Abstract: Techniques for controlling an optical system include accessing a measured value of a property of a particular pulse of a pulsed light beam emitted from the optical system, the property being related to an amount of coherence of the light beam; comparing the measured value of the property of the light beam to a target value of the property; determining whether to generate a control signal based on the comparison; and if a control signal is generated based on the comparison, adjusting the amount of coherence in the light beam by modifying an aspect of the optical system based on the control signal to reduce an amount of coherence of a pulse that is subsequent to the particular pulse.

Abstract: In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam. The laser system also includes a pump laser diode configured to produce a free-space pump-laser beam. The laser system further includes an optical-beam combiner configured to combine the seed-laser and pump-laser beams into a combined free-space beam and a focusing lens configured to focus the combined beam. The laser system also includes an optical gain fiber that includes an input end configured to receive the focused beam. The laser system also includes a mounting platform, where one or more of the optical-beam combiner, the focusing lens, and the input end of the gain fiber are mechanically attached to the platform.

Abstract: A spectroscopic sensor 1 comprises an interference filter unit 20, having a cavity layer 21 and first and second mirror layers 22, 23 opposing each other through the cavity layer 21, for selectively transmitting therethrough light in a predetermined wavelength range according to an incident position thereof; a light-transmitting substrate 3, arranged on the first mirror layer 22 side, for transmitting therethrough light incident on the interference filter unit 20, a light-detecting substrate 4, arranged on the second mirror layer 23 side, for detecting the light transmitted through the interference filter unit 20, and a first coupling layer 11 arranged between the interference filter unit 20 and the light-transmitting substrate 3. The cavity layer 21 and the first coupling layer 11 are silicon oxide films.

Abstract: A multilayered film and a method for performing spectroscopic measurements in a fluid are provided. The multilayered film includes a substrate; a porous layer adjacent to the substrate; and a reflective layer formed on the porous layer, wherein the porous layer selectively allows a component of a fluid to be optically measured when the multilayered film is immersed in the fluid. A sensor for spectroscopic measurements in crude oil samples including a multilayered film as above is also provided. A method of manufacturing a multilayered film for spectroscopic measurements in fluids as above is also provided.

Abstract: An alignment system having long term stability in illumination center wavelength is discussed. The alignment system includes a tunable radiation source and a feedback control system. The tunable radiation source includes a light source configured to provide a broadband radiation beam and a tunable multi-passband filter configured to filter the broadband radiation beam into narrow band radiation beam having a center wavelength value. The feedback control system is configured to measure the center wavelength value of the narrow band radiation beam and compare the measured center wavelength value with a desired center wavelength value. The feedback control system is further configured to generate a control signal based on the comparison in response to a difference being present between the measured center wavelength value and the desired center wavelength value and tune the tunable filter based on the control signal to eliminate or substantially reduce the difference.

Abstract: A tracking system includes a tracking arrangement including a processor, memory, and at least a first interface port; and one or more optical modules. Each optical module includes a housing having at least one input port, at least a first output port, and at least a first monitoring port. An optical power splitter arrangement and an optical receiver are disposed within the housing. The splitter arrangement splits optical signals received at the input port onto one or more output lines and one or more monitoring lines. The output lines are routed to the output ports and the monitoring lines are routed to the optical receiver. The optical receiver measures the power of optical signals received from the first monitoring line and provides a measurement signal to the first monitoring port of the housing.

Abstract: The present invention provides an interference measuring device with an optical system that can receive light reflected from a measurement object of a surface profile that is not perpendicular to an optical axis. An interference measuring device includes a light source for emitting light and an interferometric objective lens. The interferometric objective lens includes a reference mirror disposed in a reference beam path and a beam splitter that splits the incident light into a beam traveling along the reference beam path and a beam traveling along a measurement beam path. The beam splitter also combines the beam reflected off the reference mirror with the beam reflected off a measurement object disposed in the measurement beam path before emitting the combined beams.

