# 8: Polarisation¶

## Example number 8.1, Page number 16¶

In :
#importing modules
import math
from __future__ import division

#Variable declaration
mew_e=1.553;     #refractive index of extraordinary ray
mew0=1.544;    #refractive index of ordinary ray
lamda=6*10**-7;    #wavelength(m)

#Calculation
t=lamda/(4*(mew_e-mew0));   #thickness of quarter wave plate(m)

#Result
print "thickness of quarter wave plate is",round(t*10**5,3),"*10**-5 m"

thickness of quarter wave plate is 1.667 *10**-5 m


## Example number 8.2, Page number 16¶

In :
#importing modules
import math
from __future__ import division

#Variable declaration
mew_e=1.553;     #refractive index of extraordinary ray
mew0=1.544;    #refractive index of ordinary ray
lamda=6*10**-7;    #wavelength(m)

#Calculation
t=lamda/(2*(mew_e-mew0));   #thickness of half wave plate(m)

#Result
print "thickness of half wave plate is",round(t*10**5,2),"*10**-5 m"

thickness of half wave plate is 3.33 *10**-5 m


## Example number 8.3, Page number 17¶

In :
#importing modules
import math
from __future__ import division

#Variable declaration
mew_e=1.486;     #refractive index of extraordinary ray
mew0=1.658;    #refractive index of ordinary ray
lamda=6*10**-7;    #wavelength(m)

#Calculation
t=lamda/(4*(mew0-mew_e));   #thickness of quarter wave plate(m)

#Result
print "thickness of quarter wave plate is",round(t*10**7,1),"*10**-7 m"

thickness of quarter wave plate is 8.7 *10**-7 m


## Example number 8.4, Page number 17¶

In :
#importing modules
import math
from __future__ import division

#Variable declaration
mew_e=1.486;     #refractive index of extraordinary ray
mew0=1.658;    #refractive index of ordinary ray
t=1.64*10**-6;   #thickness(m)

#Calculation
lamda=2*t*(mew0-mew_e);   #wavelength of light(m)

#Result
print "wavelength of light is",round(lamda*10**6,3),"*10**-6 m"

wavelength of light is 0.564 *10**-6 m