论文部分内容阅读
In this paper, we investigate the modulation instability for generating femtosecond pulses in fibres with slowlydecreasing dispersion. Higher-order dispersion and higher-order nonlinear effects are taken into account when thecontinuous wave or quasi-continuous wave evolves into sub-picosecond and femtosecond pulses by modulation instabilityin the optical fibres. Our research results show that the gain spectrum of the dispersion-decreasing fibres is much widerthat in conventional fibres.The third-order dispersion effect has no contribution to gain spectrum, while thethanself-steepening effect reduces themaximum value and gain bandwidth, and the Raman self-scattering effect widens theextent to which the modulation instability occurs.