Sukhorukov Andrey A, Kivshar Yuri S
Nonlinear Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, ACT 0200 Canberra, Australia.
Phys Rev Lett. 2006 Dec 8;97(23):233901. doi: 10.1103/PhysRevLett.97.233901. Epub 2006 Dec 4.
We demonstrate that propagation direction and velocity of optical pulses can be controlled independently in the structures with multiscale modulation of the refractive index in transverse and longitudinal directions. We reveal that, in arrays of waveguides with phase-shifted Bragg gratings, the refraction angle does not depend on the speed of light, allowing for efficient spatial steering of slow light. In this system, both spatial diffraction and temporal dispersion can be designed independently, and we identify the possibility for self-collimation of slow light when spatial diffraction is suppressed for certain propagation directions. We also show that broadening of pulses in space and time can be eliminated in nonlinear media, supporting the formation of slow-light optical bullets that remain localized irrespective of propagation direction.
我们证明，在横向和纵向折射率具有多尺度调制的结构中，光脉冲的传播方向和速度可以独立控制。我们发现，在带有相移布拉格光栅的波导阵列中，折射角不依赖于光速，这使得慢光能够实现高效的空间转向。在该系统中，空间衍射和时间色散都可以独立设计，并且我们确定，当特定传播方向上的空间衍射被抑制时，慢光存在自准直的可能性。我们还表明，在非线性介质中可以消除脉冲在空间和时间上的展宽，这有助于形成无论传播方向如何都能保持局域化的慢光光学子弹。
