Chirp-inducing mechanisms in Mach-Zehnder modulators and their effect on 10 Gb/s NRZ transmission studied using tunable-chirp single drive devices

We study the effects of different mechanisms inducing chirp in single-drive Mach-Zehnder modulators (MZM). In particular, we compare the effect of optical power splitting ratio unbalance with radio frequency modulation unbalance on the two interferometer arms. The better transmission performances of optically unbalanced modulators are ascribed to the different shape of time resolved chirp factor. Finally, we demonstrate error-free uncompensated transmission over 130-km fiber span.