Universal Metasurfaces for Complete Linear Control of Coherent Light Transmission

Abstract

Recent advances in metasurfaces and optical nanostructures have enabled complex control of incident light with optically thin devices. However, it has thus far been unclear whether it is possible to achieve complete linear control of coherent light transmission, that is, independent control of polarization, amplitude, and phase for both input polarization states, with just a single, thin nanostructure array. Here, it is proved possible, and a universal metasurface is proposed, a bilayer array of high‐index elliptic cylinders that possesses a complete degree of optical freedom with fully designable chirality and anisotropy. The completeness of achievable light control is mathematically shown with corresponding Jones matrices, new types of 3D holographic schemes that were formerly impossible are experimentally demonstrated, and a systematic way of realizing any input‐state‐sensitive vector linear optical device is presented. The results unlock previously inaccessible degrees of freedom in light transmission control.

Stereo Jones Matrix Holography with Longitudinal Polarization Transformation

“…Recently, some methods have demonstrated the realization of arbitrary unitary matrix based on bilayer structures. [ 50,51 ] While, our article focuses on generating arbitrary polarization states along propagation direction by utilizing the imposed polarization restriction $${{{\tilde{\bf P}}}}_{{\bf n}}$$ (expressed by a unitary and symmetric Jones matrix) based on single layer metasurface with controllable linear birefringence.…”

Full Complex‐Amplitude Engineering by Orientation‐Assisted Bilayer Metasurfaces

“…Benefiting from the strong robustness of the P-B phase (it is known that P-B phase only depends on the orientation angles of nanobricks and fabrication errors usually do not change the orientation angles of nanobricks) and the rich design freedom of the bilayer metasurface, it is easy to realize arbitrary complex-amplitude modulation merely by changing the orientation angles of the nanobricks with relatively simple fabrication technology. More importantly, though multi-nanostructure meta-atom are easier to fabricate [50][51][52][53] or can control more optical parameters, [54] they inevitably lead to pixel resolution degradation. It is worth mentioning that most of the traditional complex-amplitude-modulating metasurfaces require a large amount of electromagnetic simulation to find suitable nanostructures to achieve various combinations of amplitude and phase, which is realized by merely calculating relative orientation angles in our design.…”

“…Compared with phase-or amplitude-only meta-elements, [26][27][28][29][30][31][32][33] complex-amplitude meta-elements have attracted extensive interest due to their ability to independently and flexibly manipulate the two important optical parameters, i.e., amplitude and phase. In the current state of knowledge, there are several methods to realize complex-amplitude modulation by metasurfaces: changing the angle between two arms of the V-shaped nanostructure with different lengths, [34] changing the size and orientation angle of a single nanobrick, [35][36][37][38][39] changing the opening size and orientation angle of C-shaped nanostructure, [40][41][42][43][44] changing the orientation angle between two arms of X-shaped nanostructure, [45] changing the length/width of arm and orientation angle of cross-shaped nanostructure, [46][47][48][49] and changing the orientation angles of multi-nanostructure metaatom, [50][51][52][53][54] etc. However, these methods either change the size of nanostructures thus requiring high-accuracy fabrication, or integrate several nanostructures into a unit-cell thus reducing the pixel-resolution of meta-elements.…”

Metasurface‐Based Optical Logic Operators Driven by Diffractive Neural Networks

“…Nevertheless, there are limited reports of metasurfaces on more practical quantum computing scenarios, such as quantum gate operations. [ 36 ]…”