Abstract: A method of monitoring light output from at least one solid-state light source involves sensing any light produced by the at least one solid-state light source and reflected, by at least one surface spaced apart from the at least one solid-state light source, to at least one reference location spaced apart from the at least one surface. Apparatuses and uses of the apparatuses are also disclosed.

Abstract: A two-piece optical prism includes a prism having a groove and prism having arc faces, where the prism having a groove has at least one first arc face and groove having at least one second arc face, and the prism having arc faces is placed in the groove of the prism having a groove and has at least one third arc face. The present invention can be used in the surface plasmon resonance optical system for the angle, range adjustment and control of incident light (e.g. laser light), capable of constituting an optical wide-angle, multi-angle incident system to carry out the wide-angle, multi-angle scanning detection of surface plasmon resonance, increasing the system dynamic detection range and sensitivity; and further reducing a detection chip.

Abstract: Provided herein are systems and methods of optical particle counters which account and adjust for the refractive index of the carrier fluid being analyzed. The provided systems are robust and may be implemented in a variety of optical particle counters including obscured light, reflected light, emitted light and scattered light particle counters. The described systems may be useful with any fluid, including gases or liquids. In some cases, the system can account for the differences in refractive index between two liquids, for example, ultrapure water and an acid, such as sulfuric, hydrochloric, hydrofluoric, acetic, phosphoric, chromic phosphoric, and the like. By accounting for the refractive index of the carrier fluid, the described systems and methods are also more sensitive and able to more accurately detect and characterize smaller particles, including nanoscale sized particles.

Abstract: Immersion Raman probes use collimated light as opposed to a diverging fiber bundle or lens-based focusing geometry to deliver and collect light to and from a sample, thereby eliminating problems associated with chromatic aberration. The probes convey counter-propagating excitation and collection beams to and from a distally sealed, signal-transmissive optical component such as a window immersed, in contact with, or otherwise exposed to a sample volume. The counter-propagating excitation and collection beams pass directly through the sealed optical component and into the sample volume in collimated form for Raman analysis thereof. The probe may further include a baffled sample chamber coupled to the distal end of the probe optic body, with one or more optical elements to reflect the counter-propagating beams. The sample chamber may be fixed or axially movable to facilitate path length adjustment. The invention finds utility in process Raman, microscopy and other applications.

Abstract: A flow cytometer including a flow cell in which an imaging object flows; a laser beam irradiator configured to radiate laser beam; a camera including an image sensor of N×M pixels; and an optical system configured to introduce the laser beam from the laser beam irradiator to imaging range of flow cell and to introduce signal light, such as transmitted, reflected or scattered light, from imaging range of flow cell, to camera. Optical system includes a mirror device that is placed on a Fourier plane of imaging optical system, that has at least one mirror specularly reflecting the signal light, and that is driven and rotated in conjunction with a flow in flow cell, such that each part of an image formed by the signal light is introduced into an identical pixel of the image sensor for at least a predetermined time period from a predetermined timing.

Abstract: A method for assigning chirality of carbon nanotube is provided. Firstly, carbon nanotube sample, an optical microscope with a liquid immersion objective and a liquid are provided. Secondly, the carbon nanotube sample is immersed in the liquid. Thirdly, the carbon nanotube sample is illuminated by an incident beam to generate resonance Rayleigh scattering. Fourthly, the liquid immersion objective is immersed into the liquid to get a resonance Rayleigh scattering (RRS) image of the carbon nanotube sample. Fifthly, spectra of the carbon nanotube sample are measured to obtain chirality of the carbon nanotube sample.

Abstract: A method for imaging one dimension nanomaterials is provided. Firstly, one dimension nanomaterials sample, an optical microscope with a liquid immersion objective and a liquid are provided. Secondly, the one dimensional nanomaterials sample is immersed in the liquid. Thirdly, the one dimensional nanomaterials sample is illuminated by an incident beam to generate resonance Rayleigh scattering. Fourthly, the liquid immersion objective is immersed into the liquid to get a resonance Rayleigh scattering (RRS) image of the one dimensional nanomaterials sample. Fifthly, spectra of the one dimensional nanomaterials sample are measured to obtain chirality of the one dimensional nanomaterials sample.

