Chaveamento elétrico de dispositivos para modulação óptica baseados em grafeno

• Autor(a) principal: Araújo, Maria Cecília Schineider
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/24500
• topic: modulador a base de grafeno; fibra óptica de perfil D,; capacitor de grafeno; Field Effect Transistor; chaveamento do nível de Fermi.; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA

The graphene-based electro-optic modulator composed by a D-shaped optical fiber and a capacitive structure with a polymethylmethacrylate (PMMA) superstrate of 700 nm thickness on the polished side was analyzed by simulation. The drive voltage between the Fermi level of 300 meV and 500 meV was 11.9 V for transverse electric (TE) mode, resulting in a modulation depth of approximately 3 dB at 1 GHz for the dielectric thickness of 50 nm. Based on these results, the goal of this work was to develop, characterize and evaluate the graphene electro-optic modulator manufacturing process, by analyzing the assembly of 2 structures: (1) the Field Effect Transistor (FET) structure on the commercial D-shaped optical fiber, presenting the extinction rate (ER) of 12,72% and insertion loss of 2,6 dB; (2) the capacitive structure with LiClO4 ionic gel on the glass blades presented the capacitance of 1.53 pF that was considered to calculate its relative permittivity of 5.46 and frequency of 4.8 MHz. On the D-shaped optical fiber immersed in the glass resin and polished manually, it was achieved the extinction rate of 55% and insertion loss of 13.7 dB. Although the FET structure showed lower insertion loss, the capacitive structure resulted in a higher extinction rate, demonstrating the possibility of switching and electro-optical modulation, which require the optimization of the polishing process and ionic gel solution.