Luận án phó tiến sỹ " Điều kiện tối ưu và thông số đồng dạng của một loại laser hỗn hợp 2 khí " docx

TFU10NG . &~I HOC TONG HQP THANH PH6 HO CHi MINH TRAN .TUAN OIEU K'~N TO' lfU VA THONG SO DONG D~NG CUA MOT LO~I LASER HON HQ"P 2 KHI QUANG HOC- 10218 16M TATLUk.NAN PH6 TlEN sT KHOA HOC ID~~~i; III \"'d"_"'-"'" " " ,, ~ \ ; , . ' " ' 1 I , 1 q, " .~ r-~-~' '~' . -~ THANH PHO Hb CHI MINH- 1986 . -\ CONG TRINH &UOC HOAN THANH 'iAL~~~'~_d TRUONG e~1 HOC TONG HQP TP Hb C.HrL- MINH-¥ ' NgU'ai hU'ang don khoa hQc: NGUYEN HO'U CHI, Pho Tien s7, Giao suo I. NgU'ai nh{m xet 1 : &INH VAN HOANG, Tien s7, Giao suo I. NgU'ai nh9n xet 2: T ~ vAN TUAN,Pho Tien sT. Co quan nh9n xet: Phon vi~n Khoa hQc Vi~t Nam. lu9n an se dU'gc boo v~ iQi H9i d6ng thOrn lu9n an Nha ""~at hQp tQi vao hoi gia, ngay thang nOm 1986. Co th~ tim hi~u lu9n an tQi ThU'vj~n TrU'ang &Qi HQc T6n9 H9P Thanh ph6 Ho Chi Minh. " )0 A &~T VAN 9t. V9' Iy laser 'rang may chvc: nC'lmg~n day pha' tri~n r6t nhieu, nhU'ng"!u trung co th~ chia lam 2 lann vlfe:' (i) Tim cae dge frU'ng d9ng hQe va d9C trU'ng khuech dQi e~a mol trU'o-nghoQt tinh. (ii) Xae dinh d<;1ctrU'ng cuo quafrinh phat va nhi}ng dQC trU'ng CUObCre XQphat d6i voi mo; trU'crnghoQt tlnh eho tnrac. VEin de thCr2, ph", thuge nhieu ve Iy thuyet h~ e9ng hU'ang, con van de thCr nhEit - moi trU'crng hoQt tfnh. a6i vai laser khf, moi trU'o-nghoQt tlnh thlfc chEif la trQng thai plasma. Trong nhfrng ni]m gan day, vi~c nghien eCrucac thong 56 co ban cuo plasma Irong laser d~ dieu khi~n eong suEit phaf da Ira nen quon trQng. Tuy nhien vi chU'a xac djnh dugc qui lu{tt dong dQng, nen phon Ian cae eong trinh deu . du-ng IQi a duo-ng cong thlrc nghi~m voi cac thong 56 v9t Iy cho trU'crc, cua tu-ng vQch ph61 laser. . Qui lu{1tdong dQng trong IrU'crng hgp t5ng quat rEit phCrc tQP va cO tn§ khong ton 1<;11,vi v{ly cong trinh nay tren co sa phon tfch cae qua trlnh can bang dl}ng hQc va nhi}ng qua trlnh co ban trong plasma ph6ng di~n khf d~ xae djnh b&ng Iy thuyet nhfrng thong s6 dong dQng eua loser khf, a dieu ki~n t6i U'u, trong do co ch~ kfch thfeh mCrc laser tren b&ng va ch<;tmkhong dim hoi 10Qi2 dong val fro chu yeu. Ket qua nh{1n dU'gc cuo cong trion nay khong nhi}ng gap phon giai thfen co chg hoQt d909 cuo 10Qilaser tren, ma con co th~ dung cae bi~u thll'C cua chung d~ xac dinh cac thong s6 v9t Iy trong che tQo cung nhU'Slr dvng. B N9\ DUNG lU~N AN. lu{tn an gom 3 pheln chu yeu. I - Phan t6ng quem t6ng kef co phon Hch nhi}ng c6ng frinn nghien cCruve mol trU'crng h09t Ifnh cuo laser