Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, Via Valleggio 11, IT-22100 Como, Italy.
Sci Rep. 2012;2:932. doi: 10.1038/srep00932. Epub 2012 Dec 6.
Solitons are of fundamental importance in photonics due to applications in optical data transmission and also as a tool for investigating novel phenomena ranging from light generation at new frequencies and wave-trapping to rogue waves. Solitons are also moving scatterers: they generate refractive index perturbations moving at the speed of light. Here we found that such perturbations scatter light in an unusual way: they amplify light by the mixing of positive and negative frequencies, as we describe using a first Born approximation and numerical simulations. The simplest scenario in which these effects may be observed is within the initial stages of optical soliton propagation: a steep shock front develops that may efficiently scatter a second, weaker probe pulse into relatively intense positive and negative frequency modes with amplification at the expense of the soliton. Our results show a novel all-optical amplification scheme that relies on soliton induced scattering.
孤子在光子学中具有重要意义，因为它们在光数据传输中有应用，而且还是研究从新频率的光产生到波捕获到反常波等新现象的工具。孤子也是移动散射体：它们以光速产生折射率扰动。在这里，我们发现这种扰动以一种不寻常的方式散射光：正如我们使用首次 Born 近似和数值模拟所描述的那样，通过正负频率的混合来放大光。这些效应可能观察到的最简单情况是在光孤子传播的初始阶段：形成陡峭的冲击波，这可能有效地将第二个较弱的探测脉冲散射到相对较强的正负频率模式中，代价是牺牲孤子。我们的结果显示了一种新颖的全光放大方案，该方案依赖于孤子诱导的散射。
