Fabricação e caracterização de fibras ópticas contendo nanopartículas de ouro e conversão de frequências em microrressonadores em anel

• Main Author: Oliveira, Rafael Euzebio Pereira de
• Publication Date: 2014
• Format: Doctoral thesis
• Language: por
• Source: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Download full: http://dspace.mackenzie.br/handle/10899/24261
• topic: óptica não linear; ressonadores em anel; chips fotônicos; fibras ópticas especiais; nanopartículas de ouro; plasmônica; nonlinear optics; ring resonators; photonic chips; specialty optical fibers; gold nanoparticles; plasmonics; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA

Nonlinear effects are essential for the construction of photonic devices such as modulators, optical switches and frequency converters. Aiming at the development of devices for optical frequency conversion and the generation of nonclassical states of light in photonic chips, this thesis presents the design and simulation of a frequency converter based on second harmonic generation controlled by static electric field in a silicon nitride ring resonator. The developed simulation appraises conversion efficiencies up to -8.25 dB with the advantage to provide an electrical interface to control the conversion. Optical fiber based devices are also within the scope of the thesis and a new technique is presented for manufacturing optical fibers with enhanced nonlinear response by the presence of metallic gold nanoparticles. The manufactured fibers are based on silica that is doped with aluminum and gold in the core, offering full compatibility and integration with conventional optical fibers. The nanoparticles were created by annealing in an oven or by heating with a CO2 laser beam, which offers unprecedented control over particle size and density in optical fibers. Compared to previously reported fibers with gold nanoparticles, higher concentration of nanoparticles were obtained which was estimated by the plasmonic absorption peak exceeding 800 dB/m and by a consequent increasing in the nonlinear refractive index of at least 50x under continuous wave excitation, achieving values of n2=(6,75±0,55)×10-15 m²/W. The development of these fibers and the design of the on chip frequency converter provide platforms for the development of efficient and integrated devices in fiber based optical systems and in photonic chips.