khi, d~ lam co Sa eho vi~c kneo sat cae qua trinn co ban, eung nhU' Cae qua trinh d9ng hQe trong c{>tdU'O'ngplasma loser vai eac n9i dung sou: 2 - Tom hr<?,e cae qua trinh kich thich ehu yeu trong moj trU'ong ho<;lttlnh cuo laser khf I qua trinh kich thich do va chQm di~n flr i va ehQm khong dan hoi 10Qi2 e9ng hU'ong, qua frinh chuy~n di~n tich va ion 1'100penning - Phon tich Iy Ihuyet va Ihllc nghi~m v~ tiet di~n va chQm khong dan hoi cuo cac qua lrinh kkh thich noi tq?md6i vb' Iaser hen hgp 2 khi. - Khao sat ham phon b6 theo v{m toe cuo di~n tli va m9t so h~ qua quon trc;>ngcuo phU'ong trinh Boltzmann sur '9ng: phU'ong trInh can b&ng hQI, djnh lu{11dong dQng va dong i il{ khutkh tan va d9 linh 09ng cuo hQt trong di~u ki~n khf Lorentz. - Phon Ifch cac qua trinh 09ng hQc cuo laser He-Ne va laser ion hoi kim 10Qi o~ xac djnh co che kich thich chu y'u cuo cac mlrc laser tren va dU'ai. I 1 Phan Ihl{c hanh : Boy la phan trQng tam cuo ban lu{1nvan. B&ngphon tich Iy thuyet tong Irlnh da 11mdU'gc qui lu{1td6ng dc;mg d{lc trU'ng cho loQi laser khf noj tren 0 che d9 phal toi U'u.N9i dung nghien ClrUboo gom: I. Phon loQi laser Iheo co the - laser vai va chQm knong dan kfch thich mlrc laser tren:- hOi10Qi2 c9r.g hU'ong (L~) Ao + 8m -+ At + Bo + 6E ; (I) 0 do A,B nguyen tli khf co ban va -khl-d~m i ky hi~u o,m,t trQng thai co ban, siau ben, kfch thleh (mlrc laser tren), 6E - bien dbi n9i nang cuo h~ .VI dV laser He.Ne co 3 "Qch ph6t lU'ong lrng vai cac chuy~n mlrc 352 - 3P4 ( ~390nm), 2s2 - 2p4 l1150nm)va 352- 2p4(632,8nm). - Laser vbi va chQmion hoo Penning (loP). + Ao + 8m - Bo~ At +e; (2) ~ . + a d6, At - m(rc ion kith thfch, vi dv trong laser ion hO'ikim loQi nhD'ng m(rc 3d'14s~ cuo InlI, 4d9 5s:l cua CdII / 6p cua SolI - Laser vai qua trlnll chuy~n di~n Hcll (L.C) + + Ao + Bi -At + 80 + 6.E; (3) + a do, Bi ion khf d~m a trQng thai cooban, trong tr"ong hgp + + nay At ntlm g(}n m(rc Bi / vi dv trong laser ion hO'ikim 10Qi nhCi'ngm(rc thu9c nhom 3dl0 nx cua lnll ,4dl0 nx cua CdII, 5s:l5p3 (200) cuo 10dIl. 2Phat tri~n Iy thuy~t Shottky vai tr"ong hgp tdng quat: H6n hgp n chol khi co chu Y cac 10Qi vo chQm ion hoa khat nIl" ion hoa tlrng b{lc, ion hoa Penning, chuy~n di~n tich v.v .!lr dieu ki~n m{lt d9 nguyen tv sieu bell nm khong phI,' thu9c VQOban kinh r: .,J, ~m~ Dm > 100 (4) a do. IJm - xac xuot pha vcrnm do va chQmdi~n tv, Om -h~ so khua ch tan cua nguyen IVsieu ben, la nh{ln d"gc ph"O'ng trinh can btlng hQt mang di?n trong c9' d"O'ng plasma nIl" sau: " £k on ~k (2/405)2 " - R2 kT e e (5) L k=1 a do; Zk ~k - v9n toe ion hoa va d9 linh d?ng cua ion khf k, a dieu ki~n plasma kh6ng co qua trlnh 2 bQCthl kef qua se trung '/aj Iy thuyat Sh~l!ky vai n = I, va trung vai Iythuyet Dorgela vai n == 2. 