The DDA-SI toolbox for MATLAB:

1) Standard DDA for free space light scattering calculations

2) DDA with surface interaction (DDA-SI)

3) Discrete rotational symmetry-optimized DDA, T-matrix formulation (not include in release v0.1)

Download link for beta releases,

v0.1: http://code.google.com/p/dda-si/

v0.2: https://github.com/dalerxli/dda-si

Functions from the Optical Tweezers Toolbox may be required: https://au.mathworks.com/matlabcentral/fileexchange/73541-ott-optical-tweezers-toolbox

The functions are for coordinate transformation, generating beam shape coefficients for arbitrary illumination, vector spherical wave functions etc.

Please cite the accompanying paper:

Vincent. L.Y. Loke, M. Pinar Mengüç and Timo A. Nieminen, "Discrete dipole approximation with surface interaction: Computational toolbox for MATLAB", JQSRT, Vol. 27 Issue 10, pp.2293-2303 (2010), http://dx.doi.org/10.1016/j.jqsrt.2011.03.012

Associated theoretical paper for reference:

Vincent. L.Y. Loke and M. Pinar Mengüç, "Surface waves and atomic force microscope probe-particle near-field coupling: discrete dipole approximation with surface interaction", JOSA A, Vol. 27 Issue 10, pp.2293-2303 (2010), http://www.opticsinfobase.org/spotlight/summary.cfm?URI=josaa-27-10-2293

Book chapter:

Light, Plasmonics and Particles - Nanophotonics, Chapter 10 - Discrete dipole approximation with surface interaction, https://doi.org/10.1016/B978-0-323-99901-4.00018-4

Corresponding author: loke@physics.uq.edu.au or vlyloke@gmail.com