Optical Microcavities Clad by Low-Absorption Electrode Media

Four types of high-Q optical microcavities—disk, 1-D photonic crystal nanobeam, 2-D photonic crystal slab, and 3-D photonic crystal optical microresonators—clad by low-optical-loss electrode media such as indium tin oxide are designed and evaluated by the perturbation theory and 3-D finite-difference time-domain (FDTD) method. The quality (Q) factor is obtained via perturbation theory in which the imaginary part of the cladding material is regarded as a perturbation and confirmed to agree with results from the 3-D FDTD method. Although the studied designs preserve the high-Q factor, they provide the placement of low-loss conductive electrode material proximate to high-Q microcavity modes. Further enhancement of the Q factor is possible by a reduction of the electrode volume. Microlasers based on this study would provide an excellent heat sink and efficient carrier injection into a microcavity mode, thereby resulting in the realization of continuous-wave, room-temperature microlasers with low threshold.