Optical Control of Bulk Phonon Modes in Crystalline Solids

Long-lived phonons within crystalline bulk acoustic wave (BAW) resonators have become coherent carriers of information, which can be utilized for a variety of scientific and technological applications. Herein, a brief introduction to the field of phonon control is given with an emphasis on bulk phonons at high frequencies within crystalline solids. In cavity optomechanics, the photons and phonons can be confined by material boundaries, yielding large optomechanical coupling rates at gigahertz (GHz) frequencies, but the spurious heating is detrimental to robust operation. Although electromechanical techniques can be used to access long-lived phonons in piezoelectric crystals, they are not suitable for the study of non-piezoelectric crystals. The phase-matched Brillouin interactions enable efficient optical access GHz frequency mechanical modes within macroscopic crystalline solids. Combining with the well-established framework of cavity optomechanics, efficient optical control of BAWs can be obtained. For optical phonons, strong spontaneous Raman cooling and heating based on the interaction between excitons and phonons are considered. In addition, the application of optical phonons in quantum memory at room temperature is introduced. The review finishes with a discussion of the research direction for bulk optomechanical systems and exciton-phonon coupling systems in the future.

Automated summary

Long-lived phonons within crystalline bulk acoustic wave (BAW) resonators have shown potential as carriers of information for scientific and technological applications. By utilizing phase-matched Brillouin interactions, efficient optical access to GHz frequency mechanical modes within macroscopic crystalline solids can be achieved. The review also discusses the future research direction for bulk optomechanical systems and exciton-phonon coupling systems.