Abstract:
The invention relates according to a first aspect to an interferometric inversion method for measuring a characteristic variable of a radiation source and/or of a medium through which the radiation passes between the source and an interferometer, the interferometer being capable of generating an interferogram of the radiation by creating a finite number of optical step differences between two rays that have followed the same path between the source and the interferometer, characterized by the implementation of the steps whereby a quantity characterizing an improvement in the inversion is determined, step differences that contribute mainly to optimizing the quantity characterizing an improvement in the inversion are selected without sampling regularity constraints, and a free interferogram is generated using only the selected step differences. According to a second aspect, the invention provides an interferometer for implementing the method according to the first aspect of the invention.
Abstract:
A system and method for measuring display quality by using a hyperspectral imager are disclosed. In one embodiment, the system comprises a hyperspectral imager configured to determine an intensity of light for a plurality of locations in a first area on a display for a plurality of spectral channels, and a processor configured to determine a measure of display quality based on the determined intensities.
Abstract:
A screening device and a method are described herein which can automatically handle and measure (interrogate) a plurality of sensor carriers (i.e., multiwell plates, microplates) with multi-dimensionally arranged, temperature-compensated or temperature-compensatable optical sensors, while maintaining a substantially constant temperature gradient for a relatively long period of time around the optical sensors where temperature compensation has been performed on the sensor carriers.
Abstract:
Systems and methods are disclosed for a modified Sagnac interferometer having a plurality of gratings that can be reflective or transmissive. The gratings allow measurement of wavelength spectra in counter-circulating beams of the interferometer. In one embodiment, diffraction geometries at each pair of neighboring gratings are configured so that diffractive and angular contributions reinforce each other at the second of the pair of gratings. In one embodiment, diffraction geometries at the gratings are configured so that the exiting beams of the interferometer satisfy the crossing condition wherein the exiting beams are on the opposite sides of a reference beam axis for a design wavelength input beam. Also disclosed are techniques for restoring the reinforcement and/or crossing conditions when these conditions are not otherwise met.
Abstract:
The invention relates to a spectrometer for material analysis and to a control method for a spectrometer. The spectrometer includes a radiant source (140) formed by multiple single radiation sources (141) having different central wavelengths, for generating a measuring signal, a measurement object (100) containing a material to be analyzed, at least one electrically tunable Fabry-Perot filter (120, 220) for the band pass filtering the measuring signal by at least two pass bands, and a detector (300, 400) for detecting said filtered measuring signals received from the measurement object (100). In accordance with the invention the spectrometer has means (312) for modulating each of the single radiation sources (141) and correspondingly means (307, 309) for demodulating the detected signals such that the signal from each single radiation source can be distinguished from each other in the detector (300, 400), and the spectrometer has means for detecting (300, 400) and demodulating (306, 307) multiple pass bands simultaneously.
Abstract:
A spectrometer arrangement for measuring a spectrum of a light beam emitted by a narrowband light source, such as a bandwidth-narrowed laser, includes at least one etalon, a beam splitter for splitting the light beam into a first partial beam and a second partial beam, one or more optical directing elements for directing the first partial beam n times and the second partial beam (n+k) times through the at least one etalon, wherein n and k are integers ≧1. The spectrometer arrangement further has at least one light-sensitive detector and an evaluation device for evaluating the spectra—recorded by the at least one detector—of the first partial beam that has passed through the at least one etalon n times and of the second partial beam that has passed through the at least one etalon (n+k) times in order to determine the light spectrum corrected for the apparatus function of the at least one etalon.
Abstract:
The present invention relates to a method for assessing the purity of vegetable oils by means of THz time-domain spectroscopy, comprising the steps of: measuring the THz time-domain spectra of standard vegetable oils to establish a spectral database; measuring the THz time-domain spectrum of vegetable oil to be detected; analyzing the purity of the detected vegetable oil based on the pre-built database. The present invention also relates to an apparatus for assessing purity of vegetable oil by means of THz time-domain spectroscopy, comprising: spectrum measuring device for measuring time-domain waveforms of THz pulses before and after transmitting the vegetable oil held in a container by transmission approach, or directly measuring time-domain waveforms of THz pulses before and after reflecting from the vegetable oil by reflection approach; and data processing device for extracting physical parameters of the vegetable oil in THz region according to the time-domain waveforms. Compared with the prior art, the method according to the present invention is easy, rapid and quantitative.
Abstract:
A new and novel sensor having a simple structure with high detection sensitivity. The sensor (S1) includes the following from measuring light (L1) input side in the order listed below: a first reflector (10) having semi-transmissive and semi-reflective properties; a translucent body (20); and a second reflector (30) having perfect reflection properties, or semi-transmissive and semi-reflective properties. The first reflector (10) and/or second reflector is brought into contact with a specimen, and the average complex refractive index varies with the specimen. Absorption properties for absorbing light having a particular wavelength are produced by these components, the properties of the measuring light (L1) are changed by the optical properties including the absorption properties, the output light (L2) is outputted from the first reflector (10) and/or second reflector (30), and the physical properties of the output light (L2) that vary according to the optical properties are detected.
Abstract:
An interferometer for Fourier transform infrared spectroscopy includes a fixed assembly including a housing, a beam splitter, and a mirror fixedly positioned relative to each other. A movable assembly includes a housing, a mirror, and a motor coil, fixedly positioned relative to each other. A first flat spring has an opening for providing an unobstructed optical path of radiation therethrough. A first end of the first flat spring is secured to the fixed assembly and a second end of the first flat spring is secured to the movable assembly for providing movement of the movable assembly relative to the fixed assembly via the first flat spring. An optical relationship between the beam splitter, the mirror of the fixed assembly, and the mirror of the movable assembly is maintained independent of a distance between the movable assembly and the fixed assembly.
Abstract:
In an apparatus for imaging of objects by applying optical frequency domain tomography and provided with an adjusting system for setting a relative position of photosensitive elements (174) and a spectrum image (273), the adjusting system is an automatically controlled device causing a relative displacement of at least one photosensitive element (174) of the detection device (173) of the spectrum and the spectrum image (273) between each other. The adjusting system comprises at least one actuator (14, 16) acting on the dispersion device (171) and/or the set of optical elements (172) and/or the detection device (173) and movement of which causes the relative displacement between each other of at least one photosensitive element (174) of the detection device (173) of the spectrum and the spectrum image (273) of the resultant light beam (270).