3. NhQnd"9c dieu kj~ndang dQng cua plasma phong di~n khi, khi co qua trlnh 2 b{1c. .4 M9t thong so v{lt Iy bot ky !rong laser khi deu phv thuge nhieu thong so khae. PhU'ong phap dong dc;mg eho to sop x~p cae so li~u 6y m9t each hgp Iy nhat, don gian nh6r. .Trong plasma ph6ng di~n Ihong thU'ong do c6 qui lu{lt dong dQng, ve dong, vai gia thi~t co ban la trU'ong th~ IQi 2 di~m tlTong Ilng trong ph6ng di~n 10 b6t bien. Qui .Iu{lt d6 khong ap dvng dlTgc tho laser khf, vi 6 day phai c6 dinh nghTa khat trU'ac tong su6t phat la bat bien. Tli qui lu{lt nay do rut ra dU'gc : CJ(= f (1;,Ne /P) (61 a d6 CJ(-nOng lU'gng trung binh bj m6t do t6t co va cua dl~n Ilr, c -nOng lU'gng trung binh cua di~n tlr, Ne d9 di~n Ilr, p -ap su6t. Tli h~ thlic (6) tho to kh&ng dinh rang, ngay co ktli di~n trlTong rut- gQn E/p giong nhau trong 2 ph6ng di~n, thi' v9n roC di~n Ilr chi bang nhau khi khong c6 qua trinh 2 b{lc:,' hay c6' qua Irinh 2 b{lc , nhU'ng Ne /p la dQi IlTgng b6t bf~n 4. Xu6t phat tli phU'ong Irinh d9ng hQc tong trinh do tim dlTgc dieu ki~n toi U'u va cac thong so dong dQng cua loQi laser khi n6i tren. 01 M{li d9 dao 19n lei U-u(D,Nlopt Mal do dao Ion eua laser dU'oe xae dinh b6i: . ehQm - mQt gt D,N= INt - - Ncf) 9d (7) a d6, gt ' dd ' Nt ' Nd -trQng Iu-gngth6ng ke va mQt d9 don so tlTong Ilng vai mile laser tren (t) va mile laser du-ai (d), Nt ,Nd dU'ge xae dinh tlic{lp phU'ong trinh v{ln toe, va bang:' / eB ) / BA ) . Nt =Ne NoA NoB \Qom ve \Qt vr tZmB-/Wgt (8) 5 ,Nd=N2eNoA(Q~t va) (Qilve)CGjA/Wgd vai NoA ' NoS ~rTI{1t d9 khf eo bon (A) va khf d~m (8) a tr~mg thai co bon (0) . , Wet ' Wgd ~,!x6'c,'su~t siam kfch thfCh eae' mc,e laser; ~iX - thai sian s6ng cua nguyen tu-Xa mere i; / . . Q~X v ) - hbng so v{1ntoc kfch thfch nguyen tu- X tlr merc \ If e . i I~n merc i do va chQm di~n tu-, (p~A YT)-hbng so V{1:1toe kfch thfch merc ~a$er tre~ _,(f)do , (9) va chQm khang dan hoi loQi 2, Tu- di~u ki~n ClfC trj va m{1t d9 di~n tu-: l) (,6,N) = 0 -l)N . , (101 ,'" - fa 'nh{in dirgc: (" ) "\y ~d Wed (2,405)2DljA (Q~A VT) \Q~8ve) , " We I Blol'l= K~;-iJ):t(~R)~f~ ~A:T)-(QiA v.T( Qid' v.) k ,., ,; )' " 0, do, t<-tt _soap suet rieng phbn; Dl'A -h~ so khuy~ch ton cila '" I . kM-A a ti'Qng thai nO'ngIlTgngi,'a diau' kj~n chubn r = 273 K, P = I torr. N~u ham phon bo theo nOne IlTgng cua di~n IIi la