Abstract: A spectrometer with increased optical throughput and/or spectral resolution includes a plurality of interferometers coupled in parallel. An optical splitter divides a source light beam into a plurality of input beams and directs each of the input beams to a respective one of the plurality of interferometers. One or more detectors are optically coupled to receive a respective output from each of the plurality of interferometers and is configured to detect an interferogram produced as a result of the outputs.

Abstract: An optical paired channel transceiver component comprises an optical channel interface to concurrently receive an inbound optical signal at a designated receiver frequency, and output an outbound optical signal at a designated transmitter frequency distinct from the receiver frequency; a receiver operable to process the inbound optical signal at the receiver frequency; a laser input interface to receive a laser input at the transmitter frequency to produce the outbound optical signal; and a resonant optical structure optically coupling each of the laser input interface and the receiver to the optical channel interface via respective optical paths, and having a resonance corresponding to one of the transmitter frequency and the receiver frequency such that a resonant one of the inbound signal and the outbound signal is resonantly redirected by the resonant optical structure along a resonant one of the respective paths.

Abstract: Optical Coherence Tomography (OCT) system and apparatus of this instant application is very useful for diagnosis and management of 3ophthalmic diseases such as retinal diseases and glaucoma etc. Instant innovative OCT diagnostic system leverages advancements in cross technological platforms. The Michelson interferometric system presented in this application could be used for the OCT imaging, which includes biological OCT imaging, medical OCT imaging, ophthalmic OCT imaging, corneal OCT imaging, retinal OCT imaging, and the like. A tunable filter is placed in front of the detector to make the interferometer more sensitive and accurate for examining various samples for diagnosis.

Abstract: Methods and system for transmitting data includes converting multiple optical beams to distinct respective spatial modes. Data is modulated onto each of the optical beams. The optical beams are combined into a single transmission beam. The transmission beam is launched onto a multimode optical fiber having an elliptical core.

Abstract: Embodiments include devices, systems and processes for using a white light interferometer (WLI) microscope with a tilted objective lens to perform in-line monitoring of both resist footing defects and conductive trace undercut defects. The defects may be detected at the interface between dry film resist (DFR) footings and conductive trace footing found on insulating layer top surfaces of a packaging substrate. Such footing and undercut defects may other wise be considered “hidden defects”. Using the WLI microscope with a tilted objective lens provides a high-throughput and low cost metrology and tool for non-destructive, non-contact, in-line monitoring.

Abstract: Imaging spectrometers can be used to generate hyperspectral images for medical diagnoses, contaminant detection, and food safety inspections, among other applications. An exemplary imaging spectrometer includes an integrated position sensing array that measures the relative positions of the interferometer components based on an interference pattern generated by illuminating the interferometer with a reference beam. Such an imaging spectrometer includes a processor that controls the interferometer component position by actuating a voice coil and several piezo-electric elements to align the components with respect to each other and to provide a desired optical path length mismatch between the interferometer arms. In some cases, the processor may use feedback and feed forward control, possibly based on the actuators' transfer functions, for more precise positioning. The processor may also implement adaptive and recursive spectral sampling to reduce the image acquisition period.

Abstract: There is provided a method of controlling the wavelength of a laser beam. The method includes measuring an absolute wavelength of the laser beam; calculating a difference between a reference wavelength and the absolute wavelength of the laser beam; and adjusting the reference wavelength of the laser beam based on the difference between the reference wavelength and the absolute wavelength of the laser beam, at an interval shorter than an interval for which the absolute wavelength of the laser beam is measured.

Abstract: A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.

Abstract: An all-optical information exchange device and method are provided. The all-optical information exchange device includes: a second-order nonlinear optical waveguide, a first optical coupler, a third optical coupler, a fourth optical coupler, a first optical filter, a second optical filter and a first polarization controller; the first optical filter is transmissive to a first wavelength/waveband signal light, and the second optical filter is transmissive to a second wavelength/waveband signal light during use.

