An ultrafast 3D camera developed in the lab of Lihong Wang at Caltech is capable of capturing the movement of light in three dimensions. The camera records in stereo at 100 billion frames per second. The research builds upon previous endeavors by Wang to develop compressed ultrafast photography (CUP) cameras, and relies on the same underlying technology. In CUP, all frames of the video are captured in one action without repeating the event. In this instance, Wang added stereoscopic functionality to the device to allow it to see in 3D. However, he didn’t do this by adding a second lens. “We have one lens, but it functions as two halves that provide two views with an offset,” Wang said. “Two channels mimic our eyes.” The data from those two channels feeds into a computer system that processes the information into one three-dimensional movie, similar to how the brain combines the information coming in from the eyes into one image. The technology has proved capable of capturing the polarization of lightwaves, which refers to the direction in which the waves vibrate as they travel. Wang expects the technology to be useful in a wide variety of applications; in particular, he hopes that it will help researchers understand the physics of sonoluminescence, a phenomenon in which sound waves create tiny bubbles in water or other liquids. As the bubbles collapse after their formation, they emit a burst of light. “Some people consider this one of the greatest mysteries in physics,” he said. “When a bubble collapses, its interior reaches such a high temperature that it generates light. The process that makes it happen is very mysterious because it all happens so fast, and we’re wondering if our camera can help us figure it out.” The research was published in Nature Communications (www.doi.org/10.1038/s41467-020-19065-5).