Shearing interferometer employing an acousto-optic cell

摘要

An improved shearing interferometer is provided having an acousto-optic cell wherein two sets of orthogonal diffraction gratings are formed therein by applying two electrical signals thereto having different frequencies. A wavefront to be examined is passed through the cell, and both signal frequencies applied to the cell are varied to cause the resulting shearing interferogram to be sequentially directed at a pair of orthogonal linear photodetector arrays. The degree of shear may be readily adjusted by changing the difference between the frequencies of the two signals applied to the cell.