Mode structure of coupled L3 photonic crystal cavities

Abstract

We investigate the energy splitting, quality factor and polarization of the fundamental modes of coupled L3 photonic crystal cavities. Four different geometries are evaluated theoretically, before experimentally investigating coupling in a direction at 30 degrees to the line of the cavities. In this geometry, a smooth variation of the energy splitting with the cavity separation is predicted and observed, together with significant differences between the polarizations of the bonding and anti-bonding states. The controlled splitting of the coupled states is potentially useful for applications that require simultaneous resonant enhancement of two transitions. (C) 2011 Optical Society of America