def sample1():
"""
Here's a thin non-absorbing layer, on top of a thick absorbing layer, with
air on both sides. Plotting reflected intensity versus wavenumber, at two
different incident angles.
"""
# list of layer thicknesses in nm
d_list = [inf, 100, 300, inf]
# list of refractive indices
n_list = [1, 2.2, 3.3 + 0.3j, 1]
# list of wavenumbers to plot in nm^-1
ks = linspace(0.0001, .01, num=400)
# initialize lists of y-values to plot
Rnorm = []
R45 = []
for k in ks:
# For normal incidence, s and p polarizations are identical.
# I arbitrarily decided to use 's'.
Rnorm.append(coh_tmm('s', n_list, d_list, 0, 1 / k)['R'])
R45.append(unpolarized_RT(n_list, d_list, 45 * degree, 1 / k)['R'])
kcm = ks * 1e7 #ks in cm^-1 rather than nm^-1
plt.figure()
plt.plot(kcm, Rnorm, 'blue', kcm, R45, 'purple')
plt.xlabel('k (cm$^{-1}$)')
plt.ylabel('Fraction reflected')
plt.title('Reflection of unpolarized light at 0$^\circ$ incidence (blue), '
'45$^\circ$ (purple)')
plt.show()
def get_R(self, wavelengths, thickness, theta, void_percent):
thicknesses = [inf, thickness, inf]
mat = self.mat_df.ix[wavelengths]
mat = mat[self.layers]
theta0 = theta*sp.pi/180
self.brug_transform(mat, self.layers[1], mat['Air'], void_percent)
self.index_array = np.array(mat)
self.data = tmm.unpolarized_RT(self.index_array, thicknesses, theta0, wavelengths)
R = self.data['R']
R -= min(R)
R /= max(R)
return R
def run(self, thicknesses, theta0, polarization=None):
"""
runs the model with specified parameters
:param thicknesses: list of thicknesses, first and last must be inf
:param theta0: input angle
:param polarization: polarization state 's', 'p', or None
:return: void
"""
self.index_array = np.array(self.mat_df[self.layers])
if polarization is None:
self.data = tmm.unpolarized_RT(self.index_array, thicknesses, theta0, self.wavelength)
elif polarization in ['p', 's']:
self.data = tmm.coh_tmm(polarization, self.index_array, thicknesses, theta0, self.wavelength)
def sample1():
"""
Here's a thin non-absorbing layer, on top of a thick absorbing layer, with
air on both sides. Plotting reflected intensity versus wavenumber, at two
different incident angles.
"""
# list of layer thicknesses in nm
d_list = [inf, 100, 80, 100, 80, 100, 80, 100, 80, 100, 80, 100, 80, inf]
# list of refractive indices
n_list = [
1, 1.68 + 0.03j, 1.55 + 0.14j, 1.68 + 0.03j, 1.55 + 0.14j,
1.68 + 0.03j, 1.55 + 0.14j, 1.68 + 0.03j, 1.55 + 0.14j, 1.68 + 0.03j,
1.55 + 0.14j, 1.68 + 0.03j, 1.55 + 0.14j, 1.61 + 0.085j
]
# list of wavenumbers to plot in nm^-1
ks = linspace(0.0025, .00125, num=800)
# initialize lists of y-values to plot
Rnorm = []
R37 = []
for k in ks:
# For normal incidence, s and p polarizations are identical.
# I arbitrarily decided to use 's'.
Rnorm.append(coh_tmm('s', n_list, d_list, 0, 1 / k)['R'])
R37.append(unpolarized_RT(n_list, d_list, 37 * degree, 1 / k)['R'])
kcm = ks * 1e7 #ks in cm^-1 rather than nm^-1
lamb = 1 / ks
plt.figure()
plt.plot(lamb, Rnorm, 'blue', lamb, R37, 'purple')
plt.xlabel('Wavelength (/nm)')
plt.ylabel('Fraction reflected')
plt.title('Reflection of unpolarized light at 0$^\circ$ incidence (blue), '
'37$^\circ$ (purple)')
# data file
import numpy
datafile_path = "/users/Olimpia/Desktop/datafile.txt"
datafile_id = open(datafile_path, 'w+')
data = numpy.array([lamb, Rnorm])
data = data.T
numpy.savetxt(datafile_id, data, fmt=['%.4f', '%.4f'])
datafile_id.close()
