Abstract: An optical sensor comprises a sensing element comprising a waveguide grating with a response that varies with an effective modal index experienced by light propagating in the grating and a sample window for receiving fluid which affects the effective modal index to modify the response, the sensing element arranged to receive light from a light source and to output the light after filtering; and an analyzing element comprising a second waveguide grating having a second response, and arranged to receive light output by the sensing element and to output the light after filtering for detection by an optical power detector. The combination of the two gratings converts changes in the wavelength of light output by the sensing element in response to the sample of fluid to changes in the amount of light, allowing the fluid index to be deduced from a measurement of optical power. The two elements may be fabricated on a single substrate to reduce errors from environmental disturbances such as temperature changes.

Abstract: A method of manufacturing a semiconductor device using immersion exposure in which exposure is carried out with an immersion exposure liquid interposed between a projection lens and a substrate, includes preparing a photomask on which a plurality of patterns are formed, projecting the patterns formed on the photomask, on a predetermined surface via the projection lens and the immersion exposure liquid, acquiring dimensional information on dimension acquiring patterns based on the patterns projected on the predetermined surface, adjusting a refractive index of the immersion exposure liquid on the basis of the dimensional information, and projecting patterns formed on the photomask, on a substrate via the projection lens and the immersion exposure liquid with the refractive index adjusted.

Abstract: A composite waveguide for evanescent sensing in fluorescent binding assays comprising a substrate layer having one or more thin-film waveguide channels deposited thereon. Binding molecules having the property of binding with specificity to an analyte are immobilized on the surface of the thin-film channels. In preferred embodiments, the composite waveguide includes integral light input coupling means adapted to the thin-film channels. Light coupling means may include a grating etched into the substrate prior to deposition of the thin film, or a waveguide coupler affixed to the upper surface of the thin film. The waveguide coupler has an input waveguide of high refractive index which receives the laser light through one end, propagating it by total internal reflection. Propagated light is coupled evanescently into the thin film across a spacer layer of precise thickness with a lower index of refraction than that of the input waveguide or the thin-film waveguide.

Abstract: System and method for fluorescent light excitation and detection from samples to enhance the numerical aperture and/or reduce the cross-talk of the fluorescent light.

Abstract: Method and apparatus for analysing a substance in a container, the method comprising the steps of: disposing antenna means (3) at a predetermined geometrical distance (L) from a container portion (13); transmitting a signal from said antenna means through a surface portion (12) of the substance towards said container portion; receiving a first reflected signal in said antenna means from said container portion; determining a geometrical distance (L1) from the surface portion to the container portion; varying the frequency of the transmitted signal to determine a first phase displacement between the transmitted signal and the first reflected signal; determining an optical distance from the surface portion to the container portion based on the first phase displacement; and determining the index of refraction (nt) of said substance based on the optical and geometrical from the surface portion to the container portion.

Abstract: An optical refractometer is provided for measuring the refractive index of a liquid. Such a refractometer includes a first optical block having a transparent material whereto is secured a light source, a second optical block having a transparent material whereto is secured a position sensor. The optical blocks are arranged on either side of a conduit wherein the liquid flows.

Abstract: The invention concerns an equipment for monitoring an immersion lithography device provided with a main light source and a projection optics for printing images on a wafer. The propagating medium extending from the projection optics to the wafer consists of a liquid (3). The equipment comprises: a chamber (51) for receiving at least part of said liquid (3), a diffraction grating (50) immersed in the chamber; a secondary light source (271) for emitting a secondary incident beam (20) towards the grating so as to obtain a diffracted beam; angle measuring members (57) capable of measuring at least one diffraction angle corresponding to a maximum intensity of an order of diffraction of the beam diffracted by the grating (500), and computing means (505) for calculating an estimate of a physical quantity concerning the refractive index of the liquid.

Abstract: To enable precise measurement of a cellular thickness distribution regardless of changes in the refractive index of a culture solution with the progress of culture. There is provides a culture vessel made of a transparent material with a culture surface capable of culturing cells in an adhesive manner on the bottom face, wherein a reference substance having an already known refractive index and an already known thickness dimension is fixed to a part of the culture surface.

