DFB LASERS WITH INTEGRATED ELECTROABSORPTION MODULATOR

We present high-performance 1550 nm DFB lasers with butt-coupled, bulk type integrated electroabsorption modulators of good manufacturabilit y and reliability. Key issues in device design are reviewed and the st rong influence of the exact detuning between lasing wavelength and mod ulator bandgap is demonstrated. Fibre-coupled output powers as large a s 6 dBm and attenuation efficiencies as high as 12 dB V-1 are obtained . Butterfly-packaged devices show only 1 dB penalty for 10 Gbits(-1) N RZ transmission over 50-km standard single-mode fibre (SMF) without th e use of an optical amplifier. With an optical booster amplifier, self -phase-modulation in the fibre is exploited and repeaterless 10 Gbits( -1) transmission is possible over 150-km standard SMF.