How to Define Lattice Properties for Octagonal PCF in OptiFDTD 8?

[dimplebansal]

Need on urgent basis as to design supercell lattice of pcf

 

[Cthugha]

Welcome to these forums.

PCFs based on which material? For what wavelength range?
There are many different possibilities of how (and for which purpose) to design the pcf.

A standard review explaining the basics was given by Russell (Science 299, 358-362 (2003)). If you want more details, you might have to ask a more specific question.

 

[cmos]

This link could be useful.

 

[dimplebansal]

Ok,
I want to design a pcf based on supercell arrangement based on air channel with refractive index 1.45 of core air dielectric ie i want to simulate a ieee paper i m writing its name...

Progress In Electromagnetics Research M, Vol. 11, 53{64, 2010
SUPER-LATTICE STRUCTURE PHOTONIC CRYSTAL
FIBER
D. Chen y, M.-L. V. Tse, and H. Y. Tam
Photonics Research Centre, Department of Electrical Engineering
The Hong Kong Polytechnic University
Hung Hom, Kowloon, Hong Kong SAR, China


the second paper is

Supercell lattice method for photonic
crystal fibers
Wang Zhi, Ren Guobin, Lou Shuqin, and Jian Shuisheng
Institute of Lightwave Technology, Northern Jiaotong University, Beijing 100044, China
zhiwang@center.njtu.edu.cn

 

[Cthugha]

Ok, so you actually want to do the math and simulate the pcf behavior and most probably the field inside and the far field instead of actualyy manufacturing the fiber?

There are several software packages out there which can be used for that purpose. I will not spell out there name as I do not want to advertise anything. You can find them easily by performing a google search for photonic crystal fiber design software. However, they are rather expensive if you do not already have a license. Some have short term trial versions which may help you for a short time. There are also some free alternatives like this one: http://webee.technion.ac.il/people/leviatan/smtp/index.htm or this one: http://sydney.edu.au/science/physics/cudos/research/mofsoftware.shtml, but they are typically a bit more complicated and less convenient than their commercial counterparts.

 

[dimplebansal]

thats so nice of u...

bt i actually want to calculate dispersion, confinement loss, effective index, etc for the supercell arrangement using Optifdtd software version 8...bt the thing is that i know how to design basic pcf structure using this software bt problem lies in the design of supercell arrangement as mentioned above in two papers i have quoted...i'm nt understanding the design parameters...


Dimple

 

[Cthugha]

Ok, so you have the software and the problem lies in implementing the supercell.

I am not familiar with the software you use, so let me ask you a few questions:

1) Are you able to simulate the standard PCF structure as shown for example in figure 1)b) of the first paper you linked?

2) If so, it should be no problem to design the easiest superlattice design shown in figure 1)a). Basically the innermost ring of the standard design consists of seven holes placed in a hexagonal fashion (minus the defect placed in the center of the PCF). Now all you need to do is to replace every single one of these holes with such a hexagonal structure of seven smaller holes of smaller diameter d' and smaller pitch. I do not know how to script that using your software, but if you can script the standard PCF, this version should be straightforward.

3) The elliptical structure is a bit more delilcate, I suppose, but you should postpone that anyway until you managed to simulate the superlattice PCF discussed in step 2).

 

[dimplebansal]

bt the problem is the same na...how to replace the cell using OPTIFDTD

 

[Cthugha]

Is that such a problem? Typically if you have defined some 2D hexagonal lattice you should have the crystal lattice properties dialog box and inside it you should have some section about "atom waveguides in unit cell". Typically it should be this property you need to change.

I am not familiar with that program, but either it should have an option to use some sublattice as the atom waveguide in the unit cell or you should be able to create seven small atom waveguides in this unit cell, each having a shifted origin so that they are arranged evenly around the center of the unit cell.

 

[dimplebansal]

Ya i have done that i have succedded in the design but the design is not running for 1 time through 2D simulation parameters because this is essential to see the refractive index generation for further processing...

 

[dimplebansal]

Again there is one another problem has arisen in the design of octagonal pcf structure as to how to define lattice properties for the same in optifdtd 8. Reply needed on urgent basis.

Dimple