As "the eyes" of intelligent systems such as robots and autonomous vehicles, LiDAR performance directly determines the real-time performance and accuracy of environmental perception. Traditional mechanical-scanning LiDAR offers a wide FOV but suffers from low speed. Although current inertia-free spectral scanning can achieve a point acquisition rate (PAR) of tens of MHz, it still faces three core bottlenecks: first, inter-axis rate mismatch limits the effective imaging frame rate, making it difficult to capture high-speed moving targets; second, anisotropy in spectral scanning causes beam astigmatism, significantly reducing spatial resolution; third, there is an inherent trade-off between FOV and resolution—traditional optical systems cannot simultaneously achieve wide-FOV coverage and high-resolution detection. These challenges urgently call for new optical design concepts and technical solutions.
In recent years, benefiting from the development of microfabrication technology, metasurfaces have provided a new solution for the multi-functionalization and miniaturization of optical systems, thanks to their high-degree-of-freedom multidimensional optical field manipulation capability and characteristics of being thin, light, and easy to integrate.
In a new paper published in Light: Science & Applications , a team of scientists, led by Professor Xiangang Luo from State Key Laboratory of Optical Field Manipulation Science and Technology, Institute of Optics and Electronics, Chinese Academy of Sciences, China, and co-workers have proposed an innovative scheme integrating an astigmatic metalens (AML) with spectral-acousto-optic (spectral-AO) coordinated scanning. They successfully developed a novel LiDAR architecture featuring an ultra-high frame-wise point acquisition rate (FPAR) of 36.6 MHz, a 102° wide FOV, and an angular resolution of 6.5 mrad.
Previously, the team proposed a quadratic-phase metalens based on symmetry transformation [Opt. Express, 2017, 25: 31471] and successfully achieved 178° wide-FOV passive imaging [Adv. Mater., 2021, 33: 2008157]. Building on this, the team further extended this technology to active LiDAR 3D imaging. Through the multi-dimensional innovative design of the AML, they simultaneously improved imaging resolution and speed under a wide FOV and solved the inter-axis mismatch problem, ultimately breaking the trade-off of "wide FOV, high frame rate, and high resolution" in traditional technologies. The specific technical routes are as follows: (1) Leveraging the wide-FOV advantage of the quadratic phase, using it as the base phase of the AML; (2) Innovatively introducing a high-order astigmatic phase into the quadratic phase to suppress beam astigmatism and improve angular resolution under a wide FOV; (3) Promoting the deep integration of the AML with spectral-AO scanning, which not only solves the FOV mismatch in cascaded scanning but also achieves high-frame-rate imaging. Finally, a novel LiDAR architecture with a wide FOV, high temporal resolution (high imaging frame rate), and high spatial resolution (high angular resolution) was constructed ( Fig. 1 ).
Experimentally, the team built a complete LiDAR system ( Fig. 2a ): broadband pulsed laser undergoes spectral-temporal encoding, and spectral-AO scanning is implemented via an acousto-optic deflector (AOD) and a blazed grating (BG) to achieve inter-axis rate matching ( Fig. 2b ); to enhance the spatial detection capability, the system’s backend integrates the AML, which can simultaneously expand the FOV and improve spatial resolution by introducing an additional astigmatic phase ( Fig. 2c ); target echoes are captured by a photomultiplier tube (PMT), enabling the time-of-flight (TOF) acquisition.
The proposed LiDAR architecture exhibits excellent temporal resolution ( Fig. 3a ). For dynamic testing, a scene incorporating an "F-A-S-T" letter target and a rotating fan was employed. Time-slice diagrams demonstrate an FPAR of 36.6 MHz, validating its high-speed imaging capability ( Fig. 3b ). Additionally, thanks to the reduced beam divergence angle enabled by astigmatism correction via the AML, the system ultimately achieves a high spatial resolution of 6.46 mrad ( Figs. 3c-e ).
These results confirm that the developed AML-based LiDAR architecture realizes high-speed, high-resolution imaging over a 102° wide FOV, overcoming conventional trade-offs. It also features integration and miniaturization, holding broad application prospects in autonomous driving, UAV tracking, and integrated communication and sensing. In the future, the team will further optimize laser sources and encoding technologies, expand detection distance and environmental adaptability, advance lab-to-industry translation, and support the next-generation optical intelligent agent (OIA) [Appl. Phys. Lett., 2025, 127: 010501].
Light Science & Applications
Spectral-acoustic-coordinated astigmatic metalens for wide field-of-view and high spatiotemporal resolution 3D imaging