The Monte Carlo method in optics

The Monte Carlo method in optical simulations involves statistically tracing a very large number of randomly sampled light rays to obtain a reliable picture of the light-energy distribution in a system.

How does the Monte Carlo method work?

Instead of tracing a single, deterministic ray, the algorithm generates millions or billions of rays with random directions and energies consistent with the statistics of the light source and the scattering properties of surfaces (BSDF). The more rays traced, the lower the statistical noise in the result — an irradiance or luminance map.

Applications

The Monte Carlo method is essential for stray light analysis in space instruments, designing LED luminaires, simulating light propagation in biological tissue (tissue optics), and analyzing systems with numerous reflections and scattering events.

Related terms

Non-sequential ray tracing

BSDF

Stray light