Abstract: A method for calibrating the angle-axis of signals measuring changes in an index of refraction. A pump beam is generated to propagate near a prism to induce index-changes in air by lining up air molecules outside of the prism. A generated probe beam is directed at the prism. A sinc2 pattern is then generated in a far-field based on a diffraction of a laser beam from a slit, where the laser beam is directed at the prism. An angle-axis of the sinc2 pattern is calibrated using maxima of the sinc2 pattern.

Abstract: An apparatus and method for wavefront sensing that includes: employing two moiré gratings in an optical path; optically Fourier transforming a moiré deflectogram produced by the gratings; variably transmitting the transformed moiré deflectogram; and receiving an image of the variably transmitted and transformed moiré deflectogram. The variable transmission is best accomplished by transmission filter, a transmissive optic encoding intensity information upon the moiré deflectogram as a function of fringe angle. For example, the function can be a triangular transmission function centered on the (0,0) order spatial frequency spot and oriented at 45 degrees to the y-axis. The optical Fourier transform is accomplished by a lens and the variable transmission by an apodized slit.