An optical fiber ring interferometer is provided, which is based on a common light path for two or more light beam pairs preferably originated from two or more light sources of a substantially different spectrum or from a single light source split spectrum and whereas each light beam of a specific pair is propagating in relative opposite directions, wherein at least one pair of light beams is utilized to detect acousto-mechanical events and to provide information regarding location and other characteristics of detected environmental disturbance.

A tomography convergence-type oral scanner includes an oral scanning unit comprising a projector including a first light source for generating visible light, and a camera for generating image data by receiving the visible light reflected from a tooth; an optical tomography scanning unit comprising an OCT body including a second light source that has a different wavelength from the first light source and generates a measurement light incident on the tooth, a beam splitter for splitting the measurement light into a reference light and a measurement light, a reference mirror that reflects the reference light, and a photodetector for detecting an interference light, and an OCT scan probe including a collimator for converting the measurement light into a parallel light and a MEMS mirror for reflecting the converted parallel light; and a dichroic mirror for transmitting the visible light and reflecting the parallel light, thereby irradiating a tooth to be measured.

A tomography convergence-type oral scanner includes an oral scanning unit comprising a projector including a first light source for generating visible light, and a camera for generating image data by receiving the visible light reflected from a tooth; an optical tomography scanning unit comprising an OCT body including a second light source that has a different wavelength from the first light source and generates a measurement light incident on the tooth, a beam splitter for splitting the measurement light into a reference light and a measurement light, a reference mirror that reflects the reference light, and a photodetector for detecting an interference light, and an OCT scan probe including a collimator for converting the measurement light into a parallel light and a MEMS mirror for reflecting the converted parallel light; and a dichroic mirror for transmitting the visible light and reflecting the parallel light, thereby irradiating a tooth to be measured.

Provided herein is technology relating to analysis of images and particularly, but not exclusively, to methods and systems for determining the area and/or volume of a region of interest using optical coherence tomography data. Some embodiments provide for determining the area and/or volume of a lesion in retinal tissue using three-dimensional optical coherence tomography data and a two-dimensional optical coherence tomography fundus image.

A heterogeneous integration detecting method and a heterogeneous integration detecting apparatus are provided. The heterogeneous integration detecting method includes the following. Under the condition of maintaining the same relative distance between an interference objective lens and a sample, the relative posture of the interference objective lens and the sample is continuously adjusted according to the change of an image of the sample in the field of view of the interference objective lens until a first optical axis of the interference objective lens is determined to be substantially perpendicular to the surface of the sample according to the image. The interference objective lens is replaced with an imaging objective lens and the geometric profile of at least one via of the sample is detected. A second optical axis of the imaging objective lens after replacement overlaps with the first optical axis of the interference objective lens before replacement.

A projection exposure tool for microlithography for imaging mask structures of an image-providing substrate onto a substrate to be structured includes a measuring apparatus configured to determine a relative position of measurement structures disposed on a surface of one of the substrates in relation to one another in at least one lateral direction with respect to the substrate surface and to thereby simultaneously measure a number of measurement structures disposed laterally offset in relation to one another.

A position measurement system configured to measure a position of an object. The system includes an optical system to obtain a first measurement wave and a second measurement wave from a radiation source, and to allow the first and second measurement wave to at least partially interfere with each other after interaction of at least one of the first and second measurement wave with the object to form a first detection beam. The system further includes a first detector to receive the first detection beam. The system also has a processing unit configured to receive an output from the first detector and to determine a signal representative for the position of the object from the output, wherein the optical system includes a phase modulator configured to modulate a phase difference between the first measurement wave and the second measurement wave.

Around a crankshaft (S) supported by a support device (10), a first shape measuring device (31) to a fourth shape measuring device (34) are disposed, and the crankshaft (S) and the first shape measuring device (31) to the fourth shape measuring device (34) are relatively movable in an axial direction (X direction) of the crankshaft (S). The first shape measuring device (31) and the third shape measuring device (33) are disposed so as to face to one X direction and acquire partial shape information (including the other side surfaces in the X direction of counterweights (S2)) of the crankshaft S, and further, the second shape measuring device (32) and the fourth shape measuring device (34) are disposed so as to face to the other X direction and acquire partial shape information (including one side surfaces in the X direction of the counterweights (S2)) of the crankshaft S. This makes it possible to accurately inspect a shape of the crankshaft (S) in a short time.

Interferometer (10) for the real-time measurement of absolute distances and/or relative position movements between a first and a second machine part, comprising a measurement unit (20) and a reflector unit (40). wherein the measurement unit (20) comprises a housing (21) with at least one wall made of heat-conducting material, wherein several measurement elements are arranged in the housing (21), wherein the measurement elements comprise: a laser source (22), a Peltier element (24) and a digital control (23) wherein the measurement elements are thermally coupled to the wall of the housing (21) made of heat-conducting material.

The present disclosure relates to an apparatus for measuring a thickness and a surface profile of a multilayered film structure using an imaging spectral optical system and a measuring method. More specifically, the present disclosure relates to a method and an apparatus which measure a thickness and a surface profile of a multilayered thin film structure by applying a method for obtaining an absolute reflectance value for an object to be measured having a multilayered thin film using a reflected light measuring method and extracting a phase from an interference signal with a reference mirror using a phase shift algorithm.