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.