Highly linearly polarized CdSe/CdS/ZnS nanoplatelet-assembled microsphere laser

Abstract

Highly polarized micro-lasers are of paramount importance for applications in optical communications, high-resolution imaging, and quantum information. However, their realization remains challenging due to fabrication complexities and the anisotropy limitations of gain materials. In this study, we propose an innovative approach that leverages anisotropic light-emitting nanoplatelets (NPLs) as building blocks, which are orientationally assembled to form microsphere cavities, thereby achieving a highly linearly polarized micro-laser. By the microemulsion templating method, NPLs are self-assembled into microspheres with an edge-up orientation, further enhancing the anisotropy of the assembled spheres. The synergistic orientation of the spherical cavity structure and the oriented NPLs augments light polarization within the cavity. Notably, the fabricated highly linearly polarized (0.89) micro-laser, utilizing CdSe/CdS/ZnS NPLs, exhibits excellent lasing properties, including a low threshold (≈20.4 μJ cm⁻²), and a high cavity quality factor (≈4679). In conclusion, this approach represents a significant advancement in designing highly linearly polarized micro-lasers and paves the way for their application in next-generation photonic integrated devices.