qpms/qpms/cymaterials.pyx

294 lines
11 KiB
Cython

# Cythonized parts of QPMS here
# -----------------------------
import numpy as np
import cmath
from .qpms_cdefs cimport qpms_permittivity_interpolator_from_yml, qpms_permittivity_interpolator_free, qpms_permittivity_interpolator_omega_min, qpms_permittivity_interpolator_omega_max, gsl_interp_type, qpms_permittivity_interpolator_t, gsl_interp_cspline, qpms_permittivity_interpolator_eps_at_omega, qpms_epsmu_const_g, qpms_permittivity_interpolator_epsmu_g, qpms_epsmu_const_g, qpms_lorentzdrude_epsmu_g, qpms_ldparams_triple_t, qpms_lorentzdrude_eps, cdouble
from .cycommon cimport make_c_string
cimport cython
import enum
import warnings
import os
from .constants import e as eV, hbar, c
from libc.stdlib cimport malloc, free, calloc, abort
class EpsMuGeneratorType(enum.Enum):
CONSTANT = 1
PERMITTIVITY_INTERPOLATOR = 2
LORENTZ_DRUDE = 3
PYTHON_CALLABLE = 4
cdef class EpsMu:
"""Permittivity and permeability of an isotropic material.
This wraps the C structure qpms_epsmu_t.
See Also
--------
EpsMuGenerator : generates EpsMu objects as a function of frequency.
"""
def __init__(self, *args ,**kwargs):
"""EpsMu object constructor
Parameters
----------
eps : complex
Relative electric permittivity.
mu : complex
Relative magnetic permeability.
"""
self.em.eps = 1
self.em.mu = 1
if(len(args)>=1):
self.em.eps = args[0]
if(len(args)>=2):
self.em.mu = args[1]
if 'eps' in kwargs.keys():
self.em.eps = kwargs['eps']
if 'mu' in kwargs.keys():
self.em.mu = kwargs['mu']
return
def __repr__(self):
return 'EpsMu(' + repr(self.em.eps) + ', ' + repr(self.em.mu) + ')'
def k(self, omega):
"""Wavenumber of the material at frequency omega
Parameters
----------
omega : complex
Angular frequency in 1/s.
Returns
-------
out : complex
Wavenumber of the material at omega assuming permittivity and permeability
from self.
"""
return self.n * omega / c
property n:
"""Refractive index of a material specified by this permittivity and permeability."""
def __get__(self):
return (self.em.eps * self.em.mu)**.5
property Z:
"""Wave impedance of a material specified by this permittivity and permeability."""
def __get__(self):
return (self.em.mu / self.em.eps)**.5
cdef class LorentzDrudeModel:
"""Lorentz-Drude model of material permittivity.
This wraps the C structure qpms_ldparams_t.
Some materials are available in the `lorentz_drude` dictionary.
"""
def __cinit__(self, eps_inf, omega_p, f_arr, omega_arr, gamma_arr):
cdef size_t n = len(omega_arr)
if (n != len(gamma_arr) or n != len(f_arr)):
raise ValueError("omega_arr, gamma_arr and f_arr must have equal lengths!")
cdef qpms_ldparams_t *p
p = <qpms_ldparams_t *>malloc(sizeof(qpms_ldparams_t) + sizeof(qpms_ldparams_triple_t) * n)
p[0].eps_inf = eps_inf
p[0].omega_p = omega_p
p[0].n = n
cdef size_t i
for i in range(0,n):
p[0].data[i].f = f_arr[i]
p[0].data[i].omega = omega_arr[i]
p[0].data[i].gamma = gamma_arr[i]
self.params = p
def __dealloc__(self):
free(self.params)
self.params = NULL
def __call__(self, omega):
"""Evaluates the permittivity at a given frequency
Parameters
----------
omega : complex
Angular frequency in 1/s.
Returns
-------
eps : complex
Relative permittivity from the Lorentz-Drude model
"""
return qpms_lorentzdrude_eps(omega, self.params)
cdef class _CLorentzDrudeModel:
"""Lorentz-Drude model of material permittivity.
This is an auxilliary class making the pre-compiled C Lorentz-Drude models accessible.
For defining own Lorentz-Drude models from python, use LorentzDrudeModel class instead.
"""
def __cinit__(self):
"Do not use directly. Do not use from Python. Use the link() method instead."
pass
@staticmethod
cdef link(const qpms_ldparams_t *params):
self = _CLorentzDrudeModel()
self.params = params
return self
def __call__(self, omega):
"""Evaluates the permittivity at a given frequency
Parameters
----------
omega : complex
Angular frequency in 1/s.
Returns
-------
eps : complex
Relative permittivity from the Lorentz-Drude model
"""
return qpms_lorentzdrude_eps(omega, self.params)
cdef double eh = eV/hbar
# Some basic Lorentz-Drude parameters
lorentz_drude = {
'Au_py' : # This should give the same results as 'Au'; to be removed.
LorentzDrudeModel(1, 9.03*eh,
(0.76, 0.024, 0.01, 0.071, 0.601, 4.384),
(0, 0.415*eh, 0.83*eh, 2.969*eh, 4.304*eh, 13.32*eh),
(0.053*eh, 0.241*eh, 0.345*eh, 0.87*eh, 2.494*eh, 2.214*eh)),
'Ag_py' : # This should give the same results as 'Ag'; to be removed.
