Mueller matrix calculator, based on a JVIE-T-matrix code

The calculator allows one to compute the T-matrices for arbitrary geometries, constructed as tetgen-compatible tetrahedral meshes.

Usage

Key parameters are the particle size and incident EM-field (wavelength band, currently supports logarithmic scaling). Also, for the Mueller (scattering) matrix the angular resolution (N_theta, N_phi) for scattering angle and azimuthal angle must be given.

Mueller matrix indexing

The resulting scattering (and extinction) matrices are written in a single file containing indices N_size, N_ia, and N_pts per each row. A row also contains the Mueller matrix elements S₁₁, S₁₂, ..., S₃₄, S₄₄, and the scattering (or extinction) cross section c_sca (c_ext).

• N_size: 1--bars (WILL run from the smallest size parameter to largest, i.e. opposite to the order of wavelenghts printed)
• N_ia: 0--2 (0=randomly oriented case, will limit N_pts to N_theta, 1=incident angle 90 deg, 2=incident angle 180 deg)
• N_pts: 1--N_thetaN_phi. The current indices i_theta and i_phi for theta and phi, respectively, given by i_theta = (N_pts-1)%N_theta, i_phi = floor(N_pts/N_theta). The angles theta and phi are then given by theta = pi*(i_theta+0.5)/N_theta, phi = 2pi i_phi/N_phi. NOTE: i_phi runs from 0 to N_phi-1, i_theta runs from 0 to N_theta-1.