Assembly Orientation Engineering of Organic Microcrystal Laser for Modulating Cavity Dimension

Abstract

The modulation of cavity dimension is crucial for the realization of versatile micro-/nanolasers, yet the fabrication of molecular crystals is derived from the high-orientation assembly mode of molecules, limiting the optical cavity to a low-dimensional anisotropic topography with sharp corners and high thresholds. Here, we propose an innovative strategy to achieve the assembly orientation engineering of organic microcrystals for flexibly modulating cavity dimension. The isotropic and anisotropic assembly orientations generate different-dimensional microcavity structures (one-dimensional microbelts and three-dimensional (3D) microspheres) with distinct lasing actions. The 3D microspheres with perfect spherical morphology and strong light confinement capability function as low-threshold whispering gallery-mode microlasers. Moreover, the single-crystalline microbelts with smooth lateral sides act as Fabry–Pérot-mode lateral-cavity microlasers, which are formed between two lateral faces of the microbelts. The results offer useful insights into exploiting multidimensional micro-/nanolasers for integrated photonic circuits.