Dual-Band All-Optical Logic Gates by Coherent Absorption in an Amorphous Silicon Graphene Metasurface

• Published in: Nanomaterials (Basel, Switzerland) Vol. 14; no. 4; p. 335
• Main Authors: Chen, Yixiao, Shen, Chongyang, Li, Qingyuan, Li, Jianyao, Deng, Xiaoxu
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.02.2024; MDPI
• Subjects: Absorption; all-optical logic gates; Analysis; coherent absorption; Communication; Graphene; Mechanical properties; metasurface; multipole moments; Optical properties; Silicon; China; coherent absorption; all-optical logic gates; multipole moments; graphene; metasurface
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano14040335

The dual-band polarization-independent all-optical logic gate by coherent absorption effect in an amorphous silicon (a-Si) graphene metasurface is investigated theoretically and numerically. Taking the substrate effect into consideration, the coherent perfect absorption condition of the a-Si graphene metasurface is derived on the basis of the Cartesian multipole method. The coherent nearly perfect absorption of the a-Si graphene metasurface is realized by the interference of multipole moments and the interband transition of monolayer graphene, achieving peak values of 91% and 92% at 894.5 nm and 991.5 nm, respectively. The polarization independence of the coherent absorption is revealed due to the center symmetry of the structure of the a-Si graphene metasurface. The dual-band polarization-independent all-optical XOR and OR logic gates are implemented at 894.5 nm and 991.5 nm by the a-Si graphene metasurface based on the coherent nearly perfect absorption, which has the opportunity to be utilized in all-optical computing, all-optical data processing, and future all-optical networks.