100 Gbit/s VSB-PAM-n IM/DD transmission system based on 10 GHz DML with optical filtering and joint nonlinear equalization.

We experimentally demonstrate the transmission of 100 Gbit/s and beyond vestigial sideband (VSB) n-level pulse amplitude modulation (PAM-n) signals, with a commercial 10 GHz-class directly modulated laser (DML) in the C-band, using optical filtering. To mitigate transmission impairments at the transmitter side, Nyquist pulse shaping and Kaiser Window filtering techniques are used to overcome the limited bandwidth of optoelectronic devices. At the receiver side, the joint nonlinear equalization based on cascaded multi-modulus algorithm (CMMA) and Volterra Filter (VF) is used to reduce the strong nonlinear impairments from chirp and chromatic dispersion (CD). 100 Gb/s PAM-4, 107.5 Gb/s PAM-4, and 101.25 Gb/s PAM-8 signals can be successfully transmitted over 45 km, 10 km and 10 km standard single-mode fiber (SSMF) under the bit-error-ratio (BER) of 3.8 × 10, respectively.