Abstract:
A photodiode array for entering incident light a spectroscope device equipped with a wavelength dispersion element and detecting light emanating from the spectroscope device. The arrangement of each of photodiode elements constituting the photodiode array is displaced.
Abstract:
An apparatus is described for the real-time identification of one or more selected components of a target material. In one embodiment, an infrared spectrometer and a separate Raman spectrometer are coupled to exchange respective spectral information of the target material preferably normalized and presented in a single graph. In an alternative embodiment, both an infrared spectrometer and a Raman spectrometer are included in a single instrument and a common infrared light source is used by both spectrometers. In another embodiment, a vibrational spectrometer and a stoichiometric spectrometer are combined in a single instrument and are coupled to exchange respective spectral information of the target material and to compare the spectral information against a library of spectra to generate a real-time signal if a selected component is present in the target material.
Abstract:
A Fabry-Perot cavity filter includes a first mirror and a second mirror. A gap between the first and the second mirror monotonically varies as a function of width of the filter. This filter may be used with photodetector and a channel selection filter in an optical device, such as a spectrum analyzer. The channel selection filter may be a metal nanooptic filter array which includes plurality of subwavelength apertures in a metal film or between metal islands.
Abstract:
The disclosure generally relates to a method and apparatus for compact dispersive imaging spectrometer. More specifically, one embodiment of the disclosure relates to a portable system for obtaining a spatially accurate wavelength-resolved image of a sample having a first and a second spatial dimension. The portable system can include a photon emission source for sequentially illuminating a plurality of portions of said sample with a plurality of photons to produce photons scattered by the sample. The photon emission source can illuminate the sample along the first spatial dimension for each of plural predetermined positions of the second spatial dimension. The system may also include an optical lens for collecting the scattered photons to produce therefrom filtered photons, a dispersive spectrometer for determining a wavelength of ones of the filtered photons, a photon detector for receiving the filtered photons and obtaining therefrom plural spectra of said sample, and a processor for producing a two dimensional image of said sample from the plural spectra.
Abstract:
A curved mirrored surface is used to collect radiation scattered by a sample surface and originating from a normal illumination beam and an oblique illumination beam. The collected radiation is focused to a detector. Scattered radiation originating from the normal and oblique illumination beams may be distinguished by employing radiation at two different wavelengths, by intentionally introducing an offset between the spots illuminated by the two beams or by switching the normal and oblique illumination beams on and off alternately. Beam position error caused by change in sample height may be corrected by detecting specular reflection of an oblique illumination beam and changing the direction of illumination in response thereto. Butterfly-shaped spatial filters may be used in conjunction with curved mirror radiation collectors to restrict detection to certain azimuthal angles.
Abstract:
A method and a low-cost, robust and simple system for remote sensing and analyzing spectral properties of targets as a means to detect and identify them is introduced. The system can be highly portable but is usable in fixed locations or combination thereof. An aspect of the method and system includes the capability to distribute, modulate, aperture and spectrally analyze radiation emitted or absorbed by a volumetric target chemical species (solid, liquid or gas) or a target surface. Radiation is first collected by a single light gathering device, such as a lens, telescope, or mirror, and then distributed to multiple detectors through spectrally discriminating components and if desired through apertures to achieve this desired detection and identification.
Abstract:
In a self-referencing instrument for measuring electromagnetic radiation, a mounting member to which a sample can be coupled moves the sample such that, in a first position, the electromagnetic radiation impinges on the sample, and, in a second position, the electromagnetic radiation does not impinge on the sample. A detection unit receives the electromagnetic radiation from the sample and generates a sample signal when the sample is in the first position, and the detection unit receives the electromagnetic radiation from the source and generates a reference signal when the sample is in the second position. A processor coupled to the detection unit processes the reference signal and the sample signal. This results in a continuous, accurate reference measurement, and permits the instrument to efficiently compensate for error, while offering accurate measurements.
Abstract:
The invention relates to a device, a method and a system for determining a road surface condition, where the surface condition is one of dry, wet or icy. The device comprises a reflectance spectrometer which senses the reflectance properties of the road at one or several wavelengths and uses these reflectance properties to determine the surface condition. The reflectance spectrometer is a wavelength modulation spectrometer, preferably for the near infrared region. The system determines the surface condition and indicates it to a user of the system.
Abstract:
Fluorescence emitted from a tissue can be detected efficiently, and excitation light with a plurality of wavelengths can be simultaneously emitted to simultaneously detect fluorescence with a plurality of wavelengths. A laser-scanning fluoroscopy apparatus includes a laser light source of a plurality of wavelengths; a spectroscopic device for splitting laser beams according to wavelength; a focusing lens for focusing the split laser beams; and a wavelength-selecting reflection device which includes a plurality of reflection sections disposed near the focal positions, spaced out at predetermined intervals in a split direction to reflect the laser beams with different wavelengths and a transmission section arranged adjacent to the reflection sections. The laser-scanning fluoroscopy apparatus further includes a diffraction grating for combining the reflected laser beams; a scanning section for two-dimensionally scanning the combined laser beams; an objective optical system for focusing the scanned laser beams onto a tissue; and a photodetector for detecting fluorescence emitted from the tissue. A width dimension, as measured along the split direction, of each reflection section of the wavelength-selecting reflection device is smaller than a width dimension of the transmission section.
Abstract:
Method and apparatus for analyzing radiation using analyzers and encoders employing the spatial modulation of radiation dispersed by wavelength or imaged along a line.