Can OptiFiber calculate the cladding mode of singlemode fiber or multimode fiber

Yes, OptiFiber can calculate the modal index of cladding modes.

This calculation is done the same way as any other mode. OptiFiber does not distinguish between cladding modes and core modes. It just finds modes. When you look at the mode field pattern, you may find the majority of power of some of them to be in the cladding, rather than the core. That’s a cladding mode.

In order for the cladding mode to appear, you need to make a layer in the simulation having the width of the cladding. You also need to include another layer outside the cladding, consisting of air or whatever material is found there. The refractive index of that outer layer is usually much smaller than glass, so a thin layer will suffice for the simulation.

You don’t need to observe the field pattern to determine if it is a cladding mode. There is another way to identify cladding modes. They are the ones whose modal index is smaller than the refractive index of the cladding layer. When the modal index is smaller than the cladding index, the mode number in the radial direction is a real number. Then the wavefunction follows harmonic Bessel functions and not exponential ones. That is why the field can persist to the cladding boundary. The modal field propagates out to the cladding boundary and it makes it a cladding mode.

Hi Lizzie:
You can add another circle with RI = 1.0 (air) outside the cladding.
Then you can see the calculated results of the cladding modes.
Cheers,
James Fang

Real Fiber Sample

http://https://optiwave.com/category/products/component-design/optifiber/optifiber-new-features//resources/applications-resources/optical-fiber-dispersion-shifted-fiber/

Hi,
I suggest you to visit these links:

Single Mode Fiber

Fiber Propagation Modes

Thanks,