier transform spectrometer includes a Fabry-Perot interferometer with first and second optical surfaces. The gap between the first and second optical surfaces spatially varies in a direction that is orthogonal to the optical axis of the Fourier transform spectrometer. The Fabry-Perot interferometer creates an interference pattern from input light. An image of the interference pattern is captured by a detector, which is communicatively coupled to a processor. The processor is configured to process the interference pattern image to determine information about the spectral content of the input light.

Abstract: An optical measuring system determines coordinates of points for distance measurement. The measuring system includes a radiation source for emitting electromagnetic radiation and a receiving unit having a filter unit for extracting electromagnetic radiation in a defined wavelength range and having, a detector, such that the radiation extracted by the filter unit is detectable by the detector. The filter unit includes at least two mirror elements which are at least partly reflective and constructed in a multilayered fashion. The mirror elements are substantially parallel to one another. Two adjacent mirror elements in each case enclose a cavity and are arranged at a specific distance from one another. An optical thickness is defined by a refractive index of the cavity and by the distance between the mirror elements. Optical thickness varying means operate to varying the optical thickness, such that an extractable wavelength range of the filter unit is varied.

Abstract: The invention relates to a system and a method for optical measurement of a target, wherein the target is illuminated, either actively illuminated, reflecting ambient light, or self illuminating, and a measurement light beam received from the target or through it is detected. The prior art optical measurement systems generally include mechanical filter wheels and photomultiplier tubes, which cause the equipment to be expensive, large-sized and often not sufficiently accurate and stable. The objective of the invention is achieved with a solution, in which the illuminating light beam and/or measurement light beam is led through a Fabry-Perot interferometeror a set of two or more Fabry-Perot Interferometers, and the Fabry-Perot interferometer or a set of two or more Fabry-Perot Interferometersis controlled into different modes during the measurement of a single target. The invention can be applied inoptical measurements where, for example, reflectance, absorption of fluorescence of the target is measured.

Abstract: A spectrometer includes: a tungsten lamp which emits light with no peak wavelength within a wavelength range of visible light and having a light amount increasing as the wavelength becomes longer; a violet LED which emits light having a peak wavelength within the wavelength range of visible light; a light mixer which mixes light emitted from the tungsten lamp and the violet LED; an etalon which receives light mixed by the light mixer and transmits light contained in the received mixed light and having a particular wavelength; a light receiving unit which receives light transmitted by the etalon; and a measurement control unit which changes the wavelength of light that can pass through the etalon and measures spectral characteristics of the light having passed through the etalon based on the light received by the light receiving unit.

Abstract: An image acquiring device comprises a first camera 14 for acquiring video images, consisting of frame images continuous in time series, a second camera 15 being in a known relation with the first camera and used for acquiring two or more optical spectral images of an object to be measured, and an image pickup control device 21, and in the image acquiring device, the image pickup control device is configured to extract two or more feature points from one of the frame images, to sequentially specify the feature points in the frame images continuous in time series, to perform image matching between the frame images regarding the frame images corresponding to the two or more optical spectral images based on the feature points, and to synthesize the two or more optical spectral images according to the condition obtained by the image matching.

Abstract: In an interrogation system for multiple wavelength interferometers a fringe spectrum that includes non-quadrature-spaced radiation-intensity samples is analyzed to obtain a high resolution relative phase measurement of the optical path-length difference associated with the fringe spectrum. The fringe spectrum can be analyzed to obtain a fringe number and a quadrant as well, which can be combined with the relative phase measurement to obtain a high precision measurement of the absolute optical path-length difference. An environmental condition corresponding to the absolute optical path-length difference can be measured using the measurement of the absolute optical path-length difference.

Abstract: A spectrometer with improved resolution includes a spectral domain modulator having a periodic response in the spectral domain to modulate a wideband source spectrum and cause one or more shifted bursts in the interferogram.

Abstract: A thermal sensor includes an array of pixels, each having a membrane mounted on legs over a reflector, forming a Fabry-Pérot cavity. Each membrane includes an infrared (IR) absorbing material that defines multiple spaced-apart openings separated by micron-level distances that decrease thermal capacity and increase IR absorption of the membrane. Regular pitch distances between adjacent openings provides narrowband IR absorption, with pitch distances below 7.1 ?m facilitating the detection of IR radiation wavelengths below 7.5 ?m. Multispectral thermal imaging is achieved by arranging the pixels in repeated groups (superpixels), where each superpixel detects the same set of IR radiation wavelengths. Thermal imaging devices include thermal sensors, IR lenses and device control circuitry arranged in a camera-like manner.

