4x10-Gb/s CWDM Transmission using VCSELs from 1531nm to 1591nm

Introduction Coarse wavelength-division multiplexing (CWDM) is becoming increasingly important for optical access applications [1,2]. It allows to deploy low-cost shortreach links with appreciable capacity using a 20-nm wavelength grid between 1271 nm and 1611 nm. Recent research has pushed per-channel CWDM bit rates to 10 Gb/s with transmission distances of more than 40 km using directly modulated distributed feedback (DFB) lasers [3]. Lately, the use of low-cost vertical cavity surface emitting lasers (VCSELs) has been proposed for such short-reach applications [4]. Combined with electronic dispersion compensation and forward error correction (FEC) single-wavelength transmission over 40 km was demonstrated. In this paper we report 4-channel CWDM transmission over standard single-mode fiber (SSMF) using commercially available VCSELs that cover the CWDM band from 1531 to 1591 nm. We operate at a bit rate of 10.7-Gb/s, thus enabling enhanced FEC, but we do not use any dispersion compensation, neither optical nor electronic.