Optical gain changes as a function of distance along a long distributed erbium-doped fiber amplifier were measured, using optical-time-domain reflectometry. Two dispersion-shifted erbium-doped fibers with fiber lengths of 9–19 km and doping concentrations of 0.5 (0.5 × 10−4 wt %) and 0.1 (0.1 × 10−4 wt %) parts in 106 have been tested, using 1.48-μm InGaAsP laser diode and 0.98-μm Ti:sapphire laser pump sources. It is shown how local gain and loss change with an increase in pump power.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics