A novel design for a broadband directional coupler based on a photonic crystal fiber is investigated numerically. It is shown that suitable index-depressing doping of the core regions in an index-guiding twin-core photonic crystal fiber can stabilize the coupling coefficient between the cores over an extremely broad (octave-spanning) frequency range.
© 2004 Optical Society of America
(060.1810) Fiber optics and optical communications : Buffers, couplers, routers, switches, and multiplexers
(060.2280) Fiber optics and optical communications : Fiber design and fabrication
(060.2340) Fiber optics and optical communications : Fiber optics components
Jesper Lægsgaard, Ole Bang, and Anders Bjarklev, "Photonic crystal fiber design for broadband directional coupling," Opt. Lett. 29, 2473-2475 (2004)