Short-wave infrared cavity resonances in a single GeSn nanowire

• Main Authors: Kim, Youngmin, Assali, Simone, Joo, Hyo-Jun, Koelling, Sebastian, Chen, Melvina, Luo, Lu, Shi, Xuncheng, Burt, Daniel, Ikonic, Zoran, Nam, Donguk, Moutanabbir, Oussama
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics; Emission; Luminescence
• Online Access: https://hdl.handle.net/10356/169823
• Institution: Nanyang Technological University

Nanowires are promising platforms for realizing ultra-compact light sources for photonic integrated circuits. In contrast to impressive progress on light confinement and stimulated emission in III-V and II-VI semiconductor nanowires, there has been no experimental demonstration showing the potential to achieve strong cavity effects in a bottom-up grown single group-IV nanowire, which is a prerequisite for realizing silicon-compatible infrared nanolasers. Herein, we address this limitation and present an experimental observation of cavity-enhanced strong photoluminescence from a single Ge/GeSn core/shell nanowire. A sufficiently large Sn content (~ 10 at%) in the GeSn shell leads to a direct bandgap gain medium, allowing a strong reduction in material loss upon optical pumping. Efficient optical confinement in a single nanowire enables many round trips of emitted photons between two facets of a nanowire, achieving a narrow width of 3.3 nm. Our demonstration opens new possibilities for ultrasmall on-chip light sources towards realizing photonic-integrated circuits in the underexplored range of short-wave infrared (SWIR).