Error-free 56 Gb/s NRZ modulation of a 1530-nm VCSEL link

We demonstrate a 1530 nm VCSEL that can operate error-free without DSP or FEC to 56 Gb/s. At 50 Gb/s, error-free operation is attained up to 2 km of SMF. A two-tap FFE driver is used to precompensate the response of the VCSEL. The optical spectrum of the VCSEL under equalization at 50 Gb/s is analyzed and the chirp properties are reported. The low latency of FEC-free NRZ and the distance of 2 km makes these technology suitable for optical links in both high performance computing and large data centers.