All‐Dielectric Metasurface‐Enabled Multiple Vortex Emissions. Issue 14 (27th February 2022)

• Record Type: Journal Article
• Authors: Zhang, Hui; Sha, Xinbo; Chen, Qinmiao; Cheng, Jiaping; Ji, Ziheng; Song, Qinghai; Yu, Shaohua; Xiao, Shumin
• Is Part Of: Advanced materials. Volume 34:Issue 14(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-27
• Subjects: circular polarization -- metalenses -- topological charges -- vortex emission; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202109255
• Languages: English
• ISSNs: 0935-9648

Abstract

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. Abstract : By combining an orbital angular momentum (OAM) multiplexing metalens array and semiconductor microlasers, the simultaneous generation of a vortex emission array with versatile topological charges is experimentally demonstrated, paving an essential step toward on‐chip integrated OAM sources.