LiDARs are crucial sensors widely applied in terrain exploration, species detection, autonomous driving, and numerous other fields. Its core technology mainly consists of three aspects: ranging, steering, and imaging. At present, the all-solid-state LiDAR without any mechanical moving parts is a hot research area with significant application value. However, the two main types of all-solid-state LiDAR, namely the optical switch-based LiDAR and the optical phased array (OPA) LiDAR, face the problem of limited scanning angles. Therefore, the design of a LiDAR beam steering system incorporating a new optical system holds broad application prospects. The large field-of-view scanning achieved with conventional optical systems still faces the problem that the beam is dispersed in one direction, and it is difficult to maintain collimation simultaneously in the horizontal and vertical directions. To solve this problem, we propose an optical switch-based LiDAR beam steering system that includes both a metalens and a cone lens. The results show that the system can achieve the designed horizontal field of view of 360° and a vertical field of view of 8° while maintaining a beam divergence angle of approximately 0.018° in both the horizontal and vertical directions.

Our designed beam steering system of an optical switch-based LiDAR consists of three main components: the photonics integrated circuits, the metalens, and the cone lens. In the design of the photonic integrated circuits, we simulate and analyze a single grating coupler using the finite difference time domain (FDTD) method. The divergence angles of the emitted beam in the X and Y directions for a single coupler are 11.1° and 10.9°, respectively. For the metalens, we first conduct simulations of each cell and construct the overall model of the metalens through calculations. We then analyze it by comparing the desired target phase distribution with the phase distribution achieved by the constructed metalens. The cone lens has conical upper and lower surfaces, which is scaled to meet the requirement for total internal reflection on the s₂ surface in our design. It serves as a macroscopic optical element that can be fabricated through single-point diamond machining or molding techniques, highlighting the high feasibility of our design. In this design, the key factor we consider is to expand the vertical field of view while maintaining the horizontal field of view of 360°. In some conventional systems, it is difficult to ensure collimation and narrow beam divergence in both horizontal and vertical directions, and some even use mechanical moving parts to achieve this. According to the characteristics of the optical switch-based LiDAR, we perform beam steering separately for each vertical field of view. Due to the different effects of the metalens, the beams are in total reflection at different positions on the inner surface of the cone lens and are collimated after emission. We well design the overall model in the article to solve this problem. On this basis, we analyze the optical system and obtain results such as the system design schematic and spot diagram, and view the irradiance distribution and luminous intensity distribution curves. We demonstrate the patterns of beam steering by switching between different sections of the grating couplers at four different positions.

We design an optical switch-based LiDAR beam steering system that contains photonic integrated circuits, a metalens, and a cone lens. The photonic integrated circuits consist of an array of optical switches and grating couplers, which are arranged in the form of eight ring arrays, and beam steering is achieved by switching between the grating couplers at different positions. In the study, we design each module separately and combine them for overall analysis, thus confirming the results of our design and demonstrating the possibilities of real applications. By applying our designed system, the horizontal field of view can be expanded to 360° while maintaining an 8° field of view in the vertical direction. The resolution of the system is 0.7° in the horizontal direction and 8° in the vertical direction. The results show that the system has a narrow beam divergence angle of 0.018°×0.018°.

We propose and design a beam steering system for optical switch-based LiDAR. Its core advantage is the ability to achieve a 360° horizontal range and an 8° vertical field of view compared to conventional LiDAR optical scanning systems. The system demonstrates strong application potential by utilizing the smallest possible components and a compact structure to achieve high resolution and narrow beam divergence in both the horizontal and vertical directions. In the future, we will further focus on the design of the photonic chips, and expanding the array scale will contribute to widening the field of view in the vertical direction.