Curved / chirp diffraction gratings


Hi,


The tutorial on 'Simulating diffraction efficiency of surface-relief grating using the RCWA method' assumes a unit cell comprising of one period with linear grating of fixed duty cycle. I am wondering if anyone knows if we can simulate 1. curved diffraction grating and/or 2. diffraction grating with a chirp (i.e assume  a super cell comprising of multiple unit cells with varying period and fill factor)? 


Thanks,


Arvinder


3 replies

Userlevel 2
Badge +1

Hi Arvinder,


Thank you for using the MyZemax forum feature!


For the first question, currently not available on curved surfaces, but we are planning to do something about it. The current plan is to use it on aspheric surfaces to design ODE lenses.May I ask if that's what you're looking for?


For the second question,We expect this feature to be released in version 20.3. You can refer to 'Tutorial for RCWA toolset in OpticStudio 200617.pdf' first. Please download this article from this website https://drive.google.com/drive/folders/1E7GcYQiTe-d3Rqr9N-ZjXNf3Z7hkWZru?usp=sharing


Please let us know if you have any other questions! Thanks~


Best Regsrds


Sean Lin

Hi Sean,


I was able to create the chirp files using the RCWA files. Though I had issue replicating the results (Build_SRG.zar) as provided in the verify_1997_Design_and_fabrication.zar files. Also when I changed the slant angle both in Build_SRG.zar and verify.zar file, the universal plots did not update. Can you please help update the Build_SRG.zar file so the universal plots update when grating slant angles are changed?


Thanks,


Arvinder


 


 

Userlevel 2
Badge +1

Hi Arvinder.


The reason your system is not working is that Reverse Rays are set in the light source section and the material section is not.



Also for universal plots, since the beta angle is affected by the alpha angle, you need to set up a pickup so that there are no errors in the drawing calculation process.



Please let us know if you have any other questions! Thanks~


Best Regards

Sean Lin

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