Very-low-driving-voltage electroabsorption modulators operating at 40 Gb/s

This paper has demonstrated a 40-Gb/s low-driving-voltage electroabsorption modulator (EAM) having InGaAlAs/InAlAs multiquantum-well active core. A narrow core buried with polyimide provides a strong optical and electrical confinement, resulting in a maintained large extinction ratio (ER) and an increased 3-dB down frequency. The fabricated EAM shows a 3-dB down frequency as large as 46 GHz, even for the active-core length as long as 200 /spl mu/m. The EAM operates at 40 Gb/s with an RF ER of 10.5 dB at a driving voltage as low as 0.79 V.