Abstract: A mirror (M) of a projection exposure apparatus for microlithography configured for structured exposure of a light-sensitive material and a method for producing a mirror (M). The mirror (M) has a substrate body (B), a first mirror surface (S) and a second mirror surface (S?). The first mirror surface (S) is formed on a first side (VS) of the substrate body (B). The second mirror surface (S?) is formed on a second side (RS) of the substrate body (B), the second side being different from the first side of the substrate body (B). The mirror (M) may be embodied, in particular, such that the substrate body (B) is produced from a glass ceramic material.

Abstract: A wavelength tunable interference filter includes an electrostatic actuator that changes the dimension of a gap between a fixed reflection film and a movable reflection film, a fixed drawn electrode and a movable drawn electrode that are connected to the electrostatic actuator, and a third substrate having a top surface portion and a sidewall portion. An end surface of the sidewall portion is bonded to a first substrate so that a space surrounded by the top surface portion, the sidewall portion, and the first substrate is hermetically sealed. A second substrate and the electrostatic actuator are disposed in the space, and the fixed drawn electrode and the movable drawn electrode are disposed on the first substrate and extend both inside and outside the space.

Abstract: The invention relates to a Fabry-Perot interferometer and a method for producing the same. More specifically, the invention relates to Fabry-Perot interferometers which are controllable with one or several actuators, such as piezoelectric, electrostrictive or flexoelectric actuators. In prior art technology there is a problem to achieve a sufficiently small and uniform gap between mirrors. In the present invention an intermediate structure (85a, 85b, 95a, 95b, 81a, 81b, 91a, 91b, 98a, 98b) is used between a mirror and an actuator or between two mirrors. The method of production also includes measuring the width distribution of the gap in several phases, and providing pre-actuation of actuators.

Abstract: There is provided a method for determining a noise parameter characterizing an optical Signal-Under-Test (SUT) having a signal contribution, an Amplified Spontaneous Emission (ASE) noise contribution and a non-ASE optical noise contribution, such as a carrier-leakage contribution or a depolarized-signal contribution, within an optical-signal bandwidth. The method comprises acquiring optical spectrum trace(s) of the SUT, discriminating at least the non-ASE optical noise contribution from the ASE-noise contribution using the optical spectrum trace(s) and/or a trace obtained from the optical spectrum trace(s); and determining the noise parameter using discriminated non-ASE optical noise contribution and/or the discriminated ASE-noise contribution.

Abstract: There is set forth herein an optomechanical device which can comprise a first mirror and a second mirror forming with the first mirror a cavity. In one aspect the first mirror can be a movable mirror. The optomechanical device can be adapted so that the first mirror is moveable responsively to radiation force.

Abstract: In part, the invention relates to methods, devices, and systems suitable for controlling a light source. The light source is configured for use in a data collection system such as an optical coherence tomography system. The light source can be controlled with a drive waveform. Linearizing and symmetrizing parameters of the light source such as forward and backward scan durations is achieved using a suitable drive waveform. Phase, amplitude, and other parameters for different harmonics of a fundamental wave can be identified that improve operating parameters such as the duty cycle and peak frequency matching between scans. The fundamental wave and one or more of such harmonics can be combined to generate the suitable drive wave form. The light source can include a tunable light source that includes or is in optical communication with a tunable filter.

Abstract: An optical-source monitor images and diffracts received optical signals using an optical device that has a reflective geometry. For example, the optical device may include a diffraction grating on a curved surface, such as an echelle grating. By imaging and diffracting the optical signals, the optical device may couple to the optical signals on different diffraction orders of the optical device (which have different carrier wavelengths) from input optical waveguides to corresponding output optical waveguides. Then, output power monitors may measure the output power levels of the optical signals, and control logic may provide wavelength control signals to optical sources that provide the optical signals based on measured output power levels.

