An optical receiver is provided that includes an array of photoreceivers. Each photoreceiver may be configured to receive a respective portion of a speckle pattern generated by interaction between an object beam and a scattering medium and each photoreceiver may be configured to generate respective electrical detection signals for provision to processing circuitry for summing of the electrical detection signals. A photoreceiver may include a collector, first detector and second detectors, and first and second optical splitters. The photoreceiver may be configured to generate a first electrical detection signal and a second electrical detection signal based on a received portion of the speckle pattern.

The hybrid measurement system includes an evanescent prism coupling spectroscopy (EPCS) sub-system and a light-scattering polarimetry (LSP) sub-system. The EPCS sub-system includes an EPCS light source system optically coupled to an EPCS detector system through an EPCS coupling prism. The LSP sub-system includes an LSP light source optically coupled to an optical compensator, which in turn is optically coupled to a LSP detector system via a LSP coupling prism. A support structure supports the EPCS and LSP coupling prisms to define a coupling prism assembly, which supports the two prisms at a measurement location. Stress measurements made using the EPCS and LSP sub-systems are combined to fully characterize the stress properties of a transparent chemically strengthened substrate. Methods of processing the EPCS and LSP measurements and enhanced configurations of the EPCS and LPS sub-systems to improve measurement accuracy are also disclosed.

A method for identifying a composition material of an object located in an environment surrounding at least one device, the object moving relative to the device, in which at least one sensor is mounted on the device and communicates with at least one central processing unit.

The invention aims to provide an inspection device that can sensitively detect a defect even if intensity of scattered light reflected from an inspection object greatly varies depending on portions of the inspection object. An inspection device according to the invention uses a history of detection signals to predict whether a next detection signal level exceeds a threshold. When the detection signal level is predicted to exceed the threshold, operation of the device is beforehand changed such that the detection signal level does not exceed the threshold.

A defect inspection apparatus includes: an illumination unit configured to illuminate an inspection object region of a sample with light emitted from a light source; a detection unit configured to detect scattered light in a plurality of directions, which is generated from the inspection object region; a photoelectric conversion unit configured to convert the scattered light detected by the detection unit into an electrical signal; and a signal processing unit configured to process the electrical signal converted by the photoelectric conversion unit to detect a defect in the sample. The detection unit includes a lens array configured to divide an image to form a plurality of images on the photoelectric conversion unit. The signal processing unit is configured to synthesize electrical signals corresponding to the plurality of formed images to detect a defect in the sample.

Systems and methods of performing a stress measurement of a chemically strengthened glass using a light-scattering polarimetry system include adjusting the intensity of a light beam from a light source in an illumination system using a rotatable half-wave plate and a first polarizer operably disposed between the light source and a rotating light diffuser that has a rotation time t.sub.R. The first polarizer is aligned with a second polarizer in a downstream optical compensator to have matching polarization directions by rotating the rotatable half-wave plate to a position where the exposure time t.sub.E falls within an exposure range t.sub.Rt.sub.E. The method also includes performing an exposure using the exposure time t.sub.E to obtain the stress measurement. One or both of the half-wave plate and first polarizer can be tilted to avoid deleterious back-reflected light from entering the light source.

Disclosed is an ellipsometer or scatterometer including a light source, a polarizer, an optical illumination system suitable for directing an incident polarized light beam towards a sample, a wavefront-division optical beam splitter arranged to receive a secondary light beam produced by reflection, transmission or diffraction, the wavefront-division optical beam splitter being oriented to form three collimated split beams, an optical polarization modification device and an optical polarization splitting device to form six angularly split beams, a detection system suitable for detecting the six split beams, and a processing system suitable for deducing therefrom an ellipsometric or scatterometric measurement.

A surface defect measuring apparatus and method by microscopic scattering polarization imaging is provided. The apparatus mainly comprises a laser, a first converging lens, a rotary diffuser, a second converging lens, a diaphragm, a third converging lens, a pinhole, a fourth converging lens, a polarizer, a half-wave plate, a polarizing beam splitter, an X-Y translation stage, a sample, a microscope lens, a quarter-wave plate, a micro-polarizer array, a camera and a computer. The micro-polarizer array is adopted to realize real-time microscopic scattering polarization imaging of the surface defects; a polarization-degree image is calculated to improve the sensitivity for detecting the surface defects of the ultra-smooth element, and the effective detection of the surface defects of a high-reflective coating element is also realized, and the requirement for rapid detection of the surface defects of a meter-scale large-aperture ultra-smooth element can be met.

A method and system are presented for use in measuring on patterned samples, aimed at determining asymmetry in the pattern. A set of at least first and second measurements on a patterned region of a sample is performed, where each of the measurements comprises: directing illuminating light onto the patterned region along an illumination channel and collecting light reflected from the illuminated region propagating along a collection channel to be detected, such that detected light from the same patterned region has different polarization states which are different from polarization of the illuminating light, and generating a measured data piece indicative of the light detected in the measurement. Thus, at least first and second measured data pieces are generated for the at least first and second measurements on the same patterned region. The at least first and second measured data pieces are analyzed and output data is generated being indicative of a condition of asymmetry in the patterned region.

A system for detection and monitoring includes one or more light sources configured to emit light into a monitored space. At least one of the light sources is configured to emit a respective emission cone having a respective emission cone axis. One or more light sensing devices are configured to receive scattered light. At least one of the one or more light sensing devices defines a respective acceptance cone having a respective acceptance cone axis. The emission cone axis of the emission cone, and/or the acceptance cone axis of the light sensing device is angled toward the other. A processor is operatively connected to the at least one light sensing devices to evaluate the scattered light for the presence of particulates in the monitored space.