Banca de DEFESA: NILSON HENRIQUE DE OLIVEIRA CUNHA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NILSON HENRIQUE DE OLIVEIRA CUNHA
DATE: 30/08/2024
TIME: 09:00
LOCAL: Remoto
TITLE:

Optical Biosensors Analysis Based on the SPR Effect Using New Models of Quasi-Crystalline Devices

KEY WORDS:

Micro-Structured Optical Waveguide, Refractive Indexes, SPR Optical Sensors

PAGES: 80
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

With the continuous advancement of new technologies in all areas of science, it is essential that the devices used keep up with these advances to guarantee reliable results. In this scenario, applications at very high frequencies have been explored to develop devices with ultra-fast responses. Among these applications, optical sensors have been the subject of extensive research. This work uses the surface plasmon resonance (SPR) effect to analyze optical sensors based on optical guides with almost crystalline cores. The SPR effect occurs when a metal-dielectric interface is excited by a light signal at a specific frequency, called plasmonic frequency, inducing the formation of dense clusters of electrons in the analysis region, thus enabling the detection of the material. The objective of this study is to propose and analyze four new models of plasmonic sensors derived from optical guides, including micro structured optical fibers and conventional guides. In the first approach, a micro structured optical fiber with elliptical holes was used, exploring two variations: one with an extended core and the other with two cores. The second study involved a micro structured D-type optical fiber, where a defect in the silica core was doped with different concentrations of germanium dioxide to optimize the SPR effect. The third proposed structure consisted of a rib-type optical guide with an attached microchannel, separated from the guiding region by a thin layer of gold. Finally, the last proposed structure used a quasi-periodic micro structured optical fiber, with the introduction of a liquid crystal sensitive to temperature variations to improve the coupling between the fundamental and plasmonic modes. To evaluate the effectiveness of the sensors, the electric (E) and magnetic (H) field distributions, the confinement loss (CL – Confinement Loss) and the spectral sensitivity, or wavelength sensitivity (WS – from the English Wavelength Sensitivity). These investigations aim to contribute to the development of advanced optical sensors, capable of accurately detecting variations in the refractive index of materials in both chemical and biological applications (analytes).

COMMITTEE MEMBERS:
Presidente - 1422265 - JOSE PATROCINIO DA SILVA
Interno - 2524053 - ANTONIO LUIZ PEREIRA DE SIQUEIRA CAMPOS
Interno - 1412682 - VICENTE ANGELO DE SOUSA JUNIOR
Externo à Instituição - COSME EUSTAQUIO RUBIO MERCEDES - UEMS
Externo à Instituição - HUMBERTO DIONISIO DE ANDRADE - UFERSA