*****   MONTCARL  *****

Monte-Carlo simulations of light transport in transparent or turbid media, like tissue,

with Scattering, Absorption, Fluorescence, Raman, Laser-Doppler and Photo-acoustics,

with layers and objects,   like spheres, tubes, cones, mirrors, lenses, pupils, diaphragms.


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MC transport-002Light  scattering and transport, with:

·         Events: scattering, absorption, reflection, refraction, transmission, with cross sections and attenuation coefficients,

·         Scattering functions: Mie, Dipolar, Rayleigh, Gans, Henyey-Greenstein, Gegenbauer, or Isotropic, Fournier-Forand, with fluorescence and Raman-scattering,

·         Layers and objects: tubes, spheres, blocks, toroids, cones, mirrors, lenses…

·         Ray tracing and Imaging through transparent and turbid lenses, pupils, diaphragms, mirrors….

·         Extra’s: frequency modulation, Doppler frequency, Laser-Doppler flowmetry, skin tissue, path tracking, flight tracking, Photo-Acoustic signal production.

·         Table of suggested optical properties in tissue.




randombollen1_2_000000317View MOVIES:         

1. Full DESCRIPTION OF THE PROGRAM (incl. photon transport process):  video : movie  

2. LIGHT SCATTERING BY PARTICLES, theoretical models and derivations:  pdf-file

   I. Light scattering theories and models:      video:  part I

   II. Derivations of dipolar and general scattering expressions:    video:  part II

3. TRANSPORT PROCESS OF PHOTONS in the medium: video: MP4-file

4. PHOTO-ACOUSTIC RESPONSE simulation using MONTCARL: video: movie

General objectives:



·         The program calculates Monte-Carlo simulations of LIGHT TRANSPORT IN TRANSPARENT OR TURBID MEDIA, WITH SCATTERING and/or ABSORPTION

·         optional: followed by FLUORESCENCE or RAMAN-scattering, or PHOTOACOUSTICS in turbid media, like tissue.

·         The SAMPLE may consist of a single or more LAYERS, each with its own absorption and scattering data, in the form of concentrations of scattering particles embedded in a medium.
In order to register
DOPPLER spectra, to each type of scattering particle a certain velocity vector can be associated.
In each layer a number of separately defined structures (called "
OBJECTS": with rectangular, cylindrical, spherical or conical shape) may be present, with similar characteristics as the layers. Option: spheres may be randomly distributed in a layer.
With those objects e.g.
blood vessels can be mimicked. Also transparent and turbid lenses and pupils /diaphragms….

·         Also an oblique mirror plane can be inserted.
Furthermore, the layers may be subdivided into sublayers (depth pixels, see below).

·         There are more options: internal light sources and external beams, internal and external detection, plots of distributions of various variables (photon positions, path length distributions, photon tracking, layer+object structure plots, frequency modulation by Fourier transformations, angular distributions, photo-acoustic response plots, ray tracking in lenses systems, ….



·       IMPORTANT:  Remove old versions of  Montcarl.exe  first, to avoid possible interference !!

·       Demo or full version (your first download):     Download montcarl.zzz here  to a new or suitable folder.

After download: (1) change *.zzz -> *.zip, (2) unzip *.zip into that folder,

then (3) read “READ ME FIRST”  and (4) rename MC_Install.fff   to   *.exe and run *.exe-file.

MC_Install will create  and install all necessary folders and files.

·       Updates:      Download montcarl-update.zzz     from here to your MONTCARL\PROG-folder;

After download: (1) change *.zzz -> *.zip; (2) unzip *.zip into that folder; (3) change *.fff -> *.exe and (4) run *.exe-file. This download may also contain updated versions of HELP-files (*.pdf).


More information:


·         Description of the program options

·         The physical mathematics behind the calculations

·         See also: List of publications



·         Download the demo or full version of the program and work for yourself.

·         Let us do the simulations for you (first try-out free; contact us); this will save you a lot of work and time!


Examples of screens in the program:

All screen outputs with results also have print and file output in table format, compatible with Excel-like programs.


Fig. 1. Begin screen of the program (choice of screen size and color)

Fig. 2. Menu screen (with Tabs)


Fig. 3. Overview about how to input settings and to run simulations


Fig. 4. Creation of scattering functions (called: *.MIE-files)


Fig.5. A scattering pattern (combination: Mie + Henyey-Greenstein-functions)


↓ Fig.6. Selection of scattering functions for use in layers and objects


Fig.7. Input of data for the light source (e.g. laser data)


Fig. 8. Input of data for layers (more than 1 layer possible)


Fig. 9. Input of data for objects (spheres, tubes, mirrors, cones, blocks…)


Fig. 10. Detection, calculation mode, flight and path tracking and output


Fig. 11. Structure of the layer system with 1 layer and 1 tube in Y-direction


Fig. 12. Simulation of the structure of Fig. 11. View // Y-axis (XZ-plane)




Fig. 13. Structure of a single layer with random spheres


Fig.14. Simulation of the structure of Fig. 13. View // Z-axis (XY-plane)




Fig. 15. Path tracking for selected points of emergence. Single layer


Fig. 16. Path tracking of Fig. 15: crossings with predefined planes; 1 layer.




↓Fig. 17. Plot options: choice of axes (“intensity” if vert.axis = none)


↓ Fig.18. Plot  options: settings for an intensity plot




Fig. 19. Intensity plot, with model fitting. Plots of >1 runs optional (with shifts).


Fig. 20. Scatter plot of results. Plots of >1 runs optional (with vert./hor. shifts)




Fig. 21. 2D-plot of results: total number of re-emerging photons.


Fig.22. 2D-plot of results: average scattering depth of all photons.



Fig. 23. Photo-acoustic response of absorbed photons: settings


Fig. 24. Photo-acoustic response in 10x10–detector array of 1 tube (Fig.11)




Fig. 25. Extra: frequency modulation of GHz-signals in tissue layers.


↓ Fig. 26. Imaging through a thick convex-concave lens with a few scatterers