Abstract: An apparatus includes a pipe through which a multiphase fluid flows, with a transparent window structure formed in the pipe. A collimated light source emits light through the transparent window structure into the pipe having a wavelength at which a component of a desired phase of the multiphase fluid is absorptive. A photodetector is positioned such that the emitted light passes through the multiphase fluid in the pipe to impinge upon the photodetector. The photodetector has an actual dynamic range for collimated light detection. Processing circuitry is configured to continuously adjust a power of the collimated light source dependent upon an output level of the photodetector so as to cause measurement of the emitted light over an effective dynamic range greater than the actual dynamic range, and determine a property of the multiphase fluid as a function of the power of the collimated light source.

Abstract: A method for determining a critical angle of total reflection based upon images captured at different angles of incidence of a light beam includes illuminating a sample with an excitation light beam, capturing images of at least part of the sample at a plurality of different angles of incidence of the excitation light beam, and determining a critical angle of total reflection at an interface of the sample based upon analysis of the images. An apparatus for determining a critical angle of total reflection at an interface of a sample includes a light source arrangement to illuminate a sample with an angle of incidence, an image capturing arrangement to capture an image of the sample, and a processing arrangement to determine the critical angle of total reflection at an interface of the sample on the basis of an analysis of images captured at a plurality of different angles of incidence.

Abstract: A deflecting prism for electromagnetic radiation, in particular for refractometer- and/or ATR-measurements, is part of a measuring configuration. The deflecting prism has a body produced in one piece from a mono-crystal. The body has at least two beam conductive surfaces on a side of the body opposite each other or circumferentially about the body and a measuring surface lying between the beam conductive surfaces or surrounded by the latter. The body further has at least one beam entry surface or a beam exit surface. Accordingly, the measuring surface lies on an elevation formed on the body, which crosses over via a ledge surrounding the elevation into the remaining part of the body. On the remaining part, the beam conductive surfaces and/or the beam entry surface or exit surface lie.

Abstract: An arrangement for attenuated total reflectance (ATR) infrared spectroscopy uses a reflection matrix for location-resolved spectroscopy of aqueous and/or powdery samples with a high signal-to-noise ratio and without previous complex preparation of the samples. The method of using the reflection matrix produces imaging of the sample with a high signal strength.

Abstract: An autofocus system and method designed to account for instabilities in the system, e.g. due to instabilities of system components (e.g. vibrating mirrors, optics, etc) and/or environmental effects such as refractive index changes of air due to temperature, atmospheric pressure, or humidity gradients, is provided. An autofocus beam is split into a reference beam component (the split off reference channel) and a measurement beam component, by a beam splitting optic located a predetermined distance from (and in predetermined orientation relative to) the substrate, to create a first space between the beam splitting optic and the substrate. A reflector is provided that is spaced from the beam splitting optic by the predetermined distance, to create a second space between the reflector and the beam splitting optic.

Abstract: An optical sensor apparatus includes an optically transmissive structure (e.g., a prism) having two planar faces and a third planar face that connects the two planar faces, two or more light sources located outside the structure, and a photodetector array located outside the prism. The structure, light sources, and photodetector array are configured such that light from the light sources that is totally internally reflected at an optical interface between the prism and a sample outside the structure proximate one of the two planar faces is incident on a portion of the photodetector array that depends on a refractive index of the sample. The light sources are positioned with respect to the structure and photodetector array such that the totally internally reflected light from each light source corresponds to a different range of refractive index of the sample and maps to a corresponding portion of the photodetector array.

Abstract: The present invention is directed to temperature modulated refractive index measurement. In accordance with the invention a method for determination of the complex temperature coefficient of the refractive index of a sample is provided, wherein the determination of the complex temperature coefficient of the refractive index of the sample is based on a refractive index measurement. Furthermore, the refractive index of the sample is measured over a period of time, wherein the temperature of the sample is modulated over said period of time and the complex temperature coefficient of the refractive index is calculated on the basis of the refractive index measurement over the period of time and the temperature modulation over the period of time. Additionally, a measurement system, in particular comprising a temperature control system and a processing system to carry out the above method, is disclosed.

