#importing modules
import math
from __future__ import division
#Variable declaration
lamda=500*10**-9; #wavelength(m)
mewe=1.553; #refractive index of e-ray
mew0=1.544; #refractive index of o-ray
#Calculation
t=lamda/(2*(mewe-mew0)); #thickness of quartz half wave plate(m)
#Result
print "thickness of quartz half wave plate is",round(t/10**-3,4),"mm"
#importing modules
import math
from __future__ import division
#Variable declaration
lamda=589*10**-9; #wavelength(m)
mewe=1.553; #refractive index of e-ray
mew0=1.544; #refractive index of o-ray
#Calculation
t=lamda/(4*(mewe-mew0)); #thickness of quartz half wave plate(m)
#Result
print "thickness of quartz half wave plate is",round(t/10**-3,4),"mm"
#importing modules
import math
from __future__ import division
#Variable declaration
lamda=600*10**-9; #wavelength(m)
mewe=1.5533; #refractive index of e-ray
mew0=1.5442; #refractive index of o-ray
#Calculation
t=lamda/(4*(mewe-mew0)); #thickness of quartz half wave plate(m)
#Result
print "thickness of quartz half wave plate is",round(t/10**-3,4),"mm"
#importing modules
import math
from __future__ import division
#Variable declaration
lamda=589.3*10**-9; #wavelength(m)
mewe=1.65833; #refractive index of e-ray
mew0=1.48640; #refractive index of o-ray
#Calculation
t1=lamda/(2*(mewe-mew0)); #thickness of half wave plate(m)
t2=lamda/(4*(mewe-mew0)); #thickness of quarter wave plate(m)
#Result
print "thickness of half wave plate is",round(t1/10**-3,7),"mm"
print "thickness of quarter wave plate is",round(t2/10**-3,6),"mm"
#importing modules
import math
from __future__ import division
#Variable declaration
t=0.9*10**-6; #thickness(m)
mewe=1.486; #refractive index of e-ray
mew0=1.658; #refractive index of o-ray
#Calculation
lamda1=4*t*(mew0-mewe); #wavelength for half wave plate(m)
lamda2=2*t*(mew0-mewe); #wavelength for quarter wave plate(m)
#Result
print "wavelength for half wave plate is",lamda1*10**9,"m"
print "wavelength for quarter wave plate is",lamda2*10**9,"mm"