通过光子与横向光频支声子直接耦合产生超声

Ultrasonic generation via direct interaction between photons and phonons in anharmonic lattice of ionic crystals

详细地讨论了通过光子与横向光频支（TO）声子直接耦合产生高频超声问题。着重研究如下的原则性的实验方案：在构成共振腔主体的离子晶体中掺入某种活化原子（犹如固体激光器中受到抽运的杂质原子），其受激辐射的光能用于激发TO声子，从而获得超声振动向腔外的输出。分析的结果说明，为保证运行的稳定性，体现在声子与光子的非线性耦会以及声子间耦合的晶格振动非简谐性是必要的。对这种光一声装置的工作物质的探索。

We present a theory of ultrasonic gelleration via direct interaction of transverse optic (TO) phonons withphotons in anharmonic lattice of ionic crystals. There are two methods of supplying light energy for the excitation of TOlattice wave as a high frequency ultrasound: (1) incident light comes from the source outside the cavity fulfilled withionic crystal medium; (2) photon mode of the cavity possesses the gain of amplilication by stimulated radiation of activeatoms doping in the medium. More attelltion is drawn to the case (2). The working system of case (2), as a mixture oflasing action and ultrasonic generation, has the threshold phenomena like usual laser. And the linear stability analysisshows that the nonlinear phonon-photon coupling and the interaction among phonons themselves, both of which reflectthe anharmonicity of lattice vibration, are necessary to the stable ultrasonic output. So this laser-ultrasonic generationmixture would be also a measure to investigate the lattice-dynamic nonlinearity and correlated electromagnetic propertiesof ionic crvstals.