Chang Hao, Zhong Yichi, Dong Hongxing, Wang Zhenyu, Xie Wei, Pan Anlian, Zhang Long
Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800, Shanghai, China.
State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China.
Light Sci Appl. 2021 Mar 18;10(1):60. doi: 10.1038/s41377-021-00508-7.
Quantum dot microlasers, as multifunctional optical source components, are of great importance for full-color high-pixel display, miniaturized coherent lighting, and on-chip integrated photonic and electronic circuits. Since the first synthesis of colloidal quantum dots (CQD) in the 1990s, motivation to realize high-performance low-cost CQD micro-/nanolasers has been a driving force for more than three decades. However, the low packing density, inefficient coupling of CQDs with optical cavities, and the poor thermal stability of miniaturized complex systems make it challenging to achieve practical CQD micro-/nanolasers, especially to combine the continuous working ability at high temperatures and the low-cost potential with mass-produced synthesis technologies. Herein, we developed close-packed CQD-assembled microspheres and embedded them in a silica matrix through the rapid self-aggregation and solidification of CdSe/ZnS CQD. This technology addresses the core issues of photoluminescence (PL) quenching effect and low optical gain in traditional CQD laser research. High-efficiency low-threshold CQD microlasers are demonstrated together with long-playing (40 min) working stability even at 450 K under pulsed laser excitation, which is the highest operational temperature for CQD lasers. Moreover, single-mode CQD microlasers are obtained with tunable wavelengths across the entire visible spectral range. The chemosynthesis process supports the mass-produced potential of high-density integrated CQD microlasers, promoting CQD-based low-cost high-temperature microdevices.
量子点微激光器作为多功能光源组件，对于全彩高像素显示、小型化相干照明以及片上集成光子和电子电路具有至关重要的意义。自20世纪90年代首次合成胶体量子点（CQD）以来，实现高性能低成本CQD微/纳激光器的动力一直是三十多年来的驱动力。然而，低堆积密度、CQD与光学腔的低效耦合以及小型化复杂系统的热稳定性差，使得实现实用的CQD微/纳激光器具有挑战性，特别是要将高温下的连续工作能力与低成本潜力以及大规模生产合成技术相结合。在此，我们开发了紧密堆积的CQD组装微球，并通过CdSe/ZnS CQD的快速自聚集和固化将它们嵌入二氧化硅基质中。该技术解决了传统CQD激光研究中光致发光（PL）猝灭效应和低光学增益的核心问题。展示了高效低阈值CQD微激光器，即使在脉冲激光激发下，在450 K时也具有长达40分钟的工作稳定性，这是CQD激光器的最高工作温度。此外，还获得了在整个可见光谱范围内波长可调的单模CQD微激光器。化学合成过程支持高密度集成CQD微激光器的大规模生产潜力，推动了基于CQD的低成本高温微器件的发展。
