How to manually create a ZBF file

  • 20 May 2019
  • 9 replies
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Userlevel 6
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ZBF stands for Zemax Beam File. This format is used in POP to describe the beam at a surface.

To create a ZBF text file manually, here are two useful documents:

- an Excel sheet that summarizes the syntax of the Help File :The Analyze Tab (sequential ui mode) > Laser and Fibers Group > About Physical Optics Propagation > Defining the Initial Beam > File (defining the initial beam) > Zemax Beam File (ZBF) text format > Zemax Beam File (ZBF) text format.

The E column of the tab "ZBF" of the Excel sheet is a ZBF file. To create a ZBF file, copy that column into a text file and save it with a ZBF extension under \Zemax\POP\BEAMFILES.

The two other tabs represent and plot the data as a matrix.

- the ZBF text file created from the Excel sheet

 


9 replies

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Hi Sandrine,

The Excel file is really helpful to create own ZBF file. I have one idea on this topic. Is it possible you add one sample ZBF file including non-zero imaginary profile? That means the phase of beam is not flat. Some users sometimes want to convert a beam profile generated from other EM filed simulator. In this case, they might be confused how do they think the imaginary part of ZBF file.

Userlevel 6
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Here is an update to the Excel file with non-zero imaginary profile. 

Do not hesitate if you have any comments.

Userlevel 6
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Here is a new update to the excel file.

In the Pivot_Table tab, there are now 3 columns.

  • Column I calculates the EX Intensity = Exr^2+Exi^2
  • Column J calculates the EX Phase.
  • Column K calculate the EX Irradiance = EX Intensity / pixel area

The Irradiance and phase are displayed by OpticStudio.

Hi Sandrine,

I did laser characterization, which gave me the information about laser beam waist, divergence angle, and Rayleigh in x and y separately; however I didn’t have any Ex values at all!  Does it mean I cannot define my own .ZBF? 

In this case, what can I do to define initial beam in order to use POP analysis?

Thanks,

Ying

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Hi Ying

I think that with those values you can define directly your beam in POP using Gaussian Size + Angle:

You have the divergence angle so that can be entered in Angle X and Angle Y.

Then using the Rayleigh length, the distance from the surface to the waist and the waist for the beam, you can estimate Size X and Size Y using: 

Then you can enter these values.

You can then check the properties of your pilot beam (best fit gaussian beam) in the ribbon to see if it fits your calculation. You will need to separate X and Y.

 

Let us know if that helps.

Hi Sandrine, 

Thanks for your suggestion, I even included M2 value that I got from laser characterization, which really makes full use of all the information that I could get.

 

one question here: below the laser port 1 and laser port 2 are symmetrical , how to differentiate them if they are the surface that I will define the beam? The gaussian size and angle are the same, or maybe the angle is negative VS. positive?

 

 

Thanks,

Ying

Userlevel 6
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Hello Ying

Yes you are correct, I think there can be an ambiguity in the definition here. You can check what is chosen by the software in the ribbon below POP. It indicates the best bit gaussian beam and so you will see the position from the gaussian beam. Let me know if that helps.

Would you like to create a case so we can have a look at your values?

Hello Sandrine,

I built a very simple system as shown below to test it:

 

It looks like if we switch +/- sign of the angle, it can differentiate these two situations :-)

 

 

This is cool …

 

Regards,

Ying

Userlevel 6
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OK thank you for sharing! I hadn’t realized it.

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