On-chip single-mode CdS nanowire laser

Qingyang Bao; Weijia Li; Peizhen Xu; Ming Zhang; Daoxin Dai; Pan Wang; Xin Guo; Limin Tong

doi:10.1038/s41377-020-0277-0

On-chip single-mode CdS nanowire laser

Light Sci Appl. 2020 Mar 16:9:42. doi: 10.1038/s41377-020-0277-0. eCollection 2020.

Authors

Qingyang Bao¹, Weijia Li¹, Peizhen Xu¹, Ming Zhang¹, Daoxin Dai¹, Pan Wang¹, Xin Guo¹, Limin Tong^{1

2}

Affiliations

¹ 1State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China.
² 2Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006 China.

Abstract

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/cm², 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.

Keywords: Nanowires; Silicon photonics.