Abstract: Apparatus and associated methods relate to determining a size and/or density of Super-cooled Large Droplets (SLDs) in a cloud atmosphere by comparing detected optical signals reflected from small and large sampling volumes of a cloud atmosphere. In some embodiments, an optical pulse is generated and divergently projected from a first optical fiber. A collimating lens is aligned within the divergently projected optical pulse collimating a portion thereof. The collimated and uncollimated portions of the optical pulse are projected into the small and large sampling volumes of the cloud atmosphere, respectively. The ratio of the collimated to the uncollimated portions can be optically controlled. Signals corresponding to optical pulses having different collimated/uncollimated ratios are backscattered by the cloud atmosphere, detected and compared to one another.

Abstract: A measurement system includes: a projection apparatus that projects, onto a subject, first pattern light indicating a first pattern projection image including a first pattern image corresponding to a specific bit in gray code obtained by gray-coding projection coordinates stipulated by a projection coordinate system, and a second pattern image having the same cycle as the first pattern image, but having a different phase from the first pattern image, following a projection sequence where projections of the first and second pattern images coexist; and at least one imaging apparatus that images the first pattern light and generates an imaged image.

Abstract: The entire throat height or air gap of a laser gauge's C-frame enclosure constitutes its accurate measurement range so that any material passing at any height through the air gap will be accurately measured. The laser gauge has at least one laser and usually two lasers housed in an enclosure with at least two arms that are spaced apart for receipt of a target surface in the air gap between the arms. The gauge has a first enclosure barrier attached to a first one of the enclosure arms at a first boundary of the air gap. The first enclosure barrier is positioned away from the laser at or beyond the gauge's proximal measurement limit. A second enclosure barrier is attached to a second one of the enclosure arms at a second boundary of the air gap. The second enclosure barrier is positioned away from the laser at or nearer than the gauge's distal measurement limit.

Abstract: Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly.

Abstract: A measuring apparatus includes an optical system configured to project light onto a sample and to receive light via the sample, an imaging device configured to take an image of a light source via the optical system, and a processor configured to obtain an optical characteristic of the sample based on an output of the imaging device. The processor is configured to determine a coefficient of a Wiener filter based on one of the image and a Fourier transform thereof and corresponding one of the light source (an aperture in an aperture unit) and a Fourier transform thereof, and obtain the optical characteristic based on the Wiener filter of which the coefficient has been determined, a Fourier transform of the image, and a Fourier transform of the light source.

Abstract: The present disclosure relates to a three-dimensional shape measurement apparatus for obtaining height information of a measurement target object using a prism. The three-dimensional shape measurement apparatus includes an illumination unit irradiating light on the measurement target object, a prism unit receiving reflective light reflected from the measurement target object and directing the reflective light to an image formation lens, an imaging unit receiving the reflective light from the prism unit and capturing an image of the reflective light, and a height measurement unit measuring a height of the measurement target object based on the image captured by the imaging unit.

Abstract: Disclosed is a system and method for characterizing optical filters in a flow cytometer and optionally checking the operation of detectors in the flow cytometer. In some embodiments, the system may utilize an LED board having an opening through which the fluorescence and side scatter beams, rays, or images pass and light emitting diodes around the opening that emit light having different spectral profiles. The different spectral profiles allow the system to identify the optical filters that are placed in the flow cytometer, to verify detector operation, to assist in instrumentation troubleshooting, and to provide a quantitative reference for detector comparison.

Abstract: A sensor for detecting the level of accumulation of a material along an axis in a fluid environment, the sensor comprising (a) an optically transparent body having a third refractive index and an exposed surface defining a length extending at least partially in the direction of the axis; (b) at least one light delivery source for delivering light to the body such that the light is distributed along the length of the exposed surface; and at least one light receiver for receiving reflected light from the length of the exposed surface, wherein the amount of the reflected light depends on the level of the material accumulated along the length of the exposed surface.

Abstract: An erosion detector for an exterior aircraft lighting device is configured for detecting the state of erosion of an at least partially transparent cover of an exterior aircraft lighting device and includes: at least one light source, which is configured for radiating light onto the at least partially transparent cover; at least one light detection element, which is configured for detecting light reflected by the at least partially transparent cover and for providing a corresponding detection signal; and an evaluation unit, which is configured for evaluating the detection signal for determining the state of erosion of the at least partially transparent cover.

Abstract: A light emitter is provided to emit, into an environment of interest, a plurality of different patterns of light during respective periods of time. Each of the different patterns of light varies according to angle in a first direction such the location of a light detector disposed in the environment can be determined based on illumination from the light emitter that is detected by the light detector over time. The light emitter includes an astigmatic optical element and a die on which are disposed multiple sets of one or more light emitters, each set corresponding to a respective pattern of illumination emitted from the light emitter. Such a configuration of the light emitter can provide means for producing the different patterns of illumination in an energy-efficient, low-cost, and/or size-constrained manner.

