Kartashov Yaroslav V, Vysloukh Victor A, Torner Lluis
Opt Lett. 2014 Jul 1;39(13):3826-9. doi: 10.1364/OL.39.003826.
We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.
我们在具有横向折射率梯度的多模周期性弯曲波导阵列中引入了布洛赫波拍频。这种新现象表现为布洛赫振荡幅度的周期性急剧增加，它伴随着由各个波导引导的模式的共振转换。当共振模式转换的长度大大超过布洛赫振荡的纵向周期时，发现布洛赫波拍频最为明显。当波导弯曲幅度减小时，拍频频率降低，而拍频幅度受到从弗洛凯 - 布洛赫晶格谱的第二允许带出现的布洛赫振荡幅度的限制。
