Abstract:
The disclosure relates generally to methods and apparatus for spectral calibration of a spectroscopic system which includes a fiber array spectral translator. One embodiment relates to a method for obtaining a first image of a known substance using a photon detector and a fiber array spectral translator having plural fibers, wherein the first image comprises at least one pixel; providing a second image of the substance wherein the second image comprises at least one pixel; comparing the first image with the second image; and adjusting at least one pixel of the first image based on the comparison of images to thereby obtain an adjusted image.
Abstract:
A Littrow-type spectrometer or monochromator (10) using a folded light path to provide a compact optical instrument is disclosed. Light enters the instrument through an inlet aperture on a planar mirror (14). The aperture is located at the focus of a parabolic collimetor-mirror (18). Collimated light reflected by the parabolic mirror is reflected back to the planar mirror, which is positioned at an angle to the collimated light. The light reflected from the planar mirror is directed at a planar grating (20) that produces diffracted light having all the wavelengths input into the system, including light of a selected wavelength, back towards the planar mirror. Light having the selected wavelength is thus caused to fall on the parabolic mirror. The parabolic mirror then focuses the selected wavelength of light ont a light exit aperture that is juxtaposed to the inlet light aperture. The planar grating can be rotatably mounted to scan the input light spectrum.
Abstract:
A measurement system includes an optical source (e.g., laser) to irradiate a sample (e.g., a cell); a solid-state photon detector (SSPD) to receive resultant light from the sample; and a photon counter to count photons received by the SSPD. The photon counter can include a differentiator to provide a differentiated photon signal and a crossing detector configured to count photons based on a number of times the differentiated photon signal crosses a predetermined threshold level. In some examples, a pulse detector can provide a pulse-width signal from the SSPD output photon signal, and a pulse counter can count based on both a number of pulses and widths of the pulses. The SSPD can include a silicon photomultiplier (SiPM) array or a solid-state photomultiplier. Some examples use the measurement system to measure samples in fluids, e.g., in flow cytometers or multi-well plates.
Abstract:
Apparatus for hyperspectral imaging, the apparatus including input optics that receive radiation reflected or radiated from a scene, a spatial modulator that spatially samples radiation received from the input optics to generate spatially sampled radiation, a spectral modulator that spectrally samples the spatially sampled radiation received from the spatial modulator to generate spectrally sampled radiation, a sensor that senses spectrally sampled radiation received from the spectral modulator and generates a corresponding output signal and at least one electronic processing device that controls the spatial and spectral modulators to cause spatial and spectral sampling to be performed, receives output signals and processes the output signals in accordance with performed spatial and spectral sampling to generate a hyperspectral image.
Abstract:
A side-looking optical probe for a Raman spectroscopy system is provided. The probe includes: a base for mounting the probe to an optical assembly of the system; and a prism mounted to the base, the prism configured for receiving signal light from a sample and providing the signal light to the system. A method of fabrication and a spectrometer are provided.
Abstract:
Способ удвоения спектрального диапазона на выходном торце оптического волновода спектрального цифрового наноспектрометра состоящий в том, что спектрометр снабжают поляризационным сплиттером, установленным на пути света от лазерного источника к планарному оптическому волноводу, в результате чего исследуемое излучение разлагают на компоненты ТЕ и ТМ. Разложенные компоненты затем пространственно разделяют с помощью цифровой планарной голограммы на расстояния, эквивалентные разделению выходных каналов на половину периода для случая неразделенной поляризации.
Abstract:
A system and method for standoff detection of explosives and explosive residue. A laser light source illuminates a target area having an unknown sample producing luminescence emitted photons, scattered photons and plasma emitted photons. A first optical system directs light to the target area. A video capture device outputs a dynamic image of the target area. A second optical system collects photons, and directs collected photons to a first two-dimensional array of detection elements and/or to a fiber array spectral translator device which device includes a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack. A spectrograph is coupled to the one-dimensional fiber stack of the fiber array spectral translator device, wherein the entrance slit of the spectrograph is coupled to the one dimensional fiber stack.