
5.2 SINGLE-MODE FIBER 980-NM PUMPS
Today, C and L band EDFAs are preferably pumped at 980 nm, resulting in lower
noise figure, lower overall power consumption [9], and providing ample power since
the availability of reliable high-power, Peltier-cooled 980-nm pump modules.
Undersea intercontinental links, based on dense wavelength-division multiplex-
ing (DWDM), impose the most demanding requireme nts on single-mode (SM)
fiber 980-nm pump diodes. For the undersea application, highly efficient and
reliable pump modules operating over a wide temperature range (without Peltier
temperature stabilization) had to be developed (Figure 5.1).
5.2.1 Materials