Tran Truong X, Biancalana Fabio
Dept. of Physics, Le Quy Don University, 236 Hoang Quoc Viet Str., 10000 Hanoi, Vietnam.
Opt Express. 2013 Jul 29;21(15):17539-46. doi: 10.1364/OE.21.017539.
We numerically demonstrate the formation of the spatiotemporal version of the so-called diffractive resonant radiation generated in waveguide arrays with Kerr nonlinearity when a long pulse is launched into the system. The phase matching condition for the diffractive resonant radiation that we have found earlier for CW beams also works well in the spatiotemporal case. By introducing a linear potential, one can introduce a continuous shift of the central wavenumber of a linear pulse, whereas in the nonlinear case one can demonstrate that the soliton self-wavenumber shift can be compensated by the emission of diffractive resonant radiation, in a very similar fashion as it is done in optical fibers. This work paves the way for designing unique optical devices that generate spectrally broad supercontinua with a controllable directionality by taking advantage of the combined physics of optical fibers and waveguide arrays.
我们通过数值模拟展示了，当一个长脉冲注入具有克尔非线性的波导阵列系统时，所谓的衍射共振辐射的时空形式的形成。我们之前针对连续波光束所发现的衍射共振辐射的相位匹配条件，在时空情形下同样适用。通过引入一个线性势，可以使线性脉冲的中心波数产生连续偏移，而在非线性情形下，可以证明孤子的自波数偏移能够通过衍射共振辐射的发射得到补偿，这与在光纤中所做的情况非常相似。这项工作为设计独特的光学器件铺平了道路，这些器件通过利用光纤和波导阵列的综合物理特性，能够产生具有可控方向性的光谱宽度极宽的超连续谱。