Abstract: A method for detecting a contamination of a cuvette of a turbidimeter. The turbidimeter includes a light source which emits a light beam directed to a cuvette, a scattering light detector, and a diffuser with a body and an actuator. The actuator moves the body between a parking position and a test position where the body is between the measurement light source and the cuvette, thereby interferes with the light beam, and generates a diffuse test light entering the cuvette. The method includes activating the actuator to move the body from the parking position into the test position, activating the light source, measuring a test light intensity received by the scattering light detector, comparing the test light intensity measured with a reference light intensity, and generating a contamination signal if a difference between a reference light intensity and the test light intensity measured exceeds a first threshold value.

Abstract: A system includes a shaft and a light path surface coupled to or integrated with the shaft. The light path surface is displaced as a function of twist angle at a point along the shaft. The system also includes a sensor configured to measure the light path length that varies according to displacement of the light path surface. The system also includes a processing unit that determines a twist angle value for the point along the shaft based on the measured light path length.

Abstract: An optical element includes a main body formed of a light transmissive material and including an arc-shaped optical path, and a gap formed on the arc-shaped optical path in the main body. The gap may have a notch shape. The main body may have a semicircular plate shape. The main body may have a hemispherical shape.

Abstract: An integrated metrology module includes a chuck for holding a sample and positioning the sample with respect to an optical metrology device, a reference chip for the optical metrology device, the reference chip being movable to various positions with respect to the optical metrology device, and a reference chip purge device provides a flow of purge gas or air over the reference chip while the reference chip is in the various positions. The reference chip purge device may be static or movable with the reference chip.

Abstract: Various technologies for measurement of properties of a particulate suspended in a gas phase via laser-induced incandescence (LII) are described herein. A beam of light can be emitted into a multi-pass optical cell using a laser. The multi-pass optical cell comprises a system of one or more mirrors that repeatedly reflects the beam through a measurement region, stimulating incandescence of particulates present in the measurement region. An LII detection system having a field of view that encompasses the measurement region then receives blackbody or quasi-blackbody radiation emitted by the incandescing particles and outputs data indicative of one or more properties of the particulates in the measurement region.

Abstract: Described herein is an improved displacement transducer, a closed loop control system incorporating the same, and an improved method of manufacturing of manufacturing a displacement transducer. The improved transducer has several advantages, including improved manufacturability; improved fluid flow within the sensor and reduced cavitation as a result; and the enablement of closed loop control for assisted manual or fully automatic displacement.

Abstract: Systems and methods batch calibrate environmental sensors. Candidate environmental sensors and a high-performance reference sensor are located in an enclosure with a particle excitation system that controls the particle concentration in the enclosure. The calibration process includes multiple phases with different particle concentrations, and the candidate and reference sensors continuously report their particle counts to a calibration server during these phases. Based on the collected data, the calibration server: (i) identifies for removal candidate sensors with outlying behavior through statistical analysis; and (ii) computes calibration values for the particle count estimation algorithms for the remaining candidate sensors that are optimized to minimize the error relative to the reference sensor(s).

Abstract: A site positioning system for an underground machine includes a first prism coupled with the underground machine, a second prism operatively coupled with the underground machine, a primary total station, and a reference prism may be in communication with the primary total station. A positioning controller is configured to control, responsive to receiving a High Accuracy Machine Position mode, the primary total station to monitor the first prism and the second prism and transmit a first prism position and a second prism position, respectively, to the positioning controller; control, responsive to receiving a Low Accuracy Machine Position mode, the primary total station to monitor the first prism and transmit the first prism position to the positioning controller; determine, responsive to receiving a Reference Prism Measurement mode, whether a reference prism measurement has been completed, and present positioning information for the machine based on one or more of the prism positions.

Abstract: The invention provides differential refractive index detectors and methods for the use of differential refractive index detectors. In an exemplary embodiment, a differential refractive index detector includes a flow cell body having a proximal end, a distal end, and a flow axis extending between the proximal and the distal end. The flow cell body includes a first chamber and a second chamber and the fluid conduits coupled to the flow cell body can be tapered to reduce dispersion.

Abstract: Apparatus and associated methods relate to determining a size and/or density of Super-cooled Large Droplets (SLDs) in a cloud atmosphere by comparing detected optical signals reflected from small and large sampling volumes of a cloud atmosphere. In some embodiments, an optical pulse is generated and divergently projected from a first optical fiber. A collimating lens is aligned within the divergently projected optical pulse collimating a portion thereof. The collimated and uncollimated portions of the optical pulse are projected into the small and large sampling volumes of the cloud atmosphere, respectively. The ratio of the collimated to the uncollimated portions can be optically controlled. Signals corresponding to optical pulses having different collimated/uncollimated ratios are backscattered by the cloud atmosphere, detected and compared to one another.