Proceedings Article | 16 November 2004
KEYWORDS: Raman spectroscopy, Fiber amplifiers, Fiber lasers, Optical amplifiers, Fiber Bragg gratings, Fiber optic networks, Raman scattering, Optical fibers, Wavelength division multiplexing, Optical networks
Distributed Raman amplifiers (DRAs) are an enabling technology for long- haul and metropolitan- area broadband optical networks. These devices utilize the stimulated Raman scattering process in order to achieve gain over the bandwidth of ~ 40 THz from the transmission fiber itself. While DRAs’ offer various advantages by their ubiquitous presence in the transmission path, they also pose challenges such as gain flattening in the broadband spectral regime. Evidently, one cannot use fiber Bragg gratings (FBGs) and other filtering devices such as thin-films filters. However, gain flattening over wideband can be achieved using multi–wavelength (multi-λ) pumping [1], that is accomplished with spectral slicing based on Raman fiber lasers (RFLs). Novel test amplifiers have been designed and simulated with various pump parameters such as the number of RFLs pumps, their wavelengths, and relative powers. The results obtained using a 6-λ pump module in the range 1460-1510 nm, showed a better gain-flattened amplification [2]. We have designed various network test topologies, which are simulated using commercially available software packages. A 6- λ pump module using 2 to 5 pairs of fiber Bragg gratings [2] seems optimal. The output FBGs are tunable in order to provide reconfigurable pump module. Details of the results and design optimization will be presented.
[1] Y. Cao, M. Y. A. Raja, “Gain-Flattened Ultra Wide Band Fiber Amplifiers,” J. Opt. Eng., Vol. 42,
No. 12, 3347-3451 (2003).
[2] Y. Cao, J. G. Naeini, K. Ahmad, and M. Y. A. Raja, “Gain-flattened Distributed Raman
Amplification using Multi-l Raman Fiber Laser Pumping”, presented in OISE’03, Orlando, FL.
