Conventional optical-transmission-type residual stress measuring apparatus cannot be used for completing the measurement of residual stress in an optical film having light reflective property, and conventional optical-reflection-type residual stress measuring apparatus is known failing to achieving the measurement of residual stress in an optical thin film having transparent or translucent property. In view of that, the present invention discloses a system for measuring residual stress in optical thin films, which is able to be utilized for achieving the residual stress measurement of respective optical thin film having transparent or translucent property and that of respective optical thin film having light reflective property. Therefore, it is helpful for largely reducing both the purchase cost and the maintenance cost by only purchasing the residual stress measuring system provided by the present invention instead of simultaneously purchasing the aforesaid two different types of residual stress measuring apparatuses.

A distance measuring arrangement for determining a distance from an object includes at least one light source for producing at least one first monochromatic and interference-capable light beam with a first wavelength and at least one second monochromatic and interference-capable light beam with a second wavelength, a multiplexer for coupling or combining the at least one first light beam and the at least one second light beam into a common measurement beam, an output coupling element for splitting the measurement beam into a reference beam and a signal beam, wherein the reference beam propagates along a reference path and wherein the signal beam propagates along a signal path, and a phase modulator that is arranged in the signal path and configured to modulate the phase of the signal beam periodically in time.

A device for measuring the parameters of phase elements and dispersion of optical fibers, characterized in that it contains: a light source, serially connected to fiber optic coupler, one of whose arms constitutes a part of the reference arm, and whose second arm constitutes a part of the measurement arm of the device, and a motorized linear stage is mounted on the arm of the device. One of the arms of the device is connected to at least one detector, and at least one collimator is placed in at least of the arms of the device, at least before the phase element. A method of measuring the parameters of the phase element and the dispersion of optical fibers is conducted in two stages, wherein the first stage assumes the calibration of the device and the second stage is the proper measurement.

Conventional optical-transmission-type residual stress measuring apparatus cannot be used for completing the measurement of residual stress in an optical film having light reflective property, and conventional optical-reflection-type residual stress measuring apparatus is known failing to achieving the measurement of residual stress in an optical thin film having transparent or translucent property. In view of that, the present invention discloses a system for measuring residual stress in optical thin films, which is able to be utilized for achieving the residual stress measurement of respective optical thin film having transparent or translucent property and that of respective optical thin film having light reflective property. Therefore, it is helpful for largely reducing both the purchase cost and the maintenance cost by only purchasing the residual stress measuring system provided by the present invention instead of simultaneously purchasing the aforesaid two different types of residual stress measuring apparatuses.

A measuring device used to measure a surface of an object is provided. The measuring system includes an air-flow generator, a light emitting device, and a light sensor. The airflow generator is located above the object, and is configured to inject a vapor flow onto the surface of the object and generates a condensing layer on the surface of the object. The light emitting device is located above the object and faces the condensing layer, and is configured to project a light towards the condensing layer. The light sensor is located above the object, and is configured to receive the light scattered by the condensing layer.

An optical measuring system for a measuring machine includes at least two scanning devices for intermittently moving through alternately timed sequences of static measuring positions at which a measuring beam is directed to and from a test object. An optical switch selectively routes the measuring beam through any one of the scanning devices that has settled into one of the static measuring positions.

An object of the invention is to measure an outside size of the vehicle accurately while running the vehicle. A plurality of the 1st sensors 25, 26 irradiate inspection lights to a plurality of places (4a) of the vehicle 4 of a railroad and output measurement signals which show positions and distances by receiving lights from a plurality of the places of the vehicle 4. The 2nd sensor 27, 28 or 29 irradiates an inspection light to an outside surface of the vehicle 4 and outputs a measurement signal which shows a position and a distance by receiving a light from the outside surface of the vehicle 4. The control equipment 30 or the processing equipment 41 processes the measurement signals outputted from a plurality of the 1st sensors 25, 26, detects positions and heights of a plurality of the places of the vehicle 4, processes the measurement signal outputted from the 2nd sensor 27, 28 or 29, and detects the outside size of the vehicle 4. And the control equipment 30 or the processing equipment 41 calculates amounts of a deviation of the outside surface of the vehicle 4 due to a swing of the vehicle 4 based on amounts of fluctuations of the detected positions and heights of a plurality of the places of the vehicle 4, and corrects the detected outside size of the vehicle 4 according to the calculated amounts of the deviation.

An interferometer detection system, including a beam splitter receiving a collimated light signal and splitting the signal into a first light signal and a second light signal. The system includes a first mirror receiving and reflecting the first light signal along a first path. The system includes a second mirror receiving and reflecting the second light signal along a second path via a transparent material. The system includes a 2D photosensor array configured to receive from the beam splitter the reflected first light signal merged with the reflected second light signal double passing through the transparent material and configured to generate an interference fringe pattern. A non-sinusoidal interference fringe pattern indicates geometrical variation between a wavefront of the reflected first light signal along the first path and a wavefront of the reflected second light signal double passing through the transparent material along the second path.

Devices, systems, and methods for determining a distance between at least two points are disclosed and described, wherein interferometry technology is utilized to determine such distances.

A sample may be illuminated in such a way that light passes through the sample, reflects from a set of reflectors, passes through the sample again and travels to a light sensor. The reflectors may be staggered in depth beneath the sample, each reflector being at a different depth. Light reflecting from each reflector, respectively, may arrive at the light sensor during a different time interval than that in which light reflecting from other reflectors arrivesor may have a different phase than that of light reflecting from the other reflectors. The light sensor may separately measure light reflecting from each reflector, respectively. The reflectors may be extremely small, and the separate reflections from the different reflectors may be combined in a super-resolved image. The super-resolved image may have a spatial resolution that is better than that indicated by the diffraction limit.