Abstract: A method and optical device measures the rotation of an object, including a light source emitting a collimated incident light beam, and a reflecting plane optical interface to be fastened to the object and forming a first reflected beam. The device includes a corner reflector fastened to the object, and having reflecting plane faces forming a second reflected beam, and a detection system capable of measuring the displacement ?1 of the first reflected beam, and the displacement ?2 of the second reflected beam. A processing system calculates, as a function of ?1 and of the distance D1 between the detection system and the reflecting plane optical interface, and of the measurement of ?2 and of the distance D2 between the detection system and the corner reflector, a measurement of the rotation ? of the object between an initial position and a measurement position.

Abstract: A portable liquid design system includes a portable information handling system (IHS) that employs a liquid design application capable of operating in different modes to design different liquids such as corn syrup, espresso, coffee, soda pop and others. The portable liquid design system may include a refractometer to measure the refractive index and temperature of a liquid under test. The liquid design application may apply the measured refractive index and temperature to a 3 dimensional representation of the correlation of refractive index, temperature and concentration (% total dissolved solids) to determine a particular concentration corresponding to the measured refractive index and temperature. A single 3 dimensional scale may apply to virtually all values of interest of refractive index, temperature and concentration for a particular liquid under test.

Abstract: A through-substrate optical imaging device for through-imaging of translucent work objects, includes a radiation source outputting radiation that will be transmissive through the work object and an imaging system configured for capturing inspection information from the radiation source through the work object. The radiation source is configured such that the radiation impinges on the surface of the work object under various angles of incidence. A method for through-substrate optical imaging of a translucent work object includes irradiating the translucent work object by radiation from a radiation source; capturing inspection information from the radiation source through the translucent work object, the inspection information being captured by an imaging system; and irradiating the translucent work object. The translucent work object is irradiated by radiation which impinges on the surface of the translucent work object under one of various angles of incidence and orientations.

Abstract: A transmitted light refractometer allows high measurement accuracy across a broad measurement range, even under difficult measuring conditions. The transmitted light refractometer can be connected to a process simply via a single access. In accordance with advantageous features, the transmitted light refractometer covers a measurement range for all practically relevant media and includes integrated temperature compensation. A reversing optics unit is arranged relative to an illumination optics unit such that the reversing optics unit deflects a parallel beam through the process liquid and a measurement prism into the transmitted light refractometer back to the side from which it was radiated. The illumination optics unit, an imaging optics unit, and a detector plane are arranged on the light radiation side such that only one process access is needed.

Abstract: Methods and devices related to a sensor element for use in the detection and monitoring of molecular interactions. The sensor element uses a silicon-on-insulator wafer optically coupled to a silicon prism. The wafer has a thin silicon film top layer, a silicon substrate layer, and a buried silicon dioxide layer sandwiched between the silicon film and substrate layers. The wafer is coupled to the prism on the wafer's substrate side while the interactions to be monitored are placed on the wafer's silicon film side. An incident beam is directed at the prism and the incident angle is adjusted until the beam optically couples to the silicon film's optical waveguide mode. When this occurs, a decrease in the intensity of the reflected beam can be detected. The molecular interactions affect the phase velocity or wave vector of the propagating mode. Similarly, instead of measuring the incident angle at which optical coupling occurs, the phase of the reflected beam may be measured.

Abstract: A surface plasmon measurement instrument measures a change in a property (e.g., refractive index) of a material layer. The method includes providing a prism with a rear surface having a metal layer disposed thereon; providing the material layer on the metal layer on the rear surface of the prism; directing a source beam through the prism toward the rear surface in a vicinity of the material layer; performing at least two sampled measurements to detect light reflected from the rear surface and to produce two corresponding data sets; transforming the data sets to a transform domain; processing the transformed data sets to estimate a sample shift between the two data sets; and determining a change in a property of the material layer using the estimated sample shift.

