EE 130 Introduction to Optoelectronics and Photonics EE 230 Optical Fiber Communication. Summary-2

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1 EE 3 troutio to Otoltrois a hotois EE 3 Otial Fibr Commuiatio viw ustios: ummary-. A laar wavui has thr has shits whih must total π or a mo to roaat. What ar thy?. What is aylih sattr? What is th wavlth? Why is th sky blu? Why is th sust r? 3. What is isrsio? What ks o isrsio xist a ibr? 4. ist svral tys o mhaisms or um to ahiv oulatio vrsio 5. What is a Dolr shit? How os it at th rorty o a as lasr? 6. Exla what is mat by thrshol oitios or las. 7. Dsrib th strutur o a smioutor lasr. 8. What is a htrojutio strutur? Why is it usul? 9. Why os a Er o ibr amliir work so wll? At what wavlth?. What is mo ho a lasr?. What ar th major irs btw a ED a a lasr io?. hotottors ar ivi to two lasss. What ar thy? 3. Dsrib th strutur o a io. What is th utio o th ltio layr? 4. What is th rsos wavlth o a silio io?

2 ummary o Otial Fibrs: Gomtrial-Otis Dsritio Fibrs: Otial omt otal tral rltio ll s aw: sθ sθ Critial al: θ s umrial artur A: A s θ tr-moal isrsio: B bit/s m < i G Fibrs: x roil: ibrs trmoal isrsio: m 8 8 B < umrial artur A ρ : A ρ ρ or wh la Wav roaatio Fibrs Maxwll s Euatios Fibr Mos V umbr: V π ka a λ

3 o. o mos: V V >> l-mo Fibrs V<.45 Aroximat il istributio E x w.65.69v a or a / w total A ρ / w iβz 3/.879V 6 wh. < V <.4 Cuto wavlth λ π π V.45 a a λ λ ot siz FWHM l w Disrsio l-mo Fibrs Grou vloity v a roaatio tim v Disrsio aramtr D λ D D M D W matrial wavui isrsio Disrsio-u uls broa D λ imitatios o Bit at B B B B D λ Or, ratially, w hoos B 4 Fibr oss out oss lo Attuatio oiit

4 out A B/km km - Usul ostats lak s ostat h J s Boltzma s ostat k.38 3 J K -

5 iht Emitt Dios Absortio / otaous missio / timulat missio Ctr Wavlth λ : h λ whr h.4 V µ m E E V Baa ry mioutor matrials Dirt baa matrials Bary: GaAs,, E.44 V GaA rary: Al x Ga -x As β x β E V x β x <.45 Quatrary: -x Ga x As y -y x.45 y E V y. y tral uatum iiy: η t raiativ rombatio at total rombatio at rr tot Emitt otial owr Extral uatum iiy: η xt tral otial owr otal uatum iiy owr-ovrsio iiy: hν η tot ηxtηt lt V V hoto ratio rat tral otial owr Emitt otial owr η tot t hν η η Eltrial owr V xt lt t t η xt ηthν t sosivity : η ηxt t hω

6 tral with ν tral l-with k B ν.8 h k λ λ.8 B h λ λ ν ν ν 3-B Moulatio Bawith otial a ltrial: 3B, ot 3 πτ lt τ πτ ED rasr Futio / Fruy sos: H ω iωτ Otial owr ot 3B, ot whr arrir litim iωt iωt H ω φ m m ωτ ta os ωt φ ωτ ambrtia sour: θ osθ φ t Coul Eiiy A multi-mo ibrs m mioutor asrs Ga mium - jutio with a ativ rio / um urrt jtio / Cavity Fabry-rot talo hrshol a /m t mir avity

7 ltivity l mir oitual mos Osillatio ruy m m ν a ν tral with ν a lwith λ λ ν ν λ λ ν or ν ν mos loitual o o. at uatios mir s v v G v G G t G t Γ t τ τ τ hrshol valus th th th G τ τ - urs t t th mir mir h η ω lo iiy h η ω Dirtial uatum iiy t t η η mir mir

8 Extral uatum iiy η th xt η otal uatum iiy hω E ηtot ηxt ηxt V V asr ois: rom otaous missio tsity: / has lutuatio: tral with Otial Dttors a ivrs Gral Cots sosivity a at at hotourrt it otial owr hoto ltro hν Quatum Eiiy η η th ltro - ratio rat hoto - i rat η ηλ µ m hν.4 / hν / hν /Volt or Am/Watt Absortio abs η abs w w whr w is th with o ltio rio.

9 hotoios - hotoios: rvrs bias -i- hotoios: to ras w orr to ras th absortio Avalah hotoios AD AD whr M η ηλ ηλµm M M M hν h.4v µm is multiliatio ator. ivr ois hot ois t i t i t hrmal ois ois varia Am < whr is masur. t < t > is th ark urrt,a > < i t > is th tiv ois bawith o th rivr a s o whr th ois rms ois urrt t i t i t i t i t ois varia thrmal ois rat th loa rsistor 4kB < i t > Amliir ois Amliir ois iur F Eha thrmal ois kb 4 F

10 Amliir ois 4 B F k. otal ois varia o urrt lutuatios F k t i t i t B 4 ivrs -i- ivr K. wh rah is ot : 4 ois owr owr avra sial max F k B A Es., omats ois thrmal, >> 4 4 B B F k F k AD ivr ial urrt AD M hot ois

11 hrmal ois s M k A F A h M, h whr M is th Exss ois ator : FA M k AM k A M x M small k a kb 4 F ivr sitivity & Bit-Error at M kb M FA 4 F Es. shot ois limit: F A M hrmal ois limit: 4kBF Otimal M ot i.., max wh F A MM x : M ot A 4 k x BF x Bit-Error at BE BE [ / / ] D D r r 4 r Q Q Q π wh Q D D Es., BE BE 9 Q 6 Q 7 ot: Error utio rx:

12 r x π x ay y hrshol valu D D thrmal ois limit ot: Wh, th Q Wh a, th Q ivr sitivity / Mimum Avra iv owr r ivr sitivity mimum avra riv owr ruir by th rivr to orat at a BE o -9. Mimum Avra iv owr r r r wh or r most ass Wh a th, Q r FAQ M r s. -i- rivr omat by thrmal ois M Q r i Bm lo is mw r i r i al rivr K limit by shot ois

13 or -i- io: M r Q ial hνb r whr B Bit rat, o. o hotos riv ur bit "". sitivity raatio Exttio ratio: our ois Fibr ois r x Usul ostats lak s ostat h J s Boltzma s ostat k.38 3 J K -

Lecture contents. Density of states Distribution function Statistic of carriers. Intrinsic Extrinsic with no compensation Compensation

Lecture contents. Density of states Distribution function Statistic of carriers. Intrinsic Extrinsic with no compensation Compensation Ltur otts Dsity of stats Distributio futio Statisti of arrirs Itrisi trisi with o ompsatio ompsatio S 68 Ltur #7 Dsity of stats Problm: alulat umbr of stats pr uit rgy pr uit volum V() Larg 3D bo (L is