The efficiency of evanescent coupling between a silica optical fiber taper and a silicon photonic crystal waveguide is studied. A high-reflectivity mirror on the end of the photonic crystal waveguide is used to recollect, in the backward-propagating fiber mode, the optical power that is initially coupled into the photonic crystal waveguide. An outcoupled power in the backward-propagating fiber mode of 88% of the input power is measured, corresponding to a lower bound on the coupler efficiency of 94%.
© 2004 Optical Society of America
Paul E. Barclay, Kartik Srinivasan, Matthew Borselli, and Oskar Painter, "Efficient input and output fiber coupling to a photonic crystal waveguide," Opt. Lett. 29, 697-699 (2004)