We report 400 femto-second highly stable, nearly transform-limited, pulse generation at 10 GHz in $1540{sim}1550$ nm wavelength region by adiabatic soliton pulse compression of an actively mode-locked fiber ring laser output. Without using any supermode selection device, supermode beating noise has been suppressed below -123 dB/Hz, resulting less than 100 femto-second timing jitters at the noise band of $1;kHz{sim}100;MHz$.