Multiwavelength high-order optical vortex detection and demultiplexing coding using a metasurface

Abstract

Orbital angular momentum (OAM) of an optical vortex has attracted great interest from the scientific community due to its significant values in high-capacity optical communications such as mode or wavelength division multiplexer/demultiplexer. Although several configurations have been developed to demultiplex an optical vortex, the multiwavelength high-order optical vortex (HOOV) demultiplexer remains elusive due to lack of effective control technologies. In this study, we present the design, fabrication, and test of metasurface optical elements for multiwavelength HOOV demultiplexing based on optical gyrator transformation transformations in the visible light range. Its realization in a metasurface form enables the combined measurement of OAM, the radial index p, and wavelength using a single optical component. Each wavelength channel HOOV can be independently converted to a high-order Hermitian-Gaussian beam mode, and each of the OAM beams is demultiplexed at the converter output. Furthermore, we extend the scheme to realize encoding of the three-digit gray code by controlling the wavelength or polarization state. Experimental results obtained at three wavelengths in the visible band exhibit good agreement with the numerical modeling. With the merits of ultracompact device size, simple optical configuration, and HOOV recognition ability, our approach may provide great potential applications in photonic integrated devices and systems for high-capacity and demultiplex-channel OAM communication.

Deep image prior plus sparsity prior: toward single-shot full-Stokes spectropolarimetric imaging with a multiple-order retarder

“…These advantages are helpful for promoting the development of a miniature SPI system using free-space optical components 12 , 31 , 32 , 59 as well as chip-scale integration with silicon photonic circuits 64 or metasurfaces 65 – 72 …”

“…These advantages are helpful for promoting the development of a miniature SPI system using free-space optical components 12,31,32,59 as well as chip-scale integration with silicon photonic circuits 64 or metasurfaces. [65][66][67][68][69][70][71][72] Fig. 13 Acceleration strategy of the DIP-SP processing the images of all spectral bands one by one.…”

Off-axis bifocal metalens for displacement measurement

“…They clarified that transmitted light and reflected light can propagate in any direction in their respective half space, and the propagation direction depends on the direction of the metasurface phase gradient, the numerical magnitude and the refractive index of the surrounding medium. Metasurfaces have been widely used in wavefront engineering [3][4][5][6], focusing or imaging elements [7][8][9][10][11], beam shaping [12], vortex beam generation [13][14][15][16], holographic technology [17][18][19], biosensing [20], electromagnetic concealment [21], achromatic focusing [22], electromagnetic wave modulation [23] and nonlinear interactions [24,25] have been applied in 3D imaging [26], Cellular-resolution optical coherence tomography [27], holographic imaging [28][29][30][31], optical cryptography [32,33] and wireless power transfer (WPT) system [34][35][36]. For example, researchers achieved optical information multiplexing by a designed multifocal metalens using of nonlinear coding Pancharatnam-Berry phase metasurface [37].…”

All-dielectric metasurfaces for intensity-controllable beam splitting and polarization conversion

“…These planar optical devices can flexibly manipulate the polarization, phase, and intensity of electromagnetic waves. The exceptional characteristics of metasurfaces have paved the way for their application in many fields, such as metalenses [9,10], vortex beam generators and detectors [11][12][13], waveplates [14], and holograms [15,16]. Consequently, metasurfaces have immense potential in achieving both polarization conversion and intensitycontrolled beam splitting.…”