Hi

By only 'Random_Grid_Minus' has been shown in the surface sag analyzing data, do you mean that the other .dat files do not appear? You can refresh the list by clicking on 'Update File Listings'. You can also try closing and reopening OpticStudio. If they still don't show, there might be an issue with the files themselves. 

Regarding to 'Random_Grid_Minus', we can see the sag looking at Analyze...Surface...Surface Sag:

As you can see, this is the sag added to your system. 

But the Grid Sag surface is a dummy surface, by this I mean that before this surface, the material is AIR and after this surface the material is AIR. So no matter the geometry of this surface, it will not have any impact on rays.

So maybe what you are looking for is the Grid Phase surface? The Grid Phase surface will add phase to your rays and the gradient of the phase will bend rays. So you could convert the grid sag surface into radians. One wave is 2π radians.

Also have a look at the size of your grid. It seems too small.

Let us know if you have any further questions.

Sandrine

Thank you for your response Miss Sandrine.

I have some problem to convert Grid sag into the Grid phase. Does it have the same format as the Grid sag? Can Ms Sandrine or anyone help me to give some example for the format on how to change the grid phase into the dat file that can read by the zemax. 

Next, is it important to put material on the grid sag like n-bk7 or mirror? I try not to use any material which is the surface is air, but the result at the analyze data is not change. it will only change if i use material like n-bk7 on my grid sag. 

My plan is to import the wavefront aberration data that i get from experiment into my system in zemax at infront of the lens, it means the wavefront is at the air state. It is possible to use any grid phase or grid sag in air surface? or do you guys have any idea or any example that i can look at so that i can import my data into the system based on above condition. 

Thank you.

Hello,

Thanks for your follow up question here!

The Grid Phase surface is nearly identical to the Grid Sag surface. The key differences are:

• The units of sag are radians of phase instead of units of length.



• The unitflag data is only used to scale the delx, dely, and derivative values.



• The surface shape is a plane.



• A diffraction order is supported. The diffraction order is a multiplier on the phase values. A value of zero will turn 'off' the phase effects. Setting the order to -1 will reverse the sign of all defined phase values.



• A 'shear distance' is supported.

You may find more information about the Grid Phase file format in the Help file at:


The Setup Tab > Editors Group (Setup Tab) > Lens Data Editor > Sequential Surfaces (lens data editor) > Grid Phase

Further reference about the required .DAT file format and about the construction of the Grid Sag files can be found at:


The Setup Tab > Editors Group (Setup Tab) > Lens Data Editor > Sequential Surfaces (lens data editor) > Grid Sag

You may find example .DAT files in the \Zemax\Objects\Grid Files folder. To check that the .DAT file has been imported correctly, please use the the Analyze…Surface…Phase analysis tool.

As Sandrine suggested, please have a look at the size of your gird. Currently, it looks too small:

You may find more information about Grid Sag file generation and usage in the following knowledgebase aricles. You may use the Grid Phase surface very similarly:

How to use the Grid Sag surface type

How to write a Grid Sag DAT file programmatically

If you have further questions, please let us know and we will be happy to help!

Best,

Csilla