, .
1. () . , , .
2. , , , , . () , , , , . , , .
3. ( , ), . . .20.5.
, () p/2 (x y), - ( ) . ϳ f , , . ϳ . p , d - . , . , . , . .
21.1 . ѳ . 10-12. , .
, 㳺 , . , . ˳ .21.1. , (.21.2), . , n0 . , .
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, , (. 21.2) ( .21.2) n0 . . , n0. , . , . He-Ne 6328 . 21.3.
21.2 . wq+1 - wq = W = p c/L. , . , , . :
(21.1)
, , w0 - . jn n- . (21.1) , E(t) T = 2p/W = 2L/c, .
, (21.2)
w0/W - . , jn. . .
. . . , L, , (W=p/L).
䳿 jn , . T = 2L/c = 2p/W. , jn . , , N . , En =1 jn = 0, :
, (21.3)
(21.4)
E(t)E*(t):
P(t) ~ (21.5)
P(t) .
1. = 2p/W=2L/c
2. ϳ P(sT) (s = 1, 2,3 ) N N , N , .
3. ϳ , N.
4. , , t =T/N. N = Dw/W - Dw W. t =T/N, :
t =T/N = 2p/Dw=1/Dn (21.6)
, Dn.+
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, (21.3) N=5, . 11.8. , .
. ,, ( , ), 㳿, , . T=2L/c . L , . t=T/N,
Li c ti = cT/N = 2pc/WN = 2L/N (21.7)
, sin knz sin wnt. :
(21.8)
wn =(m+n)(pc/L), kn=wn/c m - , .
. (21.9)
. . 11.4 t (21.9).
21.3. . . ( ) W=pc/L, . , , . , t
T = 2p/W (. 11.5). (, t ). . , , (21.3), 㳿 . 11.9, (Li2L/N) . , , (t) , . , 䳿 . , , , (jn=0)
. , .
He-Ne . 11.6. . , , .
. 11.7 , .
, , (, ), 䳿. . . , . . , . , , s , , .
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(21,10)
ϳ ( )
:
(21.11)
(21.10) (21.12)
. (21.11) Eb :
(21.13)
(21.14)
(21.15)
(21.15) (21.12) (21.13) .
(21.16)
.
; , (21.14), (21.17)
da,b - ij; (21.18)
ϳ (21.17) (21.16) :
(21.19)
- . ֳ . Dw :
(21.20)
, Dw - . :
ϳ (21.19) (21.20) .
( (21.21)
( =0) :
(21.22)
Ia - - . :
(21.23)
(21.20) c/Dw>>1 (c/Dw) :
(21.24)
, , . (21.24) , , . (21.24) (21.3), . , exp[i (j+p/2)] . , . , s , e. , , .
2.22.
.
, , , .
. , . , 㳿 ( ). , , w0 nW w0, - W. , , . , , , , , , . , .
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, , . . , , .
, , . , . , , .
, () . , 2L/c. < 10-3 c.
, s-1, t s-1.
³ , , 㳿, t
st << 1, .
dN1a/dt = W(N2a - N1a) + sN2a, Na = N1a + N2a, (2.22.1)
N1a N2a - () . s 2 1, W - 21. Na - .
t . / t
( / 2 ) , ᒺ
(2.22.2)
W = s M/t, s - (2). t= 0 , N1a = Na, (22.2.21) (2.22.22)
(2.22.3)
, (, 35%), la ,
(2.22.4)
㳿 / 㳿 , st, . 11.21. , , , . t s-1, Dw>>s. , .
.
. , , .
. , ( ) . . ij, , , . . 5.23. , ., , . , c/2d ( ). ϳ () . N = N2 -N1 Nc, , . , W , N Nc. Wp>Wcp , (=1, 2) .5.23 . , , Wp>Wcp . ϳ , ¢¢, ¢¢¢¢ , . , . . Wp>Wcp , , , ¢¢, ¢¢¢¢ . , , .
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(, ), (, ) . , , . , . , l/4 (.5.25). , 1 .5.25 , . 1 , (., , ...) Nc. 2, , , , 1, , 1. 2 , 1. , , ( ), ( ).
