Generation and Transmission of 100-Gb/s PDM 4-PAM Using Directly Modulated VCSELs and Coherent Detection

Abstract

We generate a 100-Gb/s polarization-division-multiplexed 4-level pulse-amplitude-modulation signal with two directly modulated 1.5-μm single-mode VCSELs. Coherent detection and digital signal processing enable the transmission over 400-km standard single-mode-fiber (SSMF) with 20% overhead hard-decision forward-error-correction.