Quang Học Phi Tuyến (KBA)

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ĐỀ NGHỊ BẠN NÀO CÓ SỦ DỤNG TÀI LIỆU THÌ ĐỀ TÊN TÁC GIẢ.CHỐN MỌI HÌNH THỨC ĂN CẮP BẢN QUYỀN

Transcript of Quang Học Phi Tuyến (KBA)

Quang Hc Phi Tuyn- Gio vin hng dn :PGS.TS Trn Th Tm - Nhm thc hin : 1. Kiu B An 2. Trnh nh Khuyn 3. Lng Vn Thoi 4. Ng c Thun

Ni Dung

Gii thiu v Quang Phi Tuyn Nhng hin tng Phi Tuyn bc hai Hiu ng Pockels v Kerr Nhng hin Tng Phi Tuyn bc ba Tn x Ramam v Brellouin ng dng Quang Phi Tuyn

Gii Thiu V Quang Phi TuynCu hi vui : C th thay i mu ca nh sng n sc khng ? p n : Mi cc bn theo di.

vo

ra

Gii Thiu V Quang Phi Tuyn

Nhng ngun sng thng thng c CT yu, E ~ 103V/cm.Vy khi nh sng truyn trong mi trng, cc tnh cht ca mi trng nh: chit sut, h s hp th v.v.. Khng ph thuc vo cng nh sng cc phng trnh ca trng in t l cc phng trnh tuyn tnh Quang hc tuyn tnh Vi ngun sng Laser th E ~ 108 V/cm.Nn thng s quang hc ca mi trng ph thuc vo cng nh sng, cc phng trnh ca trng in t tr thnh phi tuyn Quang hc phi tuyn

Gii Thiu V Quang Phi TuynQuang phi tuyn c m u bng pht minh v s to sng hi bc hai ca Peter Pranken nm 1961,mt thi gian ngn sau khi Laser ra ivo nm 1960.( Peter Pranken )

Gii Thiu V Quang Phi Tuyn

nh Ngha : Quang hc phi tuyn l mt phn ngnh ca quang hc, nghin cu v s tng tc phi tuyn tnh ca nh sng vi mi trng. Mt khi cng nh sng t n mt mc gii hn no , ta c th quan st c nhng tng tc phi tuyn tnh lin quan ch yu n s bin i phi tuyn ca vect phn cc P ca mi trng theo cng in trng E ca nh sng

Gii Thiu V Quang Phi TuynChng ta c th iu khin n bng chnh nh sng hoc iu khin mt chm tia bng chm tia khc. Tnh cht mi trng thay i C nhiu ng dng quan trng trong khoa hc

Gii Thiu V Quang Phi TuynVy : Cu tr li cho cu hi trn l c th thay i mu sc ca nh sng n sc nh chm tia Laser.

cm phi tuyn :-

Gii Thiu V Quang Phi TuynPi = Pi 0 + ij E j

M men lng cc trn mt n v th tch hoc phn cc.

-

M men lng cc trn mt n v th tch hoc phn cc.

( (2 (3 Pi = Pi 0 + ij1 ) E j + ijk ) E j Ek + ijkl) E j Ek El + ...

=>

ij

l cm tuyn tnh.

Gii Thiu V Quang Phi Tuyn phn cc :1. phn cc c nh : 2. phn cc bc nht : 3. phn cc bc hai: 4. phn cc bc ba :

P i

0

( Pi1 = ij1) E j

Pi = E j Ek2 ( 2) ijk

Pi = E j Ek El3 ( 3) ijkl

Gii Thiu V Quang Phi TuynS phi tuyn quang hc xut hin nh th no ? - Cng in trng ca sng nh sng phi vo c in trng nguyn t.

Eat = e / a

2 0

e

h

a0 N

a0 = 2 / me 2

Eat 2 10 esu

=7

Gii Thiu V Quang Phi TuynMi trng phi tuyn tnh : Trong phn ln cc trng hp cc tham s v m: , , c th xem nh khng ph thuc vo cng ca trng. Khi cc h thc trn l tuyn tnh mi trng tuyn tnh. Khi mi trng c cc tham s trn ph thuc vo cng ca trng mi trng phi tuyn.

D =0( E )E, J =( E )E,

B = 0 ( H )H ,

Hin Tng Phi Tuyn Bc 2~ E (t ) = E1e i1t

+ E2 e

i 2 t

+ C.C.

