Beat signal compression by loop mirror constructed with linear dispersion decreasing fiber

A nonlinear optical loop mirror （NOLM） constructed with linear dispersion decreasing fiber （DDF） is used to com press a beat signal. Several factors impacting on quality of output pulse in this compression system, such as dispersion slope of DDF, powersplitting ratio, incident pulse shape and peak power, are analyzed numerically. The new method for selecting device characteristics is adopted to enable both good pedestal suppression and pulse compression. As a result, the output pulse train with tunable and high repetition rate, pedestal energy of 5.09%, compression ratio of 25.6 and energy transmissivity of 50.56% is obtained by using 0.524 kinlong DDF with dispersion slope of 26 ps2/km2 and a coutler with oowersolittin ratio of 054