online ray optics simulator

[Joe Farina]

I had a problem recently where I needed to change the beam diameter of a laser at a point about 12 feet away, using lenses to modify beam divergence and make the beam smaller at that point (and also make the spot size adjustable).

I had always wanted to try my hand at a ray-tracing program, but thought the time involved learning it would be greater than the time saved using it, since it was rarely needed.

But I found a rather good online simulator which helped. No download is needed:

https://ricktu288.github.io/ray-optics/

I might suggest looking at a short video first, to see how it works:

https://www.youtube.com/watch?v=rbR7_axNTxQ&t=197s

[Loic74]

Thanks
I use this one for 2D optics, which is quite simple. It is avail. in english
http://jeanmarie.biansan.free.fr/optgeo.html