Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
Advanced Research Institute of Multidisciplinary Science, and School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Adv Mater. 2023 Apr;35(17):e2300054. doi: 10.1002/adma.202300054. Epub 2023 Mar 15.
Synthetic photonic materials exploiting the quantum concept of parity-time (PT) symmetry lead to an emerging photonic paradigm-non-Hermitian photonics, which is revolutionizing the photonic sciences. The non-Hermitian photonics dealing with the interplay between gain and loss in PT synthetic photonic material systems offers a versatile platform for advancing microlaser technology. However, current PT-symmetric microcavity laser systems only manipulate imaginary parts of the refractive indices, suffering from limited laser spectral bandwidth. Here, an organic composite material system is proposed to synthesize reconfigurable PT-symmetric microcavities with controllable complex refractive indices for realizing tunable single-mode laser outputs. A grayscale electron-beam direct-writing technique is elaborately designed to process laser dye-doped polymer films in one single step into microdisk cavities with periodic gain and loss distribution, which enables thresholdless PT-symmetry breaking and single-mode laser operation. Furthermore, organic photoisomerizable compounds are introduced to reconfigure the PT-symmetric systems in real-time by tailoring the real refractive index of the polymer microresonators, allowing for a dynamically and continuously tunable single-mode laser output. This work fundamentally enhances the PT-symmetric photonic systems for innovative design of synthetic photonic materials and architectures.
利用量子概念宇称时间（PT）对称性的合成光子材料导致了新兴的光子范例——非厄米光子学，它正在彻底改变光子科学。处理 PT 合成光子材料系统中增益和损耗相互作用的非厄米光子学为推进微激光技术提供了一个通用平台。然而，目前的 PT 对称微腔激光系统仅操纵折射率的虚部，受到激光光谱带宽的限制。在这里，提出了一种有机复合材料系统，用于合成具有可控复折射率的可重构 PT 对称微腔，以实现可调谐单模激光输出。精心设计了灰度电子束直写技术，以便在单个步骤中将激光染料掺杂聚合物薄膜加工成具有周期性增益和损耗分布的微盘腔，从而实现无阈值的 PT 对称性破坏和单模激光运行。此外，引入有机光致变色化合物通过调整聚合物微谐振器的实折射率来实时重构 PT 对称系统，从而实现动态和连续可调谐的单模激光输出。这项工作从根本上增强了 PT 对称光子系统，为合成光子材料和结构的创新设计提供了支持。
