Recently, a groundbreaking research achievement has emerged from the collaborative efforts of Professor Peng Chao's team at Peking University's School of Electronics, Academician Zheng Wanhua's team at the Semiconductor Institute of the Chinese Academy of Sciences, and Academician Yuri Kivshar's team at the Australian National University. Their innovative findings have been published in Nature Communications.

This study ingeniously employs two initially achiral metasurface structures. By twisting and stacking them, a bilayer metasurface structure with intrinsic chirality is formed. This breakthrough has successfully enabled stable chiral laser emission within the communication band.

The research leverages a gain-guiding mechanism to achieve precise optical field localization. Through the act of twisting, mirror symmetry is disrupted, and non-Hermitian interlayer coupling is introduced. This process induces intrinsic chirality in the originally achiral structure, a significant advancement in the field.

During the experiments, isotropic geometric shapes and dispersion effects play a crucial role. They lead to the hybridization of bulk guided-wave resonances, which in turn form clockwise and counterclockwise rotating collective guided-wave resonance modes. Ultimately, this results in the dominance of a single orbital chiral mode during the lasing process.

The team utilized wafer bonding technology to prepare the samples. Under room-temperature optical pumping, they achieved single-mode laser emission with a remarkably low threshold of 73 kW/cm². Moreover, the lasers demonstrated stable operation across a wide spectral range of 250 nm. The output mode presents a donut-shaped spot. Through polarization analysis and self-interference measurements, the existence of a phase vortex with a topological charge of 1 has been confirmed.

This remarkable achievement paves the way for new research directions in the field of chiral light sources and collective photonic states, holding great promise for future advancements in optics and photonics.