Reconfiguring structured light beams using nonlinear metasurfaces.

Ultra-compact, low-loss, fast, and reconfigurable optical components, enabling manipulation of light by light, could open numerous opportunities for controlling light on the nanoscale. Nanostructured all-dielectric metasurfaces have been shown to enable extensive control of amplitude and phase of light in the linear optical regime. Among other functionalities, they offer unique opportunities for shaping the wave front of light to introduce the orbital angular momentum (OAM) to a beam.

High-Efficiency All-Dielectric Metasurfaces for Ultracompact Beam Manipulation in Transmission Mode.

Metasurfaces are two-dimensional structures enabling complete control on light amplitude, phase, and polarization. Unlike plasmonic metasurfaces, silicon structures facilitate high transmission, low losses, and compatibility with existing semiconductor technologies. We experimentally demonstrate two examples of high-efficiency polarization-sensitive dielectric metasurfaces with 2π phase control in transmission mode (45% transmission efficiency for the vortex converter and 36% transmission efficiency for the beam steering device) at telecommunication wavelengths.

Manipulating complex light with metamaterials.

Recent developments in the field of metamaterials have revealed unparalleled opportunities for "engineering" space for light propagation; opening a new paradigm in spin- and quantum-related phenomena in optical physics. Here we show that unique optical properties of metamaterials (MMs) open unlimited prospects to "engineer" light itself. We propose and demonstrate for the first time a novel way of complex light manipulation in few-mode optical fibers using optical MMs.

Nonlinear light concentrators.

We propose a reconfigurable cylindrical concentrator designed using a transformation-optics approach when the core of the device contains a material with Kerr nonlinearity. We demonstrate that in the case of focusing Kerr nonlinearity of the material in the device, it functions as an axicon-like lens with a variable focus line that can be tuned by changing the incident electromagnetic field. We also numerically study the cases where the core of the device is made of a material with defocusing Kerr nonlinearity or consists of a negative index material and predict beam splitting or localized field enhancement at the boundary of the core, respectively.