L-band erbium-doped fiber amplifiers

WDM systems are being planned that will use the long-wavelength (L-band) or extended (E-Band) band of the erbium-doped fiber in coordination with the conventional band (C-band). Appending the L-band will ultimately double the available transmission bandwidth and reduce impairments due to nonlinearities in the fiber plant. The development of L-band EDFAs is proceeding at an aggressive pace, and it is anticipated that these next generation amplifiers will have a significant impact on lightwave communication systems in the very near future. This paper introduces (1) the motivation for L-band amplifiers, (2) technical issues related to development of commercial amplifiers, and (3) fundamental differences between C-band and L-band behavior.