Analysis of the interference pattern in a cross-grating interferometer

Abstract

A structured source is used to illuminate the four-beam cross-grating interferometer to cause the interference fringes to localize at different planes. When a monochromatic spatially incoherent source is used, the amplitude transmittance of the first cross grating can be imaged to different locations in various planes. With white light extended source illumination, a cross-gratinglike pattern can be formed not only near but also far away from the optical axis simply by choosing four beams of equal path length to interfere. A multicross-grating interferometer is also analyzed with special emphasis on the three-cross-grating interferometer.