Performance Analysis of Distributed Raman Amplifier Using Different Pumping Methods in DWDM Communication Systems

Abstract

The objective of this work is to investigate and compare the impact of forward, backward and bidirectional pumping methods in repeater less distributed Raman fiber amplifier system and to analyze its benefits in long haul optical communication links. The effect of different pump wavelengths and pump powers are also analyzed. By adjusting the forward pump power as well as backward pump powers carefully, the transmission performance can be improved. The pump power ratio is adjusted to 20% so that the degradation of signal due to non-linear effect is reduced. The distributed gain and pump penetration depth for different pump power ratios are also examined. A comparison of different pumping methods reveals that bidirectional pumping gives the optimum performance in terms of higher gain and lower noise figure when compared to single pumps and unidirectional pumping. Low pump power ratios lead to better transmission performance than higher pump ratios due to lesser non-linear effects. The simulation results indicate that signal power evolution decreases with the increase in length of the fiber. It is also found that the pump power is more relevant during the first 50 km of the distributed fiber line and it decreases as it goes beyond 100 km. By choosing the optimum pumping methods and number of pumps, Raman Amplifiers can be used in almost all places where optical amplifiers are required.

Investigations on the performance of distributed Raman amplifier in dense wavelength division multiplexed communication system using different modulation formats

“…So the best choice will be designing a DRA with optimized multiple bidirectional pumping 23 . We had investigated the different types of pumping that can be used for DWDM links using DRAs in our earlier work 9 . Care must be taken to use low RIN valued pumps for forward pumping because the transmission performance can be degraded due to RIN transfer at high pump powers.…”

“…We had investigated the different types of pumping that can be used for DWDM links using DRAs in our earlier work 9 . In this article, we have analyzed the performance of distributed Raman amplifier in a communication link of a maximum of 80 km length using different modulation formats based on bit error rate (BER) and Q factor through simulations.…”