# simulation for mirror geometry

#### sytem_recon

Joined Apr 21, 2009
52
How i can simulate/program through a computer that when a light ray emit from a focus of ellipsoid will reflect to the other focus of it. I have a source on the focal point emitting light in spherical shape and the mirror will be ellisoid.

#### steveb

Joined Jul 3, 2008
2,431
How i can simulate/program through a computer that when a light ray emit from a focus of ellipsoid will reflect to the other focus of it. I have a source on the focal point emitting light in spherical shape and the mirror will be ellisoid.
Can you be more clear on what you mean.

Theoretically, an ellipsoid will do exactly what you say. Are you trying to make a realistic model with imperfect geometry to verify a real design? In other words, is your source not a perfect point source, or is the location not exactly at one focus?

If you are interested in the theoretical problem, it has already been proved mathematically centuries ago.

If you want to do simulations of real devices, you can track down a ray tracing program that has been developed for optical system design. I've never used one myself, but I know they exist. Although, they could be expensive. If you are good at math and programing, you can write your own program, but it will take some work. You could also consider doing drawings in a 3D drafting software package. Perhaps something SoldWorks will let you draw up the 3D geometry and calculate the tangents and reflection angles. This might be tedious.

This is all assuming that the dimensions of the ellipsoid are much larger than the wavelength of light. If you have a very small ellipsoid (0.1 mm or less, which seems unlikely), then you need to solve Maxwell's equations. You could do a literature search to see if this problem has been solved already, or you could use a finite element program designed to solve field problems. Those programs are also expensive, unless maybe there is a freeware package available.

#### sytem_recon

Joined Apr 21, 2009
52
Yes i want to make a realistic model to verify a real design in which the source is not a point but sphere. So, i want to simulate it first. I m not very good in programming and i have no idea of drawing 3-d diagrams in programmming.

#### steveb

Joined Jul 3, 2008
2,431
Yes i want to make a realistic model to verify a real design in which the source is not a point but sphere. So, i want to simulate it first. I m not very good in programming and i have no idea of drawing 3-d diagrams in programmming.
It sounds like you need a ray-tracing program structured for optical system design. I don't know much about available programs so you may need to do your own search. For example, here is a link to one example of an available package. I don't know how good this one is, but they provide a free demo, and the purchase price is reasonable at \$599.

http://www.optics-lab.com/