LorentzDrudeModel(1, 9.01*eh,
(0.845, 0.065,0.124, 0.011, 0.840, 5.646),
(0, 0.816*eh,4.481*eh, 8.185*eh, 9.083*eh, 20.29*eh),
(0.048*eh, 3.886*eh, 0.452*eh,0.065*eh, 0.916*eh, 2.419*eh)),
'Au' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_AU),
'Ag' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_AG),
'Cu' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_CU),
'Al' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_AL),
'Cr' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_CR),
'Ti' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_TI),
'Be' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_BE),
'Ni' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_NI),
'Pd' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_PD),
'Pt' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_PT),
'W' : _CLorentzDrudeModel.link(QPMS_LDPARAMS_W),
}
cdef qpms_epsmu_t python_epsmu_generator(cdouble omega, const void *params):
cdef object fun = <object> params
cdef qpms_epsmu_t em
em.eps, em.mu = fun(omega)
return em
cdef class EpsMuGenerator:
def __init__(self, what):
if isinstance(what, str):
if what in lorentz_drude.keys():
what = lorentz_drude[what]
else:
try: what = float(what)
except ValueError:
try: what = complex(what)
except ValueError as ve:
raise ValueError("Trying to create EpsMuGenerator from a string that can't be parsed as a number (constant refractive index) nor supported lorentz-drude key") from ve
if isinstance(what, int):
what = float(what)
if isinstance(what, (float, complex)):
what = EpsMu(what**2)
if isinstance(what, EpsMu):
self.holder = what
self.g.function = qpms_epsmu_const_g
self.g.params = (<EpsMu?>self.holder).rawpointer()
elif isinstance(what, LorentzDrudeModel):
self.holder = what
self.g.function = qpms_lorentzdrude_epsmu_g
self.g.params = (<LorentzDrudeModel?>self.holder).rawpointer()
elif isinstance(what, _CLorentzDrudeModel):
self.holder = what
self.g.function = qpms_lorentzdrude_epsmu_g
self.g.params = (<_CLorentzDrudeModel?>self.holder).rawpointer()
elif isinstance(what, MaterialInterpolator):
self.holder = what
self.g.function = qpms_permittivity_interpolator_epsmu_g
self.g.params = (<MaterialInterpolator?>self.holder).rawpointer()
elif isinstance(what, EpsMuGenerator): # Copy constructor
self.holder = (<EpsMuGenerator?>what).holder
self.g = (<EpsMuGenerator?>what).g
elif callable(what):
warnings.warn("Custom python (eps,mu) generators are an experimental feature")
self.holder = what
self.g.function = python_epsmu_generator
self.g.params = <const void *> what
else:
raise ValueError("Must be constructed from a number (refractive index), EpsMu, LorentzDrudeModel or MaterialInterpolator, or a python callable object that returns an (epsilon, mu) tuple.")
property typ:
def __get__(self):
if(self.g.function == qpms_epsmu_const_g):
return EpsMuGeneratorType.CONSTANT
elif(self.g.function == qpms_lorentzdrude_epsmu_g):
return EpsMuGeneratorType.LORENTZ_DRUDE
elif(self.g.function == qpms_permittivity_interpolator_epsmu_g):
return EpsMuGeneratorType.PERMITTIVITY_INTERPOLATOR
elif(self.g.function == python_epsmu_generator):
return EpsMuGeneratorType.PYTHON_CALLABLE
else:
raise ValueError("Damn, this is a bug.")
def __call__(self, omega):
cdef qpms_epsmu_t em
if self.g.function == qpms_permittivity_interpolator_epsmu_g:
i = self.holder.freq_interval
if(omega < i[0] or omega > i[1]):
raise ValueError("Input frequency %g is outside the interpolator domain (%g, %g)."
% (omega, i[0], i[1]))
em = self.g.function(omega, self.g.params)
return EpsMu(em.eps, em.mu)
def n(self, omega):
return self(omega).n
def Z(self, omega):
return self(omega).Z
def k(self, omega):
return self(omega).k(omega)
cdef qpms_epsmu_generator_t raw(self):
return self.g
cdef class MaterialInterpolator:
'''
Wrapper over the qpms_permittivity_interpolator_t structure.
'''
def __cinit__(self, filename, *args, **kwargs):
'''Creates a permittivity interpolator.'''
cdef char *cpath = make_c_string(filename)
self.interp = qpms_permittivity_interpolator_from_yml(cpath, gsl_interp_cspline)
if not self.interp:
raise IOError("Could not load permittivity data from %s" % filename)
self.omegamin = qpms_permittivity_interpolator_omega_min(self.interp)
self.omegamax = qpms_permittivity_interpolator_omega_max(self.interp)
def __dealloc__(self):
qpms_permittivity_interpolator_free(self.interp)
def __call__(self, double freq):
'''Returns interpolated permittivity, corresponding to a given angular frequency.'''
if freq < self.omegamin or freq > self.omegamax:
raise ValueError("Input frequency %g is outside the interpolator domain (%g, %g)."
% (freq, self.minomega, self.freqs[self.maxomega]))
return qpms_permittivity_interpolator_eps_at_omega(self.interp, freq)
property freq_interval:
def __get__(self):
return [self.omegamin, self.omegamax]