Spatial coherence can be created by appropriate spatial arrangements of incoherent point sources. Lau used a source of extended light and two amplitude gratings of identical periods, separated by the quarter Talbot distance, to provide coherent light. Because of the two successive amplitude gratings, most of the power is lost. By modifying the geometry of the second grating, I designed an array illuminator, providing several compression ratios and various topologies of the output plane, with significantly reduced losses. To further improve the power efficiency of the system, I used a longitudinal mirror system to collect the light rays that are lost in the initial Lau setup. Both one- and two-dimensional geometries are considered.
© 2004 Optical Society of America
(050.0050) Diffraction and gratings : Diffraction and gratings
(050.1950) Diffraction and gratings : Diffraction gratings
(070.0070) Fourier optics and signal processing : Fourier optics and signal processing
(070.6760) Fourier optics and signal processing : Talbot and self-imaging effects
Habib Hamam, "Lau Array Illuminator," Appl. Opt. 43, 2888-2894 (2004)