Detailed theoretical investigation and comparison of the cascadability of conventional and gain-clamped SOA gates in multiwavelength optical networks

A detailed theoretical investigation of the cascadability of gain-clamped semiconductor optical amplifiers (GCSOAs) and SOAs in wavelength-division-multiplexed networks is presented. The analysis shows that the cascadability of SOAs is limited by degradation of both extinction ratio and ASE accumulation, whereas the cascadability for GC-SOAs mainly is limited by an accumulation of amplified spontaneous emission. This results in superior cascadability of GC-SOAs at a channel bit rate of 2.5 Gb/s in systems with up to at least 16 channels even when compared to short cavity SOA gates.