Dinâmica em frequência de laser semicondutor sob realimentação ótica ortogonal filtrada

• Autor(a) principal: Alves, Samuel Bezerra
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/5761
• topic: Física; Laser semicondutor; Realimentação; CIENCIAS EXATAS E DA TERRA::FISICA

When submitted to external perturbations semiconductor lasers are convenient systems for amplitude or frequency dynamics studies. Amplitude dynamics of the electromagnetic field of semiconductor devices have been studied in a large number of theoretical and experimental works in the last few decades, particularly under coherent optical feedback. New features in the operation of semiconductor lasers can be exploited when subjected to orthogonal optical feedback. In this work we present a systematic study of the dynamics in frequency observed in semiconductor lasers when subjected to an orthogonal and to a filtered orthogonal feedback. We analyze the frequency shift that occurs when part of the orthogonally polarized beam is re-injected in the cavity. We study the response of a semiconductor filtered to orthogonal feedback, considering two different spectral filters: an atomic transition and a diffraction grating. The orthogonal feedback filtered by an atomic line can be used in a technique to stabilize the laser frequency. We determine the conditions for which this stabilization is optimized and measure the response time of the semiconductor when subjected to orthogonal feedback. When we use the diffraction grating to filter the feedback light, we observe a new behavior: emission frequency oscillations. We show that the amplitude of these oscillations depends on the power of feedback and we try to measure the rate at which the laser emission frequency oscillates under these conditions.