SPASER是所报道的最小的、第一个在可见光或更宽的波长范围内工作的纳米级的有源器件。采用双稳态方法，将SPASER技术引入到改进的MIM波导结构实现表面等离子波放大器的设计，理论上采用SPASER的激光理论的Bloch方程推导得出：泵浦速率小于阈值时，增益介质反转粒子数保持为0，在泵浦速率大于阈值时，反转粒子数随泵浦速率线性增长；系统的几何特性完全由本征模式函数描述，在给定本征模式下，其性质完全取决于材料参数；选择合适的材料参数，可以使各状态的驰豫特征时间都在亚皮秒量级。模型计算结果表明：改进结构不会改变SPPs的强局域化特性；器件解决了SPASER内反馈造成的表面等离子净增益消除的难题。 研究成果可应用到生物传感、波谱检测、显微成像、超快通信等领域。

At present, SPASER(Surface Plasmon Amplification by Stimulated Emission of Radiation) is the smallest nanoscale active device, which is the first to function under visible light. In this paper, the MIM(metal-insulator-metal) waveguide structure of a double steady state was designed, which introduces the SPASER technology, namely, the surface plasmon wave amplifier. The amplifier was obtained by deriving from the Bloch equation using the SPASER laser theory. When the pumping rate was less than the threshold value, the number of the gain medium inversion particles remained 0. Otherwise, the number of the inversion particle grew linearly. The geometrical characteristics of the system could be completely described by the eigenmode function. On the central eigenmode, the system property entirely depended on the material parameters. Choosing the appropriate material parameters could make each state of the relaxation characteristic time remain at the level of the picosecond magnitude. The calculated results of the model show that the improved structure does not change the strong localized characteristics of the SPPs(Surface Plasmon Polaritons). The device solves the limitation on the surface plasmon net profit elimination caused by SPASER internal feedback.国家自然科学基金(61361011)；广西自然科学基金(2015GXNSFBA139257)；广西师范大学重点项目(2015ED03)； 广西自动检测技术与仪器重点实验室(YQ16206)