title: Optical cavity modes of a single crystalline zinc oxide microsphere.
abstract: A detailed study on the optical cavity modes of zinc oxide microspheres under the optical excitation is presented. The zinc oxide microspheres with diameters ranging from 1.5 to 3.0 µm are prepared using hydrothermal growth technique. The photoluminescence measurement of a single microsphere shows prominent resonances of whispering gallery modes at room temperature. The experimentally observed whispering gallery modes in the photoluminescence spectrum are compared with theoretical calculations using analytical and finite element methods in order to clarify resonance properties of these modes. The comparison between theoretical analysis and experiment suggests that the dielectric constant of the ZnO microsphere is somewhat different from that for bulk ZnO. The sharp resonances of whispering gallery modes in zinc oxide microspheres cover the entire visible window. They may be utilized in realizations of optical resonators, light emitting devices, and lasers for future chip integrations with micro/nano optoelectronic circuits, and developments of optical biosensors.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.
authors.forename: Rakesh Singh
authors.initials: RS
authors.lastname: Moirangthem
authors.forename: Pi-Ju
authors.initials: PJ
authors.lastname: Cheng
authors.forename: Paul Ching-Hang
authors.initials: PC
authors.lastname: Chien
authors.forename: Buu Trong Huynh
authors.initials: BT
authors.lastname: Ngo
authors.forename: Shu-Wei
authors.initials: SW
authors.lastname: Chang
authors.forename: Chung-Hao
authors.initials: CH
authors.lastname: Tien
authors.forename: Yia-Chung
authors.initials: YC
authors.lastname: Chang
mesh_terms: D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008863:Microspheres; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D015034:Zinc Oxide