{
"metadata": {
"name": "",
"signature": "sha256:a1fc86a1745331cbb94487da02761804f9fca4fd4c628ee53c6bfd5a750d81a6"
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 8: Optical Fiber Communication System"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1: PgNo-339"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"tr=40.0 # rediative life time in ns\n",
"tnr=60.0 # nonrediative life time in ns\n",
"i=35*math.pow(10,-3) # drive current in amp\n",
"y=0.85*math.pow(10,-6)# wavelength in m\n",
"h=6.626*math.pow(10,-34)# plank constant\n",
"c=3*math.pow(10,8)# the speed of light in m/s\n",
"eq=1.602*math.pow(10,-19)# charge\n",
"\n",
"# calculations\n",
"t=tr*tnr/(tr+tnr)# total carrier recombination lifetime ns\n",
"ni=t/tr # internal quantam efficiency\n",
"pil=(ni*h*c*i)/(eq*y)# internal power in watt\n",
"p_int=pil*math.pow(10,3)# internal power in mW\n",
"\n",
"# Results\n",
"print ('%s %.f %s' %(\" The total carrier recombination lifetime = \",t,\"ns\"))\n",
"print ('%s %.2f %s' %(\"\\n The internal power = \",p_int,\"mW\"))\n",
"print (\"\\n The answer is wrong in textbook \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The total carrier recombination lifetime = 24 ns\n",
"\n",
" The internal power = 30.66 mW\n",
"\n",
" The answer is wrong in textbook \n"
]
}
],
"prompt_number": 33
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2: PgNo-341"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"tr=30.0 # rediative life time in ns\n",
"tnr=50.0 # nonrediative life time in ns\n",
"i=40*math.pow(10,-3) # drive current in amp\n",
"pil=28.4*math.pow(10,-3) # internal power in watt\n",
"h=6.626*math.pow(10,-34) # plank constant\n",
"c=3*math.pow(10,8) # the speed of light in m/s\n",
"eq=1.602*math.pow(10,-19) # charge\n",
"t=tr*tnr/(tr+tnr) # total carrier recombination lifetime ns\n",
"ni=t/tr # internal quantam efficiency\n",
"y=(ni*h*c*i)/(eq*pil) # peak emission wavelength in m\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The total carrier recombination lifetime = \",t,\"ns\"))\n",
"print ('%s %.2f %s' %(\"\\n The peak emission wavelength = \",y*pow(10,6),\"um\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The total carrier recombination lifetime = 18.75 ns\n",
"\n",
" The peak emission wavelength = 1.09 um\n"
]
}
],
"prompt_number": 34
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3: PgNo-345"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"nx=3.6 # refractive index\n",
"Fn=0.68 # transmission factor\n",
"pe_pi=(Fn)/(4*math.pow(nx,2))\n",
"pi_p=0.3\n",
"nep=pe_pi*pi_p # external power efficiency\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\"The external power efficiency = \",nep*100,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The external power efficiency = 0.39 %\n"
]
}
],
"prompt_number": 35
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4: PgNo-347"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"n=3.6 # core refractive index\n",
"NA=0.15 # numerical aperture\n",
"nc=math.pow(NA,2) # coupling efficiency\n",
"l_s=-10*math.log(nc)/math.log(10) # loss in db\n",
"pe_pi=0.023*0.0013 # from ex 8.3\n",
"pc=-10*math.log(pe_pi)/math.log(10) # loss in decibels relative to Pint\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The coupling efficiency = \",nc*100,\"%\"))\n",
"print ('%s %.3f %s' %(\"\\n The loss = \",l_s,\"db\"))\n",
"print ('%s %.2f %s' %(\"\\n The loss in decibels relative to Pint= \",pc,\"db\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The coupling efficiency = 2.25 %\n",
"\n",
" The loss = 16.478 db\n",
"\n",
" The loss in decibels relative to Pint= 45.24 db\n"
]
}
],
"prompt_number": 36
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 5: PgNo-348"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"r=45*math.pow(10,-6) # radius in m\n",
"NA=0.3 # numerical aperture\n",
"rd=40 # radiance\n",
"A=3.14*math.pow((r*100),2) # area in cm^2\n",
"pe=3.14*(1-r)*A*rd*math.pow(NA,2) # optical power coupled into the fiber\n",
"Pe=pe*math.pow(10,4) # optical power coupled into the fiber uW\n",
"\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The optical power coupled into the fiber = \",Pe,\"uW\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The optical power coupled into the fiber = 7.187 uW\n"
