Amplified spontaneous emission and gain-saturation nonlinearity in high-gain optical amplifiers: The biased amplifier

Abstract

The systematics of amplified spontaneous emission and gain‐saturation nonlinearity in high‐gain optical amplifiers are explored. It is shown that of all the variations of the several dimensionless parameters that occur, only a reduction of the small‐signal gain‐length product can simultaneously minimize these two problems. Furthermore, of the various possible changes of the dimensional quantities that make up the gain‐length product, increasing the saturation intensity achieves the highest overall gain for a given measure of distortion, and the least distortion for a given value of overall gain. This leads to the concept of the biased amplifier, one version of which is then treated in detail numerically.