State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, Department of Physics, Peking University, Beijing, 100871, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
Adv Mater. 2018 May;30(21):e1706546. doi: 10.1002/adma.201706546. Epub 2018 Apr 6.
The integration of on-chip dielectric lasers and subwavelength plasmonic waveguides has attracted enormous attention because of the combination of both the advantages of the high performances of the small dielectric lasers and the subwavelength plasmonic waveguides. However, the configurable integration is still a challenge owing to the complexity of the hybrid structures and the damageability of the gain media in the multistep micro/nanofabrications. By employing the dark-field optical imaging technique with a position uncertainty of about 21 nm and combining the high-resolution electron beam lithography, the small colloidal quantum dot (CQD) lasers without any damages are accurately aligned with the silver nanowires. As a result, the integration of the CQD lasers and the silver nanowires can be flexibly configured on chips. In the experiment, the tangential coupling, radial coupling, and complex coupling between the high-performance CQD lasers and the subwavelength silver nanowires are demonstrated. Because of the subwavelength field confinements of the silver nanowires, the deep-subwavelength coherent sources (multimode, one-color single-mode, or two-color single-mode) with a mode area of only 0.008λ are output from these hybrid structures. This configurable on-chip integration with high flexibility and controllability will greatly facilitate the developments of the complex functional hybrid photonic-plasmonic circuits.
片上介电激光器与亚波长等离子体波导的集成由于兼具小尺寸介电激光器的高性能和亚波长等离子体波导的优点而受到了极大的关注。然而，由于混合结构的复杂性以及多步微纳加工中增益介质的易损性，可配置的集成仍然是一个挑战。通过采用暗场光学成像技术（位置不确定度约为 21nm）并结合高分辨率电子束光刻技术，能够精确地将小胶体量子点（CQD）激光器与银纳米线对准，而不会对其造成任何损坏。因此，可以在芯片上灵活地配置 CQD 激光器和银纳米线的集成。在实验中，演示了高性能 CQD 激光器与亚波长银纳米线之间的切向耦合、径向耦合和复杂耦合。由于银纳米线的亚波长场限制，从这些混合结构中输出了深亚波长相干光源（多模、单模一色或双模一色），其模式面积仅为 0.008λ。这种具有高灵活性和可控性的可配置片上集成将极大地促进复杂功能混合光子-等离子体电路的发展。