]
}
],
"prompt_number": 37
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6: PgNo-351"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"pc=150*math.pow(10,-6) # coupling power W\n",
"p=20*math.pow(10,-3)*2 # optical power W\n",
"npc=pc/p # overall efficiency\n",
"Npc=npc*100 # percentage of overall efficiency\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The percentage of overall efficiency = \",Npc,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The percentage of overall efficiency = 0.37 %\n"
]
}
],
"prompt_number": 38
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 7: PgNo-357"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"n=1.5 # refractive index\n",
"L=0.05 #crystal length in m\n",
"y=0.5*math.pow(10,-6) # wavelength in m\n",
"c=3*math.pow(10,8) # speed of light in m/s\n",
"q=2*n*L/y # the number of longitudinal modes\n",
"df=c/(2*n*L) # frequency separation of the modes in Hz\n",
"Df=df/math.pow(10,9) # frequency separation of the modes in GHz\n",
"\n",
"# Results\n",
"print ('%s %d ' %(\" The number of longitudinal modes = \",q))\n",
"print ('%s %.2f %s' %(\"\\n The frequency separation of the modes = \",Df,\"GHz\"))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The number of longitudinal modes = 300000 \n",
"\n",
" The frequency separation of the modes = 2.00 GHz\n"
]
}
],
"prompt_number": 39
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 8: PgNo-358"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable declaration\n",
"Eg=1.43 # bandgap energy in eV\n",
"dy=0.15*math.pow(10,-9);\n",
"c=3*math.pow(10,8) # speed of light in m/s\n",
"y=1.24/Eg # in um\n",
"y1=y*math.pow(10,-6) # wavelength of optical emission in m\n",
"df=(c*dy)/math.pow(y1,2) # the line width in Hz\n",
"Df=df/math.pow(10,9) # the line width in GHz\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The wavelength of optical emission = \",y,\"um\"))\n",
"print ('%s %.4f %s' %(\"\\n The frequency separation of the modes = \",Df,\"GHz\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The wavelength of optical emission = 0.87 um\n",
"\n",
" The frequency separation of the modes = 59.8468 GHz\n"
]
}
],
"prompt_number": 40
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 9: PgNo-362"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"n=3.6 # refractive index\n",
"c=3*math.pow(10,8)# speed of light in m/s\n",
"y=0.85*math.pow(10,-6)# wavelength in m\n",
"df=275*math.pow(10,9) # frequency separation of the modes in Hz\n",
"L=c/(2*n*df) # crystal length in m\n",
"L1=L*math.pow(10,6) # crystal length in um\n",
"q=2*n*L/y # the number of longitudinal modes\n",
"\n",
"# results\n",
"print ('%s %.2f %s' %(\" The crystal length = \",L1,\"um\"))\n",
"print ('%s %d' %(\"\\n The the number of longitudinal modes = \",int(q)))\n",
"print (\"\\n answer is wrong in textbook \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The crystal length = 151.52 um\n",
"\n",
" The the number of longitudinal modes = 1283\n",
"\n",
" answer is wrong in textbook \n"
]
}
],
"prompt_number": 41
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10: PgNo-364"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"nt=0.20# total efficiency\n",
"Eg=1.43# bandgap energy in eV\n",
"V=2.2# applied voltage in volts\n",
"nep=(nt*Eg)/V# external power efficiency\n",
"Nep=nep*100# percentage of external power efficiency\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The external power efficiency = \",Nep,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The external power efficiency = 13.00 %\n"
]
}
],
"prompt_number": 42
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11: PgNo-367"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"h=0.35*math.pow(10,-3)# irradiance W/cm^2\n",
"po=0.45*math.pow(10,-3)# power output in watt\n",
"d=1.5 # separation distance in cm\n",
"x=math.sqrt((4*po)/(3.14*math.pow(d,2)*h)) # divergence angle in radians\n",
"X=(x*180)/3.14 # divergence angle in degree\n",
"\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The divergence angle = \",X,\"degree \"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The divergence angle = 48.909 degree \n"
