Abstract:
A tunable transmissive grating comprises a transmissive dispersive element, a reflective element/ and an angle θ formed between the two elements. A first optical path is formed according to the angle θ, wherein light dispersing from the dispersive element is directed onto the reflective element and reflects therefrom. At least one element is rotatable about a rotational center to cause a second optical path and thereby tune the wavelength of the light reflecting from the reflective element. Both elements can be rotatable together around a common rotational center point according to certain embodiments, and/or each element can be independently rotated around a rotational axis associated only with that element. According to some embodiments, the relative angle θ formed between the elements is held constant; however, in other embodiments θ can vary. A control system can be used to operate the device.
Abstract:
A miniature, flexible, fiber-optic scanning endoscope for nonlinear optical imaging and spectroscopy. The endoscope uses a tubular piezoelectric actuator for activating a cantilevered optical fiber from which pulsed light produced by a laser source exits and is directed to a target region through a micro-lens. The actuator is activated by two modulated signals that achieve two-dimensional beam scanning in a desired scan pattern. A double-clad optical fiber is employed for delivery of the excitation pulsed light and collection of emitted light received from the target region. The pulsed light travels through a core of the double-clad optical fiber, and the emitted light from the target region is directed into the core and inner cladding of the optical fiber and conveyed to a proximal end, for detection and processing. The emitted light can include multiphoton fluorescence, second harmonic generation light, and spectroscopic information, for imaging.
Abstract:
Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Erhebung spektrometrischer Messignale. Der Erfindung liegt die Aufgabe zugrunde, Lösungen bereitzustellen, durch welche eine präzise Erhebung spektrometrischer Messsignale in kostengünstiger Weise ermöglicht wird. Diese Aufgabe wird erfindungsgemäss gelöst durch eine spektrometrische Messanordnung umfassend e0ine Eintrittsspalteinrichtung, zur Gestattung des Durchtritts von zu untersuchender Strahlung, eine der Eintrittsspalteinrichtung zugeordnete Rowland-Gittereinrichtung, zur Reflektion auftreffender Strahlung unter spektraler Auffächerung derselben, einer Erfassungseinrichtung, zur Erfassung eines schmalen Ausschnitts des durch die Rowland-Gittereinrichtung aufgefächerten Spektrums; und einer Führungseinrichtung zur Führung der Erfassungseinrichtung, wobei die Führungseinrichtung derart ausgebildet ist, dass diese die Erfassungseinrichtung auf einer Detektionsbahn von im wesentlichen konstanter spektraler Schärfe bewegt. Dadurch wird es auf vorteilhafte Weise möglich, die Spektralverteilung des zu untersuchenden Lichtes präzise anzugeben. Es ist möglich, Die Erfassungseinrichtung so auszubilden, oder operativ derart an ein Auswertungssystem anzukoppeln, dass etwaige Abhängigkeiten der erfassten Intensität von der Wellenlänge des auf die Erfasungseinrichtung auftreffenden Lichtes, durch Auswertungsprozeduren kompensiert werden. Kompensationsparameter können durch Eichprozeduren ermittelt und in einer geräteinternen Speichereinrichtung abgelegt werden.
Abstract:
The present invention relates to spectroscopic methods and systems for collecting electromagnetic radiation from an object using a continuously-spinning wavelength-selecting (CSWS) device, e.g., an interference filters (20) or a grating. One embodiment of the invention provides a spectroscopic system for collecting electromagnetic radiation from a target. The spectroscopic system has at least one beam of electromagnetic radiation (40) that interacts with the target (26). The system includes a continuously spinning wavelength-selecting (CSWS) device, e.g., a continuously spinning interference filter/grating driven by a DC motor, in the path of the at least one beam. The device filters the radiation with regard to wavelength to produce filtered radiation. The system further includes at least one detector (30) in the path of the at least one beam for detecting the filtered radiation.
Abstract:
The invention comprises an apparatus and method for simple fluorescence spectrometry in a down hole environment. The apparatus and method utilization of two UV light bulbs (204) and an optically clear UV coupler (202) and a fluid containment system (301, 302). The optically clear UV coupler and fluid containment system are made of sapphire. The apparatus is attached in a manner that enables light transmitted from a light source on the far side of the fluid containment system to pass through a pathway in a plate holding the UV bulbs. UV light illuminates the fluid (305), which in turn fluoresces light. The fluoresced light is transmitted back towards the UV bulb mount and through the pathway towards an optical spectrum analyzer (308).
Abstract:
A wavelength-variable light source emits to a measurement object light having its wavelength continuously changed from predetermined start wavelength to stop wavelength. A timing information output unit generates a plurality of elements of timing information indicating the output timings of lights respectively having a start wavelength, a stop wavelength and a plurality of wavelengths obtained by dividing the interval between the start and step wavelengths by specified steps. A light receiving unit receives light from the measurement object and outputs a signal representing the measurement value of the received light. A plurality of amplifiers receive a signal from the light receiving unit and amplify the signal at respective specified amplification ratios. A signal selection unit selects one signal within a specified measuring range out of signals amplified at respective amplification ratios by the amplifiers and outputs it as a measurement value by light having a wavelength defined by applicable timing information in the plurality of elements of timing information from the timing information output unit.
Abstract:
Very generally, the gas analyzer (10) of the invention includes a source of infrared energy (12), a sample cell (14) for containing an analyte gas mixture positioned in the path of infrared energy, and a monochromator (26) including a movable diffraction grating (34) for producing a beam of infrared energy wherein the constituent wavelengths are spectrally separated. The device also includes a wide band interference filter (42) for transmitting a predetermined wavelength band spanning the characteristic absorption wavelength of each of a plurality of constituent gases in the analyte gas mixture. A detector (16) positioned to receive radiation passing through the filter (42) produces an electrical response related to the infrared energy impinging thereon. The monochromator (26) includes provision (38, 40) for moving the diffraction grating (34) to sequentially cause infrared energy of different wavelengths to impinge upon the detector (16), and for intermittently causing infrared energy directed toward the detector (16) from the source (12) to be blocked by the interference filter (42).
Abstract:
A spectrometer (20) has a source of illumination radiation (21) having a plurality of spectral wavelengths, a bandpass filter (14), a dispersive beamsplitter (28), an illumination radiation rejection filter (34), and a spectrograph (32) each tunable in correspondences to a selected one of the plurality of spectral wavelengths of the source of illumination radiation. Any one of the tunable elements can comprise a holographic volume dispersion distraction grating and a mirror, both having fixed orientation displacement with respect to each other and being rotable for tuning around an avis corresponding to the interaction of the two planes coincident with the surfaces of said mirror and said grating.
Abstract:
Encoded spatio-spectral information processing is performed using a system having a radiation source (12), wavelength dispersion device (16) and two-dimensional switching array (18), such as digital micro-mirror array (DMA). In one aspect, spectral components from a sample (24) 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 (18) can be used to provide a controllable radiation source for illuminating a sample (24) with radiation patterns that have predetermined characteristics and separately encoded components. Various applications are disclosed.
Abstract:
A line in a Raman spectrum scattered from a sample (18) is selected by a diffraction grating (20) and passed to a detector (26). The grating (20) may be based on an electrostrictive device and has a variable pitch. It is tuned about the selected Raman line under the control of an oscillator (28). The output from the detector (26) is analysed synchronously with the oscillation by a phase sensitive detector (34). This rejects background light and enables, for example, confirmation of the existence of the Raman line in the spectrum, and measurement of its height above the background. The variable pitch grating (20) may be replaced by a fixed pitch grating or a tunable filter, mounted on an oscillatory drive which may comprise electrostrictive or piezolelectric elements.