Banca de QUALIFICAÇÃO: NILSON HENRIQUE DE OLIVEIRA CUNHA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : NILSON HENRIQUE DE OLIVEIRA CUNHA
DATE: 30/06/2022
TIME: 14:00
LOCAL: Remoto
TITLE:

Analysis of Optical Biosensors based on SPR Effect using New Optical Fiber Models with Quasi-Crystalline Core

KEY WORDS:

Optical sensors, Micro structured optical guide, Surface plasmon resonance, refractive index detection.

PAGES: 45
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

With the discovery of new techniques and new studies being carried out in all areas of science, it is necessary that the devices used follow this advance in order to present reliable results. In this context, applications in very high frequencies have been explored in the search for devices that present ultrafast responses. Among these applications, those that use optical sensors have been widely studied. In this work, the Surface Plasmon Resonance (SPR) effect will be used in the analysis of optical sensors based on optical fibers with quasi-crystalline core. The geometries of the proposed structures are based on models adapted for refractive index detection of chemical and biological analytes. The SPR effect occurs when a metal-dielectric interface is excited by light at a specific frequency, called plasmonic frequency, causing in the analyte region the appearance of dense electron clusters, thus making possible the detection of the material. This work aims to propose new models of plasmonic sensors obtained from micro structured optical guides, including conductive materials that allow the SPR effect. As a first analysis, it was used a micro structured optical fiber type D in which the plasmonic element used is sensitive to the refractive index variation for several analytes, enabling the identification of the material being evaluated. To increase the SPR efficiency, in this application, it was introduced a defect in the core of the fiber made of Silica (SiO₂) doped with concentrations of Germanium (GeO₂). For the analysis of the sensor capacity, were studied initially the electric field (E), the confinement loss (CL) and the spectral sensitivity, or wavelength sensitivity (WS). The results show that higher concentrations of doping cause an increase in the detection range of the sensor without considerably damaging its sensitivity, which ranges from 9700 to 12,000 nm/RIU. Next, other interactions between conductors and dielectrics will be proposed in micro-structured optical fibers based on quasi-crystalline configurations.

BANKING MEMBERS:
Presidente - 1422265 - JOSE PATROCINIO DA SILVA
Interno - 2524053 - ANTONIO LUIZ PEREIRA DE SIQUEIRA CAMPOS
Externo ao Programa - ***.200.404-** - HUMBERTO DIONISIO DE ANDRADE - UFERSA