]
}
],
"prompt_number": 43
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 12: PgNo-369"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"ni=0.09 # normal efficiency\n",
"d=2*2.54 # separation distance in cm\n",
"x=0.2 # divergence angle in radians\n",
"vf=2.0 # forward voltage in volts\n",
"i_f=65*math.pow(10,-3) # forward current in amp\n",
"pil=vf*i_f # input power in Watt\n",
"po=ni*pil # output power in Watt\n",
"H=4*po/(3.14*math.pow(d,2)*math.pow(x,2)) # irradiance in watt/cm^2\n",
"H1=H*1000 # irradiance in mwatt/cm^2\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The irradiance = \",H1,\"mwatt/cm^2 \"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The irradiance = 14.44 mwatt/cm^2 \n"
]
}
],
"prompt_number": 44
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 13: PgNo-372"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# variable declaration\n",
"tr=3.5 # relative life time in ms\n",
"tnr=50 # nonrelative life time in ms\n",
"ni=tnr/(tr+tnr) # internal quantam efficiency\n",
"\n",
"# results\n",
"print ('%s %.2f %s' %(\" The internal quantam efficiency = \",ni*100,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The internal quantam efficiency = 93.46 %\n"
]
}
],
"prompt_number": 45
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14: PgNo-375"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# initialisation of variables\n",
"ni=0.15 # internal quantam efficiency\n",
"vf=2.0 # forward voltage in volts\n",
"i_f=15*math.pow(10,-3) # forward current in amp\n",
"x=25 # acceptance angle in degree\n",
"pil=vf*i_f # input power in Watt\n",
"po=ni*pil # output power in Watt\n",
"NA=(math.sin(x*math.pi/180))\n",
"nc=math.pow(NA,2) # numerical aperture\n",
"pf=nc*po # optical power coupled into optical fiber in w\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The optical power coupled into optical fiber = \",pf*1000,\"mW\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The optical power coupled into optical fiber = 0.80 mW\n"
]
}
],
"prompt_number": 46
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 15: PgNo-378"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"tnr=10 # nonrediative life time in ns\n",
"n_inj=0.80 # injection efficiency\n",
"n_ex=0.60 # extraction efficiency\n",
"nt=0.025 # total efficiency\n",
"nr=nt/(n_inj*n_ex) # non rediative life time in ns\n",
"tr=((1/nr)-1)*tnr # rediative life time in ns\n",
"# Results\n",
"print ('%s %.1f %s' %(\" The rediative life time = \",tr,\"ns\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The rediative life time = 182.0 ns\n"
]
}
],
"prompt_number": 47
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 16: PgNo-381"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"tr=30*math.pow(10,-9) # rise time in s\n",
"Bw=0.35/tr # bandwidth in Hz\n",
"\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The bandwidth = \",Bw/math.pow(10,6),\"MHz\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The bandwidth = 11.667 MHz\n"
]
}
],
"prompt_number": 48
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 17: PgNo-384"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"y=630*math.pow(10,-9)# operating wavelength in m\n",
"w=25*math.pow(10,-6) # spot size in m\n",
"x=2*y/(math.pi*w) # divergence angle in radians\n",
"x1=x*180/math.pi # divergence angle in degree\n",
"\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The divergence angle = \",x,\"radians\"))\n",
"print ('%s %.3f %s' %(\"\\n The divergence angle = \",x1,\"degree\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The divergence angle = 0.016 radians\n",
"\n",
" The divergence angle = 0.919 degree\n"
]
}
],
"prompt_number": 49
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 18: PgNo-388"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"y1=550*math.pow(10,-3)# peak of eyes response in um\n",
"y2=10.6 # standard wavelength in um\n",
"y3=2.39 # predominant IR line of He-Ne laser in um\n",
"E1=1.24/y1 # energy in electron volts\n",
"E2=1.24/y2 # energy in electron volts\n",
"E3=1.24/y3 # energy in electron volts\n",
"\n",
"# results\n",
