Low threshold tunable spaser based on multipolar Fano resonances in disk-ring plasmonic nanostructures
Low threshold tunable spaser based on multipolar Fano resonances in disk-ring plasmonic nanostructures
复制标题
基于盘环等离子体纳米结构中多极法诺共振的低阈值可调谐SPASER
DOI：
10.1088/0022-3727/49/1/015101
复制
发表时间：
2016
影响因子：
3.4
通讯作者：
Sun Zhenrong
中科院分区：
文献类型：
--
作者：
Zheng Chunjie;Jia Tianqing;Zhao Hua;Zhang Shian;Feng Donghai;Sun Zhenrong
In this paper, we study theoretically spasers based on multipolar Fano resonances in disk-ring nanostructures covered with a silica layer doped with Yb 3+: Er 3+ used as the gain material. The electric field amplitudes at the quadrupolar mode (lasing wavelength) and the octupolar mode (pumping wavelength) are simultaneously enhanced by tens of times. Moreover, the spaser operates in a dark mode, which can reduce the radiation loss and enhance the confinement effectively. These factors work together to decrease greatly the critical gain coefficient and threshold. By adjusting the elliptic partial degrees of the nano-ring, the spasers can be tuned in the range of 1550 to 1650 nm, while the pumping light remains at the 980 nm absorption band of Yb 3+ ions. Moreover, the spasers at three Fano resonance wavelengths of the disk-ring nanostructures appear in sequence with increasing the gain coefficient. The effects of the extinction coefficient on the electric field amplitudes of the pump light are also studied.
