Abstract:
A light source unit and a spectrum analyzer are provided in which the influence of interference can be reduced under conditions where light is separated into spectral components. A spectrum analyzer 1 is equipped with a light source unit 2 for irradiating light onto sample A, a detector unit 3 for detecting the light reflected, scattered, or transmitted from the sample A, and a sample stage 4 on which a sample A is placed. A wide band light source 20 generates wide band light P1 such as supercontinuum light (SC light). Also, the light source unit 2 has an interference suppressing means for suppressing the interference of each wavelength component of the wide band light P1.
Abstract:
An optical spectrum analyzer includes an optical section 130 for executing light dispersion into a spectrum and wavelength sweep for input measured light, converting the measured light into an electric signal, and outputting the electric signal, a control section 101 for controlling the wavelength sweep of the optical section and outputting a sampling clock of a period shifting from a cycle period of the measured light for each wavelength of the wavelength sweep, and a measurement section 140 for executing sequential sampling of the electric signal from the optical section for each sampling clock.
Abstract:
A method to determine and correct broadband background in complex spectra in a simple and automatized manner includes carrying out a background correction with respect to broadband background before a calibration step. The background correction may involve recording a spectral graph and smoothing the recorded spectral graph, determining all values in the initially recorded graph having a value higher than the value of the smoothed graph and reducing such values to the value of the smoothed graph, and repeating these two steps. The background graph obtained is then subtracted from the initial graph. The smoothing of the graph is carried out by moving average, where each intensity value I at the position x in the spectrum is replaced by an average value. The characteristics of the found peaks can be stored in a file so that the calibration can be used at any time.
Abstract:
A method of generating a design pattern for a spatial radiation modulator to encode two or more selected spectral components in one or more spectral ranges for the chemometric analysis of a group of analytes. The method includes obtaining a corresponding spectrum for each of the analytes, defining a set of initial spectral windows, constructing a chemometric matrix to relate concentrations of the analytes to intensities of the spectral components, deriving optimized spectral windows, and translating the center wavelength and the bandwidth of each of the optimized spectral windows into a corresponding optimized annular region on the modulator.
Abstract:
A two-dimensional spectroradiometer has an optical system such as an objective optical system 2 and a relay lens 6 for receiving light rays La from a two-dimensional light source L to form an optical image i.e. a first image 2a and a second image 6a, a WBPF 12 as a transmittance wavelength variable filter having a spectral transmittance characteristic that transmittance wavelengths of the light rays La differ from each other depending on transmittance sites of the filter where the respective light rays La pass, a scanning WBPF 10 which scannably holds the WBPF 12 on an optical path forming the optical image, and an image sensor 7 for capturing the second image 6a composed of the light rays La passing through the WBPF 12 at a position corresponding to each of scanning steps of the WBPF 12 to acquire a plurality of images each having a different spectral sensitivity among pixels of the image at the position corresponding to the each of the scanning steps. This arrangement enables to provide a compact and inexpensive two-dimensional spectroradiometer with shortening of the measurement time.
Abstract:
Encoded spatio-spectral information processing is performed using a system having a radiation source, wavelength dispersion device and two-dimensional switching array, such as digital micro-mirror array (DMA). In one aspect, spectral components from a sample are dispersed in space and modulated separately by the switching array, each element of which may operate according to a predetermined encoding pattern. The encoded spectral components can then be detected and analyzed. In a different aspect, the switching array can be used to provide a controllable radiation source for illuminating a sample with radiation patterns that have predetermined characteristics and separately encoded components. Various applications are disclosed.
Abstract:
A calibrated spectroscopy instrument and a method for calibrating a spectroscopy instrument are disclosed. The spectroscopy instrument includes a monochromator having a drive mechanism comprising a pair of spur gears for rotating a diffraction grating of the monochromator for selecting a desired wavelength. The drive mechanism is calibrated to account for eccentricities in the spur gears to provide an accurate conversion between selected angular settings for the drive mechanism and the wavelength of the diffracted light from the monochromator. The drive mechanism comprises a pinion spur gear and a main spur gear which each have an AGMA (American Gear Manufacturers' Association) rating of at least 10, which allows errors due to random tooth to tooth variations to be neglected. A calibration algorithm is derived which is based on the error due to eccentricities in the spur gears following a precise geometric cyclic pattern.
Abstract:
An apparatus for the detection of spectral information along a geometrical line with a dispersive element, which is suspended from an axis of rotation, for the spectral dispersion of electromagnetic radiation from a range on the geometrical line into spectral constituents, a line detector for the detection of the spectral constituents of the radiation emanating from the range on the geometrical line and a dispersive-element deflector, the deflector being designed to deflect the dispersive element on the axis of rotation, so that depending on an angle of deflection a radiation from another range of the geometrical line is incident on the line detector.
Abstract:
A system for spectral analysis of a multi-wavelength signal is disclosed. The illustrative embodiment of the present invention, like the prior art, uses a grating or prism to disperse the spectral components of a multi-wavelength signal, and then uses a reciprocating or rotating mirror to direct the spectral components, one at a time, into a photodetector. The illustrative embodiment uses a telescope between the grating and the mirror to improve the spectral resolution of the system.
Abstract:
A spectral image measurement apparatus comprises: a spectral element array; a spectral element drive section for driving the elements; an inlet-side optical system for guiding a light to the element array; a detection-side optical system for forming an image with a diffracted light output from the element array; and an array sensor for detecting the diffracted light through the detection-side optical system. The element array includes: a substrate; and a plurality of micro-electrically-driven mechanical spectral elements arranged two-dimensionally on the substrate, wherein each of the elements comprises a diffraction grating having a diffraction surface, the diffraction grating being pivotably supported on the substrate; wherein each of the elements generates spectra from a light entering the diffraction surface by applying an electric field to the diffraction grating to tilt the diffraction grating; and wherein each of tilt angles of the diffraction gratings is capable of being set individually.