According to the present invention, a light source and one pixel unit formed of at least one light reception element among a light reception element array (photodiode array) are provided in a one-to-one correspondence, and a light beam is detected from at least one light reception element (one pixel unit) corresponding to the light source, only when the light source emits light. Therefore, only one collimated or further substantially condensed light beam is incident into “a foreign substance/defect” in an object to be inspected, and only scattered light can be separated by the light reception element and be detected. Accordingly, even when an object to be inspected has a light scattering property and is thick, “a foreign substance/defect” can be detected with a good signal to noise ratio (crosstalk is extremely low).

An optical system for performing an absorption measurement of a medium sample includes a laser source configured to output a laser beam having a wavelength corresponding to an absorption region of interest; a ringdown cavity comprising a chamber configured to receive the medium sample, an input mirror at an input end, an output mirror at an output end, and an optical axis that extends through the centers of the input mirror and the output mirror; a coupling device configured to couple the laser beam through the input mirror into the chamber; and a detector optically coupled with the cavity, and configured to detect an intensity of light of the wavelength corresponding to the absorption region of interest that extends through the output mirror, wherein a cavity geometry of the cavity increases the re-entrant condition of the cavity relative to a conventional cavity comprised of two spherical mirrors.

Provided is a wafer inspection apparatus including a monochromator that extracts monochromatic light, a collimator that outputs the monochromatic light as parallel light, a first polarization assembly that polarizes the parallel light and radiates the polarized light to a wafer, an imaging optical system that condenses light reflected from the wafer, a spectroscope that splits the condensed light into a plurality of spectrums, a first lens that condenses the plurality of spectrums, a second polarization assembly that outputs the plurality of spectrums as a plurality of polarized lights having different diffraction orders and a difference of 90°, a second lens that condenses the plurality of polarized lights, a third polarization assembly that outputs common polarized light based on the plurality of polarized interfering with each other, a camera that generates a phase difference image based on the common polarized light, and a signal processor that analyzes the phase difference image.

A method for determining a presence of at least one guest structure at a host structure. The method comprises a light-sensitive system receiving light from the host structure. The host structure hosts one or more optically active entities at at least one part of the host structure. The at least one part does not host the at least one guest structure. Furthermore, the optically active entities cause light emission from the at least one part. The method also comprises the light-sensitive system outputting a signal based on the received light a step of determining a light value based on the output signal. The light value indicates an amount of light from the host structure incident on the light-sensitive system. The method also comprises determining on the basis of the light value at least one of a quantity and a position of the at least one guest structure.

Techniques are disclosed for particulate matter (PM) measurement in a medium (such as air) using flat-top intensity laser sheet beam generation. The techniques for generating the laser sheet beam may include nonspecialized optical elements (e.g., aspherical, spherical, biconvex, and/or cylindrical lenses) that are cost-effective, reduce the overall footprint of the system, and also provide for relatively increased power efficiencies compared to conventional techniques. The PM measurement system may use the laser sheet beam generated in combination with a medium flow channel to pass the medium through the laser sheet beam, thereby causing particulates within the medium to scatter light, which can be detected using a light sensor (e.g., a photodetector). The scattered light signals can then be analyzed to match them with corresponding particulate sizes and the amount of signals per particulate size can also be determined to measure the size and count of particulates within the medium.

A spatial filter is made by forming a structure comprising a focusing element and an opaque surface, the opaque surface being disposed remotely from the focusing element in substantially the same plane as a focal plane of the focusing element; and by forming a pinhole in the opaque surface at or adjacent to a focal point of the focusing element by transmitting a substantially collimated laser beam through the focusing element so that a point optimally corresponding to the focal point is identified on the opaque surface and imperfection of the focusing element, if any, is reflected on the shape and position of the pinhole so formed.

Conventional optical analysis tools containing an integrated computational element may have an operational profile that is too large for convenient use within confined locales. Optical analysis tools having a miniaturized operational profile can comprise: an electromagnetic radiation source that provides electromagnetic radiation to an optical train; and an optical computing device positioned within the optical train. The optical computing device comprises a planar array detector having at least two optical detection regions. At least one of the at least two optical detection regions has an integrated computational element disposed thereon. The planar array detector and the integrated computational element are in a fixed configuration with respect to one another.

A spectral reflectometer system for measuring a substrate is provided. A light source is provided. At least one optical detector is provided. An optical cable comprises a plurality of optical fibers, wherein the plurality of optical fibers comprises a first plurality of optical fibers, which are transmission optical fibers which extend from the light source to an optical path, and a second plurality of optical fibers, which are reflection optical fibers which extend from the optical path to the at least one optical detector. A microlens array is in the optical path.

An overlay metrology system may include an illumination sub-system to sequentially illuminate an overlay target with a first illumination lobe and a second illumination lobe opposite the first illumination lobe, where the overlay target includes grating-over-grating features formed from periodic structures on a first sample layer and a second sample layer. The system may further include an imaging sub-system to generate a first image and a second image of the overlay target. The first image includes an unresolved image of the grating-over-grating structures formed from a single non-zero diffraction order of the first illumination lobe. The second image includes an unresolved image of the one or more grating-over-grating structures formed from a single non-zero diffraction order of the second illumination lobe. The system may further include a controller to determine an overlay error between the first layer and the second layer based on the first image and the second image.

A system of measuring hemoglobin and bilirubin parameters in a whole blood sample using optical absorbance. The system includes an optical-sample module, a spectrometer module, an optical fiber module optically connecting the optical-sample module to the spectrometer module, and a processor module. The optical-sample module has a light-emitting module having a LED light source, a cuvette and a calibrating-light module. The processor module receives and processes an electrical signal from the spectrometer module and transforms the electrical signal into an output signal useable for displaying and reporting hemoglobin parameter values and/or total bilirubin parameter values for the whole blood sample.