Hi Dirk,





Currently thermal expansion considerations can only be automatically controlled in Sequential Mode; you're right that the thermal pickup isn't available in NS mode. I think this is because there is much more generality required in regards to where the reference points for the expansion are. The best option would be to create some ZPL macro solves to handle the thermal expansion. Within a macro, you can retrieve the current temperature and fix the reference temperature (or retrieve it from the MCE) to find deltaT, and from here you can apply a scalar to the nominal parameter. These ZPL macro solves could be applied from within the MCE, similar to how the thermal pickup works. 





Thanks,


Zach

---

Hi Zach





Could you kindly elaborate a bit more in detail on how this is done. Supposed I have an elaborate structure, a CAD assembly with optical components and mounting structures, imported in non-sequential mode, with individual objects of the CAD assembly exploded, how may I begin investigating the effects of temperature on the structure and on the rays.

Thanks and Best Regards

Clarence

---

Hi Clarence,

On a CAD object, there is a Scale Factor parameter that can be used to model a uniform thermal expansion:

So that can work for each individual object.

Then you would need to think about the deformation of the whole structure and how each CAD object is positioned in that structure. The Ref Object parameter can be used for that.

As my colleague mentioned, you could also automate the calculation of the scale factor with a ZPLM, but I am not sure how well that would work as reading the TCE in non-sequential is not possible.

But here is an example. I have defined two configurations. I am going to work in the second configuration:

In the 2nd configuration, I am going to evaluate the change between temperatures on lines 2 and 4 of the multi-configuration editor.

So here is the ZPL solve macro called NSC_Thermal_Scale:

 

Then I can add this solve on the scale factor:

As you see, it is not really direct.

Let us know if we can help any further.

Thank you!

 

 

 

 

---

or if you have any other questions.

---

Hi Saudrine

Thanks for the help. Am I right to say that what you have shown is only limited to uniform expansion of the components and it considers the expansion based on the imported CAD material property? What then say of a thermal gradient across components and the whole assembly?

---

Yes what I have shown is limited to a uniform expansion based on the TCE value, which is hard-coded in the ZPL solve.

For a thermal gradient, you could have a look at that article which describes how to do it in sequential mode: How to model thermal gradients in an interferometer cavity.

But it may be too limited depending on what you are trying to do.

Let us know if that does help.

---

Hi, 

 

Trying to optimize an athermal Fresnel 1 design:

Thermal expansions are not handle in Non Sequential without a macro, so I did this optimization in Sequential but when I convert it to Non-Sequential mode the Fresnel lens is converted to a Fresnel 2 lens (which is supposed to be ideal).

I actually want to optimize the Fresnel lens in Non-Sequential using the NSDD operand to minimize a spot onto a detector. 

Otherwise, how can I trust the Fresnel 2 Design in Non Sequential?  How can I convert it to a Fresnel 1 making sure that all the thermal constant are right?

Thanks, 

Martin 

 

 

---