Modelling and simulation of light scattering in optical systems

In this work, we first propose a quasi-analytical phase space method to simulate light scattering in optical systems, which directly couples the excitation and acceptance of light scattering in the phase space. Since the phase space method does not involve random sampling of the probability distribution function, it is much more efficient and delivers results with high signal to noise ratio (SNR). We first implement the phase space method to simulate the autofluorescence effect in microscope lenses, based on which a comprehensive analysis of the autofluorescence effect of various types of microscope lenses is presented. Subsequently, we extend the phase space method to simulate the surface scattering in optical systems. Meanwhile, we evaluate the extended phase space model in mirror systems with and without circular symmetry and propose three possibilities to implement the phase space method, which are suitable for different types of optical systems. By comparing the three implementations, the applicability, efficiency, accuracy and limitations of the phase space method are discussed. Additionally, in order to simulate the propagation of partially coherent light in random media or by statistically perturbed surfaces, we propose a Wigner function-based method, in which the partial coherence of light is accurately modelled and the scattering of the partially coherent light by multiple scattering surfaces can be efficiently simulated. Since the Wigner function of light depicts the light distribution in the angular and spatial domain, the impact of scattering surfaces on the partially coherent light can be modelled by the convolution of the Wigner function with the bi-directional scattering distribution function (BSDF) in the angular domain. Furthermore, we show that, by a proper definition of light coherence, we are able to apply the statistical and deterministic surface models to simulate light scattering from high and mid-spatial frequency errors simultaneously.