2 P ( 2 ) =( 2 ) E1 1 2 P ( 2 ) =( 2 ) E2 2

(S G H) (S G H) (S G F ) (D G F ) (O ) R

P ( + 2 ) =2 ( 2 ) E1 E2 1* P ( 2 ) =2 ( 2 ) E1 E2 1 * * P (0) =2 ( 2 ) ( E1 E1 +E2 E2 )

Hin Tng Phi Tuyn Bc 2 phn cc bc 2 l :

~ ( 2) P (t ) = 2 ( 2 ) EE * + ( ( 2 ) E 2 e 2it + C.C.)Khi (2 )

l mt tens bc hai

2

( 2)

Hin Tng Phi Tuyn Bc 2

Hin Tng Phi Tuyn Bc 2Cc hiu ng lin quan n Phi Tuyn bc 2 :Cc hin tng Tng tn s To ho ba bc hai Hiu tn s Chnh lu tn s Khuch i tham s (OPA) Trng ti Kt qu

1, 1, 3,

2

3 = 1+ 2 3 = + = 2 3 = 1- 2 3= - = 0 1 khuch i + 2 1 + 2= 3 ging nh hiu tn s nhng ngi ta ch quan tm n 1 m khng phi l 2

2

1

To Ha Ba Bc Hainh Ngha : l hin tng mt sng sng i vo mt tinh th phi tuyn s pht ra mt sng sng c tn s gp i. To ha ba bc hai c tm ra bi P.A.Frankin, A.E.Hill, C.W.Peters v G.Weinreich i hc Michigan, Ann Arbor vo nm 1961, sau mt nm k t khi sng ch ra laser Ruby Tng tn s 1, 2 3 = 1+ 2

To ho ba bc hai

3 = + = 2

To Ha Ba Bc Hai2

2( 2)

1

1

3 = 1 + 221

ng dng : iu chnh bc x trong vng ph t ngoi

3

To Ha Ba Bc Hai

To Tn S Phch

2

2( 2)

1

1

3 = 1 22

ng dng: Photon tn s thp,khuch i trong s hin din ca photon tn s cao. Qu trnh ny c gi l khuch i tham s.

1

3

To Tn S Phch

Hiu ng quang Pockelsnh ngha: Hiu ng Pockels l mt hiu ng vt l mi trng lng chit trong trng in khng i v chit sut n(E) t l vi in trng p vo. L hiu ng Quang tuyn tnh.

Hiu ng quang Pockelsng dng : B iu bin dc, ngang. B iu bin phn tch quang B iu bin cng

HIU NG KERRnh ngha: l mt hiu ng vt l xy ra trn mt s vt liu trong sut, trong chit sut thay i di tc ng ca in trng bn ngoi. Chit sut trong hiu ng Kerr t l thun vi bnh phng ca cng in trng ngoi. => Cng l hiu ng Quang Tuyn Tnh

HIU NG KERRPhn loi : C hai loai hiu ng Kerr. 1. Hiu g Kerr DC 2. Hiu ng Kerr AC ng dng : Cng tc in quang iu bin tn hiu trong vin thng K thut o in trng bng phng php tip xc

Hin Tng Phi Tuyn Bc 3A1 A2

( 3)

Dng tng qut ca trng in ti l :

A3 A4

~ E (t ) = E1e i1t + E2 e i 2t + E3e i 3t

phn cc phi tuyn bc ba:

P (3) ( ) = 3 (3) ( = + ) | E ( ) |2 E ( )

Hin Tng Phi Tuyn Bc 3

Trng quang hc ti : cm phi tuyn :

~ it E (t ) = E ()e + C.C.

eff = (1) + 4 | E () |2 ( 3)

cm bc ba s c 22 thnh phn v s ph thuc tn s ca chng l :

,3 , ( +j + ), ( +j ) i i i k i k ( 2 +j ), ( 2 j ), i, j , k =1,2,3 i i

Chit sut :

n 2 = + eff 1 4

Hin Tng Phi Tuyn Bc 3Cc hiu ng lin quan n Phi Tuyn bc 3 :Cc hin tng Bo ho cc hiu ng tuyn tnh Bo ho cho nhau To ho ba bc ba (TGH) Trn bn sng Trng ti Kt qu

1, 2 1 , 2,

4= - + = 4 = 1- 2+ 2 = 4 = + + = 3 4 = 1- 2+ 31

3

Trn bn sng suy bin , k1 k2 k3 4 = - + =

Hiu ng Raman (hay Brilloin) cng bc

S v

= -

v

;

A

= +

v

tn s phn t

T hi t v t lch tiu

Chm Laser c dng cng tun theo phn b Gauss. N c th cm ng dng chit sut phn b Gauss bn trong mu quang phi tuyn.

