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/sub "on level"/=0 V (P/sub ave/=2 dBm), over a large range of operating conditions (laser current: 50-120 mA, temperature: 15/spl deg/-35/spl deg/C, laser wavelength: 1550 /spl plusmn/5 nn). This is a very attractive source for easy-to-implement long-haul WDM systems.