基于混合波导-表面等离极化激元结构的胶体量子点放大自发发射性能研究OA

Nanolasers based on the surface plasmon amplification by stimulated emission of radiation(Spaser)structure are an important way to achieve breakthrough beyond the diffraction limit and to realize on-chip coherent light sources.In this paper,a hybrid waveguide-surface plasmon polariton structure based on Glass/Ag/SiO2/colloidal quantum dots(CQDs)was designed and fabricated.The amplification of spontaneous emission(ASE)performance of green light ZnCdSe/ZnS core-shell quantum dots in this structure was studied.This structure supports a highly lo-calized hybrid waveguide-surface plasmon polariton mode,and the optical field is strongly localized in the ultrathin(～15 nm)SiO2 spacer layer.Influenced by the Purcell effect,compared with pure CQD films,the fluorescence life-time of CQDs in the Spaser structure is significantly shortened and presents a double-exponential decay characteris-tic.Under optical pumping conditions,this device achieved a lower threshold of TM-polarized ASE,with a threshold of 86 μJ.cm-2 and a linear polarization degree of 0.91;the divergence angle before and after the threshold decreased significantly.This study reveals the regulatory rules of the hybrid waveguide-surface plasmon polariton mode on the ASE characteristics of CQDs,providing experimental basis and physical reference for the development of on-chip in-tegrated nanometer light sources based on solution-based fabrication and polarization-controllable.