A method for detecting at least one property of a plant product, the method including: directing source light including ultraviolet (UV) light at UV wavelengths and polarized visible and/or near-infrared (VIS/NIR) light at VIS/NIR wavelengths onto a region of the plant product; blocking the polarized VIS/NIR light of the source light, and blocking polarized specular reflection from the region of the plant product, from being transmitted to a visible and/or near-infrared (VIS/NIR) spectrometer; and transmitting a portion of emitted light caused by fluorescence and/or diffuse reflection from the region of the plant product to the visible and/or near-infrared (VIS/NIR) spectrometer.

An apparatus for carrying out polarization resolved Raman spectroscopy on a sample (11), in particular a crystalline or polycrystalline sample, the apparatus comprises: at least one light source (13, 87, 93, 95, 97), in particular at least one laser, for providing excitation radiation to a surface of the sample (11), an optical system which is configured to simultaneously collect at least one on-axis Raman beam (21, 109) and at least one off-axis Raman beam (23, 111) from Raman light scattered by the sample (11) in response to exposing the surface to the excitation radiation, the at least one on-axis Raman beam (21, 109) being scattered from the sample (11) in a direction that is aligned with an optical axis of an objective (41) of the optical system for collecting the at least one on-axis Raman beam (21, 109), the at least one off-axis Raman beam being scattered from the sample in a direction that is inclined with regard to an optical axis of an objective (41) of the optical system for collecting the at least one off-axis Raman beam (23, 111), the optical system comprises at least one polarizer device (25, 113) for generating at least one polarized on-axis Raman beam (31, 33) from the at least one on-axis Raman beam (21, 109) and at least one polarized off-axis Raman beam (35) from the at least one off-axis Raman beam (23, 111), and the optical system comprises at least one spectrometer (37, 47 81, 83, 85) for generating, in particular simultaneously, an optical spectrum from each of the at least one polarized on-axis Raman beam (31, 33) and the at least one polarized off-axis Raman beam (35).

A device for imaging one dimension nanomaterials is provided. The device includes an optical microscope with a liquid immersion objective, a laser device, and a spectrometer. The laser device is configured to provide an incident light beam with a continuous spectrum. The spectrometer is configured to obtain spectral information of the one dimensional nanomaterials.

A display apparatus includes a display screen, and a controller that causes the display screen to display a composite image in which a first image acquired by imaging a space by a camera and a second image representing at least one type of aerosol existing in the space are combined. The position of the at least one type of aerosol as seen in a depth direction in the first image is reflected in the second image.

A system for optical imaging of defects on unpatterned wafers that includes an illumination module, relay optics, a segmented polarizer, and a detector. The illumination module is configured to produce a polarized light beam incident on a selectable area of an unpatterned wafer. The relay optics is configured to collect and guide, radiation scattered off the area, onto the polarizer. The detector is configured to sense scattered radiation passed through the polarizer. The polarizer includes at least four polarizer segments, such that (i) boundary lines, separating the polarizer segments, are curved outwards relative to a plane, perpendicular to the segmented polarizer, unless the boundary line is on the perpendicular plane, and (ii) when the area comprises a typical defect, a signal-to-noise ratio of scattered radiation, passed through the polarizer segments, is increased as compared to when utilizing a linear polarizer.

A method of determining a material property of an object. The method comprises: obtaining a real light intensity value for each of a first number of light source positions and each of a second number of light sensor positions, the real light intensity value indicating an intensity of light from the light source position that is reflected or diffused by an object to the light sensor position; determining a three-dimensional surface of the object; and for each of a plurality of points on the three-dimensional surface of the object, using a model that has been trained by machine learning, predicting the material property for the object at the point based on the obtained real light intensity values.

Various embodiments include a scattered light smoke detector comprising: a two-color LED for emitting light of a first wavelength and a second wavelength; a photosensor spectrally matched with said two-color LED; and a control unit connected to the two-color LED and to the photosensor. The control unit is configured to control the two-color LED to emit light of the first wavelength or the second wavelength and to detect a photosensor signal of the photosensor. The control unit is further configured to analyze the photosensor signal for a first scattered radiation intensity and a second scattered radiation intensity allocated respectively to the first wavelength and the second wavelength. There is a polarizer optically connected upstream of the photosensor or downstream of the two-color LED. The polarizer polarizes light passing through at different intensities in dependence upon the respective wavelength of said light.

A method and system for imaging thermodynamic phase of clouds includes obtaining a spatially-resolved polarimetric image of a region of the sky containing a cloud using a multipixel image sensor having multiple channels corresponding to different wavelength bands, determining a value of the Stokes S.sub.1 polarization parameter of incident light on each pixel corresponding to a portion of the image containing the cloud for multiple channels corresponding to different wavelength bands, and determining the thermodynamic phase of the cloud within the image based on the values of the Stokes S.sub.1 polarization parameter. The Stokes S.sub.1 polarization parameter values determined for a first channel corresponding to a first wavelength band is used to determine a liquid thermodynamic phase, and the Stokes S.sub.1 polarization parameter values determined for a second channel corresponding to a second, shorter wavelength band is used to determine an ice thermodynamic phase.

A method for obtaining chemical and/or material specific information of a sample based on scattered light. The method comprises receiving detection data comprising at least two images. Each image is indicative of the intensity of scattered light i) for incident light of a different wavelength, or ii) for incident light of a different polarization state, or iii) of a different polarization state. The scattered light comprises an elastic scattering component that is due to Rayleigh scattering of the incident light in at least a portion of the sample. Alternatively, each image is indicative of the intensity of scattered light i) of a different wavelength, or ii) for incident light of a different polarization state, or iii) of a different polarization state, wherein the scattered light comprises an inelastic scattering component that is due to Raman scattering of the incident light in at least a portion of the sample. The method further comprises determining the chemical and/or material specific information of the sample based on the change in intensity of the elastic scattering component in dependence on the change in wavelength and/or the change in polarization state of the incident and/or scattered light.

A method of operating a detection system includes switching the system from a normal mode for sensing smoke to a high sensitivity mode for sensing airborne particles, such that in the high sensitivity mode the detection system is configured to discriminate between particles of diameters less than 2.5 micrometers and 10 micrometers. Transmitting light from one or more light sources of the detection system into a monitored space, and detecting scattered light at one or more light sensing devices of the detection system. The detection of scattered light is indicative of one or more indoor air quality conditions in the monitored space.