"print ('%s %.3f %s' %(\" The energy = \",E1,\"electron volts\"))\n",
"print ('%s %.3f %s' %(\"\\n The energy = \",E2,\"electron volts\"))\n",
"print ('%s %.3f %s' %(\"\\n The energy = \",E3,\"electron volts\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The energy = 2.255 electron volts\n",
"\n",
" The energy = 0.117 electron volts\n",
"\n",
" The energy = 0.519 electron volts\n"
]
}
],
"prompt_number": 50
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 19: PgNo-391"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# variable initialisation\n",
"Eg=1.4 # energy in electron volts\n",
"y=1.24/Eg # cut off wavelength in um\n",
"y1=y*1000 # cut off wavelength in nm\n",
"# Results\n",
"print ('%s %.4f %s' %(\" The cut off wavelength = \",y1,\"nm\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The cut off wavelength = 885.7143 nm\n"
]
}
],
"prompt_number": 51
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 20: PgNo-394"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"y=1200*math.pow(10,-9)# operating wavelength in m\n",
"w=5*math.pow(10,-6)# spot size in m\n",
"x=2*y/(math.pi*w)# divergence angle in radians\n",
"x1=x*180/math.pi # divergence angle in degree\n",
"\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The divergence angle = \",x,\"radians\"))\n",
"print ('%s %.3f %s' %(\"\\n The divergence angle = \",x1,\"degree\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The divergence angle = 0.153 radians\n",
"\n",
" The divergence angle = 8.754 degree\n"
]
}
],
"prompt_number": 52
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 21: PgNo-395"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"n1=1.48 # core refractive index\n",
"n2=1.46 # cladding refractive index \n",
"NA=math.sqrt(math.pow(n1,2)-math.pow(n2,2)) # numerical aperture\n",
"xa=(math.asin(NA))*(180/math.pi) # acceptance angle in degree\n",
"nc=math.pow(NA,2) # coupling efficiency\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The acceptance angle = \",xa,\"degree\"))\n",
"print ('%s %.2f %s' %(\"\\n The coupling efficiency = \",nc*100,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The acceptance angle = 14.03 degree\n",
"\n",
" The coupling efficiency = 5.88 %\n"
]
}
],
"prompt_number": 53
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22: PgNo-398"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"c=3*math.pow(10,8) # speed of light in m/s\n",
"n=3.66 # for GaAs\n",
"L=150*math.pow(10,-6) # cavity length in m\n",
"dv=c/(2*n*L) #frequency separation in Hz\n",
"dv1=dv/math.pow(10,12) # frequency separation in GHz\n",
"h=6.64*math.pow(10,-34) # plank constant\n",
"q=1.6*math.pow(10,-19) # charge of an electron\n",
"dE=(h*dv)/q # energy separation eV\n",
"\n",
"# Results\n",
"print ('%s %.4f %s' %(\" The frequency separation = \",dv1,\"GHz\"))\n",
"print ('%s %.3f %s' %(\"\\n The energy separation = \",dE*1000,\"meV\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The frequency separation = 0.2732 GHz\n",
"\n",
" The energy separation = 1.134 meV\n"
]
}
],
"prompt_number": 54
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 23: PgNo-400"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# variable initialisation\n",
"po=2*math.pow(10,-3)# optical power in watts\n",
"I=100*math.pow(10,-3)# current in amp\n",
"V=2 # applied voltage in volt\n",
"pe=I*V # electrical power in watts\n",
"n=(po/pe)*100 # conversion efficiency\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The conversion efficiency = \",n,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The conversion efficiency = 1.00 %\n"
]
}
],
"prompt_number": 55
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 24: PgNo-403"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# variable initialisation\n",
"c=3*math.pow(10,8) # speed of light in m/s\n",
"h=6.64*math.pow(10,-34) # plank constant\n",
"Eg=1.43 # gap energy in eV\n",
"y=(1.24*math.pow(10,-6))/Eg # wavelength in m\n",
"dy=0.1*math.pow(10,-9) # in m\n",
"df=(dy*c)/math.pow(y,2) # width in Hz\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The wavelength = \",y*pow(10,6),\"um\"))\n",