Abstract: A refractometer for measuring refractive index of a sample comprising a prism having an interface contacting the sample, a light source that radiates light towards the interface from an entrance face of the prism, and a photoelectric sensor for receiving light reflected at the interface and directed outward from an exit face of the prism. The light source and the photoelectric sensor are secured to the prism. The refractometer comprises a sample stage arranged surrounding the interface surface. This sample stage provides a non-adhesive coating formed on the surface thereof. The refractometer comprises filter means arranged between the interface surface and the photoelectric sensor. This filter means includes a wavelength filter that selectively allows transmission of light having a wavelength within a prescribed region, including a wavelength of light of the light source.

Abstract: A method, a portable device and a measuring instrument for standardization of a satellite measuring instrument to a corresponding master measuring instrument are disclosed. The portable device includes a device for containing a reference material, and an information unit for storing information about the reference material and measurements of the reference material on the master measuring instrument. When placed in a satellite measuring instrument, information from the master instrument stored in the information unit of the portable device is transmitted automatically and wirelessly to the satellite instrument and, together with measurements by the satellite instrument of the reference masterial in the portable device, a standardization model for the satellite instrument and the sample type is obtained.

Abstract: The invention provides a method and apparatus for evaluating the product quality and performances of micromirror array devices through measurements of the electromechanical responses of the individual micromirrors to the driving forces of electric fields. The electromechanical responses of the micromirrors according to the present invention are described in terms of the rotational angles associated with the operational states, such as the ON and OFF state angles of the ON and OFF state when the micromirror array device is operated in the binary-state mode, and the response speed (i.e. the time interval required for a micromirror device to transit form one state to another) of the individual micromirrors to the driving fields.

Abstract: A soil moisture sensor uses a non-collimated light source and a photosensor, respectively, mounted at the foci of a transparent ellipsoidal plastic body. The dimensions of the body are such that emitted light rays are internally reflected toward the photosensor at the surface of the ellipsoid if the surface is dry, but refracted outwardly of the body when the surface is wet. The amount of light reflected onto the photosensor is thus a measure of the amount of moisture at the surface of the sensor. Direct illumination of the photosensor by the light source is prevented either by interposing opaque electronic components between them on a circuit board, or by taking advantage of light source characteristics to minimize the amount of transmitted light. If a circuit board is used, it is completely encapsulated against moisture penetration by fixing it in a carrier and molding the body around and onto the carrier to form a monolithic unit with the carrier and circuit board.

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: Waveguide gratings, biosensors, and methods of using a waveguide grating, including as a biosensor.

Abstract: Disclosed is a device for detecting at least one ligand contained in a sample that is to be analyzed. Said device comprises an optical waveguide, on the surface of which at least one ligand-specific receptor is directly or indirectly immobilized. The ligand bonds to said receptor during contact therewith. The inventive device comprises at least one optical source of radiation for injecting excitation radiation into the waveguide, the radiation being used for exciting emission of luminescence radiation in accordance with the bonding of the ligand to the receptor. At least one radiation receiver is integrated into the semiconductor substrate of a semiconductor chip so as to detect the luminescence radiation. The waveguide is integrated in a monolithic manner into the semiconductor substrate or is applied thereupon as a wave-guiding layer.

Abstract: A device for determining a refractive index (Rl) in a large number of points of a physical medium, comprising: a light laser for performing a series of p pulsed laser rays (PLRs) each proceeding from a starting point Ap and arriving in an arrival point Bp following the shortest optical path between the two points Ap and Bp; a timer to record a time Tp when each PLR reaches the arrival point Bp; and a computer programmed for finding the shortest optical path among all the optical paths starting from the starting point Ap and all reaching the arrival point Bp, and from p linear equations linking elementary optical paths (L) and the refraction indices (N) to the detected travel time Tp, for solving the matrix equation [N]*[L]=[T] relative to a vector of the refractive indices [N] and repeating until [L] and [N] converge.

