Method for simultaneously compensating pupil coordinate distortion and shear amount change in a process of wavefront reconstruction in grating transverse shear interference. Where a wavefront is diffracted by a grating, the shapes and light paths of the diffracted wavefronts of all the orders are different, so that on one hand, a coordinate system detected by a detector plane is distorted relative to a pupil coordinate system, and on the other hand, a shear amount changes along with a coordinate position.

Method for simultaneously compensating pupil coordinate distortion and shear amount change in a process of wavefront reconstruction in grating transverse shear interference. Where a wavefront is diffracted by a grating, the shapes and light paths of the diffracted wavefronts of all the orders are different, so that on one hand, a coordinate system detected by a detector plane is distorted relative to a pupil coordinate system, and on the other hand, a shear amount changes along with a coordinate position.

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.

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.

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 for high-accuracy wavefront measurement based on grating shearing interferometry, which adopts a grating shearing interferometer system comprising an illuminating system, an optical imaging system under test, an object plane diffraction grating plate, an image plane diffraction grating plate, a two-dimensional photoelectric sensor, and a calculation processing unit. The object plane diffraction grating plate and the image plane diffraction grating plate are respectively arranged on the object plane and the image plane of the optical imaging system under test. The shearing phase of 1.sup.st-order diffracted beam and −1.sup.st-order diffracted beam is exactly extracted through phase shifting method, and the original wavefront is obtained by carrying out reconstruction algorithm according to a shear ratio of 2s, such that the accuracy of wavefront measurement of the optical imaging system under test is improved, wherein s is the shear ratio of the grating shearing interferometer.

Object interference in biological samples generated by lateral shearing interference microscopes is addressed by a shearing microscope slide comprising a periodic structure having alternating reference and sample regions. In some embodiments, the reference regions are configured to provide references that remove sample overlap in a sheared microscopic measurement. A system for generating sheared microscopic measurements is also provided that comprises an inlet configured to receive a sample material, an outlet configured to release a portion of the sample material, and a periodic structure having a plurality of interleaved reference and sample channels. In some cases, the sample channels are configured to accommodate a flow of sample material from the inlet to the outlet and the reference channels are configured to provide references that remove sample overlap in a sheared microscopic measurement.

In a method of detecting changes in direction of a collimated coherent light beam, the light beam is split into partial light beams which are superimposed on a camera to form an interference pattern displaying light intensity minima and maxima alternatingly following to one another in a transverse direction oriented transversely to an average propagation direction of the partial beams. The light beam is focused into at least one focus located in front of the camera. Pictures of the interference pattern including a plurality of the light intensity maxima are registered with the camera. An average shift of the plurality of light intensity maxima with regard to the camera in the at least one transverse direction is determined from the pictures. A change in angular orientation of the collimated coherent light beam in the at least one transvers direction is deduced from the average shift.

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.

System and method for monitoring of performance of a mirror array of a digital scanner with a use of light, illuminating the mirror array at grazing (off-axis) incidence, and an optical imaging system that includes a lateral shearing interferometer (operated in either static or a phase-shifting condition) during and without interrupting the process of exposure of the workpiece with the digital scanner, to either simply identify problematic pixels for further troubleshooting or measure the exact magnitude of the deformation of a mirror element of the mirror array.