Scientists at the University of Rochester and Rochester Institute of Technology say they have developed a new type of squeezed phonon laser that can precisely control tiny vibrations, known as phonons, at the nanoscale.

Traditional lasers work by controlling photons, which are individual particles of light. In recent decades, researchers have extended that idea to other kinds of particles, including phonons, which are tiny units of vibration or sound.

The team said controlling phonons could open the way to new capabilities, including access to quantum effects such as entanglement.

Their findings were published in Nature Communications. The researchers said they guided these minute vibrations to act in a coordinated, laser-like way.

Nick Vamivakas, the Marie C. Wilson and Joseph C. Wilson Professor of Optical Physics with the URochester Institute of Optics, had previously demonstrated a phonon laser in 2019. That work used an optical tweezer in a vacuum to trap and levitate vibrations.

The new work focused on a problem common to all lasers: noise.

The researchers said unwanted fluctuations interfere with signals and limit accuracy, making it harder to use the system for precise measurements.

“While a laser looks to the naked eye like a steady beam, there’s actually a lot of fluctuation, which causes noise when you’re using lasers for measurement,” Vamivakas says. “By pushing and pulling on a phonon laser with light in the right way, we can reduce that phonon laser fluctuation significantly.”

To reduce that noise, the team used a technique called squeezing. The researchers said squeezing cuts the natural thermal noise in the phonon laser, which allows much more precise measurements.

According to Vamivakas, the approach can measure acceleration more accurately than methods based on traditional light lasers or radio frequency technologies.

The researchers said that added precision could make phonon lasers useful for measuring gravity and other forces with exceptional accuracy.

They also said the technology may have a role in future navigation systems. Researchers have proposed quantum compasses as highly accurate, “unjammable” alternatives to GPS that do not rely on satellites, and the team said phonon lasers could help move those ideas closer to reality.

The research was supported by the National Science Foundation.

📸 credit: Credit: University of Rochester / J. Adam Fenster