EML Based on Side-Wall Grating and Identical Epitaxial Layer Scheme

We, for the first time, present electroabsorption modulator lasers based on side-wall gratings and the identical epitaxial layer scheme using very simple fabrication processes. The devices show stable single-mode operation with little mode-hopping and a side mode suppression ratio of more than 45 dB, which is maintained until the applied current exceeds 6 times that of the threshold value. The drive voltage required to obtain a 12-dB extinction ratio is ${-}{\rm 2}~{\rm V}$ . The devices can be operated with a 3-dB bandwidth of 7 GHz allowing for error-free large signal modulation at 5 Gb/s with a dynamic extinction ratio of 11 dB.