Bahar Eyal, Ding Xiaoyue, Dahan Asaf, Suchowski Haim, Moses Jeffrey
Opt Express. 2018 Oct 1;26(20):25582-25601. doi: 10.1364/OE.26.025582.
We introduce the concept of adiabatic four-wave mixing (AFMW) frequency conversion in cubic nonlinear media through an analogy to dynamics in quantum two-level systems. Rapid adiabatic passage in four-wave mixing enables coherent near-100% photon number down-conversion or up-conversion over a bandwidth much larger than ordinary phase-matching bandwidths, overcoming the normal efficiency-bandwidth trade-off. We develop numerical methods to simulate AFWM pulse propagation in silicon photonics and fiber platforms as examples. First, we show that with a longitudinally varying silicon waveguide structure, a bandwidth of 70 nm centered at 1820 nm can be generated with 90% photon number conversion. Second, we predict the broadband generation of nanojoule energy, 4.2-5.2 μm mid-infrared light in a short, linearly tapered fluoride step-index fiber. We expect the AFWM concept to be broadly applicable to cubic nonlinear platforms, for applications as diverse as bright ultrafast light pulse generation, sensing, and conversion between telecommunications bands.
我们通过类比量子二能级系统中的动力学过程，介绍了立方非线性介质中的绝热四波混频（AFMW）频率转换概念。四波混频中的快速绝热通道能够在比普通相位匹配带宽大得多的带宽上实现相干的近100%光子数下转换或上转换，克服了常规的效率-带宽权衡。我们开发了数值方法来模拟硅光子学和光纤平台中的AFWM脉冲传播，作为示例。首先，我们表明，通过纵向变化的硅波导结构，在1820 nm中心波长处可产生70 nm的带宽，光子数转换率为90%。其次，我们预测在短的线性锥形氟化物阶跃折射率光纤中可产生宽带纳米焦耳能量、4.2 - 5.2μm的中红外光。我们期望AFWM概念能广泛应用于立方非线性平台，用于诸如明亮超快光脉冲产生、传感以及电信频段之间的转换等各种应用。
