2R-Regeneration in a monolithically integrated four-section SOA–EA chip

Optical regeneration using a monolithically integrated chip formed by a cascade of semiconductor optical amplifiers and saturable absorbers is investigated. Static transfer functions, signal reshaping, extinction ratio enhancement, noise dynamics and device dependence on operation conditions are measured. Results show that by cascading two-pairs of SOA–EAs a steep static transfer function is achieved. Dynamical measurements show large improvements in extinction ratio as well as a large improvement in the receiver-sensitivity when used as a regenerator for NRZ signals at 10 Gb/s.