An optical setup is implemented for observation and analysis of diffraction
phenomena. The device provides a two-dimensional ordered continuous displa
y of all the diffraction patterns of any one-dimensional signal. This resul
t allows a direct comparison between the observed light intensity and the p
rediction of diffraction theory, both in the near-field and the far-field r
egions. The arrangement is built with conventional laboratory optical compo
nents plus a single ophthalmic progressive lens. Experimental results for t
ypical diffracting apertures are shown. (C) 2001 American Association of Ph
ysics Teachers.