Abstract: An optical emission spectroscopic (OES) instrument includes a spectrometer, a processor and an adjustable mask controlled by the processor. The adjustable mask defines a portion of an analytical gap imaged by the spectrometer. The instrument automatically adjusts the size and position of an opening in the mask, so the spectrometer images an optimal portion of plasma formed in the analytical gap, thereby improving signal and noise characteristics of the instrument, without requiring tedious and time-consuming manual adjustment of the mask during manufacture or use.

Abstract: An emission spectrophotometer capable of inhibiting non-uniformity of spectral intensities of component elements is provided. The emission spectrophotometer generates pulse light emission by supplying an energy accumulated in an electricity accumulating and discharging unit to a gap between an electrode and a test material, and the emission spectrophotometer includes a detection unit, for detecting an energy charged to the electricity accumulating and discharging unit before the pulse light emission; and a detection unit, for detecting an energy remaining in the electricity accumulating and discharging unit after the pulse light emission. It is determined whether the detected light is emitted by fully using the energy accumulated in the electricity accumulating and discharging unit.

Abstract: Devices and methods for screening emissive properties of a cell, such as the resistance to photobleaching or other photophysical property. In one example, a device may include a microfluidic reservoir having at least an input channel for receiving the cell, a main channel fluidly coupled with the input channel, at least a first output channel and a second output channel, the first and second output channels fluidly coupled with the main channel; and a multibeam interrogation section generating a plurality of light beams impinging upon the main channel of the microfluidic reservoir. As a cell passes from the input channel through the main channel of the microfluidic reservoir, the cell is exposed to the plurality of light beams thereby generating emissions that are received by a signal processing section. A cell trapping section selectively diverts the cell to the second output channel if the cell contains desired emissive properties.

Abstract: A laser induced breakdown spectroscopy system includes a laser module having a laser source, a sample chamber, a spectrometer arranged to capture spectral data from the sample chamber, a voltage source attached to the sample chamber arranged to apply a voltage to the sample during capture, and a controller in communication with the spectrometer, the voltage source and the laser module to trigger the voltage source and the spectrometer during laser excitation of the sample. A method of operating a laser induced breakdown spectroscopy system includes applying a voltage to a set of electrodes arranged around a sample, striking the sample with a laser during a time interval in which the voltage is being applied to the electrodes, sampling spectral data from the sample after the sample is struck with the laser, and removing the voltage after the spectral data has been sampled.

Abstract: A Raman spectrometer that employs a time-gated single photon avalanche diode array as a sensor is described. The spectrometer can also perform fluorescence spectroscopy and laser induced breakdown spectroscopy (LIBS). A laser is used to provide an excitation signal to excite a specimen of interest. A spectrometer is used to separate the various intensities over a range of wavelengths, which are then caused to impinge on the array to be recorded. The time-gated single photon avalanche diode array is triggered in synchrony with the excitation signal so as to allow time resolution of the response of the sample of interest to the excitation. The array can be time-gated to resolve signals that have shorter durations as a function of time while excluding signals that have a longer time duration. Raman and LIBS signals can be observed even from specimens that fluoresce strongly.

Abstract: Methods and systems for real time feedback and control of near-field material processing are disclosed, including generating electromagnetic radiation from a USP laser coupled to a central processing unit; coupling the electromagnetic radiation to an acousto-optic modulator; coupling the electromagnetic radiation to a beam delivery system; coupling the electromagnetic radiation to a beam delivery fiber; using the electromagnetic radiation to generate a plasma on a target mounted to an adjustable stage coupled to the central processing unit; coupling the electromagnetic radiation from the plasma to a plasma spectrum collection system; coupling the electromagnetic radiation to a spectrum analysis unit; coupling the electromagnetic radiation to a detector; and coupling the detector to the central processing unit; wherein the central processing unit uses the output from the detector as feedback in making adjustments to the USP laser and the adjustable stage. Other embodiments are described and claimed.

Abstract: A laser induced breakdown spectroscopy (LIBS) analyser (10) comprises an optical path P (shown by dashed lines P1 and dash-dot lines P2) and an automatic focus (or tracking) system (12). The optical path P focuses a laser beam emitted from a laser (14) onto a portion of sample S which is to be analysed by the analyser (10), and focuses radiation emitted by the sample S when irradiated by the laser beam to a detector (16). The automatic focus system (12) is capable of varying a length of the optical path P to maintain a constant spatial relationship (i.e. distance) between a focal point (18) of the laser beam and the sample S; as well as maintaining a constant instantaneous field of view (IFOV) of the detector (16) on the focal point of the laser.

