Implementação de portas lógicas através da modulação de pulsos por posição (PPM) em filtros acústico-ópticos sintonizáveis

• Ano de defesa: 2006
• Autor(a) principal: Rios, Clauson Sales do Nascimento
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Teleinformática; Solitons; Modulação (Eletrônica); Polarização linear
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/16131

In this dissertation it was studied the application of the Acoustic Optical Tunable Filter (AOTF), with Pulse Position Modulation (PPM), aiming at to implement, using the method of Runge-Kutta of 4a order, logical gates (OR and AND) optical operating with pulses of light ultra shorts (2ps). In this work the acting of the gates is investigated, considering several lengths of the filter (  L) that integrates your internal structure, with the intention of obtaining the length of more appropriate filter for a satisfactory operation, in dispersion regime, nonlinear, without losses and with Cross Phase Modulation (XPM). This investigation is accomplished in two situations: firstly, filters are considered with Self Phase Modulation (SPM) and GVD (group-velocity dispersion). In a second moment, the same gates are obtained with effects SPM, XPM and GVD, acting together in AOTF. It was observed that for pulses of the type soliton, the effects of the dispersion, of the nonlinearity and of the cross phase modulation exercise together a strong influences in the propagation of the same, provoking the break of the pulse in the exit of the device when we used a larger length for the filters. For shorter devices, the switched pulse presented temporary and spectral compression and spread, as well as, displacement in the time in the two propagation modes (TE and TM). After the choice of a length of appropriate filter, a great temporary displacement was selected to be applied in the input pulses for us to get, in the exit of the logical gate, satisfactory temporary displacements (successes) in the application of the PPM modulation. Soon after, we introduced phases in one of the entrance pulses (TM), provoking a phase displacement among TE and TM pulses, still reducing more the margin of error PPM of operation of the gates. Finally, to the we analyze the applied phases in the pulse TM (0 to 2), we defined the best phase angle for the gates to operate in the success area of the PPM modulation.