def setThinFilmNeff(self,mode):
if dir(self).__contains__('thickness') and dir(self).__contains__('material_stack') and dir(self).__contains__('polarization'):
import thinfilms
self.neff = lambda w: thinfilms.neff(w,self.thickness,self.material_stack[0],self.material_stack[2],self.material_stack[1],self.polarization)[mode-1]
#!/usr/bin/env python
from thinfilms import neff
from RefractiveIndex import nSi,nSilica
import numpy as np
import matplotlib
import matplotlib.pyplot as plt
N=100
n = lambda w,t: neff(w,t*1E-9,nSilica(w),nSilica(w),nSi(w),pol='TE')
wavelengths = np.linspace(1450E-9,1600E-9,N)
wavem = (wavelengths[1:]+wavelengths[:-1])/2
neffs = []
for thickness in range(200,301,50):
nf = np.array([n(w,thickness)[0] for w in wavelengths]).T
neffs.append(nf)
ng = (nf[1:]+nf[:-1])/2 - wavem*np.diff(nf)/np.diff(wavelengths)
plt.plot(wavem*1E9,ng,label=str(thickness)+' nm')
plt.subplots_adjust(right=0.94)
plt.xlabel('Wavelength (nm)')
plt.ylabel('$n_g$')
plt.legend(loc='lower left',title='Si film thickness')
plt.xlim([1450,1600])
ran = range(1450,1601,25)
plt.xticks(ran,[str(i) for i in ran])
plt.text(1413,3.775,'b)')
plt.gcf().set_size_inches([3.4,2.4])
plt.savefig('slabGroupDispersion.pdf')
#plt.show()
