Diffraction on Hologram
Far-field diffraction pattern of a helium-neon laser incident on a binary amplitude hologram with an embedded-helical phase, as projected by a lens on a black cardboard. The zeroth and first-order diffractions were overexposed to show the second order. Other artifacts were a consequence of the hologram printing process (laser printing on an acetate). --Published in OPN July/August 2010. Nath Hermosa National Institute of Physics, University of the Philippines Diliman