Study of optical gain and noise characteristics in novel zirconia codoped Erbium fibres

We have fabricated new type of erbium doped fibre having core glass compositions of zirconia-yttria-alumino-phospho-silicate. With the proper combination of zirconia and aluminium with other codopants, high concentration of 4000 ppm erbium-ions was doped in the fibre core-glass by conventional MCVD and solution doping process without any phase-separation. The fabricated fibre exhibited wide gain band-width covering both C and L bands. The optical gain and noise characteristics were studied for both single-channel and multi-channel amplification at C-band regime for different input signal levels. This novel zirconia-erbium-doped fibre (Zr-EDF) has produced intrinsically flat gain of maximum gain-difference of 2dB with average optical gain 22.5dB and noise figure of 4.5 dB for simultaneous four-channel amplification at input signal level of -30dBm/channel in the optimized condition. The performances of Zr-EDF in terms of gain-flattening and noise characteristics were found to be promising for small-signal multi-channel amplification which would be applicable in dense-wavelength division multiplexing (DWDM) system.