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 optical reader system and method are described herein that directs a non-coherent light towards a biosensor, collects the non-coherent light which is reflected (or transmitted) from (or through) the biosensor, and then angularly filters the collected non-coherent light to obtain a narrow spectral response which can be analyzed to determine if a biological substance is located on the biosensor or if a biomolecular event took place on the biosensor.

Abstract: The invention relates to a measuring device (01) for measuring the refraction properties of optical lenses (07), especially spectacle glasses, comprising a measuring light grid (20) for producing a plurality of light beams (16) which are deflected by the lens (07) as a result of refraction of light, and comprising a measuring light detector (12) on which the deflected light beams are projected and are there recorded electronically, and comprising an evaluation device in which the refraction properties of the lens (07) are determined from the measurement signals of the measuring light detector (12), wherein an additional measuring system (14, 20) for electronic measurement of the geometry of the front lens surface (18) and/or the rear lens surface (19) is provided in the device, wherein the measurement result of the additional measuring system (14) is included in the determination of the refraction properties of the lens (07) in the evaluation device.

Abstract: Systems and methods for identifying refractive-index fluctuations of a target are described in this application. One embodiment includes identifying one or more properties of emergent light, the emergent light to be emergent from a target, and determining refractive-index fluctuations of the target based on the one or more properties of the emergent light. The determining refractive-index fluctuations further comprises determining one or more of the variance of the refractive-index fluctuations and the spatial correlation length of the refractive-index fluctuations. The determining refractive-index fluctuations further comprises determining one or more of the variance of the refractive-index fluctuations and the spatial correlation length of the refractive-index fluctuations.

Abstract: A method and apparatus is described for estimating terminal purity or terminal contamination for a fluid during the withdrawal of the fluid from a subsurface formation. The apparatus and method provide for measuring refractive index of the fluid over a time period, fitting a curve through the refractive index measurements or data values derived therefrom and estimating a terminal refractive index or terminal value for the data values from the fitted to curve to estimate the terminal contamination or purity for the fluid.

Abstract: A cavity ring-down sensor having an optical path of mirrors and an interface proximate to a mirror with a normal incidence optical fiber coupling. The interface may be a block of transmissive materials having different indices of refraction for receiving a light beam of normal incidence from an optical fiber and directing the beam into the optical path. The sensor may be used applications where the optical fiber needs to be straight into the sensor without unusual bending because of space limitations. One application of this sensor may be for ground water testing via a narrow well casing.

Abstract: System and method for fluorescent light excitation and detection from samples to enhance the numerical aperture and/or reduce the cross-talk of the fluorescent light.

Abstract: A photonic crystal sensor for outputting an output signal using a light source. The photonic crystal sensor includes a photonic crystal structure and a defect member disposed adjacent the photonic crystal structure. The defect member defines an operative surface. An input light signal from the light source is inputted to the photonic crystal structure and defect member and is internally reflected to thereby output the output signal. Also, the output signal relates to a condition at the operative surface.

Abstract: The invention is related to different embodiments of a kit for the simultaneous qualitative and/or quantitative determination of a multitude of analytes comprising a sensor platform comprising an optical thin-film waveguide with a layer (a) transparent at least at an excitation wavelength on a layer (b) with lower refractive index than layer (a), also transparent at least at said excitation wavelength, and at least one grating structure (c) modulated in said layer (a), for the incoupling of said excitation light into layer (a), at least one array of biological or biochemical or synthetic recognition elements immobilized in discrete measurement areas (d) directly or by means of an adhesion-promoting layer on layer (a), for specific recognition and/or binding of said analytes and/or for specific interaction with said analytes, means for laterally resolved referencing of the excitation light intensity available in the measurement areas, and optionally means for the calibration of one or more luminescences gen

Abstract: A method for improving accuracy of optical critical dimension measurement of a substrate is provided. A process parameter that influences the refractive index and extinction coefficient of a thin film in the substrate is identified. A refractive index and extinction coefficient across a plurality of wavelengths as a function of the process parameter is identified. During the regression modeling of the optical critical dimension measurement, the refractive index and extinction coefficient across the plurality of wavelengths is adjusted through the function via the process parameter.

