Research On The Robust Propagation Of Airy Beam In The Heterogeneous Medium Based On PT Symmetric Structure

In recent years,the finite energy Airy beam has attracted a lot of research due to the self-healing characteristics.The Airy beam can restore its own structure of multipeak asymmetry and the characteristics of the parabolic trajectory movement even in the case of strong interference.At the same time,a series of novel phenomena has been discovered when the beam is transmitted in a parity-time symmetric(PT)system.The refractive index modulation and gain-loss factors of the PT symmetry internal system can contend with the beam diffusion caused by the diffraction effect to form a beam that can propagates over long distances and improve the light performance.Therefore,in this paper,we used the PT symmetric structure to decompose the properties of inhomogeneous media,and studied the robust propagation of the Airy beam in a heterogeneous medium based on the PT symmetry structure by using the dimensionless Schr?dinger equation with the lossless term.The details are as follows:Firstly,on the basis of the analysis that the periodic sinusoidal PT symmetr ic medium can form a more complex periodic inhomogeneous medium through the amplitude superposition,and made use of the common sine cosine and the double exponential PT symmetrical structure medium with double symmetrical points.It was found that the stable propagation of Airy beams with different modulation parameters and depths.When the PT media system breaks,the Airy beam is almost completely captured,and the energy of the captured beam near the symmetry point grows exponentially.When the PT media system does not break,the captured light beam exhibits a state of cyclically bound oscillation.When choosing the proper modulation depth value,there are still some Airy beams that keep the sha fpe of the Airy wave packet to continue propagating and maintaining the self-accelerating characteristics.Moreover,the change of the modulation depth affects the intensity of the main lobe but does not affect the position and trajectory.Secondly,on the basis of decomposing the inhomogeneous media by using the PT symmetry Gausssian structure,we studied the the robust propagation of Airy beams under the Gaussian PT symmetric structure media with different modulation fact ors and modulation disturbances.In the absence of a break in the Gaussian PT media system,there is still an Airy wave packet that maintains its own self-bending and nondiffracting characteristics during propagation,and the lobe of the Airy beam does not change its trajectory when the Airy beam is disturbed by modulations with different modulation ranges and modulation depths.According to the characteristics of the Airy beam itself,the influence of the truncated coefficient on the stable propagation distance of the Airy beam is discussed.The larger truncated coefficient leads to the shorter distance.Taking into account the center captured light beam,the maximum power value increases with the increasement of the modulation factor,and decreases with the increasement of the modulation depth and the truncated coefficient.