Abstract: An apparatus for obtaining spectral image includes a variable spectral element capable of changing its spectral characteristics, a transmission wavelength setting unit for setting a wavelength of light to be transmitted by the variable spectral element, a variable spectral element control unit changing a first control of the variable spectral element and a second control of the variable spectral element for controlling spectral characteristics of the variable spectral element to each other, an image capturing unit capturing an image that is formed by light transmitted by the variable spectral element, and an image correction unit acquiring a difference image between a first image captured in the first control and a second image captured in the second control.

Abstract: A tunable multiport optical filter includes various types of arrays of optical ports. The tunable filter also includes a light dispersion element (e.g., a grating) and a reflective beam steering element (e.g., a tilting mirror). An optical signal exits an optical (input) port, is dispersed by the light dispersion element, reflects off the reflective beam steering element back to the light dispersion element, and on to another optical (output) port. The reflective beam steering element can be steered such that a wavelength portion of the dispersed optical signal can be coupled to the optical output port. For example, the input optical signal may be a wavelength division multiplexed signal carrying multiple channels on different wavelengths, and the tunable multiport optical filter directs one of the channels to the output optical port. Additionally, the tunable filter may be incorporated into a device acting as a wavelength reference.

Abstract: A method of optical spectroscopy and a device for use in optical spectroscopy. The device includes a substrate, and a plurality of etalon cavities affixed to or coupled to the substrate. A signal is received from a Fabry-Perot interferometer. The signal is sampled using the device according to a generalized Nyquist-Shannon sampling criterion. The signal is sampled using the device according to a phase differential criterion for wave number resolution. An input spectrum for the signal is reconstructed based on the signal sampled according to the generalized Nyquist-Shannon sampling criterion and the signal sampled according to the phase differential criterion for wave number resolution.

Abstract: Described herein are methods for mid-infrared imaging of nucleic acid microarrays by employing mid-infrared reflective labels combined with detection in the reflection mode. The methods described herein provide intrinsic image contrast, and permit detection of DNA microarray hybridization on infrared absorbing substrates such as glass slides.

Abstract: A system and method for triggering data acquisition in a semiconductor laser system including outputting electromagnetic energy from the semiconductor laser over a range of wavelengths according to a signaling path. The signaling path includes a plurality of discrete data inputs to the semiconductor laser for outputting electromagnetic energy over a range of wavelengths and the signaling path includes one or more perturbances in transitioning from one wavelength to another wavelength along the signaling path. A series of triggering signals are generated for input to a measurement system by the semiconductor laser. The series of triggering signals include a non-uniform period between at least a first triggering signal and an adjacent second triggering signal, and the non-uniform period corresponds to at least one perturbance. The electromagnetic energy output from the semiconductor laser is detected based on the series of triggering signals.

Abstract: A method of monitoring optical power in an optical channel includes directing a portion of a broadband optical signal propagating through an optical channel to an optical input of an electrically controllable tunable optical filter. The portion of the broadband optical signal is filtered with the electrically controllable tunable filter to select an optical channel for optical power monitoring. The selected optical channel is detected and an electrical signal that represents the selected optical channel is generated. An optical power of the selected optical channel is estimated from the electrical signal that represents the selected optical channel by performing an iterative deconvolution of the selected optical channel signal with a predetermined response function of the electrically controllable tunable optical filter.

Abstract: A movable body spectrum measuring apparatus includes a spectrum sensor mounted in a movable body to measure spectrum data containing information including wavelength information and optical intensity information of a measuring object, a processor mounted in the movable body to discriminate the measuring object by processing the measured spectrum data, and a signal transmission path for transmitting the measured spectrum data from the spectrum sensor to the processor. The movable body spectrum measuring apparatus further includes a data transfer device which acquires reconfigured spectrum data by reconfiguring the measured spectrum data so that selected information as predetermined information is selected from the information contained in the measured spectrum data. The data transfer device transfers the reconfigured spectrum data to the processor via the signal transmission path.