Abstract: A system includes: a splitter to branch an optical signal output by a wavelength-tunable light source into first to third optical signals; a first photodiode to perform an optical electrical conversion of the first optical signal transmitting a first etalon; a second photodiode to perform an optical electrical conversion of the second optical signal transmitting a second etalon, an FSR of the second etalon being identical to that of the first etalon, peak wavelengths of intensity of a transmitted light of the second etalon being different from those of the first etalon; a third photodiode to perform an optical electrical conversion of the third optical signal; and a controller to control the wavelength-tunable light source with use of a coefficient calculated by following formulas (1) or (2), Coefficient=(PD1?A·PD3)/(PD2?B·PD3) (1) and Coefficient=(PD2?B·PD3)/(PD1?A·PD3) (2).

Abstract: A optical module includes, a wavelength variable interference filter which include reflection films opposite to each other and an electrostatic actuator portion including a first electrostatic actuator and a second electrostatic actuator and changing a gap between the reflection films, and a voltage control portion which controls voltage which is applied to the electrostatic actuator portion, the voltage control portion includes, a bias driving portion which applies bias voltage to the first electrostatic actuator, a gap detector, and a feedback control portion which applies feedback voltage corresponding to a detected gap amount to the second electrostatic actuator.

Abstract: An “integrated” Fabry-Perot interferometer, such as for use in a spectrophotometer, is fabricated by attaching two micro-machined semiconductor-on-insulator wafers to one another. One mirror is formed on each micro-machined wafer. One mirror is supported by a thermally insulated, suspended micro-platform. In some embodiments, interferometer cavity length is adjustable. Detectors are disposed at least partially within the micro-platform. In some embodiments, the interferometer, a light source, and other circuitry and components, such as wireless communications components, are contained in a sealed package that includes a sampling region, thereby providing an integrated spectrophotometer. The integrated spectrophotometer can be implanted, for example, in animal tissue environments, such as for analyzing various compounds in the blood.

Abstract: A variable wavelength interference filter includes a first substrate having a stationary mirror, a second substrate bonded to the first substrate and provided with a movable section and a movable mirror fixed to the movable section, and a third substrate bonded to the second substrate on an opposite side to the first substrate, and is provided with a first inner space sandwiched by the first substrate and the second substrate, a first gap, through which the first inner space communicates with the outside, a second inner space sandwiched by the second substrate and the third substrate, and a second gap, through which the second inner space communicates with the outside, and the first gap and the second gap are each sealed by a sealing member.

Abstract: An image sensor includes a semiconductor substrate integrated with at least one first photo-sensing device configured to sense light in a blue wavelength region and at least one second photo-sensing device configured to sense light in a red wavelength region, a color filter layer on the semiconductor substrate and including a blue color filter configured to selectively absorb light in a blue wavelength region and a red color filter configured to selectively absorb light in a red wavelength region, and a third photo-sensing device on the color filter layer and including a pair of electrodes facing each other, and a photoactive layer between the pair of electrodes and configured to selectively absorb light in a green wavelength region.

Abstract: An interference filter includes first and second reflecting films opposed to each other across a gap, the first and second reflecting films include an Ag—Sm—Cu alloy film or an Ag—Bi—Nd alloy film, the Ag—Sm—Cu alloy film includes 0.1 atomic %?Sm?0.5 atomic %, and 0.1 atomic %?Cu and ?0.5 atomic %, and Sm+Cu?1.0 atomic %, the Ag—Bi—Nd alloy film includes 0.1 atomic %?Bi?3.0 atomic %, and 0.1 atomic %?Nd?5.0 atomic %, and the thickness of the Ag—Sm—Cu alloy film or the Ag—Bi—Nd alloy film is ?10 nm and ?40 nm.

Abstract: A method is provided for using a single-pixel imager in order to spatially reconstruct an image of a scene. The method can comprise the following: configuring a light filtering device including an array of imaging elements to a spatially varying optical filtering process of incoming light according to a series of spatial patterns corresponding to sampling functions. The light filtering device can be a transmissive filter including a first membrane, a second membrane, and a variable gap therebetween. The method further comprises tuning a controller for manipulating a variable dimension of the gap; and, measuring, using a photodetector of the single-pixel imager, a magnitude of an intensity of the filtered light across pixel locations in the series of spatial patterns. The magnitude of the intensity can be equivalent to an integral value of the scene across the pixel locations.

Abstract: The present invention relates to an actuator for moving a rigid element, e.g. an optical element such as mirror (1), the element being mechanically coupled to a frame (4) with a bendable coupling (2A), wherein actuator elements (3A, 3B) are mounted on said coupling between the frame and element, the coupling and actuator elements being adapted to provide a movement to the element when subject to signal from a signal generator.

