Ultrasonics. 2015 Mar;57:153-8. doi: 10.1016/j.ultras.2014.11.005.
The phenomenon of collinear correlated photon pairs diffraction by an ultrasonic wave is investigated within Raman-Nath and intermediate region. The numbers of single photons and photon pairs counts in discrete diffraction orders were measured as functions of the Raman-Nath parameter. Similarly, the number of coincidence photon counts in separate diffraction orders was also investigated. It was shown experimentally that the phenomenon of photon pairs diffraction by an ultrasonic wave happens at angles identical to those corresponding to single photons diffraction. It was also demonstrated that in case of Raman-Nath diffraction the number of photon pairs in a selected, n(th), diffraction order varies with the Raman-Nath parameter changes as an n(th) order Bessel function of the first kind, raised to the fourth power. Whilst in the so-called intermediate diffraction zone, the number of diffracted photon pairs varies as squared intensity of a diffracted light beam consisting of single photons. Moreover, it was revealed that correlations between photons in selected diffraction orders change with the Raman-Nath parameter variation as products of relevant intensities of light in the considered diffraction orders. Finally, it should be emphasized that the presented formulae describing diffraction of collinear correlated proton pairs by an ultrasonic wave are in a very good agreement with corresponding experimental data, for both Raman-Nath and intermediate diffraction.
在喇曼-纳斯和中间区域内，研究了超声作用下共线相关光子对的衍射现象。作为喇曼-纳斯参数的函数，测量了单光子和光子对在离散衍射级中的计数，以及在单独衍射级中的符合光子计数。实验表明，超声波作用下的光子对衍射现象发生在与单光子衍射对应的相同角度。还表明，在喇曼-纳斯衍射的情况下，所选第 n 个衍射级中的光子对数量随喇曼-纳斯参数的变化而变化，其变化形式为第一类贝塞尔函数的第 n 次幂的四次方。而在所谓的中间衍射区，衍射光子对的数量与由单光子组成的衍射光束的强度的平方成正比。此外，还揭示了所选衍射级中光子之间的相关性随喇曼-纳斯参数的变化而变化，其变化形式为考虑的衍射级中相关光强度的乘积。最后，应该强调的是，对于喇曼-纳斯和中间衍射两种情况，描述共线相关质子对被超声波衍射的公式与相应的实验数据非常吻合。
