Department of Physics, National Taiwan University, Taipei, Taiwan.
Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.
Sci Adv. 2023 Jun 2;9(22):eadf6649. doi: 10.1126/sciadv.adf6649. Epub 2023 May 31.
The experimental observation of nonlinear two-photon pumped vortex lasing from perovskite metasurfaces is demonstrated. The vortex lasing beam is based on symmetry-protected quasi-bound states in the continuum (QBICs). The topological charge is estimated to be +1 according to the simulation result. The quality factor and lasing threshold are around 1100 and 4.28 mJ/cm, respectively. Theoretical analysis reveals that the QBIC mode originates from the magnetic dipole mode. The lasing wavelength can be experimentally designed within a broad spectral range by changing the diameter and periodicity of the metasurface. The finite array size effect of QBIC can affect the quality factor of the lasing and be used to modulate the lasing. Results shown in this study can lead to more complex vortex beam lasing from a single chip and previously unidentified ways to obtain ultrafast modulation of the QBIC lasing via the finite array size effect.
从钙钛矿超构表面演示了非线性双光子泵浦涡旋激光实验观察。涡旋激光光束基于对称保护的连续域准束缚态（QBIC）。根据模拟结果，拓扑电荷估计为+1。品质因数和激光阈值分别约为 1100 和 4.28mJ/cm。理论分析表明，QBIC 模式源于磁偶极子模式。通过改变超构表面的直径和周期，可以在较宽的光谱范围内实验设计激光波长。QBIC 的有限阵列尺寸效应会影响激光的品质因数，并可用于调制激光。本研究中的结果可以从单个芯片产生更复杂的涡旋光束激光，并以前所未有的方式通过有限阵列尺寸效应获得 QBIC 激光的超快调制。
