We developed a general theory about the performance of a rotational shearing interferometer. We apply the aberration theory to the detection of planets outside our planet system. We considered cases when the mutual coherence functions of the on-axis and the off-axis system are 0 and 1.

A shock wave is a mechanical high-pressure pulse that travels inside a medium with a full width at half-maximum of a few nanoseconds that may be induced with a high-power laser pulse. A piezo-resistive measurement method to determine the shock wave pressure has been widely employed even though there is inner inaccuracy in the calibration process. We are interested in developing a precise theoretical model of laser material processing for applications in material sciences that includes the frequency dependence of the electronic post processing. We show an approach to determine the correction factor to frequency response at a high frequency of a piezo-resistive experimental setup and the results of the pressure measurements obtained in this experimental setup. The theoretical and experimental work demonstrates the feasibility of piezo-resistive methods to measure a laser-induced shock wave pressure in the nanosecond range. The correction factor of the frequency dependence calibration allows the technique to be applied in different shock wave experiments.

A laser shock wave (LSW) is a pressure wave in the range of gigapascals, duration in the order of nanoseconds, propagates at rates higher than Mach 1, and is induced by high power laser pulses. As an LSW propagates inside a solid, some physical material characteristics in the area of incidence are improved due to a residual compression stress field. However, since the LSW pressure reaches some tens of GPa, tensile stress damages the solid due to a spallation process if the material is fewer than 1 mm thick. A shock wave mitigation structure coupled to a solid reduces the LSW pressure due structure walls reflections, avoiding the spallation. In this work, a FEM simulation of LSW propagation in a 1 mm thick aluminum slab with a matrix of mitigating structures attached to the back is performed. The relationship among the induction area of the LSW, and the relative location of each mitigation structure in the matrix, has a direct influence on the pressure field distribution.

A laser shock wave is a pressure wave in a gigapascal range propagating at speeds above the speed of sound in a medium, induced by a high-power density laser pulse. Its duration is of the order of magnitude of nanoseconds. When the shock wave propagates in a solid, some materials characteristics in the area where laser beam is incident, change due to the application of compressive residual stress. These may be hardness, corrosion resistance, stress-fatigue resistance, to name a few. The shock wave has been found useful for working materials in diverse application fields such as aeronautics, defense, material science, and micro-components. The shock wave pressure decreases drastically as it propagates inside the solid, making it difficult to obtain experimental data when the shock wave propagates in solids with a thickness greater than one millimeter. We employ finite element method for the solution of shock wave propagation problems. Its primary benefit is that wave pressure and velocity may be determined upon modeling for thicknesses greater than one millimeter. We demonstrate a non-linear relationship between the material thickness and the shock wave that decreases with increasing slab thickness. In addition, the relationship between thickness and shock wave velocity is found. We estimate the material thickness by obtaining the attenuation ratio of the shock wave pressure.