Wong Wei Wen, Huang Xiaoying, Lem Olivier Lee Cheong, Jagadish Chennupati, Tan Hark Hoe
Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2600, Australia.
Australian National Fabrication Facility, Research School of Physics, The Australian National University, Canberra, ACT 2600, Australia.
Sci Adv. 2025 Sep 5;11(36):eadx6527. doi: 10.1126/sciadv.adx6527.
Surface-emitting lasers featuring optical bound states in the continuum (BICs) have recently emerged as a promising alternative to vertical cavity surface-emitting lasers. However, structural damage caused by top-down fabrication processes remains as a major obstacle that limits device performance. Here, we overcome this bottleneck by demonstrating surface-emitting quasi-BIC lasers fabricated with a bottom-up, etching-free process. We epitaxially grow arrays of crystal phase-engineered InP nanosheets with atomically smooth sidewalls as both the laser active medium and a symmetry-broken quasi-BIC cavity, strategically optimizing coupling between spontaneous emission and the lasing mode. Furthermore, we leverage the dipole selection rule associated with the wurtzite crystal structure of the nanosheets for side mode suppression, achieving single-mode lasing at room temperature with lasing threshold as low as 14 μJ cm pulse. Optimal light-cavity coupling is evidenced by spontaneous emission factors as high as 0.8, showcasing the potential of bottom-up BIC lasers in realizing near-thresholdless lasing at room temperature.
具有连续谱光学束缚态（BICs）的表面发射激光器最近已成为垂直腔面发射激光器的一种有前途的替代方案。然而，自上而下的制造工艺所造成的结构损伤仍然是限制器件性能的主要障碍。在此，我们通过展示采用自下而上、无蚀刻工艺制造的表面发射准BIC激光器克服了这一瓶颈。我们外延生长具有原子级光滑侧壁的晶相工程InP纳米片阵列，将其作为激光有源介质和对称破缺的准BIC腔，策略性地优化自发发射与激光模式之间的耦合。此外，我们利用与纳米片纤锌矿晶体结构相关的偶极选择规则来抑制边模，在室温下实现了单模激光发射，激光阈值低至14 μJ cm脉冲。高达0.8的自发发射因子证明了最佳的光腔耦合，展示了自下而上的BIC激光器在室温下实现近无阈值激光发射的潜力。
