Abstract

The Talbot image of a grating can be formed with a collimated coherent light illumination. The distance of the Talbot image depends on the illumination wavelength. Color-coded moire fringes are obtained by placing a second grating at the Talbot distance, if a white-light source is used instead of a laser. The color of the moire fringes is determined by the distance of the two gratings. If a phase object is inserted between two gratings, the color of the moire fringes is varied correspondingly to the phase variation which actually changes the optical path of light between two gratings. Therefore, a color visualization of phase object can be obtained.

© 1985 Optical Society of America