HOLOGRAPHIC CONTOURING BY USING TUNABLE LASERS

We show that it is possible to make a hologram with true-height contou rs by using dispersion compensation provided by holographic gratings i n the reference and picture beams. Holograms can be made with either a short-pulse, mode-locked laser or a tunable dye laser with 2N + 1 fre quencies each spaced by Delta v frequency. Experiments are presented t o illustrate the high-contrast contours obtained with consecutive expo sures from a tunable dye laser. Fine-scale vernier and coarse contours are obtained at intervals c/[2(2N + 1)Delta v] and c/(2 Delta v), res pectively.