2.5-Gb/s transmission over 50 km with a 1.3-μm vertical-cavity surface-emitting laser

We demonstrate error-free 50-km transmission at 2.5 Gb/s over standard single-mode fiber using an optically pumped 1.3-μm vertical-cavity surface-emitting laser operating at 25/spl deg/C. No optical isolator or amplification was used in the transmission demonstration. System backreflection sensitivity measurements were conducted for various fiber distances and reflection feedback levels. The results indicate a transmission power penalty of 0.1 dB at a bit-error rate of 10/sup -9/ for a reflection feedback level of -25 dB with the reflection originating at 5 m.