Abstract: A housing for internal components of an optical probe is provided. The housing includes a housing body including an outer surface and an inner surface opposite the outer surface. The housing body is elongated along a center longitudinal axis from a proximal end to a distal end. The inner surface defines and annularly surrounds a cavity that is open at the proximal end and closed at the distal end. The housing includes a purge channel that includes a gas inlet and a gas outlet. The purge channel extends axially relative to the center longitudinal axis from the gas inlet to the gas outlet. The purge channel is formed between the outer surface and the inner surface of the housing body. The gas outlet is located distally from the gas inlet and through the inner surface of the housing body. The gas outlet directs gas into the cavity toward the distal end.

Abstract: An optical metrology device collects data in parallel by multiplexing wavelength and associated frequencies using computer control and electro-optics in a wavelength modulator. The wavelength modulator includes a pair of crossed polarizers and an electro-optical modulator, such as a Pockels cell or Faraday rotator, disposed between the polarizers. The electro-optical modulator modulates the polarization state of the light in response to a control signal and produces a different amount of polarization rotation for each wavelength in response to each value of the control signal. The control signal causes the electro-optical modulator to modulate the plurality of wavelengths in the light at different frequencies resulting in the production of a wavelength-frequency multiplex from the wavelength modulator. The effect of the sample on the wavelength-frequency multiplex may be used to determine one or more characteristics of the sample.

Abstract: Introduced here is an approach to mitigating (e.g., lessening or eliminating) the high-frequency interference pattern that is caused by uneven surfaces along the coupling interface formed between the waveguide and probe of an interferometric sensing system. The approach is to reduce the high-frequency interference pattern caused by the interference when a waveguide—for example, in the form of an optical fiber—and a probe are directly coupled to one another. Specifically, the coupling surface of the waveguide can be treated, for example, with sandpaper, sandblasting, or acid etching, to create a frosted surface texture. In operation, the frosted surface scatters the light transmitted through the waveguide, preventing the high-frequency interference pattern from occurring.

Abstract: The present disclosure concerns a refractometer including a measurement window inside a flow channel of the flow vessel of the refractometer, the flow channel being designed to allow process fluid flow at least at the measurement window in laminar flow regime of the dedicated process liquid.

Abstract: An optical thickness measuring device includes a light source, a measuring head, an optical spectrometer with an optical component for spectrally splitting an input light, a detector, and an evaluation device. The light source is optically connected to the measuring head and is configured to generate an at least low-coherence measuring light and to direct it to the measuring head. The measuring head is optically connected to the spectrometer and is configured to direct the measuring light onto a measuring object and to direct light reflected therefrom, which originates from two different surfaces, onto a measuring object, which originates from two different surfaces, and to direct the reflected light to the spectrometer as input light.

Abstract: In a substrate processing apparatus according to the invention, a light source and an imager are arranged at a position distant from an object to be imaged such as a substrate, whereas a head unit is arranged at an imaging position. Diffused light is generated by diffusing and reflecting illumination light from the light source and illuminated a peripheral edge part of the object to be imaged. Further, reflected light from the peripheral edge part illuminated with the diffused light is guided to the imager, whereby the peripheral edge part is imaged by the imager.

Abstract: A measurement chamber extension for a spectrophotometric characterization with a NIR-spectrophotometer or a Raman-spectrophotometer of a liquid in a polymer container, wherein a measurement chamber extension comprises: an adapter plate having an adapter opening; a container holder, and an optical element, selected from a mirror and a waveguide. The adapter is configured to cover in a light-tight manner the measurement chamber of the NIR-spectrophotometer or of the Raman-spectrophotometer. The container holder is configured to allow a close placement of the optical element adjacent to the polymer container containing the liquid providing a loss-free transmission or transflection of the measurement light beam from the optical element to a detector of the NIR-spectrophotometer or Raman-spectrophotometer.

Abstract: The method for measuring the refractive index variation position of an optical fiber preform comprises: rotating the optical fiber preform about the central axis such that a straight line which is orthogonal to the central axis and which passes through two more refractive index variation positions of choice that are subject to measurement is orthogonal to the observation axis; irradiating a side surface of the optical fiber preform with light emitted from the light source, via the polarizer; receiving, with the camera and via the analyzer, the light that has been transmitted by the optical fiber preform, and acquiring a light intensity image; detecting a refractive index variation position of the optical fiber preform on the basis of the light intensity image; and moving the optical fiber preform or the observation axis parallel to the central axis.

Abstract: An object of the present invention is to provide a sensing system, a sensing method, and an analyzing device using OFDR in which a sensing range of strain/temperature is less likely to be limited by a frequency sweep width. In the sensing method using OFDR, the sensing system according to the present invention employs sequential update, per measurement by one frequency sweep of the probe light, for setting the reference spectrum to the spectrum of an immediately preceding measurement, by which a spectral shift between an n-th measurement and an (n?1)th measurement is obtained, and the spectral shifts individually obtained between the measurements are integrated.

Abstract: A method for measuring an item of geometric information of an interface of an optical element including interfaces, with a device configured to direct a measurement beam towards the optical element so as to pass through at least one of the interfaces and be reflected by the interface and generate a reflected beam, to selectively detect an interference signal between the reflected beam and a reference beam, the method including positioning a coherence area at an interface; measuring the interface so as to produce interference signals; and processing the signals including constructing a mathematical interface based on a sub-set of interference signals, determining, based on the mathematical interface and an expected shape of the interface, an item of geometric information of the interface.

