Having looked through the pst-optexp manual, it doesn't seem that there is a built-in off-axis parabolic mirror. I'm trying to make a diagram of a lab setup that goes like this:

  1. Collimated beam falls on a converging lens.

  2. The focal point of the lens is at the same point as the focal point of the OAP.

  3. OAP reflects a collimated beam at a 90 degree angle to the incident beam.

  • 1
    Welcome to TeX-SX. Can you tell us more about this thing since we are not all optics people. Best is to draw on a paper or on Paint and upload the picture to the question by editing it.
    – percusse
    Oct 2, 2014 at 17:56
  • Have you tried using my solution? If you're having problems with it, I would be glad to here about it in order to get some feedback about this feature before integrating it in the main release :)
    – Christoph
    Oct 28, 2014 at 10:51
  • @Christoph - Geez, I totally missed all of the replies to this post. I'll try implementing your solution over the weekend. percusse - An off-axis parabolic mirror is a mirror whose reflective surface is in the shape of a piece of a parabolic surface instead of a piece of a spherical surface. These are nice because they don't exhibit spherical abberations.
    – zmitchell
    Nov 18, 2014 at 17:19
  • is there a bug related to \oapmirror? I've been trying to draw one in my experimental setup sketch without success. In fact, I tried to compile the code from Christoph and it didn't work. Nov 27, 2018 at 21:45

1 Answer 1


Version 5.1 of pst-optexp contains an off-axis parabolic mirror as \oapmirror. You must specify three nodes to align the mirror properly: the input nodes, the center node, where the actual mirror center is placed, and the focal point.

Here is an example for a mirror which reflects by 90°:

\documentclass[margin=5pt, pstricks]{standalone}
    \drawbeam[ArrowInside=->, ArrowInsidePos=0.2, arrowscale=3, arrowinset=0.3, linestyle=none](In){1}

enter image description here

  • The other parameters for an OAP that would make sense would be the reflected focal length and the angle at which the reflected beam exits. From what I understand, that angle is 90 degrees in most cases (like what your solution shows here), but they are definitely also made with different exit angles. Here's a link to the specific model I'm using in my lab. On the right side of the page you can download the datasheets (one is a PDF) and look at all of the parameters: thorlabs.com/thorproduct.cfm?partnumber=MPD254254-90-F01
    – zmitchell
    Nov 18, 2014 at 17:22

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