Abstract: While objects travel through an optical cavity, the cavity provides output light that is affected by the objects, causing the output light to have a varying intensity function. The output light is photosensed to obtain sensing results that depend on the varying intensity function. The sensing results are used to distinguish at least one object, such as from its environment or from objects of other types. The objects can, for example, be particles or biological cells, and their optical characteristics, such as refractive index or absorption, can affect the output light, so that information about them is included in the output light. The output light can, for example, have a laterally varying intensity function with peaks whose features change due to the objects. The sensing results can also be used to track objects, together with other information, such as about the speed of a fluid that carries the objects through the cavity.

Abstract: This refractometer includes at least one optical waveguide (2) comprising at least one slanted Bragg grating (4), formed in a part of the waveguide, which is placed in contact with the medium (7) of which the refraction index is to be determined, a light source (10) coupled to the waveguide in order to send this light there and have it interact with the grating, means (17) for measuring the optical power of the light diffracted to the radiation-mode continuum, when the light transmitted by the source interacts with the grating, and electronic processing means (22) for supplying the value of the refraction index of the medium based on this optical power.

Abstract: There are provided a microchemical system capable of acquiring a highly accurate TLM output value and a method for calculating TLM output thereof. A microchemical system 1 comprises: a microchemical chip having a channel with a depth t in which a sample flows; an exciting light source 13 adapted to irradiate the sample with an exciting light through an objective lens 10 with a numerical aperture NA; a detecting light source 14 adapted to irradiate the sample with a detecting light coaxially with the exciting light through the objective lens 10; and a PD adapted to receive a transmitted light when the detecting light transmits the sample before and after formation of a thermal lens 12. When a TLM output is calculated in the microchemical system 1 on the basis of a received light amount of the PD, the depth t (?m) is set to the range of 75?t?300, the numerical aperture NA is set to the range of 0.04?NA?0.

Abstract: In optical line width measurement performed using the scatterometry technique, the present invention measures the line width formed on a substrate more accurately than in the prior art. After a predetermined pattern is formed in a resist film on a substrate, the refractive index and the extinction coefficient of the resist film are measured. Based on the measured values, calculation is performed to obtain calculated light intensity distributions of reflected light reflected from a plurality of virtual patterns. The calculated light intensity distributions are stored, and their library is created. The substrate for which the refractive index and so on are measured is irradiated with light, and the light intensity distribution of its reflected light is measured.

Abstract: A system and method and for analyzing dew in a system of interest are provided. A representative method comprises receiving infrared information corresponding to a degree of polarization of dew in a particular environment, and using the degree of polarization to determine dew presence in the environment. Changes in the degree of polarization can be attributed to changes in the density, size or shadowing of the dew drops. Infrared emissions information can be detected and accumulated over a range of emission angles and over a period of time. The system compares the accumulated data for the particular environment to detect the presence of dew, the rate of growth of the dew and the change in characteristics of dew over a period of time starting from a first time interval. The system also compares the accumulated data with other previous accumulated data from the environment to detect if changes should be made to the environment.

Abstract: An optical system that includes a molded optical element having a non-uniform refractive index distribution due to molding and a method of manufacturing the optical system is disclosed. Data of the non-uniformity of the refractive index distribution associated with molding of the molded optical element is acquired and used in order to determine the form of an aspheric surface of the molded optical element for correcting aberrations caused by the non-uniformity of the refractive index distribution. This data may be acquired by measuring the refractive index distribution of an optical element molded based on initial design values that are based on assuming uniformity in the refractive index distribution of the molded optical element or it may be computed based on the form of the molded optical element. The optical element may include a concave optical surface and may be a lens element that includes an aspheric surface.

