Chapter 11:Lasers

Example 11.1, Page number 11.6

In [12]:
import math

#Variable declaration
lamda = 6943.*10**-10  #wavelength(m)
T = 300.               #temperature(K)
h = 6.626*10**-34      #Planck's constant
c = 3*10**8            #velocity of light(m/s)
K = 8.61*10**-5

#Calculations
E2_E1 = (h*c)/(lamda*1.6*10**-19) #in eV
N2_N1 = math.exp(-E2_E1/(K*T))

#Result
print "The relative population of two states in a ruby laser is",round((N2_N1/1E-31),2)

The relative population of two states in a ruby laser is 8.2

Example 11.2, Page number 11.14

In [14]:
#Variable declaration
a1 = 4.   #diameter of laser beam for distance first(m)
a2 = 6.   # diameter of laser beam from second distance(m)
d1 = 1.   #First distance from laser to output beam spot(m)
d2 = 2.   #Second distance from laser to output beam spot(m)

#Calculation
D = (a2-a1)/(2*(d2-d1))

#Result
print "Divergence =",D,"milliradian"

Divergence = 1.0 milliradian