Researchers showed a significant coupling between light and high-frequency acoustic vibrations in a silica microresonator. The results open the door to creative uses of light-sound coupling in creating new technologies. It involves Brillouin scattering, a well-known nonlinear occurrence first identified in the 1920s.
In sensing equipment and communications, producing a strong coupling of photons and high-frequency phonons in the anti-Stokes process is useful. The establishment of that strong-coupling system has been complex. The British squad made a wise material choice at the outset. They developed a resonator that can sustain two light modes, one at the higher anti-Stokes frequency and one at the lower pump frequency of 1550 nm.
They found a crucial indicator of optomechanical interaction in an optical resonator system between pump photons and 11-GHz acoustic phonons. Using a heterodyne detection setup, the researchers evaluated the resonator’s spectra at different pump powers. By tweaking the cavity shape and materials and running tests at cryogenic temperatures, the efficacy of the light-sound coupling could be enhanced even more. These developments “could provide a rich avenue for developing a suite of new technologies, including coherent X-band microwave-to-optical conversion and classical and quantum information-processing applications and sensors,” the researchers write.
Related Content: Quantum Light – Super-Fast Detection With Photonic Chips