A flexible array illuminator, comprising only two conventional optical elements, with a variable density of bright white-light spots is presented. The key to our method is to obtain with a single diffractive lens an achromatic version of different fractional Talbot images, produced by free-space propagation, of the amplitude distribution at the back focal plane of a periodic refractive microlens array under a broadband point-source illumination. Some experimental results of our optical procedure are also shown.
© 1998 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(070.2580) Fourier optics and signal processing : Paraxial wave optics
(070.2590) Fourier optics and signal processing : ABCD transforms
(070.6760) Fourier optics and signal processing : Talbot and self-imaging effects
(230.3990) Optical devices : Micro-optical devices
Enrique Tajahuerce, Elvira Bonet, Pedro Andrés, Carlos J. Zapata-Rodríguez, and Vicent Climent, "White-light-modified Talbot array illuminator with a variable density of light spots," Appl. Opt. 37, 4366-4373 (1998)