High-speed 1550 nm VCSEL data transmission link employing 25 Gbaud 4-PAM modulation and Hard Decision Forward Error Correction

Current short-range optical interconnects capacity is moving from 100 Gb/s to 400 Gb/s and beyond. Directly modulation of several laser sources is used to minimize bandwidth limitations of current optical and electrical components. Either this total capacity is provided by wavelengthdivision- multiplexing or parallel optics, it is important to investigate on the ultimate transmission capabilities of each laser source to facilitate current capacity standards and allow for future demands. High-speed 4-level pulse amplitude modulation at 25 Gbaud of a 1.5 #x00EC;m VCSEL is presented in this paper. The 20 GHz 3 dBbandwidth laser is, at the time of submission, the largest bandwidth of a 1.5 #x00EC;m VCSEL ever reported. Forward error correction (FEC) is implemented to achieve transmission over 100 m virtually error-free after FEC decoding. Linerate of 100 Gb/s is achieved by emulation polarization multiplexing using 50 Gb/s signal obtained from a single VCSEL.