Abstract: An optical unit includes a light source unit emitting parallel light; a light-receiving element array; and a prism rendering emitted light from the light source unit incident on a specimen placement section and introducing totally reflected light from the specimen placement section into the light-receiving element array. The prism has an entrance surface rendering the parallel light emitted from the light source unit incident on the prism, a curved reflecting surface which reflects light passing through the entrance surface and incident on the prism toward a focal position thereof, the specimen placement section of a planar shape provided at a position including the focal position of the curved reflecting surface, and an exit surface making light totally reflected at the focal position of the curved reflecting surface in the specimen placement section emerge into the outside of the prism.

Abstract: An assay system having a channel bounded by first and second reflective surfaces adapted to accommodate a fluid material therebetween and defining a plurality of regions in an array between those surfaces with each region defining a resonant cavity and adapted to receive a capturing material on a surface thereof whereby a source of radiation illuminates each region to provide a standing wave of radiation of within the cavity indicative of binding of said capturing agent to material under investigation, a binding thereof being detected in response to radiation from each cavity indicative of a change in the standing wave pattern.

Abstract: An assay technique for label-free, highly parallel, qualitative and quantitative detection of specific cell populations in a sample and for assessing cell functional status, cell-cell interactions and cellular responses to drugs, environmental toxins, bacteria, viruses and other factors that may affect cell function.

Abstract: The invention provides a luminescent based sensor having a luminescent material optically coupled to a substrate, and adapted to be used in a medium or environment such as water or air. A detector is provided to detect light that is emitted into the substrate by the material. The substrate is adapted to redirect light that is emitted into the substrate at angles with the range ?esc ? ? ? ?lsc where ?esc is the critical angle of the environment/substrate interface and ?lsc is the critical angle of the luminescent layer/substrate interface. Examples of possible configurations are described.

Abstract: The device for detecting changes in the refractive index of a dielectric medium comprises: at least one metallic layer (300) ready to be placed in contact with the dielectric medium (200); at least one light source (20) configured to direct transversal magnetic (TM) polarized light towards such metallic layer, so that the light is reflected on such metallic layer; coupling means (10); and at least one detector (31) configured to receive light reflected by the metallic layer and to detect at least one feature of such light. According to the invention, the metallic layer contains a ferromagnetic material. The invention also relates to a method.

Abstract: A method for calibrating the angle-axis of signals measuring changes in an index of refraction. A pump beam is generated to propagate near a prism to induce index-changes in air by lining up air molecules outside of the prism. A generated probe beam is directed at the prism. A sinc2 pattern is then generated in a far-field based on a diffraction of a laser beam from a slit, where the laser beam is directed at the prism. An angle-axis of the sinc2 pattern is calibrated using maxima of the sinc2 pattern.

Abstract: An optical unit includes a light source unit emitting parallel light; a light-receiving element array; and a prism rendering emitted light from the light source unit incident on a specimen placement section and introducing totally reflected light from the specimen placement section into the light-receiving element array. The prism has an entrance surface rendering the parallel light emitted from the light source unit incident on the prism, a curved reflecting surface which reflects light passing through the entrance surface and incident on the prism toward a focal position thereof, the specimen placement section of a planar shape provided at a position including the focal position of the curved reflecting surface, and an exit surface making light totally reflected at the focal position of the curved reflecting surface in the specimen placement section emerge into the outside of the prism.

Abstract: An apparatus utilizes optical reflectivity (REF) to measure concentrations in liquids. The REF optical system is packaged in a compact and cost-effective form factor. An electronic circuit drives the optical system. The miniaturized REF sensor is situated in an optical-fluidic cell or an optical-fluidic manifold with an optical window in contact with the liquid. Changes in a total internal reflection (TIR) signal are sensitive to temperature and concentration of the liquid. These changes in the TIR signal are used to accurately determine the concentration in the liquid. The liquids may be either static or dynamic.

Abstract: A refractometer computer controls the rotation of a rotary plate upon which are mounted a prism optically coupled via an optical window to a spectroscopic cell holding a resin exhibiting a dynamic refractive index during photocuring. The computer system positions the prism and spectroscopic cell relative to a visible light laser which illuminates the prism-resin interface at selected incidence angles. A photodetector mounted on the plate generates a signal to the computer proportional to intensity of an internally reflected light beam. A curing light is selectively transmitted through the prism and into the photocurable resin. The refractometer determines the intensity of the internally reflected beam a selected incidence angles and determines the effective refractive index curve of the resin at an uncured state and, optionally, at a completely cured state.

Abstract: An apparatus utilizes optical reflectivity (REF) to measure concentrations in liquids. The REF optical system is packaged in a compact and cost-effective form factor. An electronic circuit drives the optical system. The miniaturized REF sensor is situated in an optical-fluidic cell or an optical-fluidic manifold with an optical window in contact with the liquid. Changes in a total internal reflection (TIR) signal are sensitive to temperature and concentration of the liquid. These changes in the TIR signal are used to accurately determine the concentration in the liquid. The liquids may be either static or dynamic.

Abstract: A fiber optic fluid probe is employed in determining characteristics of a fluid or solid dispersed in the fluid into which the probe is immersed. The probe transmits electromagnetic radiation from a source by way of one or more fiber optic fibers and into the fluid, and then senses how the electromagnetic radiation interacts with the fluid. The optical signal returned from the probe, by way of fiber optic cables, is interrogated by an electronic instrument, which correlates the optical response to fluid properties and/or characteristics.

Abstract: A portable refractometer is provided that includes a lens barrel having a lens barrel axis. A prism is secured to one end of the lens barrel, the prism having an entry face that provides a boundary surface between the prism and a substance to be measured. A tube shaped optical chassis is inside the lens barrel, and is rotatably supported about a predetermined rotational axis perpendicular to the lens barrel axis. An objective lens is arranged in the optical chassis, and is positioned in relation to the optical chassis. An optical scale is arranged inside the optical chassis, at the focal point of the objective lens. A mover moves the objective lens relatively in relation to the optical scale in response to changes in temperature by turning the optical chassis about the rotational axis.

Abstract: An apparatus utilizes optical reflectivity (REF) to measure concentrations in liquids. The REF optical system is packaged in a compact and cost-effective form factor. An electronic circuit drives the optical system. The miniaturized REF sensor is situated in an optical-fluidic cell or an optical-fluidic manifold with an optical window in contact with the liquid. Changes in a total internal reflection (TIR) signal are sensitive to temperature and concentration of the liquid. These changes in the TIR signal are used to accurately determine the concentration in the liquid. The liquids may be either static or dynamic.

Abstract: An apparatus utilizes optical reflectivity (REF) to measure concentrations in liquids. The REF optical system is packaged in a compact and cost-effective form factor. An electronic circuit drives the optical system. The miniaturized REF sensor is situated in an optical-fluidic cell or an optical-fluidic manifold with an optical window in contact with the liquid. Changes in a total internal reflection (TIR) signal are sensitive to temperature and concentration of the liquid. These changes in the TIR signal are used to accurately determine the concentration in the liquid. The liquids may be either static or dynamic.

Abstract: Prism elements having TIR surfaces placed in close proximity to the active area of a SLM device to separate unwanted off-state and/or flat-state light from the projection ON-light bundle. The TIR critical angle of these prisms is selected to affect either the off-state light or additionally, any portion of flat-state light reflected from the SLM. To further improve the optical performance of the system, these TIR prisms can be attached directly to the SLM package, completely eliminating the package window.

Abstract: The invention relates to refractometry and attenuated reflectance spectrometry in a wellbore environment. Specifically, it pertains to a robust apparatus and method for measuring refractive index of fluids along a continuum (rather than in steps), and for measuring attenuated reflectance spectra, and for interpreting the measurements made with this apparatus to determine a variety of formation fluid parameters. The present invention provides a method and apparatus to distinguish between gas and liquid based on the much lower index of refraction of gas. It can also be used to monitor fluid sample clean up over time. The refractive index of a wellbore fluid is determined from the fraction, R, of light reflected off the interface between a transparent window that has a known refractive index and this fluid. Preferably, the refractive index is measured at some wavelength of light for which the fluid is not highly attenuating but is optimally attenuating.

