holey fibers/Photonic crystal fibers

[Kumbirayi Nyachionjeka]

Is there anyone out there who has used optiBPM for the design of a PCF until the obtaining of transfer matrices for use in optisystem. I kindly require a pointer to the appropriate tutorial on this. I have been helped on generating a script on this but i need a tutorial on how to proceed from running the script to generating the transfer matrix etc. I have used the optimode tutorial and it has helped a lot but i would love atutorial specific to optiBPM.

[Steve Dods]

Hello Kumbirayi,

I don’t know if OptiBPM can do what you require. Certainly photonic crystal fibres were not anticipated when the transfer matrix feature of OptiBPM was first specified (more than 10 years ago now…) The problem is that

1)The transfer matrix calculation feature resolves power from the optical field into fundamental modes on waveguides. 2) OptiBPM finds the fundamental mode by using it’s own mode solver.
3)The mode solver of OptiBPM cannot find modes of photonic crystal fibres. OptiMode can find these modes, but not OptiBPM.

Here is something you could try:
OptiBPM permits starting the propagation simulation ffrom a user defined file instead of fundamental mode. You could find PXtal fibre mode with OptiMode, and use that as the starting field.
When calculating the power at output, in the Additional Output Data dialog box, you need to define how the power in output waveguide will be defined. Sefault is overlap with fundamental mode (won’t work – it can’t find PXtalfundamental mode). So try Intensity in Waveguide Boundaries. That result will need some interpretation, it is not the actual number you require.

Maybe you can find some way to make OptiBPM calculate reasonable results, but bear in mind that OptiBPM was never designed for this use.

[Author]

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