Publication: DISEÑO OPTIMIZADO DE AMPLIFICADORES RAMAN DISTRIBUIDOS (DFRAS) CONSIDERANDO MEZCLA DE CUATRO ONDAS
Loading...
Date
2012-12
Authors
LARA AQUEA, SEBASTIÁN ALONSO
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
En este trabajo se presenta un método de optimización para el perfil de ganancia de un am-
plificador Raman distribuido (DFRA) considerando la mezcla de cuatro ondas (FWM) generada
a partir de las bombas del mismo. Dicho método consiste en el uso de un algoritmo genético,
programado en forma paralela (MPI: Message Passing Interface), que considera los productos
FWM generados como nuevas bombas del DFRA, para efectos de la amplificación Raman. La
forma de incluir FWM en el proceso de optimización es utilizando el modelo matemático pre-
sentado en [23], que permite simular de manera simultánea la interacción entre el esparcimiento
Raman estimulado (SRS) y FWM. Se aplicó el algoritmo propuesto a dos sistemas WDM ampli-
ficados mediante DFRAs bombeados de manera directa; un DFRA de 20 nm de ancho de banda
y amplificado por 3 bombas, y otro de 40 nm de ancho de banda y amplificado por 4 bombas.
Además, para ambos casos el parámetro variable en cada simulación es la posición espectral de
la longitud de onda de dispersión cromática nula (ZDW). De esta manera, es posible simular
los casos crı́ticos de generación FWM, que corresponden a productos FWM degenerados y no-
degenerados. En el primer sistema WDM se obtuvieron perfiles de ganancia practicamente planos,
con ripples de potencia de salida tan bajos como 0,22 dB, cuando ZDW = 1438,14 nm, y tan
altos como 0,58 dB, cuando ZDW = 1450,72 nm. En cuanto al segundo sistema WDM, el menor
ripple obtenido es 0,41 dB, cuando ZDW = 1455,85 nm, mientras que el más alto es 0,96 dB,
cuando ZDW = 1446,70 nm. El algoritmo demostró un desempeño aceptable en la optimización
al obtener un ripple de potencia de salida menor a 1 dB, para todas las posiciones de la ZDW en
los dos sistemas WDM presentados. Los resultados obtenidos demuestran que existe un grado de
dificultad mayor al optimizar un sistema WDM con productos FWM no-degenerados, debido a
que en este caso el intercambio de energı́a entre las señales que interactúan en el proceso FWM,
posee un comportamiento oscilatorio más acentuado que en los casos degenerados.
An optimization method to obtain a flat-gain distributed fiber Raman amplifier (DFRA), con- sidering four-wave mixing (FWM) generated between the pumps, has been presented in this work. This method involves a genetic algorithm (GA) programmed under a message-passing interface (MPI) approach that takes into account FWM products as if they were new pumps for the Ra- man amplification. The mathematical model presented in [23] is used to include FWM products in the optimization process, since it allows to simulate the jointly interaction between the stimu- lated Raman scattering (SRS) and four-wave mixing. The proposed algorithm was applied in two WDM systems amplified by forward-pumped DFRAs. The first scenario has a bandwidth of 20 nm amplified by 3 pump-DFRA, while the second system has a bandwidth of 40 nm amplified by 4 pump-DFRA. Moreover, the location of the zero-dispersion wavelength (ZDW) is a variable parameter for all simulations, thus critical degenerated an non-degenerated FWM products, can be simulated. For the first WDM system, the minimum output power ripple obtained is 0,22 dB when ZDW = 1438,14 nm, and the maximum is 0,58 dB when ZDW = 1450,72nm. On the other hand, the minimun output power ripple for the second WDM system is 0,41 dB when ZDW = 1455,85 nm, while the maximun is 0,96 dB when ZDW = 1446,70 nm. All gain profiles obtained have a ripple lower than 1 dB, so the algorithm has proved to have a good perfomance trying to optimize the output power of a DFRA. The results show that is more difficult to op- timize a case with non-degenerate FWM products than a degenerate scenario, since they have a more pronounced oscillatory behavior along the fiber.
An optimization method to obtain a flat-gain distributed fiber Raman amplifier (DFRA), con- sidering four-wave mixing (FWM) generated between the pumps, has been presented in this work. This method involves a genetic algorithm (GA) programmed under a message-passing interface (MPI) approach that takes into account FWM products as if they were new pumps for the Ra- man amplification. The mathematical model presented in [23] is used to include FWM products in the optimization process, since it allows to simulate the jointly interaction between the stimu- lated Raman scattering (SRS) and four-wave mixing. The proposed algorithm was applied in two WDM systems amplified by forward-pumped DFRAs. The first scenario has a bandwidth of 20 nm amplified by 3 pump-DFRA, while the second system has a bandwidth of 40 nm amplified by 4 pump-DFRA. Moreover, the location of the zero-dispersion wavelength (ZDW) is a variable parameter for all simulations, thus critical degenerated an non-degenerated FWM products, can be simulated. For the first WDM system, the minimum output power ripple obtained is 0,22 dB when ZDW = 1438,14 nm, and the maximum is 0,58 dB when ZDW = 1450,72nm. On the other hand, the minimun output power ripple for the second WDM system is 0,41 dB when ZDW = 1455,85 nm, while the maximun is 0,96 dB when ZDW = 1446,70 nm. All gain profiles obtained have a ripple lower than 1 dB, so the algorithm has proved to have a good perfomance trying to optimize the output power of a DFRA. The results show that is more difficult to op- timize a case with non-degenerate FWM products than a degenerate scenario, since they have a more pronounced oscillatory behavior along the fiber.
Description
Keywords
DFRAS , FWM , ALGORITMO GENÉTICO , MPI , REDES ÓPTICAS WDM