Theoretical and experimental analysis of double-pass ytterbium-doped fiber amplifier

摘要

We theoretically and experimentally demonstrate a double-pass ytterbium-doped fiber amplifier. First, we numerically analyze the impact of fiber length on the amplifier. In our experiment, a laser seed with output power of ～100 μW and wavelength of 1064 nm is amplified to 51.2 mW with a signal gain of 27.1 dB. With this double-pass configuration, amplified spontaneous emission (ASE) is effectively suppressed to more than 30 dB. Compared with single pass configuration, it is found that double-pass amplification configuration enhances the gain coefficient and improves the signal-to-noise ratio.