Abstract: An electromagnetic radiation detection device is described which includes a tunable dispersive optical element configured to receive electromagnetic radiation and to change the dispersion of the received electromagnetic radiation; a sensor configured to detect the dispersed electromagnetic radiation changed by the dispersive optical element; and a controller configured to: (i) selectively tune the dispersive optical element so as to adjust the dispersion of the received electromagnetic radiation; and (ii) change one or more of operating parameters of the sensor in accordance with the adjusted dispersion. In some implementations, the radiation detection device may be configured as a spectrometer to measure one or more properties of electromagnetic radiation. A method for detecting electromagnetic radiation is also disclosed.

Abstract: The invention relates to a method for calibrating a deflection unit in a TIRF microscope, by means of which an angle of incidence of excitation light onto a specimen is adjusted, wherein a setting of said deflection unit is adjusted such that the pertaining angle of incidence is definitely greater or definitely smaller than an anticipated critical angle for total reflection of the excitation light on a surface of a used specimen, the angle of incidence is scanned by varying the setting of said deflection unit in the direction of an anticipated critical angle, an intensity of an optical response of the used specimen elicited by the excitation light being measured for each setting of the deflection unit, the intensity of the optical response of the specimen used is measured at least for a number of settings of the deflection unit until the intensity of the optical response of the specimen used traverses a flank, and the setting of the deflection unit pertaining to the flank is stored as the setting for the crit

Abstract: A method for reducing resources for selecting seed to be produced in commercial quantities or for research is disclosed. Samples of seed which are candidates for selection are collected and given an identifier. Specific tissue or structure from candidate seed is removed. A test or analysis is performed on the candidate seed or the removed tissue or structure. Results of the test or analysis are recorded and correlated to the seed's identifier. The results are evaluated and a decision is made whether to select a candidate seed for commercial production or for research. Time, space, and labor associated with growing plants in an experimental plot or greenhouse and taking tissue samples from growing plants is saved.

Abstract: A method and a device measure a chemical composition of a liquid metal suitable for coating a steel strip. The method measures a chemical composition of a liquid metal suitable for coating a steel strip for which the liquid metal is formed continuously in a first cavity, and the composition of the liquid metal is measured on a direct measurement surface thereof, for which a specimen of the liquid metal reaching the measurement surface is heated to a chosen temperature so as to isolate principally iron-based impurities from the measurement surface. Several embodiments of devices suitable for implementing the method are also presented.

Abstract: A method and apparatus is disclosed for detecting, classifying and identifying airborne and non-airborne particles on an individual basis in substantially real time by directing a particle stream to react with optical reporters and markers and then exposing the stream to an excitation source such that individual particles have their multiple identifying characteristics detected.

Abstract: The analysis apparatus 10 includes a plasma generation device 11 and an optical analysis device 13. The plasma generation device 11 generates initial plasma by energizing a substance in space to be turned into a plasma state, and maintains the plasma state by irradiating the initial plasma with electromagnetic wave for a predetermined period of time. Then, the optical analysis device 13 analyzes the target substance 15 based on a time integral value of intensity of emission from the target substance 15 in an electromagnetic wave plasma region, which is maintained by the electromagnetic wave.

Abstract: Disclosed are an apparatus and a method for detecting a surface plasmon resonance. The apparatus may radiate a polarized beam of light to a device, such as a surface plasmon resonance generator, and may measure variations in a temperature of the device to detect whether a surface plasmon resonance has occurred. The detection of a surface plasmon resonance may be associated with the presence of a particular material such as volatile organic compounds (VOCs) or materials disrupting ozone, for example.

Abstract: Described herein are methods and an apparatus to determine and replicate unknown ratios of original target liquid blends, such as hydrocarbon fuel blends or contaminants, by using an in-process fluorescence-monitored procedure. The method relies on trial-and-error mixing of the liquid ingredients into a single container. At the end of the trial-and-error procedure the formed blend becomes an exact replica of the target blend. The method can also be used to build calibration curves without employing sets of previously prepared standard solutions.

