This is now possible using the new Ray Optics Module which was released with V5.0:
www.comsol.com/ray-optics-module
Some example models can be found here:
www.comsol.com/models/ray-optics-module
Dan
www.comsol.com/ray-optics-module
Some example models can be found here:
www.comsol.com/models/ray-optics-module
Dan