The photonic crystal (PC) coupler and planar photonic band gap (PBG) coupler were theoretically investigated. Also the conventional step-index coupler was investigated for comparison with these couplers. The PC-coupler is a structure formed by the gradual tapering of the photonic-crystal holey fiber and the conventional step-index coupler -- by the gradual tapering of the conventional fiber. The planar PBG-coupler is a planar PC waveguide, in which defect region has taper-like geometry. The photonic crystal couplers are characterized by alternation of the material refractive index along the wave propagation direction, i. e. along the optical axis of the taper. In our investigation an effective refractive index model for two-dimensional photonic crystal was used. This model allows to analyze the waveguide structures, which work on the effective index waveguiding in a defect of the photonic crystal. The optical field in photonic crystal couplers, PBG couplers and conventional couplers was investigated. Also losses and mode shape distortion of all types of the couplers were calculated.

Date Published: 25 October 2004
PDF: 9 pages
Proc. SPIE 5597, Nanophotonics for Communication: Materials and Devices, (25 October 2004); doi: 10.1117/12.569650

Published in SPIE Proceedings Vol. 5597:
Nanophotonics for Communication: Materials and Devices
Michal F. Lipson; George Barbastathis; Achyut K. Dutta; Kiyoshi Asakawa, Editor(s)