We propose a class of antireflecting structures that can effectively suppress reflections for binary diffractive optics. In this structure, multiple periodic thin films with gradually varying refractive indices are used to shift all reflected diffraction to the transmitted orders. The structure is optimized to operate over broad bands and wide angles using rigorous coupled-wave analysis and genetic algorithms. We validated the structure numerically using finite-difference time-domain methods. The proposed structure may lead to more efficient diffractive devices for applications in thin-film photovoltaic, waveguide coupler, and holographic optical elements.
© 2010 Optical Society of America
Diffraction and Gratings
Original Manuscript: December 7, 2009
Revised Manuscript: February 4, 2010
Manuscript Accepted: February 12, 2010
Published: March 18, 2010
Chih-Hao Chang, Laura Waller, and George Barbastathis, "Design and optimization of broadband wide-angle antireflection structures for binary diffractive optics," Opt. Lett. 35, 907-909 (2010)