Single stage high power L-band EDFA with multiple C-band seeds

We presented a multiple co- and counter-propagating C-band seed technique and its detailed evaluation by simulations and experiment using fibre gratings (FGs) for high power and broad bandwidth applications. This technique provides over 34 dB gain with 20 dBm of saturated output power with a NF of ∼5.5 dB within a 34 nm bandwidth with <1.6 dB in gain flatness in a single stage amplifier using only 980 nm pumps. Furthermore, the combination of preamplifier and high power seed designs may provide further improved L-band amplifiers with high dynamic range and broadband gain.