A scatterometer performs diffraction based measurements of one or more parameters of a target structure. To make two-color measurements in parallel, the structure is illuminated simultaneously with first radiation (302) having a first wavelength and a first angular distribution and with second radiation (304) having a second wavelength and a second angular distribution. The collection path (CP) includes a segmented wavelength-selective filter (21, 310) arranged to transmit wanted higher order portions of the diffracted first radiation (302X, 302Y) and of the diffracted second radiation (304X, 304Y), while simultaneously blocking zero order portions (302″, 304″) of both the first radiation and second radiation. The illumination path (IP) in one embodiment includes a matching segmented wavelength-selective filter (13, 300), oriented such that a zero order ray passing through the illumination optical system and the collection optical system will be blocked by one of said filters or the other, depending on its wavelength.

A metrology system includes an illumination source configured to generate an illumination beam, one or more illumination optics configured to direct the illumination beam to a sample, one or more collection optics configured to collect illumination emanating from the sample, a detector, and a hyperspectral imaging sub-system. The hyperspectral imaging sub-system includes a dispersive element positioned at a pupil plane of the set of collection optics configured to spectrally disperse the collected illumination, a lens array including an array of focusing elements, and one or more imaging optics. The one or more imaging optics combine the spectrally-dispersed collected illumination to form an image of the pupil plane on the lens array. The focusing elements of the lens array distribute the collected illumination on the detector in an arrayed pattern.

The present invention discloses a multi-channel aerosol scattering absorption measuring instrument, comprising a light path device, a detection device and a gas path device. The light path device supplies three different wavelengths of laser entering the detection device in sequence; the detection device is provided with photoelectric detectors at multiple angles for measurement, so as to reduce the measurement error of aerosol scattering coefficient; the gas path device comprises a sample loading unit, a calibration unit and a sample discharging unit; and a light source from the light path device and a gas flow from the gas path device enter the photoacoustic cavity of the detection device respectively and are detected by a control unit. The aerosol scattering absorption measuring instrument of the present invention is characterized by multi-channel, multi-angular, full-scale and direct measurement of scattering phase function and absorption coefficient of aerosol particles, combines the function of synchronously acquiring the optical parameters of an aerosol (such as scattering coefficient, extinction coefficient, visibility, transmittance, single scattering albedo, etc.), and achieves the integrated on-line detection of different optical parameters of an aerosol with high automation degree and good stability.

A method and apparatus to measure specular reflection intensity, specular reflection angle, near specular scattered radiation, and large angle scattered radiation and determine the location and type of defect present in a first and a second transparent solid that have abutting surfaces. The types of defects include a top surface particle, an interface particle, a bottom surface particle, an interface bubble, a top surface pit, and a stain. The four measurements are conducted at multiple locations along the surface of the transparent solid and the measured information is stored in a memory device. The difference between an event peak and a local average of measurements for each type of measurement is used to detect changes in the measurements. Information stored in the memory device is processed to generate a work piece defect mapping indicating the type of defect and the defect location of each defect found.

The present relates to a measurement device (1) for the detection and/or measurement of particles in a fluid, the measurement device comprising a fluid source (11) for producing a flow of fluid (111) along a fluid flow path, a first laser source (12) positioned for emitting a first laser beam (120) of laser light in a measurement volume of the fluid flow path for light scattering; a scattered light detecting means (13) for detecting a presence of a particle in the fluid flow path through detection and measurement of laser beam light scattered on different angles by said particle, wherein it further comprises a second laser source (14) positioned for emitting a second laser beam (140) of laser light in said measurement volume of the fluid flow path for Raman and fluorescence excitation; a Raman and fluorescence detecting means (15) for detecting a Raman scattering signal emitted by the fluid and a Fluorescence signal emitted by said particle upon excitation by said second laser beam (140).

A measuring apparatus is provided with: an irradiator configured to irradiate fluid with light; a first light receiver configured to receive a forward scatter component of scattered light scattered by the fluid; a second light receiver configured to receive a backscatter component of the scattered light; a third light receiver configured to receive a side scatter component of the scattered light; and an outputting device configured to output fluid information about the fluid, which is obtained on the basis of light receiving signals of the first light receiver, the second light receiver, and the third light receiver. According to this measuring apparatus, it is possible to output accurate fluid information because of the use of the forward scatter component, the backscatter component, and the side scatter component of the scattered light.

A method for characterizing particle objects comprises generating a radiation beam, illuminating with the radiation beam an observation region transited by a particle object, collecting an interference image determined by an interference between a transmitted fraction and a part of the scattered fraction of the radiation beam that propagates around the direction of the optical axis, collecting a part of the scattered fraction that propagates at the scattering angle, and measuring at least one scattered radiation intensity value determined by the part of the scattered fraction, calculating, from the interference image, a pair of independent quantities that define the complex field of the first part of the scattered fraction, calculating, starting from the pair of independent quantities, a theoretical value of scattered radiation intensity, and comparing the measured value with the theoretical scattered radiation intensity value.

A sensor includes an inner channel with: a first portion; a second portion in communication with the first portion; a storage zone in communication with the first portion; a baffle plate extending inside the first portion; the first portion and the baffle plate being sized such that, in an air stream entering the sensor through a first, open end of the first portion and containing first particles with a diameter of 10 μm or less and second particles with a diameter of more than 10 μm, the first particles reach the second portion of the inner channel while the second particles reach the storage zone.

Described here are optical sampling architectures and methods for operation thereof. An optical sampling architecture can be capable of emitting a launch sheet light beam towards a launch region and receiving a detection sheet light beam from a detection region. The launchregion can have one dimension that is elongated relative to another dimension. The detection region can also have one dimension elongated relative to another dimension such that the system can selectively accept light having one or more properties (e.g., angle of incidence, beam size, beam shape, etc.). In some examples, the elongated dimension of the detection region can be greater than the elongated dimension of the launch region. In some examples, the system can include an outcoupler array and associated components for creating a launch sheet light beam having light rays with different in-plane launch positions and/or in-plane launch angles.

The present disclosure describes a computer implemented method, a system, and a computer program product of measuring light scattering of a sample.