High-Frequency Characteristics of 40Gb/s Electroabsorption Modulator-Integrated DFB Lasers: Effect of Traveling-Wave Electrode and Tilted Facet

We fabricated 40 Gb/s electroabsorption modulator-integrated DFB lasers (EMLs). Adopting traveling-wave (TW) electrode and tilted facet improved high-frequency characteristics of EMLs. The 3 dB bandwidth of E/O response for TW-EML was as large as 34 GHz, as compared with 27 GHz for lumped EML. Tilted facet formed by dry etching processes successfully reduced the optical feedback and the resonance in E/O response decreased to as small as 2.8 dB.