DIFFRACTION VIEWING DEVICE

摘要

A viewing device to aid in authenticating an optical surface (100). The device includes a laser diode (101) which produces a beam of light (103). The device includes a viewing screen (107) which receives a diffracted image produced by the beam (103) illuminating the surface (100). The device further includes a lens system (102) which causes the diffracted beam to be focused on the viewing screen (107).