, . , - . , .
, m i l. , 00, . , N=a2/dl . 00 . , 00. ,
00 , . , . N . , .
( m l), ( , n). ̳ Dnn=c/2d. d, Dnn>Dn0, Dn0 - . , , , ( ) . , ( ), d ( < 10 ), ᒺ , . (100 ) . , (.5.26). ³ R 1 R2, d q . (, ) , (, R=80%). , U
. OAU OBU ( , OBABU ..). OAU p , OBU 2kdcosq. , 2kdcosq - p. , . 2kdcosq - p=(2n-1) p, n - . k=2phu/c ( h- , ) , , u=nc/2hdcosq,
Du=/2hdcosq. d , , Du . , q, , . - . 5.26 . R1 R2. , , ( . 5.26 .) R1 , R2 R3. , U . OAU OBACU ( , OBACABACU ..). OAU p, OBACU 2k(d1 + d2). г 2k(d1 + d2) - p p, 2k(d1 + d2) - p =(2n -1) p. ̳ Du=c/2h(d1 + d2), h- , . d1 + d2 , . . , - ( -), ( , c/2d). , ( -, , -, ) .
, . , .
, . -, , , ( ) . , , / b a b n :
(2.22.5)
|G|2 - , - ( ). /b t=ts, (2.22.5) n ns=cts/d, d - . ts tp , /b. n . ij, , , . ,
. (2.22.5) g - gb , .
ns 2000 (2.22.5) n=ns |Ga| = |Gb| , 10 ( /b =10),
, g - gb 10-3. , -
, , . , , n s 10 20.
. , , , ( ). , . , , . . , . : , , (, ), .
: . . (, ) ( ) . , , . ( ), . . , . , , . . , ( ) ( ).
, , , , (dN2/dt)p :
(dN2/dt)p = WpNg (17.1)
Ng - , Wp- , . .
17.1 . 17.1 . . : 1) - (~ 100...) ; 2)-, . - , . , , , . . .
.17.1 .
. 17.2 , , .17.1. .17.2 , , 1. . , 17.2 ( ), . F1 , F2. : . .17.2 F1 . F2 . .
F1 F2 F1 F2
.17.2 , .
17.2 ... . , ... : ft ( 㳿) , , ( 㳿) .
fs, , , . , s(w) , :
fs =
s - , w - .
f - , , , . , , , , . , , w.
. ij, , . , , , . , . , .
.17.2 , .17.2, . 1 17..3, , . S2, S1, R1 . (.17.2).
17.2, , S1, F2. S1 , . , , .17.3, S1 S1, .17.3( ). , .17.2. .17.3.
, , , S2 . , S1 , . -, , , :
1 = sSBT4S1
sSB - -. , , , . , . , 2, S2, . , , ( ) . , 2 , 2, . 2 2 = sSBT4S2, : 2 = 2 = sSBT4S2. ft:
ft = P2i/P1 = S2/S1 = R2/R1
, . : R2 < R1. R2 >= R1 ( , , . 17.2..) .
17.3. . . . . , , . , . ij , , . , . :
1) , , , : + * + e, * . .
, ( ), . 㳿.
.17. 3 㳿 ( ). .17..3 , , - . . D k. , , - . , , ( ). , , , 㳿 . : A* + B A + B* .
. , . . Fe [/(2×)] , s , : dFe = - s NgFedz, dFe - , , dz. dz, , . s2 . : (dN2/dt)p = s2NgFe = NgNevs2, v- , Ne - . s2. s2 㳿 ( v). , 㳿 , , 㳿, 0 2. , s ( 㳿, ), .ϳ s s=s(E) . . Wp E ( ) J ( ).
() 㳿. s:
(dN/dt)AB - , , NA - , NB - v - () . vs . s DE . , , s(D) , , , D = 0. : , , . , , . 㳿 D = (h/Dtc)10-21 0,25 kT, Dtc - 䳿 .
. , , . , 䳿 , ,, . , . , , . ϳ 10-16 - 10-15 2, , 10-13 2.