M tixwellthi cae; h&ng so v{1ntoc kfch Jhfch va ion hoa ng~JY'~n ili la nhO'n g ham.o cud nhiet do dien t~ T ,do do (N ip ) t . , "e e op 6 ehi thuge voo m9t dQi h'Q'ng duy nh6t 10 Te' (Ne / p)opt = f (Tfit ) (f 2) Thay (II) voo (7) to nh{m dl1Q'em9t d9 dao 19n toi I1U: 12,405)2W gd ' K2 ( A N R 2 ) - - Dl' A - Q(T e ) W . opt - -2 (Wgt)2 I (K+I) (13) a d6, / BA \ / e8 ) 2 \Qt .VT / \Qm ve \LQ:A VT)(QjA v.) (Qj: ve) k Trong eae bi~u thlrC (II), (13), (14)d6i vai vQch phat laser (L.R) i 10 mlrC sieu ben 1m);d6i vai eae vQeh phat laser (L.P). (' .CI i 10 mlre eo ban ion (i). b) Nhi~t d9 di~n tir t6i I1U. Tu- bi~u there (13), c6 th~ rut ra dl1ge 2 h~ qua quan trQng IOU day: . - 1/ Val K eho trU'ae m9t d9 dao 19n toi I1U (LlN. R2)Opt Itlnh theo don vi lCR2)chi ph.,. thu9C voo me}tthong so duy nh6t 10 10,neu ham phon bo theo v9n toe cua di~n tir 10 Maxwell thi thong so d6 10Te . - 2/ Nhi~t de}di~n tir (Ta )opt dU'Q'cxac dinh tu-dieu ki~n; Q (Te) = 114) . / aB ) 2 \ b \ \Qm Va (- .t~- (~iA v.) (Q~Av.) \ - 0 (I-') 7 Trang bi~t.lth(re (15! cae h&l1g$0 v{m t6e chi phv thu9c veo cae hang so dC}c tnrng eho loQi kIll nhU' Vi ' Vm' Vd' VI v{1y n9hi~m tOng quat cua phU'ong trinh (15) c6 dc;mg. (Te 'opt = f (Vi' Vm I Vd ) (16) Tli (15) 'to nh{1n dU'ge bj~u there CliO nhi~1 d9 di~n tll t6i U'u ITe )opt trong 3 trU'cmghgp . ' Vai laser (loR) (T~)~pt ' +[2(V 2 IS -Vlsk ) - (V2P. + Visk ) + ~ [2(V2 IS - Visk ) - (V2p4 1 V'Sk)J2+ 16(2V21S-V2p4) (1/2 J Visk ) (17) - Vai laser (loP) ITe )opt = -i~ [2 (V2' So-ViM)-v d + ~[2(V23S,-ViM)- Vd]2 ~1/2 ] + 10(2V235 -Vd)ViM~ (18) - - Va; laser (L.C) <P B Ire lopt = - 2reos 3 + 2A (19) a cf6r =- + I -3.~~A: B2 11f2 I (190) <P = arc cas (q/r3) (19b) (1ge) . I [ 2B3 BC D ] q = 2- 27A3 ~ 3A2 + -A 8 v6i AI 8, C, D la eae ham so cua cae hong so nguyentli, Vi' Vm, Vdl Vi tlr (17.19) suy ra r6n; (T.) opt = conlt. 9ay \a dQi Iu-gngbat bien co bon nhat. vi tlr do co th~ XQ-C dinh cae dQi Iu-gngbat bien khat. Tlr (161va (121cho ta : (Ne / P)opt = const, (201 9ay la dQi Iu-gng bat bien thCr2 nh{1Odu-gc trong lo r khf a the dt} phat tal u-u. 9Qi Iu-gng bat bien nay kh&ng dinh rbng, m9c du trong laler khl co ton fQiqua trinh 2 b{lc, qui lu{lt dong dQngvan fhoo man. - cJ TIso ap suet ri€mgphon Kopt. 9ieu ki~n t6i u-u cua h~ so Kopt du-gc vH~tra tlr dOng thCre: NA+ = NS + (211 ado NA + , NB + la ndng dt} ion khf COban (AI va khf d~m- (B) trong ct}t Gu-ong plalma cualase,r. ClIng vai phu-ong t,in-h can b6ng hQt ta nh{ln du-gc bi~u there cua Ii .0 ap .uat rleng phon toi u-u Kopt: - V6ilaser (LR): K w. J-~ [ ZO~. !