Bao Qingyang, Li Weijia, Xu Peizhen, Zhang Ming, Dai Daoxin, Wang Pan, Guo Xin, Tong Limin
1State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China.
2Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006 China.
Light Sci Appl. 2020 Mar 16;9:42. doi: 10.1038/s41377-020-0277-0. eCollection 2020.
By integrating a free-standing cadmium sulfide (CdS) nanowire onto a silicon nitride (SiN) photonic chip, we demonstrate a highly compact on-chip single-mode CdS nanowire laser. The mode selection is realized using a Mach-Zehnder interferometer (MZI) structure. When the pumping intensity exceeds the lasing threshold of 4.9 kW/cm, on-chip single-mode lasing at ~518.9 nm is achieved with a linewidth of 0.1 nm and a side-mode suppression ratio of up to a factor of 20 (13 dB). The output of the nanowire laser is channelled into an on-chip SiN waveguide with high efficiency (up to 58%) by evanescent coupling, and the directional coupling ratio between the two output ports can be varied from 90 to 10% by predesigning the coupling length of the SiN waveguide. Our results open new opportunities for both nanowire photonic devices and on-chip light sources and may pave the way towards a new category of hybrid nanolasers for chip-integrated applications.
通过将独立的硫化镉（CdS）纳米线集成到氮化硅（SiN）光子芯片上，我们展示了一种高度紧凑的片上单模CdS纳米线激光器。模式选择通过马赫-曾德尔干涉仪（MZI）结构实现。当泵浦强度超过4.9 kW/cm的激光阈值时，在~518.9 nm处实现了片上单模激光发射，线宽为0.1 nm，边模抑制比高达20倍（13 dB）。纳米线激光器的输出通过倏逝耦合高效地（高达58%）导入片上SiN波导，并且通过预先设计SiN波导的耦合长度，两个输出端口之间的定向耦合比可以在90%到10%之间变化。我们的结果为纳米线光子器件和片上光源都开辟了新的机遇，并可能为用于芯片集成应用的新型混合纳米激光器铺平道路。