Abstract: Disclosed is a Natural Light Interferometer. The interferometer measures the amplitude and phase distribution of a coherent or incoherent electromagnetic signal, including natural light. In principle, the amplitude and phase distribution of any signal of any wavelength, incoherent or coherent, may be measured using this technique. The corresponding image may be reconstructed as well. The interferometer exploits Fourier transform heterodyne techniques but extends this technology to incoherent signals. The interferometer generates the analyzing signal by exploiting nanotechnology-based signal generation stimulated by the original signal. The Natural Light Interferometer applications include surveillance and reconnaissance; metrology; space-based free-flying, tethered or rigid interferometer arrays; and ground-based sparse interferometer arrays. There is also disclosed a homodyne embodiment of the Natural Light Interferometer that exploits quadrature phase techniques.

Abstract: An Etalon filter includes a first substrate, a second substrate which faces the first substrate, a first optical film which is provided on the first substrate, and a second optical film which is provided on the second substrate to face the first optical film. The reflective characteristic of the first optical film determined by the reflectance of light of each wavelength in a reflective band is different from the reflective characteristic of the second optical film determined by the reflectance of light of each wavelength in the reflective band. The first optical film can have a reflective characteristic with a first wavelength ?1 as a center wavelength, and the second optical film can have a reflective characteristic with a second wavelength ?2 different from the first wavelength as a center wavelength.

Abstract: Sensor material is arranged to interact with input light and to asymmetrically alter a spectral distribution of the input light in response to presence of an external stimulus. A detector is configured to sense the altered input light and to generate at least one electrical signal comprising information about a shift in the centroid of a spectral distribution of the altered input light relative to a centroid of the spectral distribution of the input light.

Abstract: A measuring apparatus includes an optical frequency comb source configured to emit an optical frequency comb in which a plurality of frequency components are arranged at equal frequency intervals, a beam splitter configured to split a beam emitted from the optical frequency comb source into a test beam to be irradiated onto a test surface and a reference beam to be irradiated onto a reference surface, an optical path difference changing element configured to change an optical path difference between the reference beam and the test beam, an image sensor configured to capture an interference pattern formed by interference between the test beam and the reference beam, and an analyzer configured to calculate a position of the test surface based upon a signal of the interference pattern captured while the optical path length difference is being changed by the optical path difference changing element.

Abstract: A tunable interference filter includes: first and second opposed substrates; a first reflection film provided on a first reflection film fixing surface of the first substrate; a second reflection film provided on a second reflection film fixing surface of the second substrate and separated from the first reflection film by a gap; and a first electrode provided on a first electrode surface of the first substrate facing the second substrate, wherein the first electrode surface is spaced apart from the second substrate by a different distance than the first reflection film fixing surface, and a layered part in which the first reflection film and the first electrode are stacked is provided on the first electrode surface, the layered part being spaced apart from the second substrate by a larger distance than the first reflection film fixing surface.

Abstract: A spectroscopic measurement apparatus includes a wavelength tunable interference filter that selects light of a predetermined wavelength from incident light, allows the selected light to exit, and is capable of changing the wavelength of the light that is allowed to exit, a light dividing element that divides the exiting light having exited out of the wavelength tunable interference filter into a plurality of light fluxes, and a first light receiving device and a second light receiving device that are provided in correspondence with the plurality of divided light fluxes divided by the light dividing element and have sensitivities different from each other.

Abstract: A spectral encoder includes a thin layer of lossy dielectric material whose thickness varies transversely from 0 to a thickness of about ?/4n (e.g., <100 nm), where ? is the wavelength of incident radiation and n is the dielectric material's refractive index. The dielectric layer reflects (and/or transmits) light at a wavelength that depends on the layer's thickness. Because the dielectric layer's thickness varies, different parts of the dielectric layer may reflect (transmit) light at different wavelengths. For instance, shining white light on a dielectric layer with a linearly varying thickness may produce a rainbow-like reflected (and/or transmitted) beam. Thus, the spectral encoder maps different wavelengths to different points in space. This mapping can be characterized by a transfer matrix which can be used to determine the spectrum of radiation incident on the spectral encoder from the spatial intensity distribution of the radiation reflected (and/or transmitted) by the spectral encoder.

