  We propose and experimentally demonstrate parallel LiDAR using random
intensity fluctuations from a highly multimode laser. We optimize a degenerate
cavity to have many spatial modes lasing simultaneously with different
frequencies. Their spatio-temporal beating creates ultrafast random intensity
fluctuations, which are spatially demultiplexed to generate hundreds of
uncorrelated time traces for parallel ranging. The bandwidth of each channel
exceeds 10 GHz, leading to a ranging resolution better than 1 cm. Our parallel
random LiDAR is robust to cross-channel interference, and will facilitate
high-speed 3D sensing and imaging.