Abstract: A tri-mask optical polarization diversity receiver with a single input terminal and three output terminals prevents polarization induced signal fade, and may be used in an optical interferometry system for coherent detection. The device is composed of optical collimators, non-polarizing beam splitters, linear polarizers and photodetectors. In addition, the structural design incorporates two mechanically identical modulets, as well as a beam displacement compensation mechanism for ease of alignment and assembly. Compared to fiber-based design, the free-space configuration gets rid of inevitable birefringence in fused fiber couplers which detrimentally alter the polarization state received by the polarizers. As a result, it facilitates effective and precise measurements of optical interference with optimized visibility.

Abstract: Systems, apparatuses, and methods are provided for measuring intensity using off-axis illumination. An example method can include illuminating a region of a surface of a substrate with a first radiation beam at a first incident angle and, in response, measuring a first set of photons diffracted from the region. The example method can further include illuminating the region with a second radiation beam at a second incident angle and, in response, measuring a second set of photons diffracted from the region. The example method can further include generating measurement data for the region based on the measured first set of photons and the measured second set of photons.

Abstract: A spectrometric measurement method of determining concentrations of components present in a medium of a given type exhibiting different compositions in different applications includes, for at least one new application, determining a new model for determining concentrations of target components based on measured spectra of the medium of the given type present in the new application, wherein the new model is determined based on assets for determining concentrations of reference components corresponding to the target components that have been determined for reference applications, wherein the reference components have been of interest.

Abstract: A system includes a light source, a transparent container, a detector, and a processor. The light source emits light. Liquid flows from one end of the transparent container to another end of the transparent container. The liquid comprises a first and a component. One or more droplets containing the second component are formed within the transparent container as the liquid flows from the one end to the another end of the transparent container. The detector measures light intensities from the transparent container being illuminated. The one or more droplets cast shadows on the detector. A light intensity associated with a portion of the liquid that includes the one or more droplets is different from a second light intensity associated with another portion of the liquid that does not include the one or more droplets. The processor processes the measured light intensities to determine phase entrainment metrics associated with the liquid.

Abstract: An optical instrument of very high resolution is provided that can be used for monitoring semiconductor processes. Very high resolution may be considered in this application space to be resolutions sufficient to permit resolving of individual molecular rovibrational emission lines. In one example an optical instrument is provided that includes: (1) an optical interface that receives an optical fiber, (2) a narrow band pass filter that filters out a portion of an optical signal received via the optical fiber, (3) optical components that are selectively combined to process at least a portion of the unfiltered optical signal, wherein the optical components include a sensor that receives the unfiltered optical signal, and (4) one or more processors that process electrical signals from the sensor. The optical instrument can be a spectrometer suitable for a process control instrument.

Abstract: This calibration system includes: a moving body that moves within a predetermined region and generates a vibration signal; a vibration detection means, being provided within the predetermined region, for detecting a vibration signal generated in the predetermined region; a signal analysis means for analyzing the vibration signal detected by the vibration detection means, and calculating a position on the vibration detection means where the vibration detection means detects the vibration signal; and an association means for calibrating the vibration detection means at a predetermined timing by associating the position on the vibration detection means where the vibration detection means detects the vibration signal with a position in the predetermined region, based on a generation position and a generation time of the vibration signal generated by the moving body and the position on the vibration detection means where the vibration detection means detects the vibration signal and a detection time thereof.

Abstract: Disclosed is a test system which includes a light source device. The light source device includes a first light source configured to radiate a first light, a plurality of neutral-density (ND) filters including a first ND filter attached to the first light source and configured to adjust the first light, an aperture unit including a plurality of apertures configured to adjust the first light received from the first ND filter and a diffuser configured to diffuse the first light received from the aperture unit and to radiate the first light for testing an image sensor, wherein an illuminance of the first light is adjusted based on a transmittance of the first ND filter and an aperture ratio of each of the apertures.

Abstract: A monitoring procedure for monitoring the quality of measurement spectra of a liquid medium continuously determined with a spectrometric sensor, which spectra in each case reproduce spectral values in a specified measurement wavelength range, is described with which: for each measurement spectrum, a quality parameter of the respective measurement spectrum is determined in each case based upon at least one characteristic value calculated in each case based upon the spectral values of the respective measurement spectrum, wherein each characteristic value for each measurement spectrum is determined in each case based upon the spectral values of the respective measurement spectrum in a range, specified for the respective characteristic value, of the measurement wavelength range, and, based upon the quality parameters, those measurement spectra which have spectral values that are impaired by a disturbance are identified as outliers.

Abstract: A device for measuring caustic parameters of a laser beam includes a beam splitter for splitting the laser beam into at least three spatially separated partial beams, and a detection unit for detecting images of the partial beams. A beam path from an input of the device to the beam splitter defines a beam axis for the laser beam, along which the laser beam propagates until entering the beam splitter. The beam splitter includes an optical lens, and a partially reflective surface configured to split the laser beam into the at least three partial beams by partial reflection within the optical lens. The optical lens is positioned off-axis such that an optical axis of the optical lens extends off-axis to the beam axis, and/or the optical lens is tilted such that the optical axis of the optical lens forms an angle with the beam axis that deviates from 0°.

Abstract: A measurement apparatus (10) for interferometrically measuring a shape of a surface (12) of a test object (14) in relation to a reference shape includes a diffractive optical element (30) generating a test wave (32) from measurement radiation (22), whereas a wavefront of the test wave is adapted to a target shape of the surface of the test object and the target shape is configured as a first non-spherical surface, and a reference element (38) with a reference surface (40) having the reference shape, the reference shape being configured as a further non-spherical surface and the reference element including a low thermal expansion material with a mean coefficient of thermal expansion having an absolute value of no more than 200×10?6 K?1 in the temperature range from 5 °C to 35 °C.