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 Einsteinâ € s Rings: A phenomenon dating back to 1936.
Bibliographical noteFunding Information:
R.B. gratefully acknowledges the support of the Adams Fellowship Programme of the Israel Academy of Sciences and Humanities. This research was also supported by the ICore Excellence center ‘Circle of Light’ and a grant from the US Air Force Office for Scientific Research (AFOSR). H.L. gratefully acknowledges the support of the National Natural Science Foundation of China (No’s 11321063, 61425018 and 11374151), the National Key Projects for Basic Researches of China (No. 2012CB933501 and 2012CB921500), the Doctoral Programme of Higher Education (20120091140005) and Dengfeng Project B of Nanjing University. C.S. gratefully acknowledge the support of the programme A for Outstanding PhD candidate of Nanjing University.