Looking for Ray Tracer Software

[Arvedui]

I am looking for freeware which enable the simulation of a system with 3 mirrors, a laser, and a detector. So far I've only managed to find software for lenses on the internet. Would anyone lend a hand? :D

 

[mgb_phys]

The lens software will also do mirrors, etc
Only fairly advanced packages are going to be able to accurately model a laser but any of them should be able to do a point source.

The only reasonably complete free one I know of is Oslo http://www.lambdares.com/education/oslo_edu/