This technology increases the brightness of the fundamental frequency phonon laser and its higher harmonics by more than 3 orders of magnitude, and narrows the line width and voltage equalization by more than 5 orders of magnitude. The phonon coherence represented by the second-order correlation function has also been significantly improved, and the quality factor of high-order harmonics has been increased to the 1e6 level for the first time, reaching the highest level at the mesoscopic scale. More importantly, the frequency stability of the nonlinear phonon laser has been improved by five orders of magnitude, increasing the capture lifetime of the microspheres from several minutes to more than one hour.

In 2023, the National University of Defense Technology cooperated with Hunan Normal University and other institutions to realize the nonlinear multicolor phonon laser for the first time in the world, pushing the research of phonon lasers into the nonlinear region. This opens the door to basic research such as high-order nonlinear phonon effects and quantum acoustics, and applied research such as phonon laser frequency combs, underwater coherent phonon laser sensing and communications. Researchers said that phonon lasers are a very cutting-edge research direction in quantum physics. Compared with photon lasers of the same frequency, phonon lasers have shorter wavelengths and low transmission losses in opaque media, so they have unique advantages in fields such as quantum science, underwater acoustic engineering, and life sciences.