Comparison of WDM coupler technologies for use in erbium doped fibre amplifier systems
Fused-tapered and interference filter technology are compared for specific application in 1480 nm pumped erbium doped fibre amplifiers as WDM multiplexers for signal and pump light. In particular, the temperature, polarisation and wavelength dependence of the coupling ratio are measured and the implications for amplifier gain variability are discussed.