Learning Forum

[sk6n24]

Hi all,

Based on this discussion (https://community.zemax.com/got-a-question-7/sending-collimated-light-onto-oap-3740), I have developed OAP coupling fiber to fiber coupling system. However, I am not fully confident that physical optics propagation and its coupling results are correct. Could you please suggest possible improvements in it? Specifically, is it necessary to use "Use rays to propagate to next surface" and "Use Angular Spectrum propagator" in this case?

 

[Niki Papachristou]

Hi Sanzhar,

Thank you for reaching out to us! I believe you will need to consider what it means for these options to be checked within your system. In our helpfiles we have the discription of these:  

Use Rays To Propagate To Next Surface

If checked, then the diffraction propagation algorithms will not be used to propagate the beam to the next surface. Instead, rays will be traced to the next surface and the resulting ray transfer function will be used to propagate the beam and update the pilot beam parameters. Use of this feature is required for non-sequential, birefringent, and gradient index surfaces. Multiple sequential surfaces may all have this option checked, in which case the beam will advance through all the surfaces using only ray propagation. This feature may also be used to speed up the propagation algorithm by propagating through several surfaces at once, if the distance between the surfaces is small enough so that the diffraction propagation is unimportant. The default is unchecked. Search the help files for "Considerations when using rays to propagate" for important information about using this feature near surfaces where the rays come to a focus.

Use Angular Spectrum Propagator

If selected, the angular spectrum propagator will be used for propagation through the surface instead of the propagator OpticStudio would automatically select. This option should only be used if the beam size does not change dramatically over the propagation distance. The array width will remain constant using the angular spectrum propagator. The default is unchecked.

Physical Optics

Kind Regards,

Niki

[sk6n24]

Hi Niki,

Thank you very much for the clarifications! In my final design, i adjusted Waist X, Waist Y values in Beam Definition and in Fiber Data sections of POP. 
I left unchecked "Use Rays To Propagate To Next Surface" and "Use Angular Spectrum Propagator" options. The resulting coupling looks good and matches my expectations.

Thanks again and have a great week ahead,
Kind regards,
Sanzhar

[Niki Papachristou]

Hi Sanzhar,

Happy to hear I was able to help you! Good luck with your future work and designs and feel free to come back to us at any point!

Kind Regards,

Niki