Photonic crystal waveguides and cavities in integrated optics

Min Qiu

Laboratory of Photonics and Microwave Engineering (FMI)
Department of Microelectronics and Information Technology (IMIT)
Royal Institute of Technology (KTH)
Electrum 229, 164 40 Kista

Two-dimensional Photonic crystal (2D PC) waveguides and cavities are key elements in photonic crystal based integrated. Devices based on 2D PCs are typically realized as 3D structures consisting of an array of holes (or rods) vertically etched through a slab waveguide. The existence of holes in a slab waveguide may induce strong radiation losses to the slab claddings. By employing the 2D finite-difference time-domain method, and the effective-index method to account for the vertical confinement, we show that a remarkably good agreement with experiments can be obtained, for a number of experimentally studied PC structures (cavities, waveguides and bends). Many of PC waveguides are multi-mode, thus the coupling between the different guided modes are of interests. Mode-gaps (or mini-stop-bands) may arise from Bragg diffraction of the incident mode into the counter-propagating modes. In the talk, we also present the experimental characterization and theoretical calculations of mini-stop-bands, which are important to accurately design and fabricate of PCs.