Abstract: A measuring apparatus is disclosed which includes a measuring unit equipped with a dielectric block and a thin film layer; an incidence system for making a light beam enter the dielectric block so that a condition for total internal reflection is satisfied at an interface between the dielectric block and the thin film layer; and a photodetector for receiving the light beam totally reflected at the interface. The measuring unit is measured a plurality of times, and a change in the state of attenuated total reflection during the plurality of measurements is detected. The sensor further includes a tilt measurement section for measuring the longitudinal tilt of the interface which changes the incidence angles during the plurality of measurements, and a calculating section for obtaining a measured value in which errors due to the longitudinal tilt have been corrected.

Abstract: A refractometer with a measuring prism on whose measuring surface a sample to be tested can be mounted, which sample can be illuminated by a light beam emitted by a source of light under a range of angles that includes a critical angle for total reflection, and with a reciever for recieving the reflected light. An optical device that decomposes the reflected light into a color spectrum that is mounted in the path of the reflected light between the measuring surface and the reciever.

Abstract: A hand-held automatic refractometer comprises a linear scanned array having a plurality of photoelectric cells and an optical system for directing light onto the array, the particular photoelectric cells of the array which are illuminated by said light being determined by the index of refraction of a sample substance placed on a sample surface of a prism of the optical system. A reflective surface is arranged close to the array at an acute angle thereto for directing primary light from the sample-prism boundary to the array, and for redirecting stray reflected light from the array back onto the array. The disclosed refractometer has a compact design wherein the linear array extends in a direction substantially parallel to the prism sample surface. The prism is mounted in a housing and the sample surface faces upward to allow access through a sample well of the housing, while the array is mounted in the housing facing in a downward direction.

Abstract: The invention relates to a refractometer comprising an optical module (4) arranged floatingly inside a housing structure, which module comprises an optical window (2) to be positioned in a process fluid (3), and means for forming an illuminating beam and for directing it into the process fluid (3) through the optical window (2) and for directing back the part of the illuminating beam that is reflected from the process fluid, and further, means for watching the image formed in said manner. The optical module (4) is arranged to be supported against the housing structure by means of sealing (5) arranged between the optical window (2) and the housing structure. In order to provide a device suitable for difficult conditions, the housing structure part (6) in contact with the process fluid (3) against which the optical window (2) is arranged to be supported via sealing (5) is formed of a material that is chemically durable, mechanically rigid and durable and has good thermal conductivity.

Abstract: An optical configuration for differential refractive index measurements of a test sample relative to a reference sample comprises an optical path along which an illumination beam travels to simultaneously illuminate a pair of optical interfaces on opposite sides of a meridional plane corresponding to the test sample and reference sample, respectively. Partial beams leaving the optical interfaces are optically diverged to illuminate different segments of a linear scanned array aligned in the meridional plane. The difference in location of a pair of shadowlines or a pair of resonance minimums formed by the partial beams on the array provides an indication of the refractive index difference.

Abstract: A refractometric apparatus and method for monitoring the percentage of water in hydraulic and non-hydraulic fluids employ a temperature sensitive device allowing a user to obtain accurate and correct readings of various measured properties. In particular, the temperature sensitive member comprises a prism-wedge-mirror combination in conjunction with a bimetallic strip. The combination ensures the proper angular displacement of a light beam inside the refractometric apparatus and, therefore, the correct reading of a parameter to be measured.

