NRZ, DB, and DMT performance for short-reach VCSEL-based optical interconnects

In this paper, we perform a comparison of three modulation formats: NRZ, duo binary and DMT in combination with the state of the art 850 and 910nm VCSELs for their application in short reach high speed optical links. The system for NRZ and DB utilizes feasible for deployment equalization including a 9-tap finite impulse response filter and raised cosine filtering in the transmitter and a 7-tap UI-spaced feed forward equalizer in the receiver. The 100 Gbit/s net link with DB modulation can be realized without applying receiver equalization. For DMT the highest gross data rate of 224 Gbit/s/lambda is achieved.