When replacing a mirror in a projection exposure apparatus, a mirror for replacement is initially removed (41). Position- and orientation data of the removed mirror for replacement are measured (43) by a position -and orientation data measuring device. Furthermore, position- and orientation data of a replacement mirror, to be inserted in place of the mirror for replacement, are measured (46) using the position- and orientation data measuring device. Bearing points of the replacement mirror are reworked (48) on the basis of ascertained differences between, firstly, the position- and orientation data of the mirror for replacement and, secondly, the position- and orientation data of the replacement mirror. The reworked replacement mirror is installed (54). This yields a mirror replacement method, in which an adjustment outlay of the replacement mirror in the projection exposure apparatus is reduced.

A lens inspection module comprises: a lens insertion station, at least one lens inspection station, and a lens removal station as well as a closed-loop transportation rail, a cuvette transportation shuttle with a plurality of inspection cuvettes, and a self-driving cleaning shuttle for cleaning the rail. Cleaning shuttle comprises a driving unit a cleaning head, a suction unit, and a tube connecting cleaning head and suction unit. Cleaning head is spaced apart from suction unit and driving unit in the transportation direction and is pivotally arranged about a pivot axis. Cleaning head may comprise a distance sensor for detecting the distance between cleaning shuttle and transportation shuttle. Driving unit is configured to change the speed of the self-driving cleaning shuttle when the distance between the cleaning shuttle and the transportation shuttle is shorter than a predetermined threshold distance.

A measurement device, for measuring the shape of an interface to be measured of an optical element having a plurality of interfaces, the device including: measurement apparatus with at least one interferometric sensor illuminated by a low-coherence source, for directing a measurement beam towards the optical element to pass through the plurality of interfaces, and to detect an interference signal resulting from interferences between the measured measurement beam reflected by the interface and a reference beam; positioning apparatus configured for relative positioning of a coherence area of the interferometric sensor at the level of the interface to be measured; digital processor for producing, based on the interference signal, an item of shape information of the interface to be measured according to a field of view.

A measurement method, for measuring the shape of an interface of an optical element having a plurality of interfaces is also provided.

The disclosure relates to multi-purpose eyeglass lens inspection devices, and more particularly to such a device having a lighted base with a viewing lens assembly, an inspection lens assembly, and a plurality of interchangeable lenses with integral storage for the interchangeable lenses.

The disclosure relates to multi-purpose eyeglass lens inspection devices, and more particularly to such a device having a lighted base with a viewing lens assembly, an inspection lens assembly, and a plurality of interchangeable lenses with integral storage for the interchangeable lenses.

According to one embodiment, an optical test apparatus includes a first aperture, a second aperture, an image sensor, and a first lens. The first aperture includes a first aperture plane provided with a first wavelength selecting region. The second aperture includes a second aperture plane provided with a second wavelength selecting region different from the first wavelength selecting region. The image sensor is configured to image a light beam passing through the first aperture plane and the second aperture plane and reaching an imaging plane. The first lens is configured to make a light beam passing through the first aperture plane and the second aperture plane be incident on the imaging plane.

A computer-readable, non-transitory medium storing a program that causes a computer to execute a process is provided. The process includes acquiring a backward Rayleigh scattered light from an optical fiber composite overhead ground wire which an electrical power transmission facility has; generating vibration information of a frequency band including a natural frequency of the optical fiber composite overhead ground wire, on a basis of the backward Rayleigh scattered light; and detecting abnormality of the electrical power transmission facility, on a basis of the vibration information.

A computer-readable, non-transitory medium storing a program that causes a computer to execute a process is provided. The process includes acquiring a backward Rayleigh scattered light from an optical fiber composite overhead ground wire which an electrical power transmission facility has; generating vibration information of a frequency band including a natural frequency of the optical fiber composite overhead ground wire, on a basis of the backward Rayleigh scattered light; and detecting abnormality of the electrical power transmission facility, on a basis of the vibration information.

Methods for classifying a core cane of an multimode optical fiber are disclosed. In embodiments, the method includes determining a relative refractive index profile Δ(r) of the core cane; fitting the relative refractive index profile Δ(r) to an alpha profile Δ.sub.fit(r) defined by:

[00001]${\Delta }_{\mathrm{fit}}\left(r\right)={\Delta }_{o,\mathrm{fit}}\left(1-{\left(\frac{r}{a_{\mathrm{fit}}}\right)}^{{\alpha }_{\mathrm{fit}}}\right)$

where Δ.sub.o,fit is a relative refractive index at a longitudinal centerline of the core cane, α.sub.fit is a core shape parameter, and a.sub.fit is an outer radius of the core cane; generating a non-alpha residual profile Δ.sub.diff(r)=Δ(r)−Δ.sub.fit(r) for the core cane; computing one or more metrics from Δ.sub.diff(r), and using the one or metrics in a classification of the core cane, the classification comprising a prediction of whether a bandwidth at a pre-determined wavelength of an optical fiber drawn from a preform comprising the core cane exceeds a pre-determined bandwidth at the pre-determined wavelength.

An eyeglasses lens measurement device measures an eyeglasses lens of eyeglasses. The eyeglasses lens measurement device includes a light source that emits a measurement light flux toward the eyeglasses lens, a transmissive display that transmits the measurement light flux from the light source and displays an index pattern formed by arranging a plurality of indexes, a detector that detects the measurement light flux passing through the eyeglasses lens and the transmissive display, and a controller. The controller is configured to control a display of the index pattern, acquire an optical characteristic of the eyeglasses lens, based on a detection result of the detector, and acquire lens information different from the optical characteristic of the eyeglasses lens, based on a detection result of the detector.