xopto.pf.miefractal module¶

class MieFractal(alpha: float, nsphere: float, nmedium: float, wavelength: float, drange: Tuple[float, float] = (1e-08, 1e-05), nd: int = 1000)[source]¶

Bases: xopto.pf.miepd.MiePd

Scattering phase function of fractally distributed (number density) spherical particles:

$p(d) = A\frac{1}{d^{\alpha}}$

The value of parameter $A$ is computed so as to normalize the integral of the number density function on the specified interval drange = $(d_1, d_2)$ to 1:

$A = \frac{d_1^{\alpha + 1}}{\alpha\left(1 - \left(\frac{d_1}{d_2}\right)^{\alpha + 1}\right)}$

Parameters

alpha (float) – Parameter alpha of the fractal distribution.
nsphere – Parameters passed to the xopto.pf.miepd.MiePd() base class constructor. See help of xopto.pf.miepd.MiePd class for more details.
nmedium – Parameters passed to the xopto.pf.miepd.MiePd() base class constructor. See help of xopto.pf.miepd.MiePd class for more details.
wavelength – Parameters passed to the xopto.pf.miepd.MiePd() base class constructor. See help of xopto.pf.miepd.MiePd class for more details.
drange – Parameters passed to the xopto.pf.miepd.MiePd() base class constructor. See help of xopto.pf.miepd.MiePd class for more details.
nd – Parameters passed to the xopto.pf.miepd.MiePd() base class constructor. See help of xopto.pf.miepd.MiePd class for more details.

Examples

Scattering phase function of fractally distributed microspherical particles with alpha=2.4 and diameter from 10 nm to 10 um.

>>> from matplotlib import pyplot as pp
>>> import numpy as np
>>>
>>> cos_theta = np.linspace(-1.0, 1.0, 1000)
>>> fmie = MieFractal(alpha=2.4, drange=[10e-9, 10e-6], nsphere=1.6, nmedium=1.33, wavelength=550e-9, nd=1000)
>>>
>>> pp.figure()
>>> pp.semilogy(cos_theta, fmie(cos_theta))
>>>