Double-Seeding of Er/Yb Co-Doped Fiber Amplifiers for Controlling of Yb-ASE

In this paper, we present our investigations on controlling the amplified spontaneous emission from Yb ions in erbium/ytterbium co-doped fiber amplifier by double-seeding of the amplifier with nominal (1.55 μm) and auxiliary (1 μm). The dependence of the amplifier output power on the auxiliary seed wavelength and input power is analyzed. The obtained results are discussed and compared to a conventional amplifier setup without auxiliary seed signal. Our studies show that introducing an auxiliary seed at proper wavelength from the Yb-band provides stable amplifier operation without parasitic lasing at 1 μm and can also increase output power of the nominal 1550 nm signal.