Zemax- Off Axis Parabolic Mirrors

[rifat]

Dear All,
I have a problem in Zemax. I would like to use off-axis parabolic mirrors in my simulation but I just couldn`t figure out how to do. Should I use a "user defined surface" or is there an easy way for this?

 

[cev]

Use a standard surface. There are two ways to put in your OAP.

The easy way is to decenter an on-axis parabola in the "tilt/decenter" tab of the "surface properties" dialog box. Add the appropriate amount of "before" decenter, then select "reverse this surface" to return to the original coordinate system. If you need to put in more optics aligned with the new optical axis, add an appropriate tilt to the "after surface" in addition to the compenstating decenter. Note that you will have to adjust the focus distance if you tilt the optical axis.

The problem with the above technique is that you cannot optimize the surface tilts and decenters. To do this, you have to use "coordinate break" surface types. Put one on either side of your mirror surface. Like before, the before-surface coordinate break has a decenter term. Do a reverse-pick-up on the "after surface" decenter in addition to the optional tilt (Note: the thickness of your mirror surface must be zero for the tilt to work properly).

With coordinate breaks, the curvature and decenter parameters can be optimized (With the appropriate set of optimization terms, you can automatically update the tilt while adjusting the radius of curvature and decenter terms).

CV

 

[rifat]

thanks cev,
I was able to model the mirrors. I have one question though.
Could I have used a user defined surface? It's because this way the upper part of the mirror is of no use to me. Maybe it would be more feasible if I could just model the lower part of the mirror or maybe an aperture would also do it.
anyway thanks alot

By the way, can anyone suggest me a few methods so that I can learn this program faster. I heard that there was a book with design examples. Is it useful? What do you think?

 

[cev]

Use an aperture to get rid of the extra mirror parts. I don't use user-defined surfaces, so I can't comment on their utility.

Focus Software offers intensive short courses for ZEMAX users. I've never taken one, but I've heard they are good.

http://zemax.com/

CV