Single-shot three-dimensional imaging with a metasurface depth camera

Abstract: Depth imaging is vital for many emerging technologies with applications in augmented reality, robotics, gesture detection, and facial recognition. These applications, however, demand compact and low-power systems beyond the capabilities of state-of-the-art depth cameras. Here, we leverage ultrathin dielectric metasurfaces to demonstrate a solution that, with a single surface, replicates the functionality of a high-performance depth camera typically comprising a spatial light modulator, polarizer, and three lenses. Using cylindrical nano-scatterers that can arbitrarily modify the phase of an incident wavefront, our metasurface passively encodes two complementary optical responses to depth information in a scene with a single camera snapshot. By decoding the captured data in software, our system produces a fully reconstructed image and transverse depth map of three-dimensional scenes with a fractional ranging error of 1.7%. We demonstrate the first visible wavelength and polarization-insensitive metasurface depth camera, representing a significant form factor reduction for such systems.