A nonuniform-shape photonic crystal taper integrated with a single-mode optical fiber and a photonic crystal waveguide for high-efficiency mode coupling is presented. The curvature of the tapering section is varied by the parameter α. For values of α set to 2 and 0.5, concave and convex tapers are obtained, respectively. Numerical calculations yield an average coupling efficiency greater than 97% at a short taper length of 20.52 μm for the convex-shape taper. Subsequently, the value of the parameter α is varied for investigating the effects of curvature on coupling efficiency and compactness of different types of taper.
© 2005 Optical Society of AmericaFull Article | PDF Article