Conditions for generating a dark focus surrounded by light in all three dimensions are presented. A simple technique for generating such a dark region is demonstrated experimentally. The method is compared with previous attempts at creating a three-dimensional dark focus.
© 2004 Optical Society of America
Dvir Yelin, Brett E. Bouma, and Guillermo J. Tearney, "Generating an adjustable three-dimensional dark focus," Opt. Lett. 29, 661-663 (2004)