Waveguide Dispersion: Investigating Properties & Complications

[Dimand]

Greeting.
I am currently investigating the dispersion properties of waveguides.

The dispersion of an optical fiber is usually mostly contributed to by the material dispersion.
Ignoring any dopant, this is just dependent on the refractive index of silica.
It is easy to take the Sellmeier equation to get n($$\lambda$$)
Then D=-$$\frac{\lambda}{c}$$ $$\frac{d^{2}n}{d\lambda^{2}}$$

To find the total dispersion of the waveguide however, you need to include the waveguide dispersion, this is different for each of the allowed modes in the waveguide. I could past half a page of equations here, but I don't fully understand it so I won't confuse you.

Finding information on this is easy for a basic step index fiber. I'm interested in more complicated index profiles i.e. photonic crystal fibers(solid core). Finding information on this is hard, so I'm hoping that someone here might know a bit more about this.

Once I have figured this out I will be able to figure out the dispersion curves for different allowed modes in the fiber I am using. So does anyone here know about this stuff?

 

[AndyW]

Hello!

As a fellow scientist, I can definitely relate to your interest in studying waveguide dispersion properties. You are correct in stating that material dispersion plays a significant role in the overall dispersion of an optical fiber. However, it is important to also consider other factors such as waveguide dispersion, which can greatly affect the performance of the fiber.

In terms of photonic crystal fibers, their unique index profiles can lead to more complex dispersion properties. One way to study this is by using the finite difference method, which can help calculate the dispersion curves for different modes in the fiber. Additionally, there are also various simulations and experiments that can be done to analyze the dispersion properties of photonic crystal fibers.

I would also suggest looking into research papers and articles on this topic, as there is a wealth of information available from other scientists who have studied waveguide dispersion in photonic crystal fibers. I hope this helps in your investigation and good luck with your research!