A system is described, for use in optical measurement of a sample. The system comprising: an illumination unit configured for providing coherent illumination of one or more selected wavelength ranges and directing it onto one or more selected inspection regions of the sample, a collection unit configured for collecting light returning from the inspection region and generating output data comprising a sequence of image data pieces indicative of secondary speckle patterns formed at an intermediate plane in optical path of light collection, a depth resolving module configured for affecting at least one of the illumination unit and the collection unit for determining an association between collected secondary speckle patterns and depth layers of the sample; and a control unit being connectable to said depth resolving module and configured for operating said depth resolving module and for receiving said sequence of image data pieces from the collection unit and processing said sequence of image data pieces by determining correlation functions between at least portions of said secondary speckle patterns associated with corresponding depth layers of the sample, thereby determining one or more parameter variations along depth of the sample.

Methods and devices for additive manufacturing of workpieces are provided. For analysis during production, a test is carried out using a selected test method. The test results are compared with simulated test results derived during a simulation of the manufacturing and testing. The test may use one or more of a laser ultrasound test unit, an electronic laser speckle interferometry test unit, an infrared thermography test unit, or an x-ray test unit.

A system for use in inspection of a sample is described, the system comprises: an illumination unit configured to provide coherent illumination comprising a plurality of at least two wavelengths and direct said coherent illumination onto an inspection region of a sample; and a collection unit comprising at least one detector array and configured for collecting light returning from said inspection region and generate data indicative of speckle patterns in said plurality of at least two wavelengths at a predetermined sampling rate, wherein said illumination unit is configured for directing light components of said at least two wavelengths toward corresponding two or more segments of said inspection region, and wherein said data indicative of speckle patterns corresponding with said two or more segments.

An optical interferometer (1) is used to determine information about the position, gradient or motion of a surface of an object (2) at each of a plurality of points on the surface. An image is projected onto the surface of the object (2), such that, for each of the plurality of points, the intensity or spectrum of the projected image at that point depends on the determined information about the position, gradient or motion of the surface at that point.

A defect detection method includes the following processes: a) stroboscopically illuminating the entire surface of an object within an examination area of the object while inducing a first elastic wave across the examination area on the object, and controlling the phase of the elastic wave and the timing of the stroboscopic illumination to collectively measure a back-and-forth displacement of each point within the examination area in at least three phases of the elastic wave; b) identifying a surface location which is the location of a defect on the examination area, based on the back-and-forth displacement of each point within the examination area in the at least three different phases; and c) injecting a second elastic wave into a region inside the surface location from a limited area including the surface location, and determining the location and/or size in the depth direction of the defect, based on a response wave.

A displacement measurement device 10 is provided with: a laser light source 11 for emitting laser light to a measurement area R of a measurement target object S; a focusing optical system (the beam splitter 151, the first reflecting mirror 1521, the condenser lens 155) having a front focal point in the measurement area R and a rear focal point on a predetermined imaging surface (the detection surface 1561); a non-focusing optical system (the beam splitter 151, the diffuser 153, the second reflecting mirror 1522, and the condenser lens 155) in which light from a measurement area R of a correspondence point in the measurement area corresponding to each point of the imaging surface with respect to the focusing optical system is incident on the point of the imaging surface; and a photodetector (image sensor 156) configured to detect light intensity on the imaging surface for each point. Thus, corresponding to each of a large number of points in the measurement area R, main reflected light reflected at the point and reference light reflected at the surrounding range of the point are incident on each of a large number of points in the imaging surface, and the main reflected light and the reference light interfere at a large number of points in the imaging surface. Thus, an interference pattern is obtained.

A system is described, for use in optical measurement of a sample. The system comprising: an illumination unit configured for providing coherent illumination of one or more selected wavelength ranges and directing it onto one or more selected inspection regions of the sample, a collection unit configured for collecting light returning from the inspection region and generating output data comprising a sequence of image data pieces indicative of secondary speckle patterns formed at an intermediate plane in optical path of light collection, a depth resolving module configured for affecting at least one of the illumination unit and the collection unit for determining an association between collected secondary speckle patterns and depth layers of the sample; and a control unit being connectable to said depth resolving module and configured for operating said depth resolving module and for receiving said sequence of image data pieces from the collection unit and processing said sequence of image data pieces by determining correlation functions between at least portions of said secondary speckle patterns associated with corresponding depth layers of the sample, thereby determining one or more parameter variations along depth of the sample.

A defect detection apparatus is provided that can inspect a measurement region of a target object at one time and without inconsistencies arising within the measurement region. A defect detection apparatus 10 includes: a generation unit (signal generator 11 and vibrator 12) for generating an elastic wave in a target object S; an illumination unit (pulsed laser light source 13 and illumination light lens 14) for performing stroboscopic illumination onto a measurement region of a surface of the target object S; and a displacement measurement unit (speckle shearing interferometer 15) for collectively measuring displacements in a normal direction at each point of the measurement region with respect to at least three mutually-different phases of the elastic wave by controlling a phase of the elastic wave and a timing of the stroboscopic illumination. Defects in the measurement region are detected based on the displacements in the normal direction at each point of the measurement region with respect to at least three phases that are obtained by the displacement measurement unit.

An apparatus for determining a propagation velocity for a surface wave comprises a coherent light source (105) for generating at least a first and a second light spot on a surface (103). A camera (111) captures at least one out-of-focus image of at least a part of the surface (103) comprising the light spots. The out-of-focus image comprises light spot image objects for the light spots where the light spot image objects have speckle patterns. An analyzer (113) determines the propagation velocity in response to a time difference between speckle pattern changes in the two speckle patterns. The camera may specifically use a rolling shutter allowing the determination of the propagation velocity to be based on a spatial analysis of the speckle patterns. The approach may in particular allow an efficient remote measuring of pulse wave velocities e.g. in animal tissue and in particular, in human tissue.

The laser speckle interferometric system includes a memory for storing a measurement result of a correction parameter and models for matching a result of processing the speckle pattern to the parameters of the object and a processor for stabilizing the speckle pattern detected by controlling a condition for detecting the speckle pattern in real time, processing a time-varying function representing a temporal change in the speckle pattern based on the speckle pattern and the parameters and generating data indicating tested parameters.