Abstract: Method and apparatus for setting optical imaging properties using radiation treatment, specifically a method and an apparatus for setting the imaging properties of an optical system with radiation treatment of at least one optical element of the optical system in the installed state, and a method for setting the imaging properties of an internal optical element with radiation treatment. A measurement is carried out on the optical system in order to determine one or more aberrations in a spatially resolved fashion, a correction that changes the shape and/or refractive index of the internal optical element is calculated in order to reduce the measured aberration or aberrations, and the optical element is irradiated with the aid of a processing radiation that changes the shape and/or refractive index, in accordance with the calculated correction.

Abstract: The present invention features use of evanescent field sensing to detect or evaluate unpurified, unlabeled analytes in raw samples. Capture molecules capable of binding to an analyte of interest can be immobilized to a sensing surface of an evanescent field sensor. The interaction between the analyte of interest in a raw sample and the immobilized capture molecules alters the refractive index at the sensing surface, thereby producing a detectable signal in the reflected light from the surface. Raw samples amenable to the present invention include, but are not limited to, cell lysates, tissue extracts, bodily fluid, or biologically-derived samples. Evanescent field sensors suitable for the present invention include, but are not limited to, grating-coupled waveguides.

Abstract: A method for measurement of a specimen is provided. The method includes measuring spectroscopic ellipsometric data of the specimen. The method also includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from the spectroscopic ellipsometric data. A computer-implemented method for analysis of a specimen is also provided. This method includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from spectroscopic ellipsometric data generated by measurement of the specimen. In some embodiments, the methods described above may include determining an index of refraction of the nitrided oxide gate dielectric from the spectroscopic ellipsometric data and determining the nitrogen concentration from the index of refraction. In another embodiment, the methods described above may include measuring reflectometric data of the specimen.

Abstract: A method and apparatus are provided for monitoring an immersion photolithography process, the method including supplying an immersion fluid having an initial refractive index, performing photolithography using the supplied immersion fluid, recovering the used immersion fluid; and the apparatus including a light source, one or more fluid passageways disposed relative to the light source, and a light detector disposed on an opposite side of the fluid passageways relative to the light source for measuring a refractive index of a fluid in the fluid passageways.

Abstract: An improved surface plasmon resonance (SPR) sensor is provided based on direct measurement of the Goos-Hänchen effect. Sensor sensitivity is enhanced by selecting the thickness of the metallic layer of the SPR sensor to be close to a critical thickness dcr where the effect of the surface plasmon resonance on the Goos-Hänchen shift is most pronounced. Overall sensor sensitivity is surprisingly found to improve with this approach, even though the measurement is based on a second order effect (i.e., the Goos-Hänchen shift) instead of the first order reflectance change measured in conventional SPR sensor approaches. The invention is also applicable to sensors based on measurements of other non-specular reflection parameters, such as temporal shifts, frequency shifts, and/or angular shifts.

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 swept-angle SPR measurement system deflects an optical beam over a range of deflection angles according to a control signal and maps the deflected beam to a target within a range of incidence angles that corresponds to the range of deflection angles.

Abstract: Disclosed herein is a method comprising illuminating a microstructured prism, or linear array of prisms of a prism sheet with an incident beam. The method further comprises making measurements of the refracted image of the beam on a measuring device to measure the distance disposed on an opposing side of the prism sheet from the side that the light beam is incident upon. Measurement of two angles of the refracted images of the beam on the ruled scale, measured twice, illuminating the sample at different angles are used in an equation to simultaneously provide the apex angle, the skew angle and the refractive index of the prism sheet.

Abstract: A device is presented for computing an optical center of a sensor array relative to a lens. The sensor array includes a plurality of sensor units, and each sensor unit has a position on the sensor array. The lens defines an optical axis. The device includes a configuration module and a processing circuit. The configuration module is provided for positioning the lens and the sensor array thereon. When test light is parallel to the optical axis and is incident to the lens, the sensor array receives the test light transmitted by the lens so that each sensor unit outputs a value. The processing circuit is linked to the sensor array for receiving values outputted from the sensor units and selecting positions of sensor units outputting a specific value among the values, for computing the optical center of the sensor array.

