Influence of Pump Properties on the Tunability of 1.5 μm Low-Noise Single Frequency Fiber Amplifier

In this work, we investigate the impact of the pump configuration (wavelength and pump scheme i.e., backward forward) on the tuning range in a watt level low intensity noise single-frequency Erbium/Ytterbium doped fiber amplifier. Two different pump wavelengths, 976 nm and 940 nm, and three different pumping schemes were numerically and experimentally investigated. Tunability over 47 nm (1533 nm-1580 nm) with relative intensity noise level as low as −155 dB/Hz is achieved using an unconventional pumping scheme where the active fiber is pumped in both directions with two different pump wavelengths.