Recently, multigigabit repeaterless transmission using optical amplifiers has been actively studied for terrestrial longspan transmission and undersea island or coastal link applications. Here, the main thrusts are achieving high transmitting optical power, high receiver sensitivity and minimum dispersion penalty. This paper reports a practical 5 Gb/s IM-DD system for repeaterless longspan transmission with an emphasis on its long term performance. The transmitting power is +15.5 dBm with SBS suppression and an optical pre-amplifier receiver provides a receiver sensitivity of -35 dBm for 10-15 BER (or -38 dBm for 10-9 BER). A Ti:LiNbO3 modulator transmitter allows 226 km repeaterless transmission through non-DSF with a dispersion penalty less than 2 dB, corresponding to a total dispersion of 4100 ps/nm.
© 1992 Optical Society of AmericaPDF Article