FUNDAMENTAL LIMITS ON ND3+-DOPED FIBER AMPLIFIER PERFORMANCE AT 1.3 MU-M

To explore the fundamental limits on performance at 1.3 μm, a model for Nd3+-doped fiber amplifiers which includes signal saturation and excited state absorption (ESA) at the signal wavelength has been constructed. Ignoring ESA, the difference in pump efficiency (dB / mW) between a low-performance and high-performance glass host is = 60%, indicating that ESA is the critical parameter distinguishing experimental results reported for different materials. The pump efficiency for a linear NdNd3+ amplifier is an order of magnitude less than for an Er3+ amplifier without ESA and degrades still further with its inclusion. Applications as power amplifiers are more promising because, in principle, high power conversion efficiencies can be obtained. © 1990 IEEE