Abstract: Disclosed herein is a measuring apparatus utilizing attenuated total reflection. The measuring apparatus is equipped with a dielectric block, a thin film layer formed on one surface of the dielectric block, an optical system for making a light beam enter the dielectric block so that a condition for total internal reflection is satisfied at an interface between the dielectric block and the thin film layer, and a two-piece photodiode for detecting the light beam totally reflected at the interface. When attenuated total reflection is detected a plurality of times for a single sample, the two-piece photodiode is disposed at a predetermined position relative to a dark line when a first measurement is made. The two-piece photodiode is also disposed at the same position as the predetermined position stored in a storage unit when a second measurement and measurements thereafter are made.

Abstract: A surface plasmon resonance device includes a metal thin film, a dielectric thin film on an optical member and, in addition, an electro-optically active thin film either between the metal thin film and the dielectric thin film or between the optical member and the metal thin film. The electro-optically active thin film is subject to a voltage which is varied to tune the resonance condition of the device.

Abstract: An optoelectronic liquid sensor indicates failure of operative components therein. The sensor includes a light source, a light detector, and a transparent probe which functions as a primary liquid sensing prism. The transparent probe is of a suitable configuration permitting internal reflection of light transmitted therethrough from the light source, along a primary light path for reception by the light detector, when the light-impinged surface of the primary prism is in air. When the same surface of the probe is submersed in or exposed to liquid, light from the light source traveling along the primary light path is refractively transmitted into the liquid, and therefore almost no light reaches via the primary light path. A secondary light path is provided, along which a fraction of the light from the light source is also transmitted via internal reflection within a transparent body to the light detector.

Abstract: An optical configuration for measuring a difference in refractive index between a first sample and a second sample comprises partitioned first and second optical interfaces symmetrically illuminated by an illumination beam to provide first and second partial beams defined by the refractive index of the first and second samples, respectively. First and second linear scanned arrays are positioned on opposite sides of a meridional plane of the optical configuration for respectively detecting the first and second partial beams. Thus, differential measurements are possible based on signal information from the arrays. Embodiments for critical angle and surface plasmon resonance refractive index measurements are disclosed. The disclosure also relates to methods for measuring a difference in refractive index between a first sample and a second sample in accordance with the described optical configuration embodiments.

Abstract: A sensor apparatus and associated method for sensing and monitoring specific binding of analyte to an immobilized binding layer are disclosed. The apparatus preferably comprises an automatic critical angle refractometer having a linear scanned array and an optical system for illuminating a portion of the array, which illumination depends upon the refractive index of the binding layer deposited on an optically transparent element. The apparatus further includes a flow cell for bringing the analyte in contact with the binding layer. The apparatus also includes a computer for receiving and processing refractive index data from the critical angle refractometer during the reaction between the analyte and the layer, which computer may be peripherally connected to the refractometer or enclosed within the refractometer housing.

Abstract: A refractometer which provides a “sugar” or “diet” indication when immersed on a beverage. The device is electronic and lights either a “sugar” or “diet” signal to the user. A prove has a light source and a photodetector at one end and an angled face at the other end. Depending on the refractive index of the beverage, the light is either reflected back into the probe and into the photodetector and exits out of the angled face and does not reflect back to the photodetector.

Abstract: A method and system for determining a spatially local index of refraction in optical materials is provided. Light, including a near-field intensity, is collected above a surface of the material. A probe is oscillated at a plurality of frequencies and in a substantially perpendicular manner relative to the surface of the material to detect the near-field intensity of the light. A distance of the probe from the surface of the material is modulated. Based on a ratio of the near-field intensity of the light detected at the plurality of frequencies, the local index of refraction is determined.

Abstract: An optoelectronic liquid sensor indicates failure of operative components therein. The sensor includes a light source, a light detector, and a transparent probe which functions as a primary liquid sensing prism. The transparent probe is of a suitable configuration permitting internal reflection of light transmitted therethrough from the light source, along a primary light path for reception by the light detector, when the light-impinged surface of the primary prism is in air. When the same surface of the probe is submersed in or exposed to liquid, light from the light source traveling along the primary light path is refractively transmitted into the liquid, and therefore almost no light reaches via the primary light path. A secondary light path is provided, along which a fraction of the light from the light source is also transmitted via internal reflection within a transparent body to the light detector.