Lasing Behavior Modulation for ZnO Whispering-Gallery Microcavities
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- 作者：Gangyi Zhu ; Chunxiang Xu ; Lisha Cai ; Jitao Li ; Zengliang Shi ; Yi Lin ; Guofeng Chen ; Tao Ding ; Zhengshan Tian ; Jun Dai
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：November 28, 2012
- 年：2012
- 卷：4
- 期：11
- 页码：6195-6201
- 全文大小：573K
- 年卷期：v.4,no.11(November 28, 2012)
- ISSN：1944-8252
文摘
Four configurations of whispering-gallery-mode (WGM) microcavities were designed and fabricated to modulate the optically pumped lasing characteristics by polymer modification on hexagonal ZnO microrod surfaces. On the basis of the total internal reflection (TIR) at the boundary of microcavities, the lasing characteristics were improved by raising the relative refractive index. Considering the different reflective conditions at various side surfaces, the typical lasing mode equation for whispering-gallery microcavity was modified to adapt for general situation even with unsymmetrical structure, and then employed to discuss the observed lasing behaviors, in the polyvinylcarbazole (PVK) modified ZnO microrods, such as mode position, mode numbers and quality factor. The optical field distributions for TE modes of the four configurations were also simulated by 2-dimensional finite difference time-domain (FDTD) method. The simulation agreed well with the experimental results to support the resonance mechanism.