We report a harmonically mode-locked erbium-doped fiber ring laser wit
h short solitons. A phase modulator running asynchronously with the pu
lses provides pulse start-up, continuous background cleanup, and a new
form of pulse timing stabilization. Steady-state operation of picosec
ond solitons at a repetition rate of 1 GHz was obtained with no need f
or modulator drive frequency stabilization.