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:
Correlation spectroscopy measure is improved by correcting for cross interference. This is achieved through applying different gains to the output signals whereby the effect of background interferent species can be calculated and an automatic correction factor applied.
Abstract:
In material depositing processes such as welding or thermal spraying the large variety of processes and material parameters necessitate a broad range of the resulting characteristics of the applied material. The task of the present invention is comprised of providing a process and a device for determining the quality of specific layer characteristics, in particular their adhesion or strength of joining to the base material. This task is solved thereby, that as the quality characteristic there is employed the degree of mixing of the applied material with the base material.
Abstract:
A spectrometer for determining the concentration of a substance within a sample comprises a. a radiation source (11) for supplying radiation to the sample to be measured; b. a filter (15) for filtering radiation transmitted by the sample, the filter having a number of pass bands at wavelengths corresponding to absorption peaks in the absorption spectrum of the sample to be detected, the filter being responsive to an applied signal to modulate the wavelengths of the pass bands; and, c. a detector (16) for detecting the filtered radiation, the detector being responsive to the applied signal to determine the relative intensities of the maxima and minima in the absorption spectra of the substance, characterized in that the radiation source is selectively activated in response to the applied signal.
Abstract:
A method for distinguishing samples having flourescent particles includes (a) monitoring intensity fluctuations of fluorescence emitted by the particles in at least one measurement volume by detecting sequences of photon counts by at least one photon detector, (b) determining, from the sequences of photon counts, intermediate statistical data involving at least two probability functions of the number of photon counts detected in different sets of counting time intervals, and (c) determining from the intermediate statistical data a distribution of particles as a function of at least two arguments, wherein one argument is a specific brightness of the particles, or a measure thereof, and another argument is a diffusion coefficient of the particles, or a measure thereof.
Abstract:
A programmable substance detector includes a light source, a sample cell, a programmable diffraction grating positioned to receive light from the light source and to direct diffracted light to the sample cell, and a detector associated with the cell to detect a match between a characteristic of the diffracted light and a corresponding characteristic of a substance within the cell.
Abstract:
A spectrometer for determining the concentration of a substance within a sample comprises a. a radiation source (11) for supplying radiation to the sample to be measured; b. a filter (15) for filtering radiation transmitted by the sample, the filter having a number of pass bands at wavelengths corresponding to absorption peaks in the absorption spectrum of the sample to be detected, the filter being responsive to an applied signal to modulate the wavelengths of the pass bands; and, c. a detector (16) for detecting the filtered radiation, the detector being responsive to the applied signal to determine the relative intensities of the maxima and minima in the absorption spectra of the substance, characterized in that the radiation source is selectively activated in response to the applied signal.
Abstract:
A method for characterizing samples having fluorescent particles, by monitoring fluctuating intensities of radiation emitted by said particles 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 length of time intervals between photon counts, b) determining a function or a series of functions of the length of said time intervals, c) determining a function of at least one specific physical property of said particles on basis of said function or said series of functions of the length of time intervals, by finding a close fit between the experimentally determined and a theoretical function or series of functions of the length of said time intervals, the latter of which takes into account parameters of the spatial brightness function characteristic for the optical set-up.
Abstract:
A method for adaptive spectral sensing developed for a two-dimensional image made up of picture elements. The method calls for illuminating at least one of the picture elements with an input light and deriving a time-varying spectral signal from the input light for that picture element. The time-varying spectral signal is processed with a time-varying reference signal by using a mathematical function such as convolution, multiplication, averaging, integrating, forming an inner product, matched filtering, addition, subtraction or division to obtain a processed output value for the picture element and this output value is then used in determining a spectral characteristic of the input light. The time-varying spectral signal is conveniently derived by optical filtering of the input light yielding an optical time-varying spectral signal. This method can be used by itself or in combination with at least one other adaptive technique such as adaptive spatial sensing and/or adaptive temporal sensing.
Abstract:
A method characterizes fluorescent molecules or other particles in samples by a) monitoring fluctuating intensity of fluorescence emitted by the molecules or other particles in at least one measurement volume of a non-uniform spatial brightness profile by measuring numbers of photon counts in primary time intervals by a single or more photon detectors, b) determining at least one distribution function of numbers of photon counts, {circumflex over (P)}(n), from the measured numbers of photon counts, c) determining physical quantities characteristic to the particles by fitting the experimentally determined distribution function of numbers of photon counts, wherein the fitting procedure involves calculation of a theoretical distribution function of the number of photon counts P(n) through its generating function, defined as G ( ζ _ ) = ∑ n ζ _ n P ( n ) .