The Talbot effect is a well studied phenomenon by which grating pseudoimages appear at certain periodic distances when monochromatic light is used. Recently, numerical simulations have shown a new phenomenon; when a polychromatic light beam is used in a double grating system, the intensity of the pseudoimages presents a transverse-profile that remains unaffected over a wide range of propagation distances. This effect can be used to increase the tolerances of gratings based optical devices, such as displacement measurement systems, interferometers, and spectrometers. The pseudoimages formation with a polychromatic and finite extension light source is analytically and experimentally demonstrated. Relatively simple analytical expressions for the intensity and the contrast allow us to predict when pseudoimages present a constant contrast and when they disappear. Furthermore, we experimentally obtain the pseudoimages using the proposed configuration, corroborating the theoretical predictions.
© 2008 Optical Society of America
Diffraction and Gratings
Original Manuscript: October 16, 2007
Revised Manuscript: January 30, 2008
Manuscript Accepted: February 6, 2008
Published: March 27, 2008
Luis Miguel Sanchez-Brea, Jose Saez-Landete, Jose Alonso, and Eusebio Bernabeu, "Invariant grating pseudoimaging using polychromatic light and a finite extension source," Appl. Opt. 47, 1470-1477 (2008)