Dielectric multi-momentum meta-transformer in the visible

Abstract

Metasurfaces as artificially nanostructured interfaces hold significant potential for multi-functionality, which may play a pivotal role in the next-generation compact nano-devices. The majority of multi-tasked metasurfaces encode or encrypt multi-information either into the carefully tailored metasurfaces or in pre-set complex incident beam arrays. Here, we propose and demonstrate a multi-momentum transformation metasurface (i.e., meta-transformer), by fully synergizing intrinsic properties of light, e.g., orbital angular momentum (OAM) and linear momentum (LM), with a fixed phase profile imparted by a metasurface. The OAM meta-transformer reconstructs different topologically charged beams into on-axis distinct patterns in the same plane. The LM meta-transformer converts red, green and blue illuminations to the on-axis images of “R”, “G” and “B” as well as vivid color holograms, respectively. Thanks to the infinite states of light-metasurface phase combinations, such ultra-compact meta-transformer has potential in information storage, nanophotonics, optical integration and optical encryption.

Polarization Detection Using Light's Orbital Angular Momentum

“…[20,21] In 1992, it was recognized that light beams with a helical phase structure described by exp(iℓθ), where θ is the azimuthal angle and ℓ is the topological charge of optical vortex, carry an orbital angular momentum (OAM) of ℓℏ per photon. [22,23] Twisted light beams have been applied in various research fields, including optical communication, [3] optical trapping, [24] new forms of imaging systems, [25][26][27] nonlinear material, [28,29] and quantum optics. [30][31][32] As a promising candidate, optical metasurfaces have been used to generate various twisted light beams [33][34][35] and to control the superpositions of twisted light beams.…”

Recent advances in multi-dimensional metasurfaces holographic technologies

“…Two digits of the Arabic numerals from 01 to 26 are used to represent alphabet letters from A to Z in order to achieve encrypting messages. Meanwhile, Jin et al [85] demonstrated a OAM meta-transformer with the capability of transforming the intrinsic phases of OAM (exp(ilħ)) of the incidence light into various distinct patterns in the same plane based on carefully designed phase retrieve method, as shown in Fig. 5c.…”

“…Ten high order OAM modes can be used to reconstruct ten OAMdependent digits [84]. c An OAM meta-transformer which can reconstruct "0", "3" and "6" by designed three OAM states, respectively [85]. d The principle of vortex and polarization encryption based on proposed metasurfaces.…”

Broadband metamaterials and metasurfaces: a review from the perspectives of materials and devices

“…Commonly, a dispersion-less phase modulation method, usually by using the geometric phase, is used. Image multiplexing is divided into in-plane [168][169][170] and out-of-plane [164,[171][172][173][174][175] schemes depending on where those three intensity images appear with respect to one another for a monochromatic illumination. For in-plane image multiplexing, the hologram is encoded such that the images for the three colors (for example, R, G, and B letters in Figure 15E) are located at different positions on the imaging plane [168].…”