The abstract should summarize the context, content and conclusions of the paper in less than 200 words. We fabricated a two-dimensional Y-branch photonic crystal waveguide in the near infrared region by using focused ion beam etching and depositing system. The light guide characters of the waveguide were measured for three different spaces between branches. Field intensity distributions of TE polarized wave in the branches were simulated by using the transfer matrix method. Both the theoretical and experimental results show that the shortest space between branches of the photonic crystal waveguide is about 1.4 times wavelength of transmitted light. If the space became shorter, the light in the two branches would couple to each other seriously. This result might be helpful for the design of compact wave demultiplexer and all-optical integrated circuits.
Low-loss guided modes in photonic crystal waveguides