Research Of The Propagation Properties Of Airy Pulses In Optical Fibers

In 2007,Siviloglou and Christodoulides first introduced the concept of finite-energy Airy beams(FEAB),which is exponentially truncated but still keep its key characteristics such as self-accelerating,weak diffraction,and self-healing.Since then,the FEAB has been studied extensively.In addition to spatial Airy beam,the temporal finite energy Airy pulse(FEAP)which propagates with its acceleration resulting from a varying group velocity was introduced.The FEAP can be translated from spatial FEAB as their analogy between “dispersion in time” and “diffraction in space”.Because of the controllable characteristics of dispersion and nonlinearity,the evolution of The FEAP shows some novel phenomena and applications.This thesis researched the dynamic propagation of the initial chirped Airy pulse in single-mode fibers.The innovative works of this thesis are as follows:(1)The linear analytic Airy pulse solution for the NLSE which including both group-velocity dispersion(GVD)and third-order dispersion(TOD)terms is given.The dynamic propagation of the initial chirped Airy pulse in single-mode fibers is studied numerically.It is shown that,if the positive TOD is large enough,the Airy pulse experiences an acceleration reversal.At zero-dispersion point,the Airy pulse undergoes slight compression then inverse to the opposite acceleration at a focal point with the effect of positive TOD.Under the action of GVD and positive TOD,the Airy pulse slightly compressed and pass through a breakdown area,then the pulses reconstruct a new Airy pattern with opposite acceleration.The size of breakdown area is related to the value of TOD parameter.The negative TOD increase the d epth of penetration of the wave packet and the pulse in this case can propagate for l onger distance.(2)The dynamic propagation of the initial chirped Airy pulse in single-mode fibers is studied,special attention being paid to the role of the third-order dispersion(TOD).The role of TOD in the dynamic propagation of the initial chirped Airy pulse depends on the combined sign of the group-velocity dispersion(GVD)and the initial chirp.It is shown that for the positive TOD,the Airy pulse experiences inversion and reconstruct a new Airy pattern irrespective of the sign of initial chirp.The initial chirp and the value of TOD parameter both affects the reconstruction of the new Airy pattern.Under the effect of negative TOD,the initial chirped Airy pulse disperses and the lobes split.In addition,in the anomalous dispersion region,for stron g nonlinearity,the initial chirped Airy pulse splits and enters a soliton shedding regime.The trajectories of the shedding solitons are affected by successive collisions with the side lobes and the TOD effect strength.Packet and the pulse in this case can propagate for longer distance.(3)A method of strong signal soliton manipulation using weak Airy control pulse is proposed.With specific frequency,the control pulse is normally dispersive while the signal remains in the anomalous regime.In this condition,for the Airy pulse can maintain its shape and accelerate to soliton,it is better than Gaussian pulse to control the soliton.With the same peak power,the Airy pulse can shift the time position of soliton pulse more than Gaussian pulse do.The weak Airy pulse can control the soliton signal pulse propagation parameters.The soliton experienced time position and intensity changes as changing the parameters of Airy pulse such as the amplitude ratio,the truncation coefficient,the time delay and the relative phase.