Polarization Characteristics Of Complex Scattering System Based On IPPs

The intrinsic properties of light include frequency,intensity,phase and polarization.The state of polarization,a fundamental physical property of light,carries important information.It not only includes the important information of detecting target,but also reflects the distribution characteristics of transmission medium.This dissertation mainly uses Monte Carlo algorithm to simulate the transmission of polarized light in different scattering systems(including monodispersion and polydispersion systems).The emphasis is on exploring the use of a different representational method,the Indexs of Polarization Purity(IPPs)was used to study the depolarization characteristics of different dispersion systems.In the isotropic scattering environment,the influence of the wavelength of incident light,the size of the scattering particle and the relative refractive index of the scattering particle and the surrounding medium on the depolarization performance of the system was investigated.The depolarization effect of the scattering system including optical rotation is also analyzed.In this dissertation,some biological tissues were simulated to study the factors affecting tissue canceration on depolarization of light,and the specific properties of Mueller Matrix were used to explore the changes in blood glucse.The main research contents of this dissertation are as follows:(1)The basic theory of polarization and scattering is introduced.Due to the complexity of the transmission of polarized light in the scattering medium,we use Monte Carlo algorithm to simulate the transmission of light in different scattering media based on the Mie scattering theory.The main steps of Monte Carlo algorithm applied in this dissertation are briefly introduced.(2)Several common characterization methods of polarized light and the characterization of the scattering system by the Indexs of Polarization Purity(IPPs).This dissertation mainly introduces three common characterization methods of polarized light: Jones vector method,stokes vector method and Poincare Sphere method.In addition the Indexs of Polarization Purity(IPPs)method is used to characterize the depolarization ability of the scattering system.(3)The Indexs of Polarization Purity(IPPs)method was used to investigate the depolarization characteristics and regulars of different scattering media.Based on Monte Carlo ray tracing technology,the effects of scattering particle density,incident light wavelength and relative refractive index on the polarization state of the emitted light and the depolarization performance of the system are analyzed.At the same time,the depolarization effect of the mixed scattering medium is studied,this is related to the mixing ratio of Rayleigh scattering particles and Mie scattering particles.The relationship between the mean and standard deviation of scattering particles and the depolarization ability of the system is also investigated.(4)The effect of optical rotation in scattering medium on the depolarization performance of the system was investigated.In the scattering medium containing spherical scattering particles,chiral substances are added to represent optical rotation.The effect of optical rotation on the mueller matrix for forward detection is analyzed,and the influence of changing the scattering effect in the scattering medium containing chiral materials on the depolarization effect of the whole system is also verified.Simulating the changes of glucose concentration in the blood,a parameter in the Indexs of Polarization Purity(IPPs)was used to characterize the changes in blood glucose.