A three-dimensional measurement device includes: an optical system that splits incident light into two lights and radiates lights to a measurement object and to a reference surface, and recombines the two lights to emit combined light; a first irradiator that emits first light including first polarized light and entering a first surface; a second irradiator that emits second light including second polarized light and entering a second surface; a first imaging system to which the first output light enters wherein the first output light is emitted from the first surface when the first light enters the first surface; a second imaging system to which the second output light enters wherein the second output light is emitted from the second surface when the second light enters the second surface; and an image processor that performs three-dimensional measurement based on interference fringe images obtained by the first and second imaging systems.

The invention relates to a method and system for monitoring at least one parameter of an object. There is provided an imaging system for monitoring at least one parameter of movement of a moving object, the system comprises at least one imaging unit comprising an optical transformer configured and operable for applying spatial image space transformation of at least one parameter of movement into geometric relation, by translating different components of six degrees of freedom of movement in a three-dimensional space into a lateral translation; wherein the imaging unit is configured and operable for imaging the moving object on an image plane and generating image data indicative of the moving object in an x-y plane; the imaging system generating motion data indicative of the six degrees of freedom of movement.

A fiber optic sensor arrangement is disclosed that includes a plurality of optical fiber based sensor elements, the sensor elements configured to modify an associated optical carrier signal in accordance with changes in a sensed quantity at a location of the sensor element and a phase modulation arrangement for phase modulating each optical carrier signal in accordance with respective uncorrelated pseudorandom binary sequence signals. The sensor arrangement also includes an interferometer module for receiving each of the phase modulated optical carrier signals, the interferometer module operable to convert a change in the phase modulated optical carrier signals to a change in optical intensity of the corresponding optical carrier signal to generate a combined modulated optical intensity signal, an optical intensity detector for measuring the combined modulated optical intensity signal and generating a time varying electrical detector signal and an analog to digital convertor to convert the time varying electrical detector signal to a time varying digitized detector signal. Also included in the sensor arrangement is a decorrelator arrangement for decorrelating the time varying digitized detector signal against the respective uncorrelated pseudorandom binary sequence corresponding to each of the optical carrier signals to recover each of the modulated optical carrier signals and a demodulator for demodulating each of the modulated optical carrier signals to recover the respective optical carrier signal to determine the changes in the sensed quantity at the location of the sensor element.

In an optical position measuring device for the interferential determination of the relative distance of two objects which are movable relative to each other in at least one measuring direction, a bundle of rays emitted by a light source is split up into at least two partial bundles of rays, which fall on a grating or a plurality of gratings on separate optical paths and undergo distance-dependent phase shifts as a result. The partial bundles of rays are superpositioned at a mixing grating, whereupon at least three pairs of interfering partial bundles of rays propagate in different directions in space. Via the mixing grating, each pair of interfering partial bundles of rays is focused on a detector element so that at least three position-dependent, phase-shifted incremental signals are detectable via the detector elements.

A frequency shift light modulator includes a resonator and a diffraction grating including a plurality of grooves arranged in parallel in a displacement direction of the resonator, and the diffraction grating is provided on the resonator. By providing the diffraction grating on the resonator, it is easy to realize miniaturization and increase in accuracy of the frequency shift light modulator. Further, it is easy to realize application to a high frequency region in a MHz band, that is, high frequency modulation. It is possible to efficiently obtain an effect based on a combination of the resonator and the diffraction grating.

Aspects of the subject technology relate to particulate matter sensors for electronic devices. A particulate matter sensor may include three lasers, three total-internal-reflection lenses, and three detectors for detecting changes in the operation of the three lasers due to the principles of self-mixing interferometry. The three total-internal-reflection lenses may use internally reflective surfaces to tilt the three beams into three corresponding directions that form an orthogonal basis in the three dimensional space, so that a gas flow speed can be determined while maintaining a small, modular form factor for implementation of the sensor in portable electronic devices.

A shape measurement method of the present invention includes: a step of irradiating a measurement object with an optical pulse train in which a plurality of optical pulses that have predetermined frequency distributions on a time axis are disposed chronologically in numerical order; and a step of measuring an optical shape of the measurement object in accordance with a correspondent relation between numbers of the optical pulses of a plurality of detection target optical pulse trains after the emitted optical pulse train acts on the measurement object and a correspondent relation between the frequency distributions in the optical pulses.

The disclosure discloses a phase delay extraction and compensation method in a PGC phase demodulation technology. The sinusoidal phase modulation interference signal is converted into a digital interference signal by an analog-to-digital converter after amplification and filtering, and the digital interference signal is subjected to orthogonal downmixing of first-order, second-order, and fourth-order harmonics simultaneously to obtain three pairs of orthogonal harmonic amplitude signals. The three pairs of orthogonal harmonic amplitude signals are used to extract phase delay, and the result is used to calculate the corresponding phase delay correction coefficients, and the phase delay correction coefficient are multiplied by the corresponding absolute harmonic amplitude signal equal to the sum of the absolute value of the orthogonal harmonic amplitude signals to obtain a new harmonic amplitude signal that is not affected by the phase delay, then the phase to be measured is obtained through the arc tangent operation.

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.

Systems, methods and apparatuses are used for monitoring material processing using imaging signal density calculated for an imaging beam directed to a workpiece or processing region, for example, during inline coherent imaging (ICI). The imaging signal density may be used, for example, to monitor laser and e-beam welding processes such as full or partial penetration welding. In some examples, the imaging signal density is indicative of weld penetration as a result of reflections from a keyhole floor and/or from a subsurface structure beneath the keyhole. The monitoring may include, for example, automated pass/fail or quality assessment of the welding or material processing or parts produced thereby. The imaging signal density may also be used to control the welding or material processing, for example, using imaging signal density data as feedback. The imaging signal density may be used alone or together with other measurements or metrics, such as distance or depth measurements.