Unique dispersion effects on transmitting and amplifying of picosecond pulses in fiber optical parametric amplifiers

On amplifying of picosecond pulses in fiber optical parametric amplifiers, group-velocity dispersion (GVD) and third-order dispersion (TOD) effects are numerically investigated. It comes to two very interesting results. One is that GVD of the signal (idler) induces obviously the idler (signal) pulse broadening even though GVD of the idler (signal) is zeroed. The other is: on condition that signs of TOD coefficients for signal and idler are quite the contrary, TOD would lead to two oscillatory structures respectively near the trailing edge and the leading edge, rather than conventional one oscillatory structure. In conclusion, any dispersion-induced modifying of the signal (idler) pulse shape will be coupled to the idler (signal) and result in corresponding modifying of the idler (signal) pulse shape. It is extremely helpful for further experimental study.