A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of n.sub.eff, a numerical aperture of NA, a scatter of R.sub.p.fwdarw.r.sup.(fiber) that varies axially along the optical fiber, a total transmission loss of α.sub.fiber, an in-band range greater than one nanometer (1 nm), and a figure of merit (FOM) in the in-band range. The FOM being defined as: $\mathrm{FOM}=\frac{R_{p.fwdarw.r}^{\left(\mathrm{fiber}\right)}}{{{\alpha }_{\mathrm{fiber}}\left(\frac{\mathrm{NA}}{2n_{\mathrm{eff}}}\right)}^2}.$

The present invention relates to a method for evaluating the thermal expansion properties of a titania-containing glass body. On the basis of measured values, obtained at a certain temperature, for a physical parameter that changes depending on the titania concentration and a physical parameter that changes depending on the fictive temperature, the thermal expansion coefficient of the titania-containing silica glass body and the slope of the thermal expansion coefficient are calculated using a linear relational expression represented by a plurality of physical properties. The thermal expansion properties of the titania-containing silica glass body are evaluated on the basis of the calculated thermal expansion coefficient and thermal expansion coefficient slope.

The present disclosure describes a computer implemented method, a system, and a computer program product of determining intrinsic viscosity and Huggins constant of an unknown sample. In an embodiment, the method, system, and computer program product include receiving concentration detector signal values over time from a concentration detector corresponding to a series of aliquots of an unknown sample injected into an instrument chain, receiving specific viscosity values over time from a viscometer corresponding to the series of aliquots, calculating a total mass of each of the aliquots, calculating a first intermediate viscosity value of each of the aliquots, calculating a second intermediate viscosity value of each of the aliquots, and fitting the total mass, the first intermediate viscosity value, and the second intermediate viscosity value to a fitting, resulting in a calculated intrinsic viscosity of the unknown sample and a calculated Huggins constant of the unknown sample.

The present disclosure describes a computer implemented method, a system, and a computer program product of determining intrinsic viscosity and Huggins constant of an unknown sample. In an embodiment, the method, system, and computer program product include receiving concentration detector signal values over time from a concentration detector corresponding to a series of aliquots of an unknown sample injected into an instrument chain, receiving specific viscosity values over time from a viscometer corresponding to the series of aliquots, calculating a total mass of each of the aliquots, calculating a first intermediate viscosity value of each of the aliquots, calculating a second intermediate viscosity value of each of the aliquots, and fitting the total mass, the first intermediate viscosity value, and the second intermediate viscosity value to a fitting, resulting in a calculated intrinsic viscosity of the unknown sample and a calculated Huggins constant of the unknown sample.

Multilayered product structures are formed on substrates by a combination of patterning steps, physical processing steps and chemical processing steps. An inspection apparatus illuminates a plurality of target structures and captures pupil images representing the angular distribution of radiation scattered by each target structure. The target structures have the same design but are formed at different locations on a substrate and/or on different substrates. Based on a comparison of the images the inspection apparatus infers the presence of process-induced stack variations between the different locations. In one application, the inspection apparatus separately measures overlay performance of the manufacturing process based on dark-field images, combined with previously determined calibration information. The calibration is adjusted for each target, depending on the stack variations inferred from the pupil images.

A continuous dust accumulation monitoring system, device and method monitors and measures dust accumulation via an enclosure and a machine vision subsystem which can include a digital camera. A dirty optics detection subsystem monitors optical clarity and can invoke a cleaning assembly to help maintain clarity of optics for monitoring and measuring dust accumulation.

A continuous dust accumulation monitoring system, device and method monitors and measures dust accumulation via an enclosure and a machine vision subsystem which can include a digital camera. A dirty optics detection subsystem monitors optical clarity and can invoke a cleaning assembly to help maintain clarity of optics for monitoring and measuring dust accumulation.

An interferometry apparatus comprising: a laser source operable to emit a first light beam; a beam splitter arranged to split the first light beam into an object beam and a reference beam, the object beam passing along an object beam arm and the reference beam passing along a reference beam arm; an adaptive delay line located a distance along the reference beam arm, the adaptive delay line being configured to provide, in use, one or more length-adjusted reference beams; a beam splitter arranged to recombine the object beam from the object beam arm and the length-adjusted reference beam(s) from the reference beam arm; and a photodetector operable to detect interference between the object beam and the length-adjusted reference beam(s).

A measurement apparatus according to an embodiment of the present technology includes a light source, a filling portion, and a detector. The light source emits illumination light. The filling portion includes a first surface portion and a second surface portion which are provided on an optical path of the illumination light and are opposite to each other, the filling portion enabling a cavity between the first and second surface portions to be filled with liquid including a cell. The detector detects an interference fringe of the illumination light passing through the cavity, the interference fringe being caused by the liquid including the cell.

An optical water quality sensor includes a holder base having a first light-transmitting portion and a second light-transmitting portion extending in the same direction, a first receiving groove and a second receiving groove respectively extending into the first light-transmitting portion and the second light-transmitting portion and a first light-condensing side and a second light-condensing side respectively located on the inner sides of the first light-transmitting portion and the second light-transmitting portion, and a sensor module with a circuit board assembled in the accommodating space. The circuit board has a first arm plate and a second arm plate respectively inserted into the first receiving groove and the second receiving groove, and a light emitter and a light receiver respectively located on the first arm plate and the second arm plate to face the first light-condensing side and the second light-condensing side.