Abstract: A process for real-time classification of materials, the process including: conducting laser induced breakdown spectroscopy on the material (LIBS), wherein at least one second laser pulse is directed to the plume so as to selectively energize only a portion of the plume; measuring optical emissions from the energized portion of the plume; and assessing the elemental composition of the material on the basis of the optical emissions from the excited portion of the plume; wherein the energized portion of the plume is substantially smaller than the entire plume so that the measured optical emissions are relatively independent of the size of the entire plume and hence are relatively independent of the optical absorption and vaporization characteristics of the material, thereby allowing a more accurate assessment of the elemental composition of the material than if the assessment was based on the optical emissions from the entire plume.

Abstract: A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

Abstract: The present invention relates to a process control system which can measure the physical properties of a CIGS thin film in real-time in a continuous production line of a CIGS thin film solar cell, more specifically to a system for real-time analysis of material distribution of a CIGS thin film comprising: a header, which comprises a laser irradiation unit producing plasma from the CIGS thin film by irradiating a laser beam to a part of the CIGS thin film; and a spectrum detection optical unit detecting a spectrum generated from the plasma; a transfer unit, which transfers the header at the same rate and to the direction with the transfer rate and direction of the CIGS thin film; and a spectrum analysis unit, which analyzes the spectrum detected by the spectrum detection optical unit.

Abstract: The present disclosure provides fully integrated microfluidic systems to perform nucleic acid analysis. These processes include sample collection, nucleic acid extraction and purification, amplification, sequencing, and separation and detection. The present disclosure also provides optical detection systems and methods for separation and detection of biological molecules. In particular, the various aspects of the invention enable the simultaneous separation and detection of a plurality of biological molecules, typically fluorescent dye-labeled nucleic acids, within one or a plurality of microfluidic chambers or channels. The nucleic acids can be labeled with at least 6 dyes, each having a unique peak emission wavelength. The present systems and methods are particularly useful for DNA fragment sizing applications such as human identification by genetic fingerprinting and DNA sequencing applications such as clinical diagnostics.

Abstract: A method, apparatus, and system for a sorting flow cytometer include an objective lens having an optical axis coaxially aligned with the flow path at the focal point. A controllable energy source selectively alters an analyte according to a determination of whether the analyte is in a desired sub-population. In various embodiments, one or both of the emission from the controllable energy source and/or the emission from an illumination energy source passes through the objective lens. In some embodiments in which the emission from the controllable energy source passes through the objective lens, the objective lens may focus the emission from the controllable energy source at a different point than the focal point of a signal detected from the analyte and, in particular, at a point closer to the objective lens.

Abstract: An analytical assembly within a unified device structure for integration into an analytical system. The analytical assembly is scalable and includes a plurality of analytical devices, each of which includes a reaction cell, an optical sensor, and at least one optical element positioned in optical communication with both the reaction cell and the sensor and which delivers optical signals from the cell to the sensor. Additional elements are optionally integrated into the analytical assembly. Methods for forming and operating the analytical system are also disclosed.

Abstract: Automatic process and installation for inspecting and/or sorting objects or articles belonging to at least two different categories, and made to advance approximately in a single layer, for example on a conveyor belt or a similar transport support. The process includes subjecting the advancing flow of objects or articles to at least two different types of contactless analysis by radiation, whose results are used in a combined manner for each object or article to perform a discrimination among these objects or articles and/or an evaluation of at least one characteristic of the latter, the analyses including at least one surface analysis process able to determine the physical and/or chemical composition of the outer layer of an object or article exposed to the radiation used in this process, and at least one volume analysis process able to determine the equivalent thickness of material of the same object or article.

Abstract: A cable identification system is provided. The cable identification system includes a cable sleeve with some predetermined unique properties. The cable sleeve is adapted to receive a cable therein. The cable includes one or more electrical conductors therein. The cable identification system further includes a portable measuring device configured to detect the predetermined unique properties of the cable sleeve when positioned adjacent the cable at any point along the cable.

Abstract: The invention provides improved fiber optic probe assemblies which utilize a configuration of gradient index (GRIN) lenses to deliver light to a focal point and collect light for analysis from the same focal point. Also provided are methods for manufacturing the probe assemblies and related methods of spatially precise spectroscopy using the probe assemblies.

