Study on the dynamics of a gain spectral hole in silica-based erbium-doped fiber at $77\mathrm{K}$

Abstract

A study on the dynamics of gain spectral hole burning (GSHB) in a silica-based erbium-doped fiber amplifier at $77\mathrm{K}$ was performed. When a saturation signal was input into an ${\mathrm{Er}}^{3+}$-doped fiber, a multigain spectral hole structure that consisted of nine gain spectral holes, was observed in the wavelength region from $1510\text{to}1640\mathrm{nm}$ at $77\mathrm{K}$. As for the ${\mathrm{Er}}^{3+}$ ion concentration dependence of these gain spectral holes, the depth of the gain spectral hole at around $1530\mathrm{nm}$ was found to become shallower in the silica-based erbium-doped fiber that had higher ${\mathrm{Er}}^{3+}$ ion content. This ${\mathrm{Er}}^{3+}$ ion concentration dependence of the gain spectral hole depth suggests that the contribution of the energy-transfer interaction between ${\mathrm{Er}}^{3+}$ ions excited to the Stark levels within the ${}^{4}I_{13∕2}$ manifold plays an important role in the gain spectral hole formation at $77\mathrm{K}$. As far as we know, this is the first report of the ${\mathrm{Er}}^{3+}$ ion concentration effect on the GSHB in the ${\mathrm{Er}}^{3+}$-doped fiber. The dynamics of GSHB is discussed in relation to the effect of energy transfer between ${\mathrm{Er}}^{3+}$ ions. In addition, the relation between gain spectral hole structure and the Stark energy structure of ${\mathrm{Er}}^{3+}$ ion is also discussed.

© 2005 Optical Society of America