Abnormal high-Q modes of coupled stadium-shaped microcavities

作者：Ryu Jung Wan; Lee Soo Young; Kim Inbo; Choi Muhan; Hentschel Martina; Kim Sang Wook^*

来源：Optics Letters, 2014, 39(14): 4196-4199.

DOI：10.1364/OL.39.004196

It is well known that the strongly deformed microcavity with fully chaotic ray dynamics cannot support high-Q modes due to its fast chaotic diffusion to the critical line of refractive emission. Here, we investigate how the Q factor is modified when two chaotic cavities are coupled, and show that some modes, whose Q factor is about 10 times higher than that of the corresponding single cavity, can exist. These abnormal high-Q modes are the result of an optimal combination of coupling and cavity geometry. As an example, in the coupled stadium-shaped microcavities, the mode pattern extends over both cavities such that it follows a whispering-gallery-type mode at both ends, whereas a big coupling spot forms at the closest contact of the two microcavities. The pattern of such a %26quot;rounded bow tie%26quot; mode allows the mode to have a high-Q factor. This mode pattern minimizes the leakage of light at both ends of the microcavities as the pattern at both ends is similar to the whispering gallery mode.

• 出版日期2014-7-15