A distributed gas detection system includes one or more hollow core fibers disposed in different locations, one or more solid core fibers optically coupled with the one or more hollow core fibers and configured to receive light of one or more wavelengths from a light source, and an interrogator device configured to receive at least some of the light propagating through the one or more solid core fibers and the one or more hollow core fibers. The interrogator device is configured to identify a location of a presence of a gas-of-interest by examining absorption of at least one of the wavelengths of the light at least one of the hollow core fibers.

A method and apparatus for introducing droplets of liquid sample into an analysis device using a gas stream, the droplets being produced by the application of acoustic energy to a quantity of liquid sample. Acoustic energy may be applied to a quantity of liquid sample located on a solid surface of a sample support so as to eject a droplet of sample from the quantity of sample; the droplet of sample may be entrained in a gas stream; and the droplet of sample may be transported into the analysis device using the gas stream.

Provided is a sample-analyzing system used for identifying a target sample from its measurement data obtained using a plurality of analyzing devices including at least one device selected from a fluorescent X-ray analyzer, atomic absorption photometer and inductively coupled plasma emission analyzer as well as at least one device selected from an infrared spectrophotometer and Raman spectrophotometer. The system includes: a storage section for holding measurement data obtained for each of the reference objects using the analyzing devices; a measurement data comparator for comparing, for each analyzing device, the measurement data of the target sample with those of the reference objects and for determining the degree of matching of the target sample with each reference object; an integrated degree-of-matching calculator for calculating an integrated degree of matching from the degrees of matching determined for the analyzing devices; and a comparison result output section for outputting information concerning a predetermined number of reference objects in descending order of the integrated degree of matching.

An optical cell comprises first and second opposed reflecting elements, an entrance aperture in the first reflecting element and an exit aperture in the second reflecting element, wherein the entrance and exit apertures are configured such that, in operation, light introduced into the cell via the entrance aperture is reflected at least once by the second reflecting element and at least once by the first reflecting element before leaving the cell via the exit aperture.

A device and method of use are provided for measuring the concentration of fatty acid methyl ester (FAME) in jet fuel to a limit of detection of 1 ppm. The device measures concentration of FAME in jet fuel via Fourier transform infrared spectroscopy (FTIR) with a spectral resolution of 1 cm.sup.−1. The device can use an infrared light emitting diode (IR LED) and mercury cadmium telluride (MCT) detector in which the spectral output of the IR LED and the spectral response of the MCT detector is centered on the spectral absorbance of an ester bond, a defining spectral characteristic of FAME. Other IR LEDs with differing spectral outputs can be used to measure the presence and/or concentration of different analytes in different fluids.

A method of detecting a geometrical phase change of an intrinsic property of a molecular isomerization includes a series of steps, such as simulating molecular isomerization of the molecule through application of a single shaped pulse to generate a molecular polarization. The steps include separating the real and imaginary parts of a nonlinear susceptibility in a detected molecular signal by controlling a phase of a reference field. The steps include assigning a phase function to obtain separation of the real and imaginary parts. Furthermore, a broadened vibrational lineshape is calculated. The step of identifying conical intersections also occurs. Various pathways of a wave packet in an excited state potential energy surface is discussed and may include multiple laser pulses and methods of detection. The spectral phase may be used to create interference of the wave packet in the excited state to identify and control a wavepacket's pathway and control photoisomerization.

In some embodiments, a system for detecting the presence of a contaminant on a surface includes an infrared light source configured to shine infrared light on the surface, an infrared light detector configured to detect infrared light reflected from the surface, and a computing device configured to receive an infrared reflectance signal from the infrared light detector and detect the presence of the contaminant from a feature in the reflectance signal.

Provided is a gas absorption spectroscopic system and gas absorption spectroscopic method capable of accurately measuring the concentration or other properties of gas even in high-speed measurements. Laser light with a varying wavelength is cast into target gas. A spectrum profile representing a change in the intensity of the laser light transmitted through the target gas with respect to wavelength is determined. For this spectrum profile, polynomial approximation is performed at each wavelength point within a predetermined wavelength width, using an approximate polynomial. Based on the coefficients of the terms in the approximate polynomial at each point, an nth order derivative curve, where n is an integer of zero or larger, of the spectrum profile is created. A physical quantity of the target gas is determined based on the thus created nth order derivative curve.

A diffuse optical spectroscopic imaging (DOSI) apparatus for tissue spectroscopy measures absorption and scattering properties of tissue using multi-frequency frequency domain photon migration in a modular or networkable platform to provide full broadband information content. The apparatus includes: a broadband signal generator; a driver having an input coupled to the signal generator; a light source coupled to the driver, the light source for exposing the tissue to broadband modulated light at a plurality of wavelengths; an optical detector for receiving returned light from the tissue; an amplitude detection circuit communicated to the optical detector; a phase detection circuit communicated to the optical detector; and a plurality of filters and amplifiers, wherein the optical detector, amplitude detection circuit and phase detection circuit are interconnected with each other by corresponding ones of the plurality of filters and amplifiers to isolate signals and increase signal-to-noise ratio.