Photonic Entanglement Based on Nonlinear Metamaterials

Abstract

Metamaterials consisting of deep subwavelength artificial “atoms” have been utilized to demonstrate a series of novel phenomena such as negative refraction and epsilon‐near‐zero. In recent times, metamaterials have been developed as an up‐and‐coming platform for quantum optics. Here the generation and modulation of photonic entanglement are investigated based on the parametric down conversion processes in metamaterials with considerable optical nonlinearity. Through flexible nanostructure design, the nonlinear photonic interaction in the metamaterial system can be effectively tailored. The distributions of optical parameters of the system are inhomogeneous, based on which the spatial properties of the generated photonic state can be steered as desired. The theoretical framework to describe this system is established based on the nonlinear Huygens–Fresnel principle, and a differential approach is utilized to deal with the intrinsic loss of the system. The generation of orbital angular momentum entangled states is actually considered as an illustration. This platform could be valuable for the practical applications of quantum information processing.

Creating Composite Vortex Beams with a Single Geometric Metasurface

“…Several composite modes with different combinations of l 1 , l 2 , and l 3 at z = 0 are initially simulated. The selected combinations include (l 1 , l 2 , l 3 ) = (2, 3, 5), (2,4,8), and (2,5,11), where…”

“…The nontrivial behaviors of phase give rise to diverse intriguing phenomena, opening up the area of singular optics. [1] Optical vortices (known as singular light beams) have been used in many fields ranging from particle manipulation [2,3] to quantum information [4,5] due to their unique optical properties. The singularity structure of a wavefront plays an important role in the physical properties of vortex beams.…”

Quantum photonics based on metasurfaces

“…Over the past few decades, there has been so many works concerning how to augment and control nonlinear frequency conversion, and these works provide enormous and rich knowledge for manipulation of quantum source. In fact, 5 times enhancement of SP-DC efficiency is attainable from subwavelength films made of GaP 86 , the enhancement originates from Fabry-Perot resonance inside the nonlinear films. Take it further, Y. Ming et al theoretically demonstrated that by judiciously designing metamaterials, desired quantum state could be prepared from metamaterials 87 .…”

Nonlinear Wavy Metasurfaces with Topological Defects for Manipulating Orbital Angular Momentum States

“…From Figure 1b, it can be seen that the absolute value of χ (2) varies with the arm and base lengths L a and L b of meta-atom, and the sign of χ (2) changes when the orientation of meta-atom is inverted. 13 Based on this approach, any wavy distribution of χ (2) can be acquired through designing the nanostructures of nonlinear metasurfaces in theory. However, as the meta-atoms are discretized, the variation of χ (2) is quasi-continuous.…”

“…For linear optical applications, various functional devices like phase-only transmissive spatial light modulator and electromagnetically induced absorber have been demonstrated based on metasurfaces with rationally designed nanostructures. Recently, as a further step, the potential of nanopatterned interfaces in the field of nonlinear optics draws considerable attention. − In early studies, nonlinear interactions at such interfaces always suffer from low conversion efficiency. , The exploitation of multi-quantum-wells (MQWs) with giant second-order nonlinearity for metasurfaces substantially eases the problem, − which paves the way for further development of this direction.…”