Dinâmica em freqüência de lasers semicondutores sob realimentação ótica ortogonal e aplicação: chaveamento todo-ótico em frequência

• Ano de defesa: 2010
• Autor(a) principal: Sorrentino, Taciano Amaral
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Física; Programa de Pós-Graduação em Física; UFPB
• Palavras-chave em Português: Lasers semicondutores; Realimentação ótica; Dinâmica em frequência; Biestabilidade; Chaveamento ótico; Semiconductor lasers; Optical feedback; Frequency dynamics; Bistability; Optical switching; CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/5775

We analyze the dynamics of semiconductor lasers radiation frequency when these lasers are subject to different conditions of optical feedback, and we demonstrate how it is possible to control the emission frequency using the different configurations explored. In the first system studied a semiconductor laser is fed back with light which polarization is orthogonal to the output polarization, spectrally filtered by a cesium atomic vapor. This system, besides presenting an effective technique to stabilize the laser frequency and reduce the laser linewidth, was the first to exhibit frequency bistable and multistable optical regimes with amplitude practically constant. This unique feature opens the way for applications in all-optical FM logical devices. The bistable and multistable regimes are interpreted through a phenomenological model, and, for the bistable regime, we discuss a rate equation model, built taking in account thermal effects and gain saturation. We also present an all-optical frequency switch, the first of his kind. The second system is used to investigate the behavior of the emission frequency of a semiconductor laser with an external cavity, inside which is placed an atomic filter. For different values of the injection current we observe the laser frequency locking in the atomic line, bistability and reproducible frequency instabilities.