PHOTONICS CRYSTAL FIBER

PROPERTIES OF BIREFRINGENCE OF THE (PCF)

In this presentation presents a numerical study of high birefringence properties of the photonic crystal fiber(PCF).

By using different sizes of elliptical air holes in the photonic crystal fiber.

The numerical simulation is carried out by using finite element method the statistical correlation between birefringence and varies parameters are obtained.

Based on our results the birefringence's is found to be largely dependent on the variation up the normalized wave length and size of the air hole diameter .

Birefringence properties:

Birefringence is the optical property of material having a refractive index that depends on the polarization and propagation direction of light.

These optically anisotropic material are said to be birefringent. The birefringence is often quantified as the maximum difference

between effective index of the Fundamental mode(FM). Birefringence is responsible for the phenomenon of double

refraction.

Comsol simulation technique:

Comsol multiphysics is a finite element analysis ,solver and simulation software for various physics and engineering application especially coupled phenomenon and multiphysics .

In this project I adopted comsol multiphysics for analyzing the cross section of a triangular photonic crystal fiber(PCF) .

At first I choose wave optics domain in that electro magnetic waves. Basically wave optics module provides dedicated tool for electro magnetic wave propagation in linear and non-linear optical media.

The module can be used to model high frequency electro magnetic wave stimulation in either frequency or time domain in optical structures.

Mesh properties: Meshing with comsol multiphysics 4.3b In mesh settings there are two types of modules are there. 1) Sequence type. 2) Element size. In sequence type there are two types of settings. 1)Physics controlled mesh. 2) User controlled mesh. The Element size there are 9 different pattern for selecting

element size in mesh. From extremely fine to extremely coarse. User controlled mesh user as to define every thing. Were as in

physics controlled mesh can automatically by clicking mesh.

Boundary conditions :

At first open the comsol and go to the model wizard and select 2d model and then selecting in optics wave optics again the clicking wave optics electro magnetic wave, frequency domain(ewfd).

By selecting study type mode analysis. Then we had complete model builder .These are the boundary conditions.

Simulation results : By increasing wave length the effective mode index of ‘x ‘is

decreasing and effective mode index of ‘y’ also decreasing. By repeating the same for wave length starting from 1.50 [µm] to

1.60 [µm] by taking interval of 0.1[µm] and we got some sequence wise decreasing effective mode index of ‘x’ and ‘y’.

In this project we need to calculate the birengence properties of photonic crystal fiber as shown in the figure.

By calculating the effective mode index of ‘x’ and ‘y’ and calculated birefringence at air hole diameter 0.45Λ

B= |neff,FMx-neff,FMy |

By calculating the effective mode index of ‘x’ and ‘y’ and calculated birefringence at air hole diameter 0.6Λ.

By calculating the effective mode index of ‘x’ and ‘y’ and calculated birefringence at air hole diameter 0.75Λ.

Conclusion :

As per the process I observed as the wave length and air hole diameter increases. The birefringence increases in the negative axis.

THANKYOU PRAMOD