Real-Time 100 Gb/s NRZ and EDB Transmission With a GeSi Electroabsorption Modulator for Short-Reach Optical Interconnects
Transceivers based on electroabsorption modulators (EAM) are considered as a promising candidate for the next generation 400 GbE short-reach optical networks. They are capable of combining high bandwidth and low-power operation with a very compact layout, removing the need for traveling wave electrodes and dedicated 50  <inline-formula><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula> termination. In this paper, we demonstrate the first silicon-based EAM, in combination with an in-house developed SiGe BiCMOS transceiver chipset, capable of transmitting single-lane 100 Gb/s non-return-to-zero in real-time. Transmission over 500 m of standard single mode fiber and 2 km of nonzero dispersion shifted fiber is demonstrated, assuming a forward-error coding scheme is used with a bit-error ratio limit of <inline-formula><tex-math notation="LaTeX">$3.8\times 10^{-3}$ </tex-math></inline-formula>. Due to the high line rate, transmission over longer fiber spans was limited by the chromatic distortion in the fiber. As a possible solution, electrical duobinary modulation is proposed as it is more resilient to this type of fiber distortion by reducing the required optical bandwidth. We show improved performance for longer fiber spans with a 100 Gb/s electrical duobinary link, resulting in real-time sub-forward error coding operation over more than 2 km of standard single-mode fiber without any digital signal processing. Finally, the possibility of a 100 Gb/s EAM-to-EAM link is investigated.