Bragg scattering of polaritons by a coherent acoustic wave is mediated and strongly enhanced by the exciton states resonant with the acoustic and optic fields in the intraband and interband transitions, respectively. In this case, in contrast with conventional acousto-optics, the resonantly enhanced Bragg spectra reveal the multiple orders of diffracted light. For polaritons in GaAs microcavities driven by a surface acoustic wave of νSAW=1 GHz and Iac≲100 W/cm2 the main acoustically induced band gap can be as large as ΔMCac≃0.6 meV and the Bragg replicas up to n=3 can be observed.
展开▼
机译：相干声波对极化子的布拉格散射通过分别与带内和带间跃迁中的声场和光场共振的激子态来介导和增强。在这种情况下，与传统的声光相反，共振增强的布拉格光谱揭示了多级衍射光。对于由表面声波½SAW = 1 GHz和Iac≥100 W / cm2驱动的GaAs微腔中的极化子，主要的声感应带隙可以大到ΔMCac≥0.6 meV，并且布拉格副本最多n =可以观察到3。
展开▼