Abstract: A method is described for providing a continuous flow of a target material past a laser to enable repeated firings of the laser beam at the material in a controlled and uniform fashion. The objective is to provide a means to characterize the target material using laser induced breakdown spectroscopy. The method can be employed in a laboratory or field environment providing improved methods for characterizing in real time the properties of bulk materials.

Abstract: A fluorescence detection device includes a flow cell body including a flow channel through which a measurement object flows, a laser light source unit that irradiates, with a laser beam, the measurement object passing through a measurement point in the flow channel, a light-receiving unit that receives fluorescence emitted from the measurement object irradiated with the laser beam and outputs a light-reception signal, and a processing unit that outputs an output value of fluorescence intensity based on the light-reception signal outputted by the light-receiving unit. The flow cell body has a lens provided on a surface thereof so as to traverse an optical path of the laser beam.

Abstract: A system for laser-induced breakdown spectroscopy (LIBS) is provided. The system for the LIBS includes a laser module generating a first pulse laser and a second pulse laser. An optical delay device incident by the second pulse laser is used to increase an optical path of the second pulse laser. A Kerr medium incident by the second pulse laser generates a time gate, and allows a plasma light beam generated from a sample incident by the first pulse laser, passing through the time gate and being output at a time point. A detection device receives and measures the plasma light beam output at the time point to generate a signal. A processing module connected to the detection device detects a signal, and compares the signal with a data base to obtain information concerning a composition and element concentrations of the sample.

Abstract: Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification.

Abstract: Optical devices and methods for measuring samples while minimizing stray light are described. Such methods and devices are applicable to multiple fluid chambers with multiple sources as an integrated optical element. Light sources can be embedded onto a chip or microarray with multiple chambers, or can be part of an instrument arrangement.

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

Abstract: A hand-held, self-contained, battery-powered test instrument for analyzing composition of a sample includes an exciter for exciting at least a portion of the sample, a compact cross-dispersed spectrometer for receiving an optical signal from the excited portion of the sample and a processor for processing spectral data about the optical signal from the spectrometer. The exciter may include a spark generator and a counter electrode, a laser or other device for generating the optical signal from the sample portion. The spectrometer has a wavelength range broad enough to enable the test instrument to detect and determine relative quantities of carbon, phosphorous, sulfur, manganese, silicon, iron and other elements necessary to identify common alloys. The spectrometer includes a structural member made of a light-weight material having a small coefficient of thermal expansion (CTE).

Abstract: Disclosed is a spectrometer apparatus using a continuous wave laser and a photomultiplier tube. The spectrometer apparatus includes a continuous wave laser irradiating part to irradiate a continuous wave laser to introduced particles, a scattering light measuring part to measure a scattering light emitted from the particles due to the continuous wave laser, a triggering signal generator to generate a triggering signal if a measurement value of the scattering light measuring part is greater than a preset value or equal to the preset value, a pulse laser irradiating part to receive the triggering signal to irradiate a pulse laser to the particles, and a spectral analysis part to measure an emission light generated from the particles due to the pulse wave laser to analyze elements consisting of the particles.

Abstract: The invention concerns methods and apparatuses for quantitatively determining the concentration of fluorophores of a substance in a sample. A constant portion of the reference light of a reference light wave length (?r) emitted by a reference light source is coupled in by an optical element in the direction of a receiving element. A first value corresponding to the portion of the reference light coupled in which is incident on the receiving element is detected. The sample is irradiated with the excitation light of an excitation wave length (?ex) emitted by an excitation light source. A second value corresponding to the portion of the fluorescent light of an emission wave length (?em) emitted by the sample which is incident on the receiving element. The ratio of the second value to the first value is determined. The number of fluorophores in the substance is determined based on the ratio.

Abstract: A material can be analyzed using short pulses by applying a first pulse and a second pulse to the material in which the second pulse is delayed relative to the first pulse. The first and second pulses are directed toward a material along collinear paths, and the material is ablated using the first pulse to cause particles to be emitted from the surface of the material. The emitted particles are atomized and/or ionized using the second pulse, and the radiation from the atomized and/or ionized particles is analyzed.

Abstract: Herein are disclosed methods and devices for evaluating the quality of oils (e.g., cooking oil or flying oil). The methods can provide an indication of the free fatty acid content of the oil. The methods use an optical interrogation device to provide an indication of free fatty acid based on quantitative measurements of optical reflectance from test zones on a sampling substrate.

