Micro-lightwave circuits based on photonic crystal

Micro-lightwave circuit technologies based on photonic crystal slabs were studied to realize integrated photonic node circuits for use in photonic networks. First, a unique optical multi-exposure technique, which is suitable for drawing large-area, two-dimensional, photonic crystal lattice patterns, is introduced here. The relationship between the resolved pattern size and the light-beam wavelength used for exposure is also discussed. Next, a high-density optical intercounection technique with photonic crystal line-defect waveguides and Si channel waveguides is introduced. A low-loss connection structure for both waveguides and their low bending loss characteristics are also discussed. Furthermore, slab-type, photonic crystal-based optical devices, such as channel-drop filters and optical switches, for constructing the photonic node circuits were proposed and their characteristics investigated by FDTD simulations. A high wavelength resolution for the filters and extremely small switching power for the optical switches were predicted. Before fabricating the optical switches, directional couplers based on photonic-crystal slabs were fabricated and the basic properties of complementary power splitting to two output ports were demonstrated. These results strongly support the possibility of realizing integrated photonic node circuits with photonic crystals.