Tm-doped fiber amplifiers in the 1480nm region with 980nm/1550nm pumps

Thulium doped fiber amplifier performance in S band using two different complementary pumping wavelengths

“…In this case, 1550 nm pump injects Tm ions into the 3F4 level through ground-state absorption. These excited ions are elevated further by 980 nm pump to 3F2 and 3F3 levels, and then relax rapidly down to the 3H4 level [6]. In the 1047 nm pump the cross-section of the excited state absorption (ESA) at about 1047 nm is higher than the cross-section of the ground state absorption (GSA) from the level 3F4 at this range of wavelength.…”