Acoustic lasers, created by manipulating phonon particles, have great potential for applications in medicine and deep-sea exploration.
Chinese scientists have made important progress in developing more powerful lasers using sound waves instead of light, SciTechDaily reported on October 4. New research published in the journal eLight.
Conventional lasers are inherently interesting. They were first created by humans in the 1960s. “Lasers produce a narrow beam of light in which all the light waves have very similar wavelengths. The laser’s light waves travel together, the Their peaks are all aligned, or in phase. This is why the laser beams are very narrow, very bright and can be focused into a very small spot,” NASA explains.
Although sound and light have differences, physicists have worked to create acoustic lasers by manipulating phonons.
“Similar to photons that make up beams of light, phonons – indivisible quantum particles – make up beams of sound. These particles arise from the collective motion of millions and billions of atoms, like ‘pitch waves’. movement’ in a sports arena due to the movement of thousands of fans. When you listen to a song, you’re hearing a stream of these microscopic quantum particles,” said Andrew N. Cleland, professor in the School of Engineering. Molecular Pritzker of the University of Chicago, explains.
Originally used to explain the heat capacity of solids, phonons were predicted to obey the same quantum mechanical rules as photons. However, phonon production and detection technology is still far behind photons.
Previously, phonon lasers formed from small objects that were affected by weak and imprecise sound waves, reducing their usefulness. The new method helps overcome this problem by “locking” the sound waves in a more stable and powerful state.
In new research, a group of Chinese scientists took a silicon oxide (SiO2) microsphere and suspended it with beams of light. This vibrates the sphere, creating an internal beep-like sound with a very high pitch and sound beyond human hearing. Next, they began manipulating the vibrating microsphere with an alternating electric field to create resonance, amplifying the sound waves 1,000 times at those frequencies.
The experiment took place in a vacuum to better measure sound waves (confined inside the microsphere), bringing us closer to creating an acoustic laser that could be used for many purposes, from exploration and mapping acoustic oceanography to improved medical imaging techniques. Acoustic lasers can also have applications in materials science, quantum computing and many other fields.