When a ray of collimated light, such as from a laser, is incident upon a semitransparent medium, it can experience both absorption and scattering. This means that the incident light is both converted to thermal energy and redirected. Under certain assumptions, these phenomena can be modeled using a diffusive approximation in the COMSOL Multiphysics® software. This modeling approach has applications in laser heating of living tissue as well as materials processing. Let’s learn more!