High-Q unidirectional emission properties of the symmetric half-spiral microcavities

摘要

Mode field patterns and light emissions of novel symmetric half-spiral microcavities (SHSMs) are investigated by the two-dimensional (2-D) finite-difference time domain (FDTD) method. The calculation results show that an SHSM can support high-quality (Q) (Q > 10(4)) distorted whispering-gallery modes with directional emissions. Moreover, artificial controls on the Q factor and emission directionality are realized in the coupled size-mismatched SHSMs, and unidirectional emission from the coupled cavity structure with a divergence of 19 degrees is achieved. (C) 2010 Optical Society of America