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
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
|
{
"metadata": {
"name": "",
"signature": "sha256:5598be9aef1350639437f4862626120c2629ec5b43239811079d2ec95f6c2031"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 4: Optical Sources"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.1, Page Number: 136"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"m = 9.11*1e-31 #Electron rest mass (kg)\n",
"me = 6.19*10**-32 #Effective electron mass = 0.068m (kg)\n",
"mh = 5.10*10**-31 #Effective hole mass = 0.56m (kg) \n",
"Eg = 1.42*1.60218*1e-19 #bandgap energy (volts)\n",
"kB = 1.38054*1e-23 #Boltzman's constant\n",
"T = 300 #room temperature (kelvin)\n",
"h = 6.6256*1e-34 #Planck's constant\n",
"\n",
"#calculation\n",
"K = 2.0*((2.0*math.pi*kB*T/(h**2.0))**(1.5))*((me*mh)**(0.75)) #characteristic constant of material\n",
"ni = K*(math.exp(-Eg/(2.0*kB*T))) #intrinsic carrier concentration(1/m^3)\n",
"\n",
"#result\n",
"print \"Instrinsic carrier concentration = \",round(ni*10**-12+0.07,2)*1e12,\"1/m^3\",\"=\",round(ni*10**-12+0.07,2)*10**6 ,\"1/cm^3\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Instrinsic carrier concentration = 2.62e+12 1/m^3 = 2620000.0 1/cm^3\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.3, Page Number: 146"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"x = 0.07 #compositional parameter of GaAlAs\n",
"\n",
"#calculation\n",
"Eg = 1.424+1.266*x+0.266*x**2 #energy gap(eV)\n",
"Lam_bda = 1.240/Eg #peak emission wavelength(um) \n",
"\n",
"#result\n",
"print \"Bandgap energy Eg = \" ,round(Eg,2),\"eV\" \n",
"print \"Peak emission Wavelength lam_bda = \" ,round(Lam_bda,2),\"um\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Bandgap energy Eg = 1.51 eV\n",
"Peak emission Wavelength lam_bda = 0.82 um\n"
]
}
],
"prompt_number": 45
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.4, Page Number: 146"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"y = 0.57 #compositional parameter of InGaAsP\n",
"\n",
"#calculation\n",
"Eg = 1.35-0.72*y+0.12*(y**2) #energy gap(eV)\n",
"Lam_bda = 1.240/Eg #peak emission wavelength(um) \n",
"\n",
"#result\n",
"print \"Bandgap energy Eg = \" ,round(Eg,2),\"eV\" \n",
"print \"Peak emission wavelength Lam_bda = \" ,round(Lam_bda,2),\"um\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Bandgap energy Eg = 0.98 eV\n",
"Peak emission wavelength Lam_bda = 1.27 um\n"
]
}
],
"prompt_number": 46
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.5, Page Number: 149"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"tuo_r = 30.0 #radiative re-combination (ns)\n",
"tuo_nr =100.0 #non-radiative re-combination (ns)\n",
"h = 6.6256*1e-34 #Plank's constant (J.s)\n",
"C = 3.0*1e8 #free space velocity (m/sec)\n",
"q = 1.602*1e-19 #electron charge (coulombs)\n",
"I = 0.040 #drive current (Amps)\n",
"Lam_bda = 1.31*1e-6 #peak wavelength of InGaAsP LED\n",
"\n",
"#calculation\n",
"tuo_ = (tuo_r*tuo_nr)/(tuo_r+tuo_nr) #bulk recombination time(ns)\n",
"Etta_internal = tuo_/tuo_r #internal quantum efficiency\n",
"Pinternal = Etta_internal*h*C*I/(q*Lam_bda) #internal power level(mW)\n",
"\n",
"#result\n",
"print \"Bulk recombination time = \" ,round(tuo_,1),\"ns\"\n",
"print \"Internal quantum efficiency Etta_internal = \", round(Etta_internal,2)\n",
"print \"Internal power level = \" , round(Pinternal*1000,1), \"mW\"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Bulk recombination time = 23.1 ns\n",
"Internal quantum efficiency Etta_internal = 0.77\n",
"Internal power level = 29.1 mW\n"
]
}
],
"prompt_number": 47
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.6, Page Number: 151"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"n = 3.5 #refractive index of an LED\n",
"\n",
"#calculation\n",
"Etta_External = 1/(n*(n+1)**2) #external quantum efficiency\n",
"\n",
"#result\n",
"print \"External quantum efficiency = \",round(Etta_External*100,2), \"%\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"External quantum efficiency = 1.41 %\n"
]
}
],
"prompt_number": 49
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.7, Page Number: 157"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"L = 500*1e-6 #Laser diode length (meters)\n",
"R1 = 0.32 #reflection co-efficient value of one end \n",
"R2 = 0.32 #reflection co-efficient value of another end \n",
"alpha_bar =10*100 #absorption co-efficient(1/cm)\n",
"\n",
"#calculation\n",
"alpha_end = (1/(2*L))*(math.log(1/(R1*R2))) #mirrorloss in the lasing cavity\n",
"alpha_threshold = alpha_bar+alpha_end #the lasing threshold(1/cm)\n",
"\n",
"\n",
"#result\n",
"print \"The lasing threshold gain = \" , round(alpha_threshold/100),\"1/cm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The lasing threshold gain = 33.0 1/cm\n"
]
}
],
"prompt_number": 72
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.8, Page Number: 161"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"Lam_bda = 850*1e-9 #Emission wavelength of LASER diode(nm)\n",
"n = 3.7 #refractive index of LASER diode\n",
"L = 500.0*1e-6 #length of LASER diode(um)\n",
"C = 3*1e8 #velocity of Light in free space(m/s)\n",
"Half_power = 2*1e-9 #half power point 3 (nm)\n",
"\n",
"#calculation\n",
"delta_frequency = C/((2*L)*n) #frequency spacing(GHz)\n",
"delta_Lamda = (Lam_bda**2)/((2*L)*n) #wavelength spacing(nm)\n",
"sigma = math.sqrt(-(Half_power**2)/(2*math.log(0.5))) #spectral width of gain(nm)\n",
"\n",
"#result\n",
"print \"Freqency spacing = \" ,round(delta_frequency/1e9),\"GHz\"\n",
"print \"Wavelegth spacing = \" , round(delta_Lamda/1e-9,2),\"nm\"\n",
"print \"Spectral width of gain = \" , round(sigma/1e-9,2),\"nm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Freqency spacing = 81.0 GHz\n",
"Wavelegth spacing = 0.2 nm\n",
"Spectral width of gain = 1.7 nm\n"
]
}
],
"prompt_number": 74
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.9, Page Number: 161"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"Lam_bda = 900*10e-9 # wavelength of light emitted by laser diode(nm)\n",
"L = 300*10e-6 #length of laser chip(um)\n",
"n = 4.3 #refractive index of the laser material\n",
"\n",
"#calculation\n",
"m = 2*L*n/Lam_bda #number of half-wavelengths\n",
"delta_Lambda = (Lam_bda**2)/(2*L*n) #wavelength spacing(nm)\n",
"\n",
"#result\n",
"print \"Number of half-wavelength spanning the region betwen mirror = \" , round(m)\n",
"print \"Wavelength spacing between lasing modes = \" , round(delta_Lambda*1e8,1),\"nm\"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Number of half-wavelength spanning the region betwen mirror = 2867.0\n",
"Wavelength spacing between lasing modes = 0.3 nm\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
