Performance improvement of wideband EDFA by ASE injection from C band to L band amplifier

We propose a novel structure for an wideband EDFA, which use backward amplified spontaneous emission from the C-band EDFA as the injection seed source for the L-band amplifier. Experimental results show gain and noise figure improvement over 2.6 dB and 0.6 dB respectively for the L-band EDFA at -3.5 dBm input signal, with negligible crosstalk between the amplifiers.