In conventional sensing methods, noise is always a problem, especially in systems that are meant to detect changes in their environment that are hardly bigger or even smaller than the noise in the system. Encountering this problem in his experiments with interacting photons, AMOLF physicist Said Rodriguez thought of a way around it. In an article that will be published in Physical Review Applied, he demonstrates how noise can be turned into a resource for optical sensing rather than a problem.
“Using noise to improve sensing methods is counterintuitive,” says Said Rodriguez. “Imagine trying to see the largest letters in a vision test and failing. Then, imagine how a sudden earthquake helps you to see even the smallest letters in the test. Shaking air molecules between the screen and your eyes help you to read the tiny letters. This is similar to what happens in the optical sensor that I propose.”
Rodriguez works with resonant systems that can detect tiny changes in their environment. A typical optical sensor is based on a cavity, an empty space with laser light resonating between two mirrors. The resonance frequency depends on what happens in and around the cavity.