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{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Ch-3 Electroluminescent Sources"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.1 Page no 80"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Calculation of barrier potential\n",
"#Given data\n",
"p=5# # Resistivity of p-region\n",
"n=2# # Resistivity of n-region\n",
"mu=3900#\n",
"k=0.026# #Boltzmann constant\n",
"ni=2.5*10**13# #Density of the electron hole pair\n",
"e=1.6*10**-19# #charge of electron\n",
" \n",
"#Barrier potential calculation\n",
"r0=(1/p)# # Reflection at the fiber air interface \n",
"r1=(1/n)#\n",
"m=r1/(mu*e)#\n",
"p=6.5*10**14# #Density of hole in p -region\n",
"Vb=k*log(p*m/ni**2)#\n",
"print \"Barrier potential = %0.3f V\"%Vb\n",
"\n",
"# The answers vary due to round off error"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Barrier potential = 0.175 V\n"
]
}
],
"prompt_number": 19
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.15 Page no 484"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Calculation of external efficiency \n",
"#Given data\n",
"ne1=0.20# #Total efficiency \n",
"V=3# # Voltage applied\n",
"Eg=1.43# # Bandgap energy\n",
"\n",
"# External efficiency\n",
"ne=(ne1*Eg/V)*100#\n",
"print \"External efficiency of the device = %0.1f %% \"%(ne)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"External efficiency of the device = 9.5 % \n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.16 Page no 484"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import exp\n",
"# Calculation of ratio of threshold current densities\n",
"# Given data\n",
"To1=160# # Device temperature\n",
"To2=55# # Device temperature\n",
"T1=293#\n",
"T2=353#\n",
"J81=exp(T1/To1)# # Threshold current density \n",
"J21=exp(T2/To1)#\n",
"J82=exp(T1/To2)## \n",
"J22=exp(T2/To2)## \n",
"cd1=J21/J81# # Ratio of threshold current densities\n",
"cd2=J22/J82#\n",
"\n",
"print\"Ratio of threshold current densities= %0.2f \"%(cd1)\n",
"print\"Ratio of threshold current densities= %0.2f \"%(cd2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ratio of threshold current densities= 1.45 \n",
"Ratio of threshold current densities= 2.98 \n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.17 Page no 484"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Computation of conversion efficiency \n",
"#Given data\n",
"i=10*10**-6# # Device current\n",
"p=5# # Electrical power\n",
"op=50 *10**-6# # Optical power\n",
"ip=5*10*10**-3# # Input power\n",
"\n",
"#Conversion efficiency\n",
"c=op/ip*100# \n",
"print \"Conversion efficiency = %0.1f %% \"%(c)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Conversion efficiency = 0.1 % \n"
]
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.18 Page no 485"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Calculation of total power emitted\n",
"#Given data\n",
"r=0.7# # Emissivity\n",
"r0=5.67*10**-8# # Stephen's constant\n",
"A=10**-4# # Surface area\n",
"T=2000# # Temperature\n",
"\n",
"# Total power emitted\n",
"P=r*r0*A*T**4# \n",
"\n",
"print\"Total power emitted = %0.1f Watts \"%P"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total power emitted = 63.5 Watts \n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.19 Page no 485"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Computation of total energy\n",
"#Given data\n",
"h=6.63*10**-34# # Planck constant\n",
"v=5*10**14# # Bandgap frequency of laser\n",
"N=10**24# # Population inversion density\n",
"V=10**-5# # Volume of laser medium\n",
"\n",
"# Total energy\n",
"E=(1/2)*h*v*(N)*V# \n",
"\n",
"print \"Total energy = %0.1f J \"%E"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total energy = 1.7 J \n"
]
}
],
"prompt_number": 13
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3.20 Page no 485"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Computation of pulse power\n",
"# Given data\n",
"L=0.1# # Length of laser\n",
"R=0.8# # Mirror reflectance of end mirror\n",
"E=1.7# # Laser pulse energy\n",
"c=3*10**8# # Velocity of light\n",
"t=L/((1-R)*c)# # Cavity life time\n",
"\n",
"# Pulse power\n",
"p=E/t# \n",
"\n",
"print\"Pulse power = %0.0f W \"%p"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Pulse power = 1020000000 W \n"
]
}
],
"prompt_number": 20
}
],
"metadata": {}
}
]
}