Abstract: A spectrometer (10) for gas analysis is provided, the spectrometer comprising a measurement cell (28) having a gas to be investigated, a light source (12) for the transmission of light (14) into the measurement cell (28) on a light path (16), a filter arrangement (22) having a Fabry-Perot filter (24a-c) in the light path (16), in order to set frequency properties of the light (14) by means of a transmission spectrum of the filter arrangement (22), as well as a detector (36, 38) which measures the absorption of the light (14) by the gas (30) in the measurement cell (28). In this connection the filter arrangement (22) has a plurality of Fabry-Perot filters (24a-c) arranged behind one another in the light path (14) and a control unit (44) for the filter arrangement (22) is provided in order to change the transmission spectrum by setting at least one of the Fabry-Perot filters (24a-c).

Abstract: The invention relates to controllable Fabry-Perot interferometers which are produced with micromechanical (MEMS) technology. Micromechanical interferometers of the prior art have a disadvantage of significantly attenuating infrared radiation. In the inventive solution there is a gap in at least one mirror, serving as a layer of the mirror. The other layers of the mirrors can be made of polycrystalline silicon, which has a negligible attenuation at the infrared range. It is also preferable to provide a hole or a recess in a substrate at the optical area of the interferometer.

Abstract: An optical module comprising a tunable interference filter including a first substrate, a second substrate facing the first substrate, a first reflective film formed on the first substrate, a second reflective film formed on the second substrate and facing the first reflective film, a gap changing unit changing a gap between the first reflective film and the second reflective film, and a driving electrode line electrically connected to the gap changing unit, a temperature sensor detecting temperature of the tunable interference filter and including a first sensor wiring and a second sensor wiring, the first sensor wiring being electrically connected to the driving electrode line, a switch electrically connected to the second sensor wiring, and a temperature detecting circuit electrically connected to the switch.

Abstract: A micro-machined optical measuring device including: a set of photosensitive detector elements situated on a given face of a first support; a second support, assembled to the first support, forming a prism and including a first face through which a visible radiation is intended to penetrate and a second face, forming a non-zero angle ? with the first face and a non-zero angle ? with the given face of the first support, the second face being semi-reflective, the first support and the second support being positioned such that an interferometric cavity is made between the second face and the given face, the distance between the given face of the first support and the second face of the second support varying regularly.

Abstract: A wavelength monitor monitors wavelengths of laser beams emitted from a laser source and transmitted through a collimating lens. The wavelength monitor comprises an etalon that serves as an optical filter, and an optical detector. The etalon has a transmittance that is periodic with respect to a frequency, and is disposed such that a pair of collimated beams, emitted through a pair of emitting ports of the laser source and then transmitted through the collimating lens, is incident on the optical filter at symmetrically positive and negative angles. The optical detector receives the pair of collimated beams transmitted through the etalon, and detects the intensities of the pair of collimated beams.

Abstract: Various methods and systems are provided for generation of a laser pulse with massive pulse-front tilt (PFT) and its use for measurement of laser pulses. In one embodiment, a method includes directing a laser pulse into an etalon and propagating the laser pulse through the etalon to form a tilted pulse. Another embodiment involves directing pulses into an etalon and propagating the pulses through the etalon in opposite directions to form a pair of massively tilted pulses that are tilted in opposite directions. In another embodiment, a system includes a Fresnel biprism configured to produce a pair of pulses from an input pulse and a lens configured to direct each pulse through an opening (or openings) in an input surface of an etalon, where the etalon is configured yield a pair of pulses tilted in opposite directions, each pulse having a massive PFT.

Abstract: An optical sensor having one or more sensing interference elements is disclosed. A first detector function generates a coarse optical path difference signal for example using a discrete Fourier transform of a detected interference spectrum, and a second detector function generates a refined optical path difference signal using the coarse optical path difference signal and for example a cross correlation of the interference spectrum with one or more sets of periodic transfer functions.

Abstract: A method for producing a mirror plate for a Fabry-Perot interferometer includes providing a base slab, which includes a substrate coated with a reflective multilayer coating, forming one or more intermediate layers on the base slab such that the lowermost intermediate layer substantially consists of silica, and such that the multilayer coating is at least partially covered by the lowermost intermediate layer, forming one or more capacitive sensor electrodes by depositing conductive material on top of the intermediate layers, and removing material of the lowermost intermediate layer by etching in order to form an exposed aperture portion of the multilayer coating.

Abstract: The present disclosure describes cavity enhanced spectroscopy (CES) apparatuses, and systems, and methods of forming the same. An example of a CES apparatus includes a first partial reflector, an optical cavity to expose a sample to electromagnetic radiation below the first partial reflector, and a semiconductor wafer with the first partial reflector and the optical cavity formed thereon.

