Utilização da arquitetura pedestal para fabricação de guias de onda com ilhas de ouro visando desenvolvimento de dispositivos fotônicos que operem na região do infravermelho.

Abstract

This work aims to produce passive waveguides using a pedestal structure with TeO2 -ZnO (TZ) and GeO2 -PbO (GP) matrices, in order to test the guidance of light in the visible and near infrared regions. A new process was used to manufacture the waveguides that replaces the chromium mask by the use of the silicon dioxide (SiO2). The profile of the guides was analyzed by Scanning Electron Microscopy and the Atomic Force Microscopy technique was used to characterize the gold islands. Films were produced using the Sputtering technique and propagation loss measurements were made using the top view technique using 632 nm and 980 nm laser. The guides with GP core did not demonstrate guidance in the visible and therefore the influence of O2 on the deposition of this film was studied, but it did not influence satisfatorily the process. Guides with TZ core demonstrated guidance in the visible (632 nm) and near infrared (980 nm) regions. For the cases of guides produced with gold islands, nucleation was carried out through several thermal treatments following procedures previously established by the group. The presence of gold islands significantly reduced the propagation loss in the near infrared region (980 nm) for all guides (1-10 µm and 80 µm wide) with GP core. For the case of guides with TZ core, this reduction was more significant for the narrower guides (1-10 µm in width). Finally, the lowest loss obtained in the visible region was 2 dB/cm for the 80 µm width guide with TZ core without gold islands and in the near infrared region it was 2.08 dB/cm for the 80 µm width guide with GP core with gold islands. It is important to highlight that guides with GP core without gold islands, showed at 980 nm, loss of 3.31dB/cm, for 80 µm width guide. Simulations were performed to theoretically determine guided modes and compare them with experimental results. This new production process with a pedestal platform brings advantages, as it promotes a low surface roughness, eliminating the concern about the micromasking effect resulting from the use of the chrome mask and simplifies the process steps, allowing the use of conventional microelectronic techniques already consolidated (lithography, oxidation and corrosion) based on silicon technology for the construction of the pedestal, proving to be applicable in the construction of photonic devices.