Abstract: A method and apparatus for analyzing a target material is provided. A first laser beam pulse can be incident on a target material to create an ablation event so as to produce an ablation plume of target material. Such ablation events can include plasma ablation, sub-plasma ablation, and thermal desorption. At least a portion of the ablation plume of target material can then be transported a sufficient distance away from the ablation event that a second laser beam pulse can interact with the at least a portion of the ablation plume of target material to create an analytical plasma such that the analytical plasma is uncoupled from the ablation event. The creation of the analytical plasma results in one or more elements of the at least a portion of the ablation plume of target material undergoing atomic emission, which can be collected and analyzed.

Abstract: The present invention regards methods and devices for detecting plaque on a surface in the oral cavity to which a fluorescent agent capable of binding to plaque has been applied, whereby a radiation source emits incident radiation for contacting the surface, reflected light and fluorescent emission resulting from contact of the radiation with the surface is collected by an optical collector and conveyed by an optical pathway in the device, where the optical light signal of the reflected light and fluorescent emission is converted to an electrical signal, and where the electrical signals of the fluorescent emission and the reflected light are then mathematically manipulated to provide a compensated plaque value as a function of the distance from the optical collector and the surface of the oral cavity to which the fluorescent agent has been applied.

Abstract: Adhesive compositions useful for bonding fluorescent material-containing cellulosic substrates such as envelopes may be formulated using an adhesive polymer such as an emulsion of polyvinyl acetate in water and one or more compounds capable of reducing the degree of fluorescence exhibited by the substrate in areas of the substrate surface having the adhesive coated thereon. When irradiated by short wavelength light, the surface areas containing the adhesive coating appear darker than the surface areas that are free of adhesive, allowing quality control problems associated with application of the adhesive to be readily monitored and corrected. At the same time, however, the adhesive may be formulated such that the fluorescence-reducing compound does not alter the appearance of the adhesive coating when viewed under normal daylight conditions.

Abstract: The present application has a proposition to provide a highly efficient laser excitation fluorescent microscope. Accordingly, a laser excitation fluorescent microscope of the present application includes a laser light source part radiating at least two types of excitation lights having different wavelengths; a light collecting part collecting the two types of excitation lights on a sample; a high-functional dichroic mirror, disposed between the laser light source part and the light collecting part, reflecting the two types of excitation lights to make the excitation lights incident on the light collecting part, and transmitting two types of fluorescence generated at the sample; and a detecting part detecting light transmitted through the high-functional dichroic mirror, in which an incident angle ? of the excitation lights and the fluorescence to the high-functional dichroic mirror satisfies a formula of 0°<?<45°.

Abstract: A method for conducting FCS measurements includes providing a sample volume, emitting a target light having a first wavelength from a target light source, and marking an FCS volume in the sample volume with the target light by directing the target light onto the sample volume. An illuminating light having a second wavelength is emitted from an illuminating light source, the second wavelength being different than the first wavelength, and the illuminating light is directed onto the sample volume.

Abstract: A laser induced breakdown spectroscopy system includes a laser module having a laser source, a sample chamber, a spectrometer arranged to capture spectral data from the sample chamber, a voltage source attached to the sample chamber arranged to apply a voltage to the sample during capture, and a controller in communication with the spectrometer, the voltage source and the laser module to trigger the voltage source and the spectrometer during laser excitation of the sample. A method of operating a laser induced breakdown spectroscopy system includes applying a voltage to a set of electrodes arranged around a sample, striking the sample with a laser during a time interval in which the voltage is being applied to the electrodes, sampling spectral data from the sample after the sample is struck with the laser, and removing the voltage after the spectral data has been sampled.

Abstract: There is provided a portable measuring system having a biophotonic sensor. The portable measuring system also includes a tunable light source, an output intensity detector and an output wavelength detector, which are mounted therein. The portable measuring system can precisely measure a variation in the reflectivity spectrum and/or the transmittance spectrum of the biophotonic sensor before and after an antigen-antibody reaction by varying the wavelength of the tunable light source. Thus, the concentration of the antigen is precisely measured.

