Researchers build a phonon laser that could one day replace GPS

Yesterday 11:40

By: Dakir Madiha

Researchers build a phonon laser that could one day replace GPS

Researchers at the University of Rochester and the Rochester Institute of Technology have developed a new type of laser that manipulates sound particles rather than light, a breakthrough they say could eventually contribute to navigation systems immune to jamming. The findings, published March 30 in Nature Communications, describe the first thermomechanically squeezed bimodal phonon laser, a device that produces coherent, low-noise vibrations using an optically levitated nanoparticle.

A phonon is the quantum unit of vibration, or sound, analogous to the photon in light. The team, led by Nick Vamivakas of Rochester's Institute of Optics, traps a tiny silica nanosphere in vacuum using an optical tweezer, a highly focused laser beam, and manipulates the particle's mechanical oscillations until they synchronize, replicating the coherent output of a conventional laser.

The key advance lies in a technique called squeezing, which reduces the thermal noise present in any mechanical system. Vamivakas explained in a university press release that pushing and pulling on a phonon laser with light in the right way can substantially reduce fluctuations in its output. Below the device's operating threshold, both oscillation modes remain in thermal states; above it, they transition to coherent, laser-like behavior while retaining the low-noise properties of a squeezed source.

Vamivakas and his collaborator Mishkat Bhattacharya, a theoretical quantum optics researcher at RIT, first demonstrated an optical tweezer phonon laser in 2019 in a paper published in Nature Photonics. The new device extends that earlier work by combining lasing with bimodal squeezing in a phononic system for the first time, producing what the researchers describe as a bright source of coherent and classically correlated phonons.

It is the noise reduction that gives the technology potential beyond the laboratory. Vamivakas said the squeezed phonon laser could enable measurements of gravity and other forces with absolute precision, capabilities that are central to inertial navigation. Scientists have long explored quantum compasses as unjammable alternatives to GPS that operate without satellites, and Vamivakas said he is intrigued by the possibility that the phonon laser could be a step toward such systems.

The research fits within a broader surge of interest in quantum navigation. Groups around the world are developing satellite-free positioning technologies for both military and civilian use, driven by growing concerns about GPS vulnerability to electronic warfare. The Rochester team's work, funded by the National Science Foundation, represents what the authors describe as a necessary step in the long-term development of a quantum extension of their device.