Nothing moves too fast for Andreas Velten’s camera—not even light. Last year Velten, who built the camera while a postdoc at the MIT Media Lab’s Camera Culture Group, made a video of laser light zipping through a plastic soda bottle. Capturing the equivalent of 600 billion frames per second, the slow-mo footage showed a ghostly light moving from one end of the bottle to the other. Equally remarkable, the camera can harness light reflected off surfaces to see around corners. Because the camera is so fast, it can detect how long it takes the different light rays to reach it, and an image can be reconstructed from that information.
It’s not just amazing gimmickry. Velten’s technology could lead to ultrafast medical imagers and scanners that use light instead of sound to detect tiny imperfections, whether in cancerous tissue or in airplane wings. It also suggests an approach to taking high-quality photos of scenes lit only by the tiny flash on a cell phone.
Velten’s table-mounted camera uses 672 carefully positioned and timed optical sensors, each capable of capturing a trillionth of a second’s worth of reflected laser light. The technical advance was figuring out how to modify a streak camera, a common piece of equipment in chemistry labs that measures the optical properties of laser light. That type of camera can capture only one horizontal line, or “streak,” of light at a time. Velten, combining his expertise in optics and computer science, developed custom software to repeat the scan over and over and combine the resulting data.
Now at the Morgridge Institute at the University of Wisconsin, Velten is applying his ultrafast imaging techniques to help develop new types of microscopy and biomedical imaging for clinical applications. One of the tools he envisions, for example, is a less invasive endoscope that could travel shorter distances to see deeper inside the body.