pyMMF.IndexProfile#

class pyMMF.IndexProfile(npoints, areaSize)[source]#

Class representing the refractive index profile of the fiber.

Parameters:

npointsint: The number of points in each dimension of the grid.
areaSizefloat: The size in um of the area (let it be larger that the core size!)

Parameters:

npoints (int)
areaSize (float)

Methods

`fromFile`(filename)	Load the index profile from a file.
`getOptimalSolver`([curvature])	Returns the optimal solver based on the index profile and curvature flag.
`initFromArray`(n_array)	Initializes the index profile from a numpy array.
`initFromRadialFunction`(nr)	Initializes the index profile from a radial function.
`initParabolicGRIN`(n1, a, NA[, alpha])	Initializes the refractive index profile for a parabolic GRIN fiber.
`initStepIndex`(n1, a, NA)	Initializes the step index profile.
`load`(filename)	Load the index profile from a file.
`plot`()	Plot the 2d index profile map.
`save`(filename)	Save the index profile to a file.

Methods

`__init__`(npoints, areaSize)
`fromFile`(filename)	Load the index profile from a file.
`getOptimalSolver`([curvature])	Returns the optimal solver based on the index profile and curvature flag.
`initFromArray`(n_array)	Initializes the index profile from a numpy array.
`initFromRadialFunction`(nr)	Initializes the index profile from a radial function.
`initParabolicGRIN`(n1, a, NA[, alpha])	Initializes the refractive index profile for a parabolic GRIN fiber.
`initStepIndex`(n1, a, NA)	Initializes the step index profile.
`load`(filename)	Load the index profile from a file.
`plot`()	Plot the 2d index profile map.
`save`(filename)	Save the index profile to a file.

Attributes

`npoints`	Number of points in each dimension of the grid
`n`	Index profile
`areaSize`	Size in um of the area
`X`	X coordinate of the grid (2d array)
`Y`	Y coordinate of the grid (2d array)
`TH`	Azimuthal coordinate of the grid (2d array)
`R`	Radial coordinate of the grid (2d array)
`dh`	Spatial resolution of the grid
`radialFunc`	Radial function (if initialized from a function)
`type`	Type of index profile (custom, GRIN, SI)

R: ndarray#: Radial coordinate of the grid (2d array)

TH: ndarray#: Azimuthal coordinate of the grid (2d array)

X: ndarray#: X coordinate of the grid (2d array)

Y: ndarray#: Y coordinate of the grid (2d array)

areaSize: float#: Size in um of the area

dh: float#: Spatial resolution of the grid

classmethod fromFile(filename)[source]#

Load the index profile from a file.

Parameters:

filenamestr: The name of the file where the index profile is saved.

Returns:

IndexProfile: The index profile loaded from the file.

Parameters:

filename (str)

Examples

import pyMMF
filename = "index_profile.pkl"
profile = pyMMF.IndexProfile.fromFile(filename)

getOptimalSolver(curvature=False)[source]#

Returns the optimal solver based on the index profile and curvature flag.

Parameters:

curvature (bool): Flag indicating whether curvature is considered.

Returns:

str: The optimal solver based on the index profile and curvature flag.: Possible values are “SI” (for self.type == “SI” and not curvature), “radial” (if self.indexProfile.radialFunc is not None), or “eig” (default).

Parameters:: curvature (bool)

initFromArray(n_array)[source]#

Initializes the index profile from a numpy array. Use this function to define a custom index profile.

Parameters:

n_arraynp.ndarray: 2d array containing the index values. Each value correspond to a pixel with coordinates given by (self.X, self.Y) in the cartesian coordinate system, or (self.R, self.TH) in the polar coordinate system.

Returns:

None

Parameters:

n_array (ndarray)

Return type:

None

Examples

Square fiber index profile:

import numpy as np
import pyMMF
n1 = 1.45
n2 = 1.44
npoints = 64
core_size = 10
areaSize = 20
profile = pyMMF.IndexProfile(npoints=npoints, areaSize=areaSize)
index_array = n2*np.ones((npoints,npoints))
mask_core = (np.abs(profile.X) < core_size/2) & (np.abs(profile.Y) < core_size/2)
index_array[mask_core] = n1
profile.initFromArray(index_array)

initFromRadialFunction(nr)[source]#

Initializes the index profile from a radial function. Use this function to define a custom axisymmetric index profile.

Parameters:

nrCallable[[float], float]: A callable function that takes a float argument and returns the refractive index.

Returns:

None

Parameters:

nr (Callable[[float], float])

Return type:

None

Examples

Ring core fiber index profile:

import numpy as np
import pyMMF
n1 = 1.445
n2 = 1.45
n3 = 1.44
a = 5
b = 10
npoints = 256
areaSize = 25
profile = pyMMF.IndexProfile(npoints=npoints, areaSize=areaSize)
def radialFunc(r):
    if r < a:
        return n1
    elif r < b:
        return n2
    else:
        return n3
profile.initFromRadialFunction(radialFunc)

initParabolicGRIN(n1, a, NA, alpha=2.0)[source]#

Initializes the refractive index profile for a parabolic GRIN fiber.

[ begin{eqnarray} n(r) &=& sqrt{n_1^2 left[1 - 2 (r / a)^alpha Delta n right]} quad forall , r leq a \ n(r) &=& n_2 quad forall , r > a end{eqnarray} ]

with

[ Delta n = frac{NA^2}{2 n_1^2} ]

Parameters:

n1float: The refractive index at the core center.
afloat: The core radius.
NAfloat: The numerical aperture.
alphafloat, optional: The exponent of the parabolic profile. Default is 2.0.

Returns:

None

Parameters:

n1 (float)
a (float)
NA (float)
alpha (float)

Return type:

None

Examples

Parabolic GRIN fiber:

import pyMMF
n1 = 1.45; a = 10; NA = 0.2
npoints = 64
areaSize = 20
profile = pyMMF.IndexProfile(npoints=npoints, areaSize=areaSize)

profile.initParabolicGRIN(n1=n1, a=a, NA=NA)

initStepIndex(n1, a, NA)[source]#

Initializes the step index profile.

Parameters:

n1float: The refractive index inside the core region.
afloat: The core radius.
NAfloat: The numerical aperture.

Returns:

None

Parameters:

n1 (float)
a (float)
NA (float)

Return type:

None

Examples

import pyMMF
n1 = 1.45; a = 10; NA = 0.2
npoints = 256
areaSize = 20
profile = pyMMF.IndexProfile(npoints=npoints, areaSize=areaSize)
profile.initStepIndex(n1=n1, a=a, NA=NA)

load(filename)[source]#

Load the index profile from a file.

Parameters:

filenamestr or dict: The name of the file where the index profile is saved, or a dictionary containing the index profile data.

Returns:

None

Parameters:

filename ([<class 'str'>, <class 'dict'>])

Return type:

None

n: ndarray#: Index profile

npoints: int#: Number of points in each dimension of the grid

plot()[source]#

Plot the 2d index profile map.

Returns:

None

Return type:

None

radialFunc: Callable[[float], float]#: Radial function (if initialized from a function)

save(filename)[source]#

Save the index profile to a file.

Parameters:

filenamestr: The name of the file where to save the index profile.

Returns:

None

Parameters:

filename (str)

Return type:

None

Examples

import pyMMF
npoints = 256
areaSize = 20
profile = pyMMF.IndexProfile(npoints=npoints, areaSize=areaSize)
...
profile.save("index_profile.pkl")

type: str#: Type of index profile (custom, GRIN, SI)

pyMMF.IndexProfile#

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