Signal amplification in rare-earth doped heavy metal germanium tellurite glass fiber

Abstract

Rare-earth doped heavy metal germanium tellurite (NZPGT) glass fibers with lower maximum phonon energy of 793 cm−1 and UV-sensitivity property have been designed and fabricated. Bright and compact upconversion traces have been observed in Er3+/Yb3+ and Tm3+/Yb3+ codoped NZPGT glass fibers, which exhibit favorable flexibility and excellent thermal stability, indicating that the NZPGT glasses are a desirable candidate for fiber amplifiers. The Er3+/Yb3+ codoped NZPGT glasses present a broad emission at ~1.5 μm with the FWHM of 72.7 nm, and the maximum internal gain of 12.59 dB with a remarkable gain coefficient of 2.38 dB/cm in the C-band were achieved in a Er3+/Yb3+ codoped NZPGT glass fiber. The efficient three-photon blue and two-photon near-IR upconversion emissions of a Tm3+/Yb3+ codoped NZPGT glass fiber demonstrate that low phonon energy NZPGT glasses have promising potential applications in Tm3+ single-doped glass fibers for S-band signal amplification, and the further development of O- and U-band fiber amplifiers and lasers in Pr3+ and Ho3+ doped NZPGT glass fibers.