Abstract: One of first and second beams (28) of corresponding first and second light (13) are projected into an atmosphere (20) and at least one physical property of the atmosphere (20) is detected from the interference pattern (47) generated from the resulting scattered light (30). The first and second beams (20) are selected responsive to either a detected signal-to-noise ratio (SNR) or a detected aerosol-to-molecular ratio (AMR). The wavelength (740) of the first light (13) provides for either molecular or aerosol scattering, whereas the wavelength (738) of the second light (13) provides for primarily only aerosol scattering. In accordance with a second aspect, scattered light (30) from one or more beams (28) of substantially monochromatic light (13) projected into the atmosphere (20) and received from a plurality of interaction regions (17) or measurement volumes (52) provides for determining wind power (P*) within a region of the atmosphere (20).

Abstract: A wavelength variable interference filter includes: a first substrate which has a light transmissive property; a second substrate which has a light transmissive property and is disposed to face one surface of the first substrate and is bonded thereto; a first reflection film which is provided on the first substrate; a second reflection film which is provided on the second substrate; and a variable section which varies the gap; wherein the second substrate includes: a first layer which has a movable section; and a second layer which is laminated to a surface of the first layer facing the first substrate, is formed in a plate shape with a uniform thickness, and has a support section configured to displaceably support the movable section; and the first layer is not laminated to at least a region overlapping with the support section in the planar view.

Abstract: A device comprising measurement (7) and reference (3) interferometers is disclosed. Each interferometer is configured to receive light from the same light source (1) and to emit light to respective detectors (6) and has a respective operating point. The measurement interferometer (7) is configured to respond to variations in a physical parameter by varying the intensity of light emitted, whereas the reference interferometer (3) is configured to be unresponsive to variations in the physical parameter. The device further comprises a signal processor for generating a differential output signal depending on respective output signals generated by the detectors (6).

Abstract: The invention relates to a Fabry-Perot interferometer and a method for producing the same. More specifically, the invention relates to Fabry-Perot interferometers which are controllable with one or several actuators, such as piezoelectric, electrostrictive or flexoelectric actuators. In prior art technology there is a problem to achieve a sufficiently small and uniform gap between mirrors. In the present invention an intermediate structure (85a, 85b, 95a, 95b, 81a, 81b, 91a, 91b, 98a, 98b) is used between a mirror and an actuator or between two mirrors. The method of production also includes measuring the width distribution of the gap in several phases, and providing pre-actuation of actuators.

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: A Fabry-Perot interferometer includes an input mirror and an output mirror arranged facing the input mirror via a gap. Each mirror includes a pair of high-refractive layers and a space layer arranged selectively between the high-refractive layers. At least one of an input-side bridge part and an output-side bridge part arranged crossing the gap, is movable as a membrane. Each bridge part includes a transmission portion and a periphery portion. Each transmission portions includes a mirror element in which the space layer is sandwiched by the pair of high-refractive layers. In a second direction perpendicular to the first direction, the mirror element of the input mirror has a width larger than seven times of a maximum wavelength of a transmission light output from the output mirror, and functions as a diffraction restriction mirror.

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: The invention relates to a laser device, comprising a laser configured to generate laser light and a laser control module configured to receive at least a portion of the laser light generated by the laser, to generate a control signal and to feed the control signal back to the laser for stabilizing the frequency, wherein the laser control module comprises a tunable frequency discriminating element which is preferably continuously frequency tunable, and where the laser control module is placed outside the laser cavity.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for Doppler light detection and ranging (LIDAR). According to an example embodiment of the invention, a method is provided for measuring atmospheric wind speed. The method includes tuning, in sequence, light output of a laser to a first wavelength and a second wavelength, wherein the first wavelength and the second wavelength are symmetric about a maximum transmission wavelength peak associated with a Fabry-Perot etalon; directing the light output to one or more portions of the atmosphere; receiving backscattered light from the one or more portions of the atmosphere; directing the received backscatter light through the Fabry-Perot etalon; detecting a transmission signal corresponding to light transmitted through the Fabry-Perot etalon; and determining, by at least the transmission signal, atmospheric wind speed at one or more portions of the atmosphere.

