A diode-laser-pumped, Er³⁺-doped fibre laser operating at 1.57µm

Abstract

Erbium-doped fibers show promise as stable narrow-linewidth laser sources and optical amplifiers operating in the third telecommunications window around 1.55 μm Diode laser pumping is possible using the weak pump-band located at 807nm, although this band suffers severely from excited-state absorption (ESA), which reduces gain and pump efficiency. At the low pump power available from diode lasers the Er³⁺ behaves as a quasi four-level system. However, by codoping the core glass heavily with Yb³⁺, it is possible to excite the Er³⁺ ions indirectly using energy transfer. The Yb³⁺ provides an intense broad pump-band centered at 900nm, which reduces the effect of ESA. As a consequence of the resulting higher pump efficiency, the laser will oscillate at the required shorter wavelengths.

OFC '89 Houston USA Feb (1989)

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