Researchers at CU Boulder Design New Quantum ‘Stopwatch’ that Can Improve Imaging Technologies

(Colorado.edu) Researchers at CU Boulder have designed one of the most precise stopwatches yet.
The team’s invention could lead to big improvements in a range of imaging technologies—from sensors that map out entire forests and mountain ranges to more detailed devices that can diagnose human diseases like Alzheimer’s and cancer.
Bowen Li, lead author of the new study, said that the research focuses on a widely-applied technology called time-correlated single photon counting (TCSPC). It works a bit like the timers you see at the Olympics: Scientists first shine a laser light at a sample of their choice, from individual proteins all the way up to a massive geologic formation, then record the photons that bounce back to them. The more photons researchers collect, the more they can learn about that object.
“TCSPC gives you the total number of photons. It also times when each photon hits your detector,” said Li, a postdoctoral researcher in the Department of Electrical, Computer and Energy Engineering (ECEE) at CU Boulder. “It works like a stopwatch.”
Now, that stopwatch has gotten better than ever. Using an ultrafast optics tool called a “time lens,” Li and his colleagues show that they can measure the arrival of photons with a precision that’s more than 100 times better than existing tools.
The researchers still have some work to do before time lenses become common in scientific labs. But they hope that their tool will one day allow humans to view objects, from the very small to the very large, all with a clarity that was previously impossible.