On-chip orbital angular momentum detection using a catenary grating metasurface

Abstract

Vortex lights with optical orbital angular momentum (OAM) have shown great promise in the areas of optical communication, optical manipulation and quantum optics. However, traditional methods for detecting the topological charge of vortex beams, such as interference and diffraction, are still challenging in miniaturization of the detection system and perfect matching of wave vectors. Here, a detection approach is proposed for measuring the topological charge of Laguerre-Gaussian (LG) vortex beam based on a catenary grating metasurface. According to the wave vector matching principle, the LG vortex beam can be coupled into surface plasmon polaritons (SPPs) waves propagating in different directions by using the well-designed catenary grating structure. The positive and negative of the topological charge can be distinguished by different arrangement of the catenary gratings. Besides, the propagation angle of the launched SPPs waves increases with the value of the topological charge. We believe that the proposed device would have a broader application prospect in high compact photonic integrated circuits.

Monolithic Spiral Metalens for Ultrahigh‐Capacity and Single‐Shot Sorting of Full Angular Momentum State

“…Notably, our SML has the widest mode detection range with the largest SMION, both far outperforming all the previous works. [50][51][52][53][54][55][56][57][58][59][60][61][62] To provide a proof-of-concept demonstration, we design and fabricate an SML based on the geometric phase principle. Initially, we employ a hexagonal periodic unit cell in the configuration of the SML.…”

“…Notably, our SML has the widest mode detection range with the largest SMION, both far outperforming all the previous works. [ 50–62 ]…”

“…Besides, on-chip plasmonic metasurface dual-function detectors have emerged as another promising solution for simultaneously identifying OAM and SAM. [57][58][59][60][61] However, this methodology typically operates at a specific wavelength range, and it is difficult to distinguish more than 10 modes. Recently, a photonic momentum transformation approach has been put forward to design a spin-decoupled metasurface for the simultaneous detection of SAMs and OAMs.…”

Computational hyperspectral devices based on quasi-random metasurface supercells

“…[16][17][18][19] They have been applied in the fields of lithography, [20][21][22] achromatic metalens, [23][24][25][26] optical waveguides, 27,28 extraordinary Young's interference, 29,30 and vector light field. [31][32][33] Researchers have been exploring the use of lightweight spectral devices based on metasurfaces as a replacement for bulky traditional spectrometers. [34][35][36] Fast spectrometers can be realized with broadband metasurface filters and a spectral reconstruction algorithm based on compressed sensing, with the principle as shown in Fig.…”

Polarization-dependent multidirectional coupler based on Y-branch silicon waveguide integrated with single optimized catenary antenna

“…To meet the above needs, electromagnetic modulation technology based on subwavelength optical structure [3][4][5][6][7][8] came into being. The technology with the characteristics of flexible design and precise control of multiple parameters [6,7] not only greatly diminishes the size and weight of the optical devices, but also derives many emerging fields such as sub-wavelength electromagnetics [7], surface plasmon optics [9][10][11][12], and metamaterials [5][6][7][13][14][15], etc. Accordingly, the devices based on sub-wavelength structures have been designed to exhibit novel optical phenomena, holding applications in fields such as chromatic aberration control [16,17], detection of spin, and orbital angular momenta [18,19], extraordinary Young's interference phenomenon [20,21], wide-angle metalens [22][23][24], and onchip lens [24][25][26].…”