Groupe index VS core index

Imports

from PyFiberModes import FiberFactory, HE11, HE12, HE22
import matplotlib.pyplot as plt
import numpy

Generating the fiber structures

Here we create the different fiber design that we want to explore

core_indexes = numpy.linspace(1.454, 1.494, 30)
factory = FiberFactory(wavelength=1550e-9)
factory.add_layer(name="core", radius=7e-6, index=core_indexes)
factory.add_layer(name="cladding", index=1.4444)

Preparing the figure

figure, ax = plt.subplots(1, 1)

ax.set(
    title='Groupe index vs core index',
    xlabel='Core refractive index',
    ylabel='Group index'
)

for mode in [HE11, HE12, HE22]:
    neff = []
    for fiber in factory:
        effective_index = fiber.get_group_index(mode)
        neff.append(effective_index)

    ax.plot(core_indexes, neff, label=str(mode))

plt.legend()
plt.show()


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