The 40 Gbit/s TDM transmission configurations of the amplifier span in
some references are analyzed. The reasons that good system performanc
e cannot be obtained are explained Some methods to improve the perform
ance of 40 Gbit/s TDM are presented. The 800 hm transmission distance
is increased by the new transmission configuration. (C) 1997 John Wile
y & Sons, Inc.