An open waveguide cavity formed by a pair of planar waveguides, in which one guiding layer is a negative index medium and the other is a positive index medium, is theoretically demonstrated. For such a waveguide cavity the resonant frequency is independent of the total length of the waveguide system. With the coupled mode theory it is shown that energy flow circulation can be established through the special coupling between the waveguides at the resonant frequency, and thus the wave fields are localized. This phenomenon is further verified numerically with the finite-difference time-domain method. The quality factor of the open waveguide cavity is also discussed.
© 2008 Optical Society of America
Original Manuscript: June 12, 2008
Revised Manuscript: October 16, 2008
Manuscript Accepted: October 20, 2008
Published: November 24, 2008
Wei Yan and Linfang Shen, "Open waveguide cavity using a negative index medium," Opt. Lett. 33, 2806-2808 (2008)