Guan Jun, Sagar Laxmi Kishore, Li Ran, Wang Danqing, Bappi Golam, Wang Weijia, Watkins Nicolas, Bourgeois Marc R, Levina Larissa, Fan Fengjia, Hoogland Sjoerd, Voznyy Oleksandr, de Pina Joao Martins, Schaller Richard D, Schatz George C, Sargent Edward H, Odom Teri W
Graduate Program in Applied Physics, Northwestern University, Evanston, Illinois 60208, United States.
Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
ACS Nano. 2020 Mar 24;14(3):3426-3433. doi: 10.1021/acsnano.9b09466. Epub 2020 Feb 12.
The tailored spatial polarization of coherent light beams is important for applications ranging from microscopy to biophysics to quantum optics. Miniaturized light sources are needed for integrated, on-chip photonic devices with desired vector beams; however, this issue is unresolved because most lasers rely on bulky optical elements to achieve such polarization control. Here, we report on quantum dot-plasmon lasers with engineered polarization patterns controllable by near-field coupling of colloidal quantum dots to metal nanoparticles. Conformal coating of CdSe-CdS core-shell quantum dot films on Ag nanoparticle lattices enables the formation of hybrid waveguide-surface lattice resonance (W-SLR) modes. The sidebands of these hybrid modes at nonzero wavevectors facilitate directional lasing emission with either radial or azimuthal polarization depending on the thickness of the quantum dot film.
相干光束的定制空间偏振对于从显微镜学到生物物理再到量子光学等一系列应用都很重要。集成的片上光子器件若要产生所需的矢量光束，就需要小型化光源；然而，这个问题尚未解决，因为大多数激光器依赖笨重的光学元件来实现这种偏振控制。在此，我们报道了量子点 - 等离子体激光器，其具有可通过胶体量子点与金属纳米颗粒的近场耦合来控制的工程化偏振模式。在银纳米颗粒晶格上对CdSe - CdS核壳量子点薄膜进行共形涂层，能够形成混合波导 - 表面晶格共振（W - SLR）模式。这些混合模式在非零波矢处的边带有利于产生具有径向或方位角偏振的定向激光发射，这取决于量子点薄膜的厚度。
