Banca de QUALIFICAÇÃO: SUELEN LIMA DE CARVALHO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : SUELEN LIMA DE CARVALHO
DATE: 11/07/2025
TIME: 14:00
LOCAL: Remoto
TITLE:

Quasi-Crystalline Photonic Structures Optimization Using Artificial Intelligence for Application in Optical Sensors and Filters

KEY WORDS:

Artificial Intelligence (AI), Photonic Quasi-Crystals, Optical Sensors, Optical Filters.

PAGES: 50
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

In recent years, photonic structures have gained prominence due to their ability to manipulate light at wavelength-comparable scales, which allow precise control of the propagation, dispersion and confinement of electromagnetic radiation. Among these structures, photonic quasi-crystals emerge as promising alternatives to conventional photonic crystals. In this scenario, this work suggests the application of Artificial Intelligence (AI) to improve the results obtained in an optical filter and sensor. Initially, an optical filter designed to operate at the initial wavelengths of the near-infrared (NIR) range was developed, based on a two-dimensional quasi-crystalline photonic optical fiber (2D-PQCF). The structure consists of a microstructured fiber with an air hole distribution organized by the six-fold repetition of a quasi-periodic unit cell. The introduction of a defect in the quasi-crystalline substrate allows the confinement of the optical signal in the central core. The filter operates using the Brillouin scattering effect, which causes destructive interference for electromagnetic fields at certain wavelengths. Optical excitations in the range of to were tested, and the filter blocked only wavelengths below . The study also evaluated the fiber birefringence, confinement losses and field intensities as a function of the wavelengths and physical parameters of the microstructure. In addition, a miniaturized and highly sensitive optical sensor based on surface plasmon resonance (SPR) integrated into a photonic quasicrystal fiber (PQCF) was developed. The sensor structure is composed of quasi-periodic unit cells modified by defects that form a central core and two lateral cores, all coated with a gold layer to activate the plasmonic effect. This configuration allowed the accurate detection of analytes inserted into the fiber. The sensor also incorporates a temperature-sensitive liquid crystal, which extends its functionality to detect thermal variations. Artificial Intelligence techniques will then be applied with the aim of optimizing performance and improving the analysis of the proposed structures.

COMMITTEE MEMBERS:
Presidente - 1422265 - JOSE PATROCINIO DA SILVA
Interno - 1141792 - RODRIGO PRADO DE MEDEIROS
Externo à Instituição - EDGARD DE MACEDO SILVA - IFPB