150-µm-band gain-shifted thulium-doped fiber amplifier with 105- and 156-µm dual-wavelength pumping

We propose and demonstrate a $1.50‐\mathit{\mu }\mathrm{m}‐\mathrm{band}$ gain-shifted thulium-doped fiber amplifier (TDFA) by using a novel dual-wavelength $\left(1.05 \mathrm{and} 1.56‐\mathit{\mu }\mathrm{m}\right)$ pumping scheme for what we believe is the first time. By providing a small amount of $1.56‐\mathit{\mu }\mathrm{m}$ power to a conventional upconversion-pumped TDFA, we successfully demonstrated a small-signal gain larger than 25 dB and a noise figure of 5 dB in a 1475–1510-nm band.