Intermodulation distortion in optical amplifiers from carrier-density modulation

Abstract

We present a theoretical model describing the generation of intermodulation products (IMPs) in semiconductor optical amplifiers by signal-induced carrier-density modulation. The IMPs depend strongly on the linewidth-enhancement factor and the ratio of output intensity to the saturation intensity of the amplifier. Calculation of the total intermodulation penalty for multichannel amplifier applications is possible using the expressions presented.