New WDM optimized integrated laser-electroabsorption modulator for 1000-km 2.5-Gb/s transmission over a wide range of operating conditions

The performances of electroabsorption (EA) modulators integrated with a DFB laser (EA-DFB) are limited by optical feedback and chirp characteristics. Moreover, these devices are very sensitive to the operating conditions due to their very sharp characteristics. We report a new EA-DFB design that totally suppresses optical feedback and shows very smooth characteristics. Transmission over 1000 km of standard dispersion fiber is achieved reproducibly with V-{''}on level{''} = 0 V (P-ave = 2 dBm), over a large range of operating conditions (laser current: 50-120 mA, temperature: 15 degrees C-35 degrees C, laser wavelength: 1550 +/- 5 nm), This is a very attractive source for easy-to-implement long-haul WDM systems.