We experimentally demonstrate a metal–film bidirectional surface wave splitter for guiding light at two visible wavelengths in opposite directions. Two nanoscale gratings were patterned on opposite sides of a subwavelength slit. The metallic surface grating structures were tailored geometrically to have different plasmonic bandgaps, enabling each grating to guide light of one wavelength and prohibit propagation at the other wavelength. The locations of the bandgaps were experimentally confirmed by interferometric measurements. Based on these design principles, a green–red bidirectional surface wave splitter is demonstrated, and the observed optical properties are shown to agree with theoretical predictions.
© 2010 Optical Society of America
Optics at Surfaces
Original Manuscript: August 23, 2010
Revised Manuscript: November 17, 2010
Manuscript Accepted: November 19, 2010
Published: December 13, 2010
Qiaoqiang Gan and Filbert J. Bartoli, "Bidirectional surface wave splitter at visible frequencies," Opt. Lett. 35, 4181-4183 (2010)