Abstract: A method for characterizing samples having units, by monitoring fluctuating intensities of radiation emitted, scattered and/or reflected by said units in at least one measurement volume, the monitoring being performed by at least one detection means, said method comprising the steps of: a) measuring in a repetitive mode a number of photon counts per time interval of defined length, b) determining a function of the number of photon counts per said time interval, c) determining a function of specific brightness of said units on basis of said function or the number of photon counts.

Abstract: Disclosed is a fluorescence meter for analyzing a sample, comprising a main beam path and at least one optical module. The fluorescence meter is embodied so as to provide at least one electromagnetic beam for exciting the sample and receive at least one electromagnetic beam emitted by the sample, at least some sections of at least two of the electromagnetic beams being located on one plane while extending along the main beam path.

Abstract: The apparatus for measuring concentrations of fuel mixtures using depth-resolved laser-induced fluorescence is a fluorometer equipped with a sample container holder that is movable in the path of the beam from the light source. Fluorescent emissions from the sample mixture pass at 90° to the excitation light path through a slit that is narrow enough that the emission intensity is effectively produced by a thin layer of the sample and focused on a monochromator, with successive thin layers receiving nonuniform excitation radiation due to reduction of intensity along the excitation light source path with increasing depth penetration and due to reabsorption of emitted fluorescence from adjacent layers. The method has a first mode in which the emission spectrum is scanned at a fixed depth, and a second mode in which the sample is moved relative to the emission monochromator slit to vary the depth while keeping the emission wavelength fixed.

Abstract: The present invention has a laser and a second energy source act in combination to produce a plasma that emits characteristic radiation for a prolonged period of time. The laser energy is directed to a sample for a period of time to ignite a plasma containing the sample material and to either ablate or vaporize the sample. Energy from a second energy source is supplied to the plasma for a second period of time so that the characteristic radiation emitted by the plasma is maintained. The emitted radiation is used to identify chemical elements contained in the sample. The second period of time is typically larger than the first period of time and may be as long as many milliseconds. Supplying energy for this longer period of time allows the plasma to grow in size and contributes to the large enhancement in the detection sensitivity of the present invention.

Abstract: Provided are laser induced breakdown spectroscopy (LIBS) devices. Embodiments of the devices are configured to obtain a spatial resolution of 10 ?m or less. Also provided are methods of using the subject LIBS devices to determine whether one or more elements of interest are present in a target sample. The devices and methods find use in a variety of applications, e.g., submicron and nanoscale chemical analysis applications.

Abstract: Two-color (two-photon) excitation with two confocal excitation beams is demonstrated with a Raman shifter as excitation light source. Two-color excitation fluorescence is obtained from Coumarin 6H dye sample (peak absorption=394 nm, peak fluorescence=490 nm) that is excited using the first two Stokes outputs (683 nm, 954 nm, two-color excitation=398 nm) of a Raman shifter pumped by a 6.5 nsec pulsed 532 nm-Nd:YAG laser (Repetition rate=10 Hz). The two Stokes pulses overlap for a few nanoseconds and two-color fluorescence is generateven with focusing objectives of low numerical apertures (NA?0.4). We observed the linear dependence of the two-color fluorescence signal with the product of the average intensities of the two Stokes excitation beams. The two-color fluorescence distribution is strongly localized around the common focus of the confocal excitation beams.

Abstract: A system and method processes a structure comprising embedded material. The system includes a laser adapted to generate light and to irradiate an interaction region of the structure. The system further includes an optical system adapted to receive light from the interaction region and to generate a detection signal indicative of the presence of embedded material in the interaction region. The system further includes a controller operatively coupled to the laser and the optical system. The controller is adapted to receive the detection signal and to be responsive to the detection signal by selectively adjusting the laser.

Abstract: The invention provides an apparatus and method for generating quantum-correlated and/or polarization-entangled photon pairs with unequal wavelengths. The photon pairs generated collinearly with respect to the pump light via a nonlinear process in a nonlinear optical medium are collected into a single mode fiber and split using a dichroic device. The wavelengths of photons constituting a pair are selected such that, first, their efficient propagation in the same single mode optical fiber, and second, their efficient splitting with high switching ratio, is possible. A detected rate ˜105-106 pairs/s and >98% quantum interference visibility of polarization entanglement is observed. This source, given its performance, robustness and minimum alignment requirements is ideal for quantum communication schemes, in particular for entanglement-based quantum cryptography.