This defect inspection apparatus (100) is provided with an excitation unit (1), a laser illumination unit (2), an interference unit (30), an imaging unit (31), a holding member (4) for holding the imaging unit at a position spaced apart from an inspection target (90) by a predetermined distance, a connecting member (5) for connecting the holding member or the imaging unit and the excitation unit, and a controller (6) for generating an image (61) related to the propagation of an elastic wave on an inspection target.

This defect inspection apparatus (100) is provided with an excitation unit (1), a laser illumination unit (2), an interference unit (30), an imaging unit (31), a holding member (4) for holding the imaging unit at a position spaced apart from an inspection target (90) by a predetermined distance, a connecting member (5) for connecting the holding member or the imaging unit and the excitation unit, and a controller (6) for generating an image (61) related to the propagation of an elastic wave on an inspection target.

Shearography systems provide independent setting of fringe frequency and shear magnitude by situating an interferometer with a tiltable reflector proximate a pupil plane of an imaging optical system. Fringe frequency can be selected based on a modified Savart plate. In other examples, a Wollaston prism or a polarization grating is translated with respect to an image sensor to vary shear magnitude while maintaining a substantially fixed fringe frequency.

Shearography systems provide independent setting of fringe frequency and shear magnitude by situating an interferometer with a tiltable reflector proximate a pupil plane of an imaging optical system. Fringe frequency can be selected based on a modified Savart plate. In other examples, a Wollaston prism or a polarization grating is translated with respect to an image sensor to vary shear magnitude while maintaining a substantially fixed fringe frequency.

A defect inspection apparatus generates a surface layer inspection image which is an image representing displacement of an inspection target in a measurement region based on an intensity pattern of interfered laser light. The defect inspection apparatus is configured to generate an appearance inspection image which is an image of an outer surface of the measurement region based on an intensity pattern of incoherent light.

A method and apparatus for performing shearography where the shear length and direction can be set in image processing, thus allowing all shear sizes to be computed and tested from a single data set, which can be collected in a single pass over a test surface or test object. The present process assures that a single data set can be processed with optimal shear length for multiple target types, thus reducing or eliminating the chance of missing a target detection while additionally enhancing target shape analysis by allowing the calculation of target response versus shear length and shear direction.

A splitting and recombining optical component with an increased field of view while maintaining or only minimally increasing the space requirements therefor is provided. Further, the combination of the changes in physical geometry and refractive index of the beam splitting and recombining optical device can increase the field of view of a system while maintaining, or even reducing, the mass of the system in which the present beam splitting and recombining optic may be utilized

A light intensity fluctuation-insensitive projection objective wave aberration detection device and a detection method thereof, comprising a light source and illumination system, an object plane marking plate, an object plane displacement table, a tested projection objective, an image plane marking plate, a two-dimensional photosensor, an image plane displacement table and a control processing unit; the object plane marking plate and the image plane marking plate are provided with grating marks for shear interference test and marks for light intensity test, the shear interferograms and the light intensity information are simultaneously received through the two-dimensional photosensor, the light intensity fluctuation error corresponding to each phase-shifting interferogram is corrected through the light intensity information, improving the detection precision, reducing the complexity and the cost of the system, and improving the detection speed.

An example system for in-situ inspection of a composite structure includes a surface-strain imaging apparatus and a controller. The surface-strain imaging apparatus is configured to image an area of an outer surface of the composite structure while a temperature of the composite structure warms to thermal equilibrium with a surrounding environment and a temperature gradient exists within the composite structure. The controller includes a processor and a memory, and is configured to detect, using data received from the surface-strain imaging apparatus, an out-of-plane displacement of the outer surface in the area caused by the temperature gradient. The controller is also configured to determine that the out-of-plane displacement satisfies a threshold condition and, based on determining that the out-of-plane displacement satisfies the threshold condition, flag the area of the outer surface for further inspection.

An example system for in-situ inspection of a composite structure includes a surface-strain imaging apparatus and a controller. The surface-strain imaging apparatus is configured to image an area of an outer surface of the composite structure while a temperature of the composite structure warms to thermal equilibrium with a surrounding environment and a temperature gradient exists within the composite structure. The controller includes a processor and a memory, and is configured to detect, using data received from the surface-strain imaging apparatus, an out-of-plane displacement of the outer surface in the area caused by the temperature gradient. The controller is also configured to determine that the out-of-plane displacement satisfies a threshold condition and, based on determining that the out-of-plane displacement satisfies the threshold condition, flag the area of the outer surface for further inspection.