100 GBd Intensity Modulation and Direct Detection With an InP-Based Monolithic DFB Laser Mach–Zehnder Modulator

Abstract

We demonstrate 100 GBd operation of an optical transmitter module including a distributed feedback laser monolithically integrated with a Mach-Zehnder modulator (DFB-MZM), to the best of our knowledge for the first time. Combining high-speed optics and electronics with digital signal processing (DSP), different schemes for intensity modulation and direct detection at 100, 200, and 300 Gbit/s are analyzed, using electrical signals from a 100 GSa/s BiCMOS DAC. Due to close-to-zero transmitter chirp, 100 Gbit/s NRZ transmission over 1.8 km and 200 Gbit/s PAM4 transmission over 1.2 km at 1550 nm with a bit error rate (BER) below the 7% overhead forward error correction (FEC) threshold (3.8 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ) is achieved. At 200 Gbit/s PAM4, the DFB-MZM module consumes only 0.85 pJ/bit, making it a promising device for attractive dual-lane 400 Gbit/s systems. We also achieve 300 Gbit/s PAM8 transmission over 1.2 km with a BER below the 20% overhead FEC threshold (1.9 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ) by implementing advanced DSP based on a pattern-dependent lookup table to mitigate the electrical and optical device bandwidth limitations.