40 GB/s Tandem Electro-Absorption Modulator

We have developed a tandem electro-absorption modulator with an integrated semiconductor optical amplifier that is capable of both NRZ and RZ data transmission at 40 GB/s. The tandem modulator consists of a broadband data encoder and a narrow band pulse carver. The pulse carver is able to produce 5 ps pulses with more than 20 dB of extinction. The on chip SOA provides up to 8.5 dB of fiber-to-fiber gain and enables the modulator to be operated with zero insertion loss. Devices have been realized with greater than 40 Ghz bandwidth, and 13 dB dynamic extinction for a 2.5V swing. For optimized designs, bandwidths as high as 60 GHz have been realized. Using these devices, penalty free RZ data transmission over a 100 km dispersion compensated fiber link has been demonstrated with a received power sensitivity of -29 dBm.