Noise figure of saturated erbium-doped fiber amplifiers: electrical versus optical measurement

It has been predicted that erbium-doped fiber amplifiers (EDFAs) might show a reduction of the noise figure (NF) when operating in saturation. Recently Willems and van der Plaats reported significant reduction in the electrically measured NF of a saturated EDFA compared to the values obtained using an optical NF measurement technique. In this paper we describe a comparison using an electrical NF measurement technique. We show the experimental setup for electrical NF measurement. The noise power is measured using an RF power meter (RFPM) and an electrical bandpass filter (BPF).