Transmission characteristics of uncooled and directly modulated 1.3 micrometers distributed feedback laser diode for serial 10 Giga bit Ethernet

We have developed uncooled and directly modulated /spl lambda//4 shifted 1.3 /spl mu/m DFB laser diodes for 10 Gb/s Ethernet. By adopting a short cavity structure, a high relaxation oscillation frequency of 12.0 GHz at 25/spl deg/C was obtained. Even at 70/spl deg/C, it was over 10.4 GHz. The extinction ratio was 9.8 dB and the frequency bandwidth was 14 GHz at 25/spl deg/C. The power penalty of 0.6 dB at a BER of 10/sup -11/ through a +40 ps/nm dispersion SMF was obtained. This device is useful for 10 Gb/s Ethernet using over 20 km SMF without cooler.