Sometimes it is useful to visualize an optical design and calculate the optical quality. A free program for doing that is BEAM4 from

I had used an earlier test version, but now it is available as a free version and more user friendly, so I gave it a try.

I chose the Czerny spectrograph example and modified it to calculate spot diagrams.

first result, optimized for resolution
quick spot diagram, only a few rays calculated, showing nicely the astigmatism of this design (focus optimized for spectral resolution)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.