Researcher Ma Renmin's research group from the School of Physics realizes a magic angle laser based on the localization mechanism of the mode coupling optical field

Peking University's School of Physics, State Key Laboratory of Artificial Microstructures and Mesoscopic Physics, and Researcher Ma Renmin's research group at the Center for Frontier Science of Nano Optoelectronics realized a magic angle laser based on the localization mechanism of mode coupling optical fields in a defect-free periodic structure

Micro-nano lasers use an effective optical feedback mechanism to localize the optical field to the wavelength level or smaller, thereby enhancing the interaction between light and matter, improving laser performance, and achieving low energy consumption and high modulation rate coherent lasing.

Recently, Peking University's School of Physics, State Key Laboratory of Artificial Microstructures and Mesoscopic Physics, and Researcher Ma Renmin’s research team from the Center for Frontier Science of Nano-Photonics has achieved magic angles based on the localization mechanism of mode-coupled light fields in a defect-free periodic structure.

Figure 1.

Different from the magic angle structure of the electronic system formed by twisting two layers of graphene, the research team used micro-nano processing technology to make two sets of twisted photonic crystal lattices in the same layer of semiconductor material (Figure 2a,b), thus forming For a Moiré superlattice with a larger period, the corresponding Brillouin zone will flatten the energy band of the photonic crystal due to the coupling between the two sets of photonic crystal modes, and the corresponding real-space wave function distribution will also be localized.

Figure 2.

In addition, the research team also studied in detail the energy band structure, mode localization characteristics, and lasing characteristics of magic angle lasers with rotation angles of 4.

Figure 3.

Related research results are titled " Magic-angle lasers in nanostructured moiré superlattice ", published online on August 16, 2021 in " Nature Nanotechnology " ( Nature Nanotechnology ) ; School of Physics 2019 doctoral student Mao Xinrui, Shao Zengkai associate researcher, 2020 doctoral student Luan Hongyi and Wang Shaolei are the co-first authors; Ma Renmin is the corresponding author

The above-mentioned research work was supported by the Beijing Municipal Natural Science Foundation, the National Natural Science Foundation of China, the National Key Research and Development Program, the State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, the Frontier Science Center of Nano Optoelectronics, and the Yangtze Delta Optoelectronics Research Institute of Peking University

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