SIGNAL TRANSMISSION PERFORMANCE AT 1550NM OVER DIFFERENT FIBER LINKS

We experimentally characterized and optimized the performance of a vertical cavity surface-emitting laser (VCSEL) in a communication link. VCSEL at 1550nm transmission windows was chosen for data rate of 10 G bps for metro networks due to its wavelength tune ability, cost and energy efficiency. The optical link was evaluated through Bit Error Rate (BER) measurements for 17 km over G.652 traditional fiber and compared to 24.69 km of Single Mode Fiber-Reduced Slope (SMF-RS) at 5.5mA bias current. The corresponding eye diagrams at telecommunication BER threshold of 10-9 were captured on the scope. The BER for the two measurements were then compared. Transmission over 24.69 km on G.655 SMF-RS was achieved with a penalty of 1.39dB with respect to B2B. The G.652 fiber at 1550 nm yields non optimal performance due to its high dispersion coefficient of 17ps/(nm.km)and this therefore provided a better platform to compare performance of the two fibers. The maximum transmission distance of 74.91km was achieved over G.655 fiber with a penalty of 0.717dB with respect to Back to Back (B2B). At transmission distance of 24.69km a power penalty of 0.131dB was incurred while at 49.42 km a power penalty of 0.391dB was incurred. This therefore proved that shorter distances yielded better results which were observed with high receiver sensitivity. Therefore, with the increase in distance high power is needed to compensate for dispersion effects. This study is vital in enhancing awareness on the effects of CD on the already laid fibers and hence looking for methods to mitigate the effects for the next-generation optical fiber networks.