Microcavities composed of point defects and waveguides in photonic crystals

A novel two-dimensional photonic crystal (PC) microcavity composed of a point defect, where a point emitter is placed, and a line defect (waveguide) was proposed and studied numerically. The results show that the light radiated from the point defect can be coupled into the waveguide with a more than 97% coupling efficiency under certain conditions. Because the PC waveguide can guide light around a sharp corner with a high efficiency, the radiation can be directed to any area in a PC by using our design. The microcavity quality factor and coupling efficiency can be adjusted through changing the space and the number of cylinders between the point defect and the waveguide, and the oscillation frequency can be tuned by changing the mode volume of the point defect. This may be valuable for the design of microwave integrated devices and all-optical integrated circuits. (C) 2001 Elsevier Science B.V. All rights reserved.