An ultra-sensitive speckle-analyzing system is disclosed which includes an image capture device configured to receive a scattered field having a speckle configuration and thereby capture i) a reference speckle image, and ii) a subsequent speckle image, each of the reference and the subsequent speckle images having a plurality of speckles on a background; and a processor configured to generate a cross-correlation between the plurality of speckles of the reference and the subsequent speckle images, to thereby represent a change in the speckle configuration.

A shearography a system and method for regularizing phase resolved shearograms with an arctan regularization function to produce regularized phase resolved shearogram outputs is provided. The system and method of the present disclosure optimizes the processing of phase resolved shearography allowing interference fringe analysis techniques to be applied to the regularized phase resolved shearogram output results of the processing.

The disclosure relates to a method for fabricating a speckle for high temperature deformation measurement of a shaped refractory material. A technical solution includes mixing a hercynite micropowder and a liquid mixing agent in a mass ratio of (3-6):1, and ultrasonically treating to obtain a speckle mixture; polishing a surface of a shaped refractory material to be measured, removing impurities, and spraying the speckle mixture on the surface of the shaped refractory material to be measured with a pneumatic airbrush in a time hood to obtain an uncured speckle; heating the uncured speckle to 60-80° C., keeping for 1-3 h, then heating to 100-120° C., and keeping for 1-3 h to obtain a speckle for high temperature deformation measurement of a shaped refractory material. The fabricated product is suitable for high temperature deformation measurement of a shaped refractory material at 1,600° C.

Surface changes are estimated using multiple speckle interferograms acquired using beams incident at different angles. Beam irradiation conditions can be changed to increase signal to noise ratio with averaging, such as weighted averaging. Irradiation conditions can be varied with a tilt plate, a wedge, or by changing beam wavelengths.

A method, device and electronic apparatus for estimating physical parameters are disclosed. The method includes: reading a Newton's rings fringe pattern obtained by performing an interferometric measurement on a unit to be measured; obtaining the number and length of first-direction signals of the Newton's rings fringe pattern; performing, for each of the first-direction signals, a discrete chirp Fourier transform (DCFT) on the first-direction signal based on each first chirp rate parameter within a range of the length of first-direction signals, to obtain a first magnitude spectrum of an intensity distribution signal in a DCFT domain; determining a first chirp rate parameter and a first frequency parameter corresponding to a first magnitude peak value based on the first magnitude spectrum; and estimating the physical parameters involved in the interferometric measurement at least according to the first chirp rate parameter and first frequency parameter corresponding to the first magnitude peak value. In this way, the physical parameters involved in the interferometric measurement can be estimated with high accuracy and stably.

A system may include an optical source and an adjustable spatial light modulator coupled to the optical source. The system may further include a medium coupled to the adjustable spatial light modulator. The system may further include a beam splitter coupled to the optical source and the adjustable spatial light modulator. The beam splitter may generate a first optical signal and a second optical signal using the optical source. The system may further include an optical detector coupled to the beam splitter and the medium. The optical detector may obtain a combined optical signal including a resulting optical signal and the second optical signal. The resulting optical signal may be produced by transmitting the first optical signal through the medium at a predetermined spatial light modulation using the adjustable spatial light modulator.

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 ultra-sensitive speckle-analyzing system is disclosed which includes an image capture device configured to receive a scattered field having a speckle configuration and thereby capture i) a reference speckle image, and ii) a subsequent speckle image, each of the reference and the subsequent speckle images having a plurality of speckles on a background; and a processor configured to generate a cross-correlation between the plurality of speckles of the reference and the subsequent speckle images, to thereby represent a change in the speckle configuration.

A shearography system uses a Geometric phase or Pancharatnam-Berry (PB) phase element to shear an image. A PB phase element provides a non-dynamical phase change used for wavefront control and results in uniform half-wave of retardation. Geometric phase may also be utilized to capture snapshot phase-resolved wavefront measurements and shearograms via a focal plane array with micro-patterned linear polarizers of different orientations. Wavefront shape control arises when the local orientation of the retarding media is spatially varied. One or more PB phase elements can be flipped or rotated to perform multiple tasks depending on its orientation. Two PB elements can be used in succession in order to provide a variable purely spatial shift between interfering wavefronts. The spatial offset of the light exiting the second element can be adjusted simply by changing the spacing between the two geometric phase surfaces. In shearography, this corresponds to an adjustable shear length.

A defect detection device 10 includes: an excitation source 11 capable of being placed at any position on a surface of an inspection target object S, the excitation source 11 being configured to excite an elastic wave within the inspection target object S, the elastic wave being predominant in one vibration mode and propagating in a predetermined direction; an illumination unit (pulsed laser light source 13, illumination light lens 14) configured to perform stroboscopic illumination on an illumination area of the surface of the inspection target object by using a laser light source; a displacement measurement unit (speckle shearing interferometer 15) configured to collectively measure a displacement of each point in a front-back direction within the illumination area in at least three different phases of the elastic wave, by speckle interferometry or speckle shearing interferometry; and a reflected wave/scattered wave detector 16 configured to detect either one or both of a reflected wave and a scattered wave of the elastic wave, based on the displacement measured by the displacement measurement unit.