Fabrication of polymeric microresonators doped with nanodiamonds for quantum information technologies

• Ano de defesa: 2024
• Autor(a) principal: Couto, Filipe Assis
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Centros de cor; Color centers; Fotopolimerização por absorção de dois fótons; Modos de galeria sussurrante; Two-photon polymerization; Whispering gallery modes
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/76/76134/tde-20082024-093927/

Color centers have attracted significant attention for their applications in quantum technology, making their integration into photonic structures an essential area of research to advance the realization of quantum platforms. In particular, resonant cavities offer a promising platform for enhancing the light-matter interaction of color centers. This work explores the fabrication of microcavities embedded with fluorescent nanodiamonds using two-photon polymerization (2PP). We investigate the trade-off between nanodiamond concentration in the photoresist and the resulting structural quality and cavity Q-factor. Our results demonstrate the successful integration of nanodiamonds into cylindrical cavities doped with 0.002 wt% concentration. These cavities maintain good quality factors on the order of 105 and contain one to three fluorescent color centers. The position of the fluorescent nanodiamonds within the microcavities is confirmed using fluorescence spectroscopy, laser scanning microscopy (LSM), and Raman spectroscopy. Additionally, utilizing Finite-Difference Time-Domain (FDTD) simulations, we explore novel designs for efficient emitter-cavity coupling with color centers in 4H-Silicon Carbide (SiC) nanostructures. We optimized a double nanobeam cavity design supporting high-quality factor resonances and a \"sawfish\" cavity design for improved fabrication and light-matter interaction with color center in SiC. Building upon this knowledge, we discuss future directions for leveraging 2PP fabrication to integrate nanodiamonds with novel Whispering Gallery Modes (WGM) cavities, aiming at achieving low mode volumes to explore the Purcell effect. Therefore, this research paves the way for developing integrated devices containing nanodiamonds and WGM cavities for quantum technology applications.