Study On Scattering Of An Airy Beam By Complex Spherical Particles

Airy beams are widely used in particle capture,microscope imaging,plasma,atmospheric turbulence and other fields,due to their properties of non-diffraction and self-bending.In recent years,Airy beams have attracted many researchers'attention and achieved a series of research results.However,there are few studies on the scattering of one-dimensional?1D?Airy beams by particles.This article focuses on the topic of the scattering characteristics of complex spherical particles by 1D Airy beams,and studies the scattering of Airy beams by single-layer spherical particles,concentric spherical particles and chiral spherical particles.According to the inverse modeling theory,the scattering of Airy beams by single-layer spherical particles is taken as an example to invert particle's parameters,such as sphere radius,refractive index,etc.First,the scattering characteristics of 1D Airy beams by single-layer spherical particles are studied.Based on the Mie theory and plane wave spectrum,the far-field scattering expressions of Airy beams illuminating single-layer spherical particles are derived.The effects of parameters,such as the radius and refractive index of the sphere,on the scattering intensity are simulated and analyzed.The correlation coefficient is employed to describe the relationship between Airy beam scattering and plane wave scattering.The research results show that when the full width at half maximum?FWHM?of Airy beam's main lobe is at least twice as the sphere radius,the correlation between Airy beam scattering and plane wave scattering is high,even close to 1.Secondly,the scattering characteristics of 1D Airy beams by concentric spherical particles are studied.The concentric sphere model includes concentric double-layer spheres and concentric multi-layer spheres.The effects of parameters such as sphere radius and sphere refractive index on the scattering intensity are simulated and discussed.The results show that the maximum radius of the sphere,whether it is a concentric double-layer sphere or a concentric multi-layer sphere,has a much greater effect on the scattering intensity than the first-layer sphere radius of the sphere.Then,the scattering characteristics of 1D Airy beams by chiral spherical particles are studied.The far-field scattering expressions of Airy beams illuminaiting a chiral sphere are derived,and the effects of changes in parameters such as chiral parameters and sphere radius on the scattering intensity are simulated and analyzed.The results show that compared with the scattering of single-layer spherical particles,the chiral sphere makes the scattering intensity decrease rapidly in a certain area,and the scattering intensity is more sensitive to the change of z₀-position.Finally,a combination method of machine learning and genetic algorithm is proposed to invert the particle parameters.A database is established based on the scattering of 1D Airy bemas by single-layer spherical particles.The database was input to a multilayer perceptual neural network for rough parameter estimation.Meanwhile,the genetic algorithm is used to accurately estimate the parameters.The influence of scattering intensity noise on the inversion results is also studied.The results show that the proposed method can efficiently and accurately retrieve the particle's parameters,and can be widely applied to various instruments based on the principle of scattering.