Spatially multiplexed X-Y lateral shear interferometer with varying shears using holographic lens and spatial Fourier transform.

ABSTRACT

Current methods in shear interferometry provide shear only along one direction at a time. We propose a method in which interferograms with shear along the x, y, and xy directions can be obtained simultaneously from a single exposure recording via the concept of spatial multiplexing. The method utilizes holographic lenses, which have been recorded on a single plate with their optical centers translated along the x and y directions. The phase information is extracted through the Fourier transform method. In addition, this technique also provides a method to obtain interferograms with shear in multiples of the original shear along the x and y axis in one single frame capture due to the nonlinearity inherent in the phase holographic lens.