title: Vertical surface emitting open coupled-cavities based on photonic crystal surface modes.
abstract: Two types of vertical surface emitting photonic crystal cavities based on beaming mechanism and coupled surface modes are studied. It is shown that vertical emission with a zero divergence angle and a high quality factor can be easily achieved by the back-to-back cavity design. The periodic modulation to the cavity surface alters nonradiative surface modes into radiative surface modes, and the constructive interference of the radiative waves gives rise to vertical emission and improves the quality of the output beam. A high quality factor can be attributed to the nonradiative surface mode on the cavity back whose small part of energy can be transferred into the cavity surface by coupling. The resonant property and the coupling efficiency of the cavities are investigated and optimal cavity configurations are obtained. These open coupled-cavities are good candidates of highly directional light sources.
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.
authors.forename: Deyin
authors.initials: D
authors.lastname: Zhao
authors.forename: Xunya
authors.initials: X
authors.lastname: Jiang