Quantum-interference effects for gain leveling in optical fibers

Abstract

A four-level system is proposed to explore the quantum-interference effects on optical amplification. It is found that the gain of the probe including positions and values of gain peaks can be adjusted by changing the coherent field and the incoherent pumping. As an application of the results, a scheme composed of three same ${\mathrm{Er}}^{3+}$-doped ${\mathrm{ZrF}}_{4}\ensuremath{-}{\mathrm{BaF}}_{2}\ensuremath{-}{\mathrm{LaF}}_{3}\ensuremath{-}{\mathrm{AlF}}_{3}\ensuremath{-}\mathrm{NaF}$ Optical Fibers with different coherent fields and incoherent pumpings is brought forward to equalize the gain of the probe.