-L°B~ - ~,oBB + ~ ( loA . !-LG~!\_ opt 2 ZO fLo ~° - t ZO !-L° B AA <~A B AA fLOB~ ) 2 + 4 loA . !-L°BB/12 ] J-L°BA loB fJ-°AA ~ (22) [...]... 6 32, 8nm (ii) v6'i laser (L P) cae vQch phat dugc khao sat la 441,6nm 15a22Ds /2- 5p1 Ps /2) ' 325 ,Onm (5S22DS /2- 5p2 Pll2) cuo laser He - Cd, 747,8nm 14 .2: 1Dsl2 4p2 Ps /2) ' 589,4nrri (4 522 Dsl2- - 4p2 P1i2) cua laser H - In, 684,4nm (6p2 P1 /2- 6 .2 51 /2) va - 645,3nm (6p2 Psl2 6v 51 /2) cua las.r - He So (iii) voi laser (l.C) cae vQch poot dU'gc khao sat la 758,8nm (5p2 P'Ih - 55:1 Sl/:JJ cua lo r H -In, 522 ,7nm... 522 ,7nm (5p4 12 '.0°,', :". 014P5f':!) ua4ase'r?He-S~, c , 7,~~,n' ,t 'J" - b~,j8} 507,8nm (103.106°, :: a559~5/:1) '0 ' c:a'~vQ'th;'P't1C5f loser (loC):"dongphong di~n Jop :" rat Ian hon lopf ciia~'cac vQch phat 'laser IloR( va (loP), nen ,.qUo trlnh l.;ng,.,b{1c 9"' Pt5y d6ng val fro,Iqvan trQng Do d6 i (Te) opt cuo laser (LC) ,nhe') hon Ic1ser (l~RIva laser (loP) \6 ,:::' :"' rn 'L h,gply j ", 3/ Nho co di,~u kj~-{b toj U'u( K)opt i' neri';cac bi~u thCrc do; , Y;6;i\P~)opr ' ~" p'(L9iqJ)"h:r:~~... linh d9ng cuo di~n tll', E - di~n trU'ang tren trve c9t dU'ong TII (30 eta rut ra dU'go: (J/R)ept = CX~2A-~o (A-eo v ) G (Te) !PR)~pt ; (31) ;"i:-: ,- :", '~ ~"' .' ,',~:~,'1 1~~ ~" .\~~~ ~"~ ;' ,' ~.'.'L'.\ I II t ! ! -1 v6'i C = 1,36 (~r/4 GITe) BA (Q t = gd gt Wg d W vT )( eB Qm ; L-:r "' ;;1 (D ) gt ve ". _1 ; IA ) (L Q:A ) (Q~A ve) ( Q~A Ve) ; vT k a do X - ph?!n n{jng hrgng cua di~n hi bj mat do va... (27 ) V6i laser (L.C): ° T 1 /2 o 1 (PR)opt = 2, 405 27 3 ~ -~~~~_~et 0! 2( ZB - K Zc NhU' v9Y, (PR)opt (28 ) ! cDng 10 m9t dQI lU'gng bot (PR)opt el (26 ) ' ] V6i laser (LP) : (PR)opt = 2, 405 Tn 0 /LBA IJ-BB = f IT ) opl ' bien: (29 ) Dong phong di~n loj U'U: Dong phong di~n trong c9t dU'ong plasma v6i ban kfnh R eo dQng : = J a do, N 2J(e~'e E J~ rNe (r) dr ; (30) - nong d9 di~n Ill' Iren trve c9t dU'ong, . 6 32, 8nm (3 52 -2p4) cua loa.r H. -N (ii) v6'i laser (L P) cae vQch phat dugc khao sat la 441,6nm 15a22Ds /2- 5p1 Ps /2) ' 325 ,Onm (5S22DS /2- 5p2 Pll2) cuo laser He - Cd, 747,8nm 14 .2: 1Dsl2 -4p2. 747,8nm 14 .2: 1Dsl2 -4p2 Ps /2) ' 589,4nrri (4 522 Dsl2- 4p2 P1i2)cua laser H. - In, 684,4nm (6p2 P1 /2- 6 .2 51 /2) va 645,3nm (6p2 Psl2-6v 51 /2) cua las.r He -So. (iii) voi laser (l.C) cae vQch. . ' Vai laser (loR) (T~)~pt ' + [2( V 2 IS -Vlsk ) - (V2P. + Visk ) + ~ [2( V2 IS - Visk ) - (V2p4 1 V'Sk)J2+ 16(2V21S-V2p4) (1 /2 J Visk ) (17) - Vai laser (loP) ITe )opt = -i~ [2 (V2'