Abstract:
An optical absorption spectrometer is provided for determining the concentration of a substance within a sample. The optical absorption spectrometer comprises a first radiation source for supplying radiation to the sample to be measured; at least one cavity for containing the sample during measurement; and a detector assembly for detecting radiation transmitted along first and second optical paths through the sample, the length of the first optical path being greater than that of the second optical path.
Abstract:
The invention relates to a mobile remote detection device for accumulations of methane, comprising an emitter device having a light source in order to generate light, the wavelength of said light source being tuned with the spectral signature of methane, whereby the light can be directed onto a measuring field. The detection device also comprises a detector device for detecting backscattered light, and an evaluation device. The aim of the invention is to improve the remote detection device in such a manner that it has a high degree of measuring sensitivity with a compact and stable structure. According to the invention, the light source generates light with a wavelength at which methane is absorbed, wherein the wavelength lies between 3200 nm and 3300 nm, and the light source has an optical parametric oscillator with injection seeding, the oscillator being associated with a pump laser.
Abstract:
Preferred embodiments of the invention provide for methods and systems of 2D spectroscopy using ultrafast, first light and second light beams and a CCD array detector. A cylindrically-focused second light beam interrogates a target that is optically interactive with a frequency-dispersed excitation (first light) pulse, whereupon the second light beam is frequency-dispersed at right angle orientation to its line of focus, so that the horizontal dimension encodes the spatial location of the second light pulse and the first light frequency, while the vertical dimension encodes the second light frequency. Differential spectra of the first and second light pulses result in a 2D frequency-frequency surface equivalent to double-resonance spectroscopy. Because the first light frequency is spatially encoded in the sample, an entire surface can be acquired in a single interaction of the first and second light pulses.
Abstract:
A sensor system featuring a field angle compression telescope optical system for measuring atmospheric trace gases is provided. According to an embodiment of the present invention, the telescope optical system condenses the field angle of received light with respect to a cross track plane, while leaving the field angle with respect to an along-track plane uncompressed. Such an anamorphic telescope design provides a wide field of view, while allowing information regarding the altitude or height distribution of a gas to be obtained. According to another embodiment of the present invention, the field angle of received light is compressed by magnifying the received light by a value less than 1.0 in all directions.
Abstract:
Method and system for wavelength-based processing of a light beam. A light beam, produced at a chemical or physical reaction site and having at least first and second wavelengths, λ1 and λ2, is received and diffracted at a first diffraction grating to provide first and second diffracted beams, which are received and analyzed in terms of wavelength and/or time at two spaced apart light detectors. In a second embodiment, light from first and second sources is diffracted and compared in terms of wavelength and/or time to determine if the two beams arise from the same source. In a third embodiment, a light beam is split and diffracted and passed through first and second environments to study differential effects. In a fourth embodiment, diffracted light beam components, having first and second wavelengths, are received sequentially at a reaction site to determine whether a specified reaction is promoted, based on order of receipt of the beams. In a fifth embodiment, a cylindrically shaped diffraction grating (uniform or chirped) is rotated and translated to provide a sequence of diffracted beams with different wavelengths. In a sixth embodiment, incident light, representing one or more symbols, is successively diffracted from first and second diffraction gratings and is received at different light detectors, depending upon the wavelengths present in the incident light.
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:
The invention features a method of assaying for the interaction of a probe and an unknown target, said method including a) exciting a sample with radiation, the sample including at least one unknown target, at least one probe, and at least one fluorescent tag, b) measuring the fluorescence from a subvolume of the sample, and c) analyzing the fluctuations of the fluorescence.
Abstract:
Disclosed is a portable fluorescence correlation spectroscopy instrument that includes an excitation source, at least one of a light focusing element positioned to receive light emitted by the excitation source, a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source, and a correlator coupled to the detector, the correlator for processing data received at the detector and providing data including autocorrelation data, crosscorrelation data, or a combination thereof.
Abstract:
A process for recording pulse signals of at least two input channels includes sampling the input channels with a predetermined sampling frequency for events which have occurred, and after detection of an event in at least one of the input channels, or after overflow of a counter, storing the present state of all the input channels in a memory register together with a magnitude characterizing a time interval to the last storage operation. The device for recording pulse signals of at least two input channels according to the process includes a clock oscillator, a sampler that samples the input channels, a counter, and a memory. The detection of a first event in one of the input channels or the overflow of the counter, according to which event occurs first, triggers and operation of storage of the states of all the input channels and of the last counter state at the occurrence of the event.
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.