Researchers at the University of Colorado at Boulder have developed a quantum stopwatch to count single photons.
The team’s new development will improve imaging technologies, from sensors that display entire forests and mountain ranges to more accurate devices that can diagnose Alzheimer’s and cancer. All these are visual and technical means of information transmission, which depend on the accuracy of information transmission. The new development will help improve the quality of their work.
Bowen Lee, lead author of the new study, said they used a technology called Time Correlated Single Photon Counting (TCSPC) in their work.
This is similar to the timer used to count the results of athletes: Scientists first direct a laser beam at a sample of their choice, from individual proteins to a massive geological formation, and then record the photons that bounce off them. The more photons the researchers collect, the more they can learn about this object.
TTCSPC gives you the total number of photons and shows you the time each photon hits your detector, so the new device is a bit like a stopwatch.
Bowen Lee, lead author of the new study.
In order to improve this technology, the authors of the new work used a temporary lens optical instrument to measure the arrival of photons with an accuracy more than 100 times superior to existing instruments.
To understand how this works, imagine two photons as two runners moving close and very fast so that neither is inferior to the other. Lee and his colleagues send both of these photons through a temporary lens made up of loops of silica filaments. In the process, one of the photons slows down while the other accelerates. There is a large gap between the runners, which can be fixed by the detector.