GOAD - Geometric Optics with Aperture Diffraction

GOAD is a Rust-based physical-optics hybrid light scattering model based on geometric optics with aperture diffraction. It computes the 2D Mueller matrix by using geometric optics and a polygon clipping algorithm to compute the electric field on the particle surface. The surface field is then mapped to the far-field on the basis of the electromagnetic equivalence theorem, which takes the form of a vector surface integral diffraction equation. Green's theorem is used to reduce the surface integral to a line integral around the contours of outgoing beam cross sections, which leads to fast computations compared to some other methods. Compared to the PBT method, GOAD uses a beam clipping algorithm instead of ray backtracing on a meshed geometry, which makes the computation more accurate and faster if the particle has smooth planar surfaces.

📖 Reference Paper If you use this code in your work, please cite: A Light Scattering Model for Large Particles with Surface Roughness H. Ballington, E. Hesse JQSRT, 2024

For documentation, see the wiki.