The LiDAR sensor serves as the eyes for autonomous vehicles by assisting in determining the distance to surrounding objects as well as the speed or direction of the vehicle. LiDAR recognizes objects by shining light upon them. The sensor must be able to sense the sides and back of the car in addition to the front in order to recognize unusual road conditions and react swiftly. Since the LiDAR sensor turned, it was hard to see both the front and back of the vehicle at the same time.
Professor Junsuk Rho (Departments of Mechanical Engineering and Chemical Engineering) and Ph.D. candidates Gyeongtae Kim, Yeseul Kim, and Jooyeong Yun (Department of Mechanical Engineering) from POSTECH worked with Professor Inki Kim (Department of Biophysics) from Sungkyunkwan University to create a fixed LiDAR sensor with a 360° view to solve this problem.
Since this new sensor is made of the metasurface, an incredibly thin flat optical device that is only one thousandth the thickness of a human hair strand, it is gaining interest as a novel technology that can enable an ultra-small LiDAR sensor.
The metasurface can significantly increase the LiDAR’s field of vision for three-dimensional object recognition. The study team was able to increase the LiDAR sensor’s viewing angle to 360° by making design changes and irregularly spacing the nanostructures that make up the metasurface.
By scattering more than 10,000 dot arrays of light from the metasurface to the objects and taking pictures of the irradiation point pattern, it is possible to get three-dimensional information about objects in all 360° directions.
Face Recognition on the iPhone uses this kind of LiDAR sensor (Face ID). The iPhone uses a device called a “dot projector” to make the point sets, but it has some problems, such as a big size and less consistency in the point pattern.
The discovery is important because nano-optical components are used in the technology that enables smartphones, augmented and virtual reality (AR/VR) glasses, and autonomous robots to recognize the 3D information of their surroundings. As the key technology for future displays, nanoimprint technology makes it simple to print the new device on a variety of curved surfaces, including flexible substrates and glasses. This enables applications for AR glasses.
We have demonstrated that we can regulate the propagation of light in all directions by creating a technology that is more sophisticated than the traditional metasurface devices, according to Professor Junsuk Rho. He went on to say that this new technology will make it possible to make a full-space, ultra-compact 3D image sensor platform.
The Samsung Research Funding & Incubation Center helped pay for this study, which was just published in Nature Communications.
