Amplificador Raman discreto para utilização em transmissão CWDM na banda O

• Autor(a) principal: Saito, Lúcia Akemi Miyazato
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/24353
• topic: amplificador óptico; amplificador Raman discreto; banda O; CWDM; optical amplifier; lumped Raman amplifier; O-band; CWDM; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA

Most of researches about Raman amplifier had been made in C and L bands (1530-1625 nm), which is possible to found more data of Raman efficiency gain and the requirements for design is consolidated. The first issue that should be considered when the amplifier is to use in another band, like our project (O-band) is to consider the decrease of effective area and wavelength in the calculation of Raman efficiency, not only the pump wavelength. We have two configuration types: for the first one, the gain is obtained in the transmission fiber and for the second that is demonstrated in this work, we need special fibers as DSF, DCF and Raman fiber to amplifier the signals. Note that the amplification can be obtained in any band of optical spectrum, which depends on the pump wavelength that is used for made it. Our studies demonstrated that the discrete Raman amplifier that was made of Raman fiber of OFS Fitel Denmark was more efficient in short wavelengths and has more improvement when it was working in O-band. In spite of the higher attenuation, we can have higher Raman gain efficiency (CR) because the effective area (Aeff) decreased in short wavelengths. The characteristics of Raman fiber were studied when we found the Raman gain efficiency peak of 3.9 (W.km)-1 for a pump laser of 1240 nm wavelength. For this case, the gain of O-band amplifier was about 50 % higher when we compared with the C-band. For a CWDM system, we need to design a multi-pump amplifier. It is necessary four pump lasers to amplifier a bandwidth of 70 nm and six pump lasers to cover all O-band. The gain value depends on the pump power and if we want a good result, we should verify the total power of channels in the input of amplifier to avoid the device saturation. In addition, the noise figure of Raman amplifier was studied and then we found results that demonstrated higher noise values in short wavelengths specially, when we need to locate some pump lasers between signal wavelengths.