26 Gbit/s Direct Modulation of AlGaInAs/InP Lasers with Ridge-Waveguide Structure Buried by Benzocyclobutene Polymer

26 Gbit/s direct modulation of 1.3degm wavelength AlGaInAs/InP distributed feedback lasers with the ridge-waveguide structure (ridge width of 1.0degm) buried by the benzocyclobutene polymer was achieved. The high electrical bandwidth of more than 20 GHz was acquired with this ridge-waveguide structure. Consequently, a clear eye-opening with extinction ratio of 6 dB was confirmed in the measurement temperature of 25degC.