Calculation of propagation loss in straight and bent waveguide

[Alvin HuiParticipant]

I am going to carry out a simulation of propagation loss in straight and bent waveguide. Can any one suggest what simulation tool is suitable. I have tried to use the OptiFDTD by placing observation lines over prolonged waveguide and obtain the power remained in the waveguide at that location. However, no accurate result was obtained until the waveguide was over 100 micrometers. Can anyone suggest proper method for the study as well. Thanks!

[Damian MarekParticipant]

OptiBPM would be an excellent tool here, if the loss is relatively low and the bends are not very sharp.

[Alvin HuiParticipant]

Thanks Damian!! Could you define more how is “the bends are not very sharp”. I would like to determine the bending with curvature radius down to 1 micrometer. The cases of bending includes 90 degrees, 180 degrees (i.e. like a u-turn) and 360 degrees (i.e. a closed ring). Will it be possible to use OptiBPM to simulate the bending losses of the abovementioned cases?

[Damian MarekParticipant]

In this case I would say they are too sharp! Now what you could do is run the OptiBPM simulation for the straight section of the waveguide and then import the field into OptiFDTD and simulate the bend with the other method. Then you could bring the results back in to OptiBPM.

Regards

[Dr. MohammadMahdi AriannejadParticipant]

I also have problem with bend wave guide a lot loss any how to change the radius still alot loss, anyway to describe this?

[Dr. MohammadMahdi AriannejadParticipant]

with s bend still I can see alot loss how to fix this? would you please let me know is there any optimization in this software or not and how to use optimization? thanks

[Damian MarekParticipant]

The largest bend that you can perform depends also on the waveguide structure and material. Highly confined waveguides may actually cause more error when using the BPM numerical engine.

Please attach your project and I can make some suggestions.

Regards