arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1509.02187nlin.PS
收藏

非局域光介质中色散shock waves的辐射

Radiating dispersive shock waves in nonlocal optical media

Gennady A. El, Noel F. Smyth

摘要:

我们考虑描述相干光束在双折射液晶中传播的方程组的阶跃Riemann问题,双折射液晶是描述非线性波在许多不同物理应用中传播的一般系统。当光束方程为散焦非线性薛定谔方程时,在此初始条件下产生的色散激波(DSW)与散焦非线性薛定谔方程的标准DSW解有很大差别。特别地,我们发现DSW具有正极性,并产生共振辐射在其前面传播,值得注意的是,DSW的铅孤子的速度由经典激波速度决定。使用WKB近似获得辐射波列的解。它示出,对于足够小的初始跳跃的DSW是渐近的Korteweg-de Vries方程与五阶色散,这明确地显示了共振产生的辐射的DSW的前面。所构造的渐近理论与直接数值模拟的结果吻合良好。

英文摘要:

We consider the step Riemann problem for the system of equations describing the propagation of a coherent light beam in nematic liquid crystals, which is a general system describing nonlinear wave propagation in a number of different physical applications. While the equation governing the light beam is of defocusing nonlinear Schrödinger equation type, the dispersive shock wave (DSW) generated from this initial condition has major differences from the standard DSW solution of the defocusing nonlinear Schrödinger equation. In particular, it is found that the DSW has positive polarity and generates resonant radiation which propagates ahead of it. Remarkably, the velocity of the lead soliton of the DSW is determined by the classical shock velocity. The solution for the radiative wavetrain is obtained using the WKB approximation. It is shown that for sufficiently small initial jumps the nematic DSW is asymptotically governed by a Korteweg-de Vries equation with fifth order dispersion, which explicitly shows the resonance generating the radiation ahead of the DSW. The constructed asymptotic theory is shown to be in good agreement with the results of direct numerical simulations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