Pattern effect reduction scheme for high-speed all-optical amplification system

A method for high-bit-rate optical pulse amplification without a pattern effect (PE) phenomenon is numerically analyzed and presented. In the proposed new scheme, the input signals are applied to a series of 1×2 optical switches and semiconductor optical amplifiers (SOAs). Based on the input signal bit rate and the desired PE reduction rate, it is shown that the number of these devices can be easily optimized. For reducing the SOA nonlinearities on the output signal, a high-birefringent fiber loop mirror is used as an optical Gaussian filter. The achieved results depict that symmetry and the time-bandwidth product of the output signal obtained by this filter are significantly improved. The simulations are performed for high bit-rate signals (<50  Gbps); therefore, in the SOA model, all relevant nonlinear effects that occur in the subpicosecond regimes are taken into account.