( 3)

S trn sng

= 2n0S in /2 ) (

Lin hp pha quang hcGng lin hp phaPCMM

s M

PCM

iu chnh lch bng PCM

Mi trng gy lch

PCM

s

Mi trng gy lch

PCM

Trn 4 sng suy bin (DFWM)

Tt c 3 chm tia ti A1, A2 v A3 nn c xut pht t mt ngun kt hp. Chm th 4 A4, s c pha, phn cc, v hng truyn ging nh A3. Cng ca A4 c th ln hn A3

A1

A2

( 3)

A3 A4

Tn x Raman & Brellouin

Tn x Brillouin: bao gm sng m, s dch chuyn tn s nh Tn x Raman : dao ng phn t cc phonon quang hc, dch chuyn ln hn

Qu trnh Raman & BrellouinTrn cc dao ng c hc bng chm nh sng trong mi trng phi tuyn Mechanical var. : khong cch ni nguyn t trong phn t hoc mt trong cht rn hoc lng Ph tn s ca nh sng b thay i trong khi phonon c pht ra hoc hp th

Tn x Brillouin

n l hm ca cng , hiu ng DebyeSears (sng m tn x nh sng vi s dch chuyn Doppler ) Ri s phn cc in t to ra s bin i p lc nh sng c th bm mt sng m Sau n b tn x tr li vi tn s hi khc cht t.

Tn x Brillouin

My tn x Brillouy H Hawii

Tn x Raman

Khong cch ni nguyn t trong phn t b thay i khi m my electron dch chuyn v tr Lin quan n nhng trng thi dao ng ca phn t y bin l vi m trong khi trong Brillouin l v m

Tn x Raman

S my quang ph Raman

ng dng Quang Phi Tuyn

Nghin cu chit sut phi tuyn dn n ch to cc vt liu phi tuyn c nhiu ng dng trong k tht, bin i tnh cht ca nhiu vt liu nh s nan phi tuyn, kim cng phi tuyn (do BBO) ch to

Kim cng PT do BBO ch to

ng dng Quang Phi Tuyn

Hiu ng phi tuyn nh Tn x Raman & Brellouin c nhiu ng dng quan trng nh nh nhn bit cc cht (laser Ramam ), to c s cho nghin cu v lnh vc quang t To c s cho vic nghin cu khoa hc ng dng

ng dng Quang Phi Tuyn

Lu Quang Phi Tuyn l mt lnh rng v n nay vn cn c nghin cu.V vy trong khun kh mt bi tiu lun nn chng ti khng th n cp ht cc vn .Chng ti s gi cho cc bn nghin cu tip cc vn sau nu cc bn quan tm n n : M t phng php sng ca tng tc phi tuyn L thuyt c hc lng t ca mt cm quang phi tuyn Ngun gc phn t ca p ng phi tuyn Bin c cm ng quang hc v hp th photon Quang hc phi tuyn cng mnh v cc mnh.

1. 2. 3. 4. 5.

Kt LunNghin cu v Quang Phi Tuyn cn nh nhng vn sau :1.

2.

3. 4.

nh Ngha QPT :Nghin cu v s tng tc phi tuyn tnh ca nh sng vi mi trng. S phi tuyn bc 2 , 3 v cc hiu ng lin quan n n. Hiu ng in quang Pockels v Kerr. Tn x Ramam v Brellouin.

Ti Liu Tham Kho[1].Ti liu nghin cu ca lp cao hc Nng. [2].Ti liu ca lp cao hc HKHTN TP.H Ch Minh. [3].http://vi.wikipedia.org/wiki/Quang_h%E1%BB%8Dc_phi_tuy %E1%BA%BFn. [4].http://dictionary.bachkhoatoanthu.gov.vn/default.aspx?... [5]. http://people.na.infn.it/~marrucci/labpage/index.htm [6].GT Quang Hc ca Nguyn Trn TRc Dip Ngc Anh. [7].N.Bloembergen, Nonlinear optics (Nobel prize 1981), 1977 [8].http://www.mientayvn.com/Cao%20hoc%20quang%20dien %20tu/Sach/Qu ang%20hoc20phi%20tuyen/Cap_nhat/Cap_nhat.html [9] Mt vi hnh nh ti http://images.google.com.vn/