"print ('%s %.4f %s' %(\"\\n The width = \",df/pow(10,9),\"GHz\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The wavelength = 0.867 um\n",
"\n",
" The width = 39.8979 GHz\n"
]
}
],
"prompt_number": 56
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 25: PgNo-407"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable declaration\n",
"tr=25.0 # rediative life time in ns\n",
"tnr=90.0 # nonrediative life time in ns\n",
"i=3.5*math.pow(10,-3) # drive current in amp\n",
"y=1.31*math.pow(10,-6) # wavelength in m\n",
"h=6.625*math.pow(10,-34) # plank constant\n",
"c=3*math.pow(10,8) # the speed of light in m/s\n",
"eq=1.6*math.pow(10,-19 )# charge\n",
"t=tr*tnr/(tr+tnr) # total carrier recombination lifetime ns\n",
"ni=t/tr # internal quantam efficiency\n",
"pil=(ni*h*c*i)/(eq*y) # internal power in watt\n",
"p_int=pil*pow(10,3) # internal power in mW\n",
"P=p_int/(ni*(ni+1)) # power emitted in mW\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The total carrier recombination lifetime = \",t,\"ns\"))\n",
"print ('%s %.2f ' %(\"\\n The internal quantam efficiency = \", ni))\n",
"print ('%s %.2f %s' %(\"\\n The internal power = \",p_int,\"mW\"))\n",
"print ('%s %.2f %s' %(\"\\n The power emitted = \",P,\"mW\"))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The total carrier recombination lifetime = 19.57 ns\n",
"\n",
" The internal quantam efficiency = 0.78 \n",
"\n",
" The internal power = 2.60 mW\n",
"\n",
" The power emitted = 1.86 mW\n"
]
}
],
"prompt_number": 57
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 26: PgNo-409"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"nt=0.18 # total efficiency\n",
"Eg=1.43 # band gape energy eV\n",
"V=2.5 # appied voltage in volt\n",
"n_ex=(nt*(Eg/V))*100 # external efficiency\n",
"\n",
"# Results\n",
"print ('%s %.2f %s' %(\" The external efficiency = \",n_ex,\"%\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The external efficiency = 10.30 %\n"
]
}
],
"prompt_number": 58
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 27: PgNo-411"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"c=3*math.pow(10,8) # speed of light in m/s\n",
"n=3.6 # for GaAs\n",
"df=278*math.pow(10,9) # separation in Hz\n",
"y=0.87*math.pow(10,-6) # wavelength in m\n",
"L=c/(2*n*df) # cavity length in m\n",
"l=L*math.pow(10,6) # cavity length in um\n",
"L1=math.floor(l)*math.pow(10,-6) # cavity length in m\n",
"q=(2*n*L1)/y # number of longitudinal modes\n",
"# Results\n",
"print ('%s %.3f %s' %(\" The cavity length = \",l,\"um\"))\n",
"print ('%s %d' %( \"\\n The number of longitudinal modes = \",int(q)))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The cavity length = 149.880 um\n",
"\n",
" The number of longitudinal modes = 1233\n"
]
}
],
"prompt_number": 59
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 28: PgNo-415"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Initialisation of variables\n",
"ac=14 # acceptance angle in degree\n",
"nc=math.pow((math.sin(ac*math.pi/180)),2) # coupling efficiency\n",
"l_s=-10*math.log(nc)/math.log(10) # loss in decibels\n",
"\n",
"# results\n",
"print ('%s %.3f ' %(\" The coupling efficiency = \",nc))\n",
"print ('%s %.3f %s' %(\"\\n The loss = \",l_s,\"decibels\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The coupling efficiency = 0.059 \n",
"\n",
" The loss = 12.326 decibels\n"
]
}
],
"prompt_number": 60
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 29: PgNo-417"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"# Variable initialisation\n",
"c=3*math.pow(10,8)# speed of light in m/s\n",
"n=3.7 # for GaAs\n",
"L=500*math.pow(10,-6) # cavity length in m\n",
"y=850*math.pow(10,-9)\n",
"df=c/(2*n*L) #frequency separation in Hz\n",
"df1=df/math.pow(10,9) # frequency separation in GHz\n",
"dy=(y*y)/(2*L*n) # wavelength in m\n",
"dy1=dy*math.pow(10,9) # wavelength in nm\n",
"\n",
"# Resultsh\n",
"print ('%s %.4f %s' %(\" The frequency separation = \",df1,\"GHz\"))\n",
"print ('%s %.3f %s' %(\"\\n The wavelength separation = \",dy1,\"nm\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The frequency separation = 81.0811 GHz\n",
"\n",
" The wavelength separation = 0.195 nm\n"
]
}
],
"prompt_number": 61
}
],
"metadata": {}
}
]
}