1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
{
"metadata": {
"name": "",
"signature": "sha256:1a1f7133700fa452f49cfaeb319a776f69d7e64235d3f11f1abd2825b262e6e8"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"chapter6 - Optical sources"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3.1, page 6-7 "
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"x=0.07 \n",
"Eg=1.424+1.266*x+0.266*x**2 \n",
"lamda=1.24/Eg #computing wavelength\n",
"print \"Wavlength is %.3f micrometer.\" %lamda "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Wavlength is 0.819 micrometer.\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3.2, page 6.12"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"n=1.7 #refractive index\n",
"L=5*10**-2 #distance between mirror\n",
"c=3*10**8 #speed of light\n",
"lamda=0.45*10**-6 #wavelength\n",
"k=2*n*L/lamda #computing number of modes\n",
"delf=c/(2*n*L) #computing mode separation\n",
"delf=delf*10**-9 \n",
"print \"Number of modes are %.2e.\\nFrequency separation is %.2f GHz.\"%(k,delf) "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Number of modes are 3.78e+05.\n",
"Frequency separation is 1.76 GHz.\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.7.1, page 6-26"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"tr=50 #radiative recombination lifetime\n",
"tnr=85 #non-radiative recombination lifetime\n",
"h=6.624*10**-34 #plank's constant\n",
"c=3*10**8 #speed of light\n",
"q=1.6*10**-19 #charge of electron\n",
"i=35*10**-3 #current\n",
"lamda=0.85*10**-6 #wavelength\n",
"t=tr*tnr/(tr+tnr) #computing total recombination time\n",
"eta=t/tr #computing internal quantum efficiency\n",
"Pint=eta*h*c*i/(q*lamda) #computing internally generated power\n",
"Pint=Pint*10**3\n",
"print \"Total recombinaiton time is %.2f ns.\\nInternal quantum efficiency is %.3f.\\nInternally generated power is %.2f mW.\" %(t,eta,Pint) \n",
"#answer in the book for Internal quantum efficiency & Internally generated power is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total recombinaiton time is 31.48 ns.\n",
"Internal quantum efficiency is 0.630.\n",
"Internally generated power is 32.20 mW.\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.8.1, page 6-34"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from numpy import sqrt, pi\n",
"f1=10*10**6 #frequency\n",
"f2=100*10**6\n",
"t=4*10**-9 \n",
"Pdc=280*10**-6 #optincal output power\n",
"w1=2*pi*f1 #computing omega\n",
"Pout1=Pdc*10**6/(sqrt(1+(w1*t)**2)) #computing output power\n",
"w2=2*pi*f2 #computing omega\n",
"Pout2=Pdc*10**6/(sqrt(1+(w2*t)**2)) #computing output power\n",
"print \"\"\"Ouput power at 10 MHz is %.2f microwatt.\n",
"Ouput power at 100 MHz is %.2f microwatt.\n",
"Conclusion when device is drive at higher frequency the optical power reduces.\"\"\" %(Pout1,Pout2) \n",
"BWopt = sqrt(3)/(2*pi*t) \n",
"BWelec = BWopt/sqrt(2) \n",
"BWopt=BWopt*10**-6 \n",
"BWelec=BWelec*10**-6 \n",
"print \"3 dB optical power is %.2f MHz.\\n3 dB electrical power is %.2f MHz.\" %(BWopt,BWelec) \n",
"#calculation error. In the book square term in the denominater is not taken.\n",
"#answers in the book are wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ouput power at 10 MHz is 271.55 microwatt.\n",
"Ouput power at 100 MHz is 103.52 microwatt.\n",
"Conclusion when device is drive at higher frequency the optical power reduces.\n",
"3 dB optical power is 68.92 MHz.\n",
"3 dB electrical power is 48.73 MHz.\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.8.2, page 6-35"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"n1=3.5 #refractive index\n",
"n=1 #refractive index of air\n",
"F=0.69 #transmission factor\n",
"eta = 100*(n1*(n1+1)**2)**-1 #computing eta\n",
"print \"eta external is %.1f percent i.e. small fraction of intrnally generated opticalpower is emitted from the device.\" %eta \n",
"r= 100*F*n**2/(4*n1**2) #computing ratio of Popt/Pint\n",
"print \"Popt/Pint is %.1f percent\" %r\n",
"#printing mistake at final answer."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"eta external is 1.4 percent i.e. small fraction of intrnally generated opticalpower is emitted from the device.\n",
"Popt/Pint is 1.4 percent\n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.8.3, page 6-39"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from numpy import log, exp\n",
"beta0=1.85*10**7 \n",
"T=293 #temperature\n",
"k=1.38*10**-23 #Boltzman constant\n",
"Ea=0.9*1.6*10**-19 \n",
"theta=0.65 #thershold\n",
"betar=beta0*exp(-Ea/(k*T)) \n",
"t=-log(theta)/betar \n",
"print \"Degradation rate is %.1e per hour.\\nOperating lifetime is %.1e hour.\" %(betar,t) \n",
"#answer in the book for Degradation rate & Operating lifetime is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Degradation rate is 6.3e-09 per hour.\n",
"Operating lifetime is 6.8e+07 hour.\n"
]
}
],
"prompt_number": 12
}
],
"metadata": {}
}
]
}
|
