Lightwave propagation through a 120 degrees sharply bent single-line-defect photonic crystal waveguide

We have demonstrated 1.55 mu m wavelength lightwave propagation through a 1 20 degrees sharply bent waveguide formed in a triangular-lattice two-dimens ional photonic crystal (2D PC). Such propagation has not previously been ex perimentally confirmed. The photonic crystal was fabricated in a silicon-on -insulator (SOI) wafer with the top silicon layer of the wafer used as a co re layer. A 877-mu m-long single-line-defect waveguide was formed in the PC with a sharp 120 degrees bend near the middle of the waveguide. A tapered- hemispherical-end fiber was coupled to the input end of the waveguide for t he light input, and the output from the other end of the waveguide was dire ctly observed by scanning its near-field profile with another tapered-hemis pherical-end fiber. (C) 2000 American Institute of Physics. [S0003-6951(00) 01208-0].