Provided are a Raman signal measuring method and apparatus which use a difference in a time scale between Raman scattered light and fluorescence. Thus, after exciting light is incident upon a target object, light scattered from the target object may be detected before the target object generates fluorescence in response to the exciting light. As a result, a Raman signal in which background fluorescence is reduced may be obtained.

A spectrometry system may include an etalon array having a first etalon and a second etalon. The first etalon may be configured to process light to at least generate a first transmission pattern. The first transmission pattern may have at least a first transmission peak corresponding to a first wavelength in an original spectrum of the light. The second etalon may be configured to process the light to at least generate a second transmission pattern. The second transmission pattern may have at least a second transmission peak corresponding to a second wavelength in the original spectrum of the light. The first etalon may have a different thickness than the second etalon in order for the first transmission pattern to have at least one transmission peak that is at a different wavelength than the second transmission pattern. The first transmission pattern and the second transmission pattern may enable a reconstruction the original spectrum of the light.

Described herein are a spectrometer system and a spectrometer device, which are suited for investigation or monitoring purposes, in particular, in the infrared (IR) spectral region, and for a detection of heat, flames, fire, or smoke.

The spectrometer device allows capturing incident light from an object and transferring the incident light to a length variable filter with a particularly high concentration efficiency. Apart from the spectrometer device, the spectrometer system further includes an evaluation unit designated for determining information related to a spectrum of an object by evaluating the detector signals provided by the spectrometer device.

An optical assembly is disclosed including two laterally variable bandpass optical filters stacked at a fixed distance from each other, so that the upstream filter functions as a spatial filter for the downstream filter. The lateral displacement may cause a suppression of the oblique beam when transmission passbands at impinging locations of the oblique beam onto the upstream and downstream filters do not overlap. A photodetector array may be disposed downstream of the downstream filter. The optical assembly may be coupled via a variety of optical conduits or optical fibers for spectroscopic measurements of a flowing sample.

A spectrometer and a spectral detection and analysis method implemented by the spectrometer. The spectrometer includes an optical device and a detection device. The optical device includes at least one light filter, each of which including at least two light filtering units, so that the optical device can emit at least two kinds of monochromatic light. The detection device includes at least one detector, each of which comprising at least two detection units facing at least two light filtering units in the corresponding light filter in a one-to-one relationship. The monochromatic light emitted from the light filtering unit is emitted along the direction perpendicular to the direction of the light emitting surface.

Disclosed is a resonant wavelength measurement apparatus, including a light source and a measurement unit. The measurement unit has a guided-mode resonance filter and a photosensitive element. The guided-mode resonance filter has a plurality of resonant areas, and each resonant area has a different filtering characteristic, to receive first light in the light source transmitted by a sensor or receive second light in the light source reflected by the sensor. The first light has a first corresponding pixel on the photosensitive element, the second light has a second corresponding pixel on the photosensitive element, and the first corresponding pixel and the second corresponding pixel correspond to a same resonant wavelength.

A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

An optical assembly is disclosed including two laterally variable bandpass optical filters stacked at a fixed distance from each other, so that the upstream filter functions as a spatial filter for the downstream filter. The lateral displacement may cause a suppression of the oblique beam when transmission passbands at impinging locations of the oblique beam onto the upstream and downstream filters do not overlap. A photodetector array may be disposed downstream of the downstream filter. The optical assembly may be coupled via a variety of optical conduits or optical fibers for spectroscopic measurements of a flowing sample.

A Multichromatic Calibration (MC) method of at least a spectral sensor which is one of a list comprising at least a spectrometer, a multispectral sensor, a hyperspectral sensor, a spectral camera, a color camera. The method comprises a. generating a plurality of different multichromatic spectra, wherein i. a spectrum from the plurality of different multichromatic spectra contains light intensity measurable by the at least one spectral sensor and by a reference spectral device, and ii. a spectrum from the plurality of different multichromatic spectra contains light centered around at least two different wavelengths and is configured to be integrated during an exposure time of a single measurement from any of the at least one spectral sensor or the reference spectral device; b. measuring each multichromatic spectrum of the plurality of different multichromatic spectra with the reference spectral device and the at least one spectral sensor; and from all data of the measured multichromatic spectra, compute a transfer function which relates a response of the at least one spectral sensor to a corresponding response of the reference spectral device, without measuring the spectral response of the at least one spectral sensor.

An infrared spectrometer for operation in the mid-infrared spectral range is presented, where the spectrometer includes a Bragg-mirror-based spectral filter that is operative for providing an interrogation signal whose spectral content is dispersed along a first direction at a filter aperture. The filter aperture is imaged through a sample by a thermal-imaging camera to create a focused image that is based on the interrogation signal and the absorption characteristics of the sample. As a result, embodiments in accordance with the present disclosure can be smaller, less complex, and less expensive than infrared spectrometers known in the prior art.