Light in slow motion

You may have heard about billion- and trillion-FPS cameras in the past, but those were likely “streak cameras” that do a bit of cheating to achieve those numbers. If a pulse of light can be replicated perfectly, then you could send one every millisecond but offset the camera’s capture time by an even smaller fraction, like a handful of femtoseconds (a billion times shorter). You’d capture one pulse when it was here, the next one when it was a little further, the next one when it was even further, and so on. The end result is a movie that’s indistinguishable in many ways from if you’d captured that first pulse at high speed.

This is highly effective — but you can’t always count on being able to produce a pulse of light a million times the exact same way. Perhaps you need to see what happens when it passes through a carefully engineered laser-etched lens that will be altered by the first pulse that strikes it. In cases like that, you need to capture that first pulse in real time — which means recording images not just with femtosecond precision, but only femtoseconds apart. That’s what the T-CUP method does.

Via Michael J. Coffey.

Originally shared by Gible Fog
https://techcrunch.com/2018/10/12/at-10-trillion-frames-per-second-this-camera-captures-light-in-slow-motion/