All‐Dielectric Metasurface‐Enabled Multiple Vortex Emissions

Abstract

On‐chip integrated micro‐ and nanoscale vortex lasers are key elements for addressing the exponentially growing demand for information capacity. Although tunable vortex microlasers have been reported, each laser pulse still possesses one particular topological charge and requires additional multiplexing. In this study, the simultaneous generation of coherent laser arrays with different topological charges by combining metalenses with semiconductor microlasers is demonstrated. A TiO2 vortex metalens converts two orbital angular momentum beams into the same diffraction‐limit spot with opposite circular polarizations through spin‐to‐orbital conversion. Consequently, the microlaser emission at the focal spot, which can be decomposed into two circularly polarized beams, is collimated into vortex microlaser beams with two different topological charges through a time‐reversal process. This concept is extended to a 2 × 2 metalens array by introducing off‐axis terms, and eight topological charges are produced simultaneously. This research is a significant step toward the on‐chip integration of micro‐ and nanolasers.

Recent Advances in Tunable Metasurfaces: Materials, Design, and Applications

“…Photonic spin–orbit interactions have recently attracted much attention due to their similarity with the spin–orbit interaction of electrons in solids . PCM metasurfaces offer a rich degree of freedom to dynamically manipulate the spin and orbital angular momenta of light. , The Pancharatanam-Berry (PB) phase and propagation phase of GST nanofins were utilized to realize the conversion from spin angular momentum (SAM) to orbital angular momentum (OAM) . The PB phase remained unchanged across different phase states, while the propagation phase varied accordingly.…”

Creating Longitudinally Varying Vector Vortex Beams with an All‐Dielectric Metasurface

“…Metasurfaces have developed rapidly in recent years, and can manipulate electromagnetic wave parameters including frequency, amplitude and phase by designing subwavelength structures. [18][19][20][21][22] These capabilities offer great potential in metalens, [23][24][25] sensing, [26,27] holography, [28] and vortex generators [15,17] applications. Based on the ability of these subwavelength arrays to control the light field, polarization conversion [29,30] and versatile polarization generation [31] have been proposed.…”

Curved Photodetectors Based on Perovskite Microwire Arrays via In Situ Conformal Nanoimprinting

“…[5][6][7][8][9][10] In the medical field, the implantation of curved optoelectronic devices on complex surfaces of the skin or artificial organs is important for biological information compared with those of conventional materials. [37][38][39][40][41][42][43][44] For example, Zhang et al fabricated top-down etched microdisks and high-performance micro-lasers based on the CH 3 NH 3 PbBr 3 (MAPbBr 3 ) perovskite. [45] However, many technical challenges remain in fabricating perovskite-based micro/nano photodetectors (PDs) directly on curved substrates for curved-surface image sensors.…”

“…Perovskite materials play an important role in the development of micro/nanodevices because of their superior photoelectric properties compared with those of conventional materials. [ 37–44 ] For example, Zhang et al. fabricated top‐down etched microdisks and high‐performance micro‐lasers based on the CH 3 NH 3 PbBr 3 (MAPbBr 3 ) perovskite.…”