Sheng Chong, Bekenstein Rivka, Liu Hui, Zhu Shining, Segev Mordechai
National Laboratory of Solid State Microstructures &School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, China.
Department of Physics and Solid State Institute, Technion, Haifa 32000, Israel.
Nat Commun. 2016 Feb 22;7:10747. doi: 10.1038/ncomms10747.
The past decade has witnessed remarkable progress in wavefront shaping, including shaping of beams in free space, of plasmonic wavepackets and of electronic wavefunctions. In all of these, the wavefront shaping was achieved by external means such as masks, gratings and reflection from metasurfaces. Here, we propose wavefront shaping by exploiting general relativity (GR) effects in waveguide settings. We demonstrate beam shaping within dielectric slab samples with predesigned refractive index varying so as to create curved space environment for light. We use this technique to construct very narrow non-diffracting beams and shape-invariant beams accelerating on arbitrary trajectories. Importantly, the beam transformations occur within a mere distance of 40 wavelengths, suggesting that GR can inspire any wavefront shaping in highly tight waveguide settings. In such settings, we demonstrate Einstein's Rings: a phenomenon dating back to 1936.
过去十年见证了波前整形领域的显著进展，包括自由空间中的光束整形、表面等离子体波包整形以及电子波函数整形。在所有这些情况中，波前整形都是通过外部手段实现的，如掩模、光栅以及超表面反射。在此，我们提出在波导环境中利用广义相对论（GR）效应进行波前整形。我们展示了在具有预先设计的折射率变化的介质平板样品内进行光束整形，以便为光创造弯曲的空间环境。我们使用这种技术构建了非常窄的无衍射光束以及沿任意轨迹加速的形状不变光束。重要的是，光束变换仅在40个波长的距离内发生，这表明广义相对论能够在高度紧凑的波导环境中激发任何波前整形。在这种环境中，我们展示了爱因斯坦环：这一现象可追溯到1936年。
