Compensation of the pattern effect in SOAs

Degradation of high power signals is observed at bitrates comparable to the gain recovery in Semiconductor Optical Amplifiers (SOA). The device studied here reduces this pattern effect of SOAs. It is a non-linear Mach-Zehnder interferometer with a SOA in each branch. It has an unequal input power distribution over the branches, which themselves are identical. This causes destructive interference at the output for low power inputs. Conversely, different phase shifts for high power inputs result in constructive interference. Therefore, gain saturation is observed for much higher input powers. This results in reduced pattern effects. Simulations and experiments confirm the performance