Abstract: A first core layer and a second core layer, serving as optical waveguides, whose refractive indexes are greater than that of a substrate are placed on the surface of the substrate that functions as a cladding layer. An interval between the first core layer and the second core layer is partially narrowed so that lightwaves progressing through these core layers may develop an optical mode coupling. Disposed in this optical mode coupling area is a detector, which comes in contact with liquid or gas and interacts with a substance to be detected, such as chemical or biological substance. A receptor material which selectively captures the substance to be detected is fixed on a surface of the detector. Antibody, enzyme, cell, ionophore, single-strand DNA and the like are examples of the receptor material.

Abstract: A real-time method of determining paste solids includes: correlating the refractive index of a paste with solute concentration in a solvent using a plurality of paste solids concentrations, typically including at least two paste solids concentrations greater than about 5 percent; submersing a fiber optic refractometer sensor into a sample and allowing it to equilibrate for a period of from about 30 seconds to about 20 minutes prior to measuring refractive index of the sample; measuring the refractive index of the paste sample with the fiber optic refractometer sensor; and determining the concentration of solute in the sample using the correlation.

Abstract: Methods and apparatus for measuring a critical dimension of an optically-anisotropic feature, including extracting a number of values each descriptive of the optically-anisotropic feature, including values corresponding to ordinary and extraordinary measurements of one or more optical characteristics of the optically-anisotropic feature. The optical characteristics can include the index of refraction and/or the extinction coefficient of the optically-anisotropic feature, among others. Additionally, the values can be input into an optical critical dimension (OCD) measurement model, such that the critical dimension can be verified via optical measurement based on the OCD measurement model. The optical measurement of the critical dimension can also be verified via scanning electron microscope (SEM) measurement.

Abstract: Methods and apparatuses for measuring the optical properties of solids, gels, and liquids are disclosed. The apparatuses may be constructed on miniature substrates using conventional semiconductor wafer and packaging processes. The substrates may be mass-produced on wafers, which are then diced to provide individual miniature substrates. High measurement precision, low-manufacturing costs, and other benefits are provided by the present inventions.

Abstract: A lens meter for measuring refractive power distribution of a progressive power lens and displaying its distribution map, has a lens rest having an aperture, an optical system including an axis, a source projecting a light bundle along the axis, a plate having targets and a two-dimensional image sensor detecting images by the bundle passing through the lens, aperture and plate, a part calculating the distribution within a measurement region from detection results, a part detecting a lens-position in a two-dimensional direction orthogonal to the axis, a device guiding movement on the rest to shift the measurement region and obtaining the distribution within an analysis region including distance, progressive and near portions, a part storing the distribution in the measurement region in association with the detected position, a display part, and a part controlling to display the distribution map within the analysis region based on the stored distribution and position.

Abstract: Systems and methodology for determining not only precise and repeatable results, but accurate values of the refractive index of solids, fluids and liquids.

Abstract: A method of optimizing the predictability of a vision correction procedure by comparing historical data, including the vision defect, the correction method and outcome, in terms of wavefront aberrations with a patient's condition to select an acceptable procedure. The patient's eye is examined and an optical model is created and compared to the historical data to select an acceptable procedure. The procedure is performed and the outcome is included in the data base.

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 system for measuring an index of refraction that has a light emitting diode and a plurality of reference fibers not in contact with a sample to be measured and that receive light from the light emitting diode. A plurality of sensing fibers with different-shaped plasmon sensors are in contact with the sample and receive light from the light emitting diode. Detectors sense an output of the light from the fibers. The sensing fibers can be arrayed in a planar arrangement, or in a bundle. A cylindrical lens can be used for directing light into the fibers. A plurality of light emitting diodes can be used, each directing its light output into a corresponding fiber. A ball lens can be used for directing the light into the reference fiber. A plurality of wavelength filters can be placed between the light emitting diode and the sensing fiber, and a wavelength of the light entering the fiber may be selected using the filters.