16 Gbit/s transmission experiments using a directly modulated 1.3 mu m DFB laser

A 16 Gb/s electrically time-division-multiplexed lightwave link is discussed. The 16 Gb/s electronic signal was generated by multiplexing together eight copies of the 2-Gb/s pseudorandom sequence (length 2/sup 15/-1) produced by a commercial BER test set. A 22-km transmission distance was achieved using a directly modulated, 1.3- mu m wavelength DFB laser and a 50- Omega p-i-n receiver. Receiver sensitivity for a BER of 10/sup -9/ was -2.0 dBm. The addition of an optical preamplifier required a more sensitive receiver to avoid saturation-induced distortion in the preamplifier. This was accomplished by reducing the 2-Gb/s word length to 24 b, thereby lowering the intersymbol interference penalty and effectively increasing the receiver sensitivity. Under these conditions, the optical preamplifier receiver sensitivity was -19 dBm, and a 64.5-km transmission was demonstrated.<
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