Home Forums FDTD Help with Effective refractive index for a PCF

• Author
Posts
• #15810

Hello All,

I wanted to model a desired structure of a photonic crystal fiber. Then i want to calculate it’s effective refractive index.

Please provide the steps. Thank you

• #15816
davcm
Participant

Please, could you be more specific with your problem? I don’t understand what you’re interested in.

Thanks and regards,

David.

• #15817

Sure David,

A fig attached below gives a cross section of PCF. The air-holes are arranged in a hexagonal lattice configuration while input field is given in core (center) of the structure. There are refractive indexes of core and cladding material separately defined. Such as if it is a solid core , then n=1.45 (Si) , the air cladding holes will have n=1.0. Now if we consider the refractive index of whole structure, it is said to be dependent on the input wave’s coverage in cladding area, known as Effective Refractive Index (Neff). Through this term dispersion is calculated for a fiber. I wanted to know the option of calculating this Neff in Optifdtd.

Thank you

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• #16370
Damian Marek
Participant

You can also find the effective index of refraction of the propagating mode using the OptiMODE application that comes along with OptiFDTD. After solving for the modes, the field profile and also the modal index or effective index is shown.

• #15821
davcm
Participant

I attach you the response to someone that asked something very similar to you.

PCF simulation

I hope you find the answer.

DCM

• #15835
Saurav Chanda
Participant

Try using matlab. Refer to Igor V Sukhoivanov for details.

• #15839
davcm
Participant

Hello,
What I’d do is to run the PWE bandsolver and then fit the curves I’m interested in, so I can relate ‘w’ with ‘k’. Then I’d derivate tihs expression (dw/dk = vg) and I’d obtain vg, which is the group velocity and it gives us the neff.

Regards,

DCM

• #15864

Hey DCM,

Please see the attached bandgap picture, obtained after running the PWE bandsolver. Now what I have to do.

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• #15866

Hi Saurav,

I saw the Igor V Sukhoivanov profile, can you specify which paper of him would help in finding Neff.

Thanks

• #15896
Saurav Chanda
Participant

Hey Subhashish,
Try to check his book, there are some informative data which can help you though and it can be done using matlab as far I know.

Regards,
Sourav

• #15931

Is the book name “Photonic Crystals: Physics and Practical Modeling (Springer Series in Optical Sciences)”

Thanks

• #15942
vignes
Participant

yes that book only did u get

• #15945
Saurav Chanda
Participant

Yes you got it.

• #15993