Institute of photonics and optical fiber technology, Harbin University of Science and Technology, Harbin 150080, China.
National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150001, China.
Sci Rep. 2017 Jan 10;7:40526. doi: 10.1038/srep40526.
Stimulated Brillouin scattering (SBS), a fundamental nonlinear interaction between light and acoustic waves occurring in any transparency material, has been broadly studied for several decades and gained rapid progress in integrated photonics recently. However, the SBS noise arising from the unwanted coupling between photons and spontaneous non-coherent phonons in media is inevitable. Here, we propose and experimentally demonstrate this obstacle can be overcome via a method called orbital angular momentum mode division filtering. Owing to the introduction of a new distinguishable degree-of-freedom, even extremely weak signals can be discriminated and separated from a strong noise produced in SBS processes. The mechanism demonstrated in this proof-of-principle work provides a practical way for quasi-noise-free photonic-phononic operation, which is still valid in waveguides supporting multi-orthogonal spatial modes, permits more flexibility and robustness for future SBS devices.
受激布里渊散射（SBS）是一种在任何透明材料中光与声波之间发生的基本非线性相互作用，已经被广泛研究了几十年，并在最近的集成光子学中取得了快速进展。然而，SBS 噪声是由于介质中光子和自发非相干声子之间的不希望的耦合而不可避免的。在这里，我们提出并通过一种称为轨道角动量模式分束滤波的方法来证明这个障碍是可以克服的。由于引入了一个新的可区分自由度，即使是非常弱的信号也可以从 SBS 过程中产生的强噪声中被区分和分离出来。该原理验证工作中展示的机制为实现准无噪声光子-声子操作提供了一种实用的方法，这种方法在支持多正交空间模式的波导中仍然有效，为未来的 SBS 器件提供了更大的灵活性和鲁棒性。
