Long-range all-solid-state flash LiDAR sensor for autonomous driving

LiDAR sensors have gathered lot of interest in the field of autonomous driving. Still, the offering of mass-produced, small form-factor all-solid-state LiDAR sensors remain scarce. Furthermore, most of the sensor applications are currently designed for short-range (<50 feet) and medium-range (50-300 feet) applications. There’s a requirement for an efficient solution for long range LiDAR sensor that can be used to monitor the road in front of the vehicle. It must be powerful enough to cover long ranges (300 –800 feet) with high enough refresh rate and minimize detection noise while maintaining eye-safety. For these requirements a flash type LiDAR illuminator would be ideal for fast data collection and minimizing the power density. We propose a novel solution for long-range all-solid-state LiDAR application by using a segmented flash illumination and readout concept utilizing state-of-the-art laser diode technology and CMOS imaging at <1μm wavelength. Employing a stack of individually addressable high-power nanostack arrays as the illumination source allows to produce series of 3D flashes, which significantly improves the transverse resolution of the LiDAR, while at the same time mitigating the requirements for the smallest detector pixel size. The design makes it possible to achieve eye-safety even when targeting long ranges with silicon-based detectors. With this approach, the high illumination intensity requirements for the long range can be fulfilled while at the same time maintaining eye-safe operation. Additionally, the design allows for higher refresh rates while the heat management and the power consumption of the system can be minimized.