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: 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: A method involves obtaining a first beam image on a focal plane of a first camera and a second beam image on a focal plane of a second camera from light scattered by ambient atmospheric aerosols in the path of a laser beam. First and second projected beam images are formed, representing the respective first and second beam images in the projected scenes of the respective first and second cameras. First and second ambiguity planes are then formed from the respective first and second projected beam images. An intersection of the first and second ambiguity planes is then determined, identifying the position of the laser beam. A source of the laser beam is then determined, along with a camera-source plane. A beam elevation angle with respect to this plane is then determined, as well as beam azimuth angles with respect to lines between the respective camera and the source.

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 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 integrated apertured micromirror is provided in which the micromirror is monolithically integrated with a micro-optical bench fabricated on a substrate using a lithographic and deep etching technique. The micromirror has an aperture therein and is oriented such that the micromirror is optically coupled to receive an incident beam having an optical axis in a plane of the substrate and to at least partially transmit the incident beam therethrough via the aperture.

Abstract: Provided is an optical surface profilometer. The optical surface profilometer includes a Fabry-Perot resonator into which liquid crystals are inserted, a light source which supplies coherent light to the Fabry-Perot resonator, and a convex lens which is disposed in an interference pattern emitting plane of the Fabry-Perot resonator, wherein the coherent light supplied from the light source is incident to the Fabry-Perot resonator, wherein, when the light is incident, the Fabry-Perot resonator emits an interference pattern generated in a resonance mode, and wherein the interference pattern is configured so that a number of circular fringes having the same center are disposed non-linearly. As a voltage is applied to the liquid crystal layer of the Fabry-Perot resonator, an effective refractive index is changed, so that a resonance mode condition of the Fabry-Perot resonator is changed. As a result, a diameter of the interference pattern is also changed.

Abstract: Present invention relate to a physical/chemical sensor and a physical/chemical phenomenon sensing device that can detect minute change of surface stress and can be reduced in size and arrayed and to provide a method for manufacturing the same In the sensor of the present invention, an air-gap 3 is formed on a surface of the light receiving surface 1a of a photodiode 1. The sensor comprises a membrane section 2 which is oppositely deposited, and the air-gap is blocked air-tightly or liquid-tightly. The membrane section has optical transparency and flexibility, the membrane section and the surface of the light receiving surface form a Fabry-Perot resonator. The sensing device of the present invention comprises a reference sensor, which comprises no air-gap, in addition to the sensor.

Abstract: A portion of a first portion of light (13, 90, 90?) from a source of light (11) is masked by a mask (138), and the resulting masked first portion of light (90?) is combined using a beam splitter optic (136) with at least one second portion of the light (30) that had been subject to scattering by a medium (20, 20?, 20?). The mask (138) is configured so that interference patterns (104, 47) generated from the first and at least one second portions of light are substantially mutually exclusive even though those interference patterns (104, 47) would otherwise overlap one another absent the mask (138).

Abstract: A fringe pattern from an interferometer is imaged onto a digital micromirror device containing an array of micromirrors in an associated pattern of pixel mirror rotational states that provide for sampling the circular fringe pattern in cooperation with one or more associated photodetectors, so as to provide for generate a corresponding set of associated complementary signals. A plurality of different sets of associated complementary signals generated for a corresponding plurality of mutually independent associated patterns of pixel mirror rotational states are used to determine at least one metric associated with the circular fringe pattern.

Abstract: Embodiments of environmental stimulus sensors comprising multiple sources and detectors for interrogating one or more optically resonant cavities that are responsive to one or more environmental stimuli are disclosed. Such sensors have, among other advantages, improved immunity to source and/or detector noise.