Enhanced Contrast Holographic Interferometry
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
To enhance fringe contrast requires considering the polarization of all beams present. In making the original hologram, the polarizations of the object and reference beams are parallel, a condition for interference. In typical interference holography, no change of object polarization is made at playback. The present method consists of rotating the polarization of the object beam by 90 degrees at playback before impinging on the recorded hologram. At this point, there are no interference fringes seen, since the two polarizations are orthogonal. We next pass the light emerging from the hologram through a second polarizer at 45 degrees to the vertical, and again obtain interference fringes.