Abstract: Electrically tunable Fabry-Perot interferometers produced with micro-optical electromechanical (MOEMS) technology. Micromechanical interferometers of the prior art require high control voltage, their production includes complicated production phases, and the forms of the movable mirrors are restricted to circular geometries. In the inventive solution, there is a gap in the movable mirror, whereby mirror layers opposite to the gap are connected with anchoring. The anchoring is such that the stiffness of the mirror is higher at the optical area than at the surrounding area. This way it is possible keep the optical area of the mirror flat even if the control electrodes extend to the optical area. Due to large electrodes, lower control voltages are required.

Abstract: In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

Abstract: Various systems and methods for performing optical analysis downhole with an interferogram (a light beam having frequency components with a time variation that identifies those frequency components. The interferogram is produced by introducing an interferometer into the light path, with the two arms of the interferometer having a propagation time difference that varies as a function of time. Before or after the interferometer, the light encounters a material to be analyzed, such as a fluid sample from the formation, a borehole fluid sample, a core sample, or a portion of the borehole wall. The spectral characteristics of the material are imprinted on the light beam and can be readily analyzed by processing electronics that perform a Fourier Transform to obtain the spectrum or that enable a comparison with one or more templates. An interferometer designed to perform well in the hostile environments downhole is expected to enable laboratory-quality measurements.

Abstract: A light measurement device comprising an optical sensor that includes a tunable interference filter and a detecting section detecting light passed through the tunable filter, a storing section that stores a first correlation data and a second correlation data, and a CPU that obtains amount of the light by controlling the optical sensor based on the first correlation data and a second correlation data.

Abstract: A Fabry-Pérot tunable filter device is described with reflecting elements separated by an optical path length to form an optical resonator cavity. A first actuator means is directly or indirectly coupled with a first reflecting element. And the first actuator means is configured to modulate the optical path length between first and second reflecting elements by a modulation amplitude to thereby sweep the optical resonator cavity through a band of optical resonance frequencies with a sweep frequency of 70 kHz or more. And the mechanical coupling between selected elements of the arrangement is sufficiently low such that when operated at the sweep frequency, the selected elements act as a system of coupled oscillating elements. In addition or alternatively, the first actuator means is directly or indirectly coupled with the first reflecting element so as to substantially drive the first reflecting element only.

Abstract: A spectrophotometer includes a fixed substrate having a fixed reflecting film, a movable substrate having a movable reflecting film, a tunable interference filter having a static actuator changing the gap distance of an inter-reflecting film gap between the fixed reflecting film and the movable reflecting film, a detecting section detecting the light intensity of a light extracted by the tunable interference filter, a voltage setting section and a voltage controlling section that apply a continuously-varying analog voltage to the static actuator, a voltage monitoring section monitoring the voltage applied to the static actuator, and a light intensity obtaining section obtaining the light intensity detected by the detecting section when the voltage monitored by the voltage monitoring section becomes a predetermined voltage to be measured.

Abstract: An optical filter includes a first substrate, a second substrate opposed to the first substrate, a first optical film provided on a surface of the first substrate facing the second substrate, a second optical film provided on the second substrate and opposed to the first optical film via a gap, a first electrode provided on the surface of the first substrate facing the second substrate, and a second electrode provided on the second substrate and opposed to the first electrode, wherein a first charged body film with charge is formed on top of the first optical film, a second charged body film with charge is formed on top of the second optical film, and the first charged body film and the second charged body film are charged with the same polarity and opposed.

Abstract: An etalon is provided with a fixed substrate and a movable substrate opposed to the fixed substrate. The fixed substrate is provided with a first bonding surface to be bonded to the movable substrate via a bonding film and a first electrode surface on which a part of the first electrode is formed. The movable substrate is provided with a second bonding surface to be bonded to the first bonding surface via the bonding film and a second electrode surface on which a part of the second electrode is formed. In the state in which the fixed substrate and the movable substrate are bonded to each other with the bonding film, the first electrode formed on the first electrode surface and the second electrode formed on the second electrode surface have contact with each other.

Abstract: An optical filter includes fixed substrate, a movable substrate opposed to the fixed substrate, a first reflection film provided on a surface of the fixed substrate facing the movable substrate, a second reflection film provided on the movable substrate and opposed to the first reflection film across a gap, a first electrode formed to cover the first reflection film and to extend beyond an outer circumference of the first reflection film, and a second electrode provided on a surface of the movable substrate facing the fixed substrate and opposed to a part of the first electrode, and the first electrode is formed of a light-transmissive material, and the first electrode and the second reflection film are electrically connected at the same potential.