GHz 18 2
1 1 3 1.1....................................... 3 1.2....................................... 3 1.3................................... 3 2 (LDV) 5 2.1................................ 5 2.2....................... 6 2.3 LDV............................... 7 2.4 LDV.............................. 8 3 9 3.1.................................. 9 3.2 (AOM)............................. 9 3.3.................................. 10 3.4 (EOM)............................. 12 4 13 4.1 FBG(Fiber Bragg Grating)........................ 13 4.2....................................... 13 5 16 5.1................................ 16 5.2.............................. 17 5.2.1.................... 17 5.2.2................ 19 6 LDV 20 6.1...................................... 20 6.2 3 db................................... 22 7 LDV 24 7.1................................ 24 7.2............................ 24
2 7.3 SAW.............................. 26 8 27 9 28 10 29 30 31 A 32
3 1 1.1 LAN ID SAW 100 MHz5 GHz [1] (LDV) 1.2 LDV 20 MHz LDV (AOM) LDV AOM AOM (EOM) 10 GHz GHz(3 GHz ) LDV 1.3 1 2 (LDV) 34 5 6 LDV
1 4 7 8910
5 2 (LDV) 2.1 v(t) v(t) ν 0 ν l 0 E(t) = E cos{ν 0 t k 0 nl 0 } (2.1) k 0 n l E(t) = E cos{ν 0 t 2k 0 nl} (2.2) v(t) l l = l 0 v(t)dt (2.3) E(t) = E cos{ν 0 t 2k 0 n(l 0 v(t)dt)} = E cos{ (ν 0 + 2k 0 nv(t))dt 2k 0 nl 0 } = E cos{ (ν 0 + 4πn λ v(t))dt 2k 0nl 0 } (2.4) λ ν = ν 0 + 4πn v(t) (2.5) λ
2 (LDV) 6 (2.5) n = 1 c ν = ν 0 + 4π λ v(t) = ν 0 + 2v(t) ν 0 c = ν 0 + 2v(t) c v(t) ν 0 = c + v(t) c v(t) ν 0 (2.6) ν (2.6) ν = ν ν 0 = 2v(t) c v(t) ν 0 2v(t) ν 0 c = 2v(t) (c v(t)) λ (2.7) 2.2 ν v(t) = V 0 sin ωt ν ν = ν 0 + ν = ν 0 + 2V 0 λ sin ωt (2.8) (FM) 2V 0 λ 0 m f = 2V 0 λf FM f = ω 2π a 0 V 0 = a 0 ω m f m f = 2v 0 λf = 4πV 0 λω = 4πa 0 λ (2.9)
2 (LDV) 7 f m f J n (m f ) = J n ( 4π λ a 0) 2.3 LDV Fig.2.1 LDV V ν ν = 2V c V ν 2V λ (2.10) E 1 E 2 E 1 = A 1 cos(2πνt 2π νt + φ) (2.11) E 2 = A 2 cos(2πνt) (2.12) φ i E 1 + E 2 2 = A2 1 2 + A2 2 2 + A 1A 2 cos(2π νt φ) (2.13) ν Mirror from laser E 2 V Half Mirror E1 Photo Detector Fig. 2.1:
2 (LDV) 8 2.4 LDV LDV E 2 f B E 2 = A 2 cos(2πνt 2πf B t) (2.14) i E 1 + E 2 2 = A2 1 2 + A2 2 2 + A 1A 2 cos(2π(f B + ν)t φ) (2.15) f B ν FM ν f B from laser Mirror E 2 Modulator Half Mirror E1 Photo Detector Fig. 2.2: LDV
9 3 (EO) (AO) 3.1 n n(z, t) = n sin(ω s t k s z) (3.1) (v s ω s k s v s = ω s k s ) θ OA+OB λ θ 2λ s sin θ = λ (3.2) L >> λ s 2 λ 3.2 (AOM) (AOM) TeO 2 PbMoO 4 (LiNbO 3 ) Λ f v Λ = v f y Λ L -
3 10 f B f B Fig. 3.1: (AOM) n(z, t) = n 0 + n sin(ωt Kz) (3.3) Ω K y E(y, z, t) = E 0 sin[ωt (n 0 + n sin(ωt Kz)) 2π λ y] (3.4) E(y, z, t) = E 0 m Jm ( 2π λ nl) sin[(ω + mω)t (2π λ y + 2πm z)] (3.5) Λ - ω + mω 3.3 E = E 0 e i(k r ωt) (3.6)
3 11 Fig. 3.2: (3.7) i = x, y, z D m = D i m i = 0 m 2 x 1/n 2 1/ɛ x + D = ɛ 0 n 2 {E m(m E)} (3.7) D i = ɛ 0 n 2 { D i ɛ 0 ɛ i m i (m E)} (3.8) D i m i = m2 i ɛ 0(m E) 1/n 2 1/ɛ i (3.9) m 2 y 1/n 2 1/ɛ y + m 2 z 1/n 2 1/ɛ z = 0 (3.10) m, x, y, z v, v x, v y, v z n, n x, n y, n z v = c 0 n y = 1 ε 0 µ 0 ε i = ( C0 n i (3.11) ) 2 (3.12) () m 2 x v 2 v 2 x + m2 y v 2 v 2 y + m2 z v 2 v 2 z = 0 (3.13) m 2 x(v 2 v 2 y)(v 2 v 2 z) + m 2 y(v 2 v 2 z)(v 2 v 2 x) + m 2 z(v 2 v 2 x)(v 2 v 2 y) = 0 (3.14) v 2 m
3 12 ε x = ε y ε z v x = v y = v 0 v x = v e (v 2 v0){(m 2 2 x + m 2 y)(v 2 ve) 2 + m 2 z(v 2 v0)} 2 = 0 (3.15) m φ m 2 x + m 2 y + m 2 z = 1 m 2 x + m 2 y = sin 2 φ (3.16) m 2 z = sin 2 φ (3.17) (3.15) v 2 1 = v 2 0 (3.18) v 2 2 = v 2 e sin 2 φ + v 2 0 cos 2 φ (3.19) δ 3.4 (EOM) LiNbO 3 z x y y z
13 4 4.1 FBG(Fiber Bragg Grating) FBG FBG Bragg Bragg FBG λ = 2nΛ (4.1) λ (Bragg ) Λ n Bragg R B λ B L n R B = tanh 2 ( πl nη ) (4.2) λ B λ B = { λ2 B πnl } π 2 + ( π nl ) λ 2 (4.3) B η z 0 z L n(z) n(z) = n 0 + n cos(kz)k = 2π/Λ (4.4) n 0 n Λ Bragg λ B 4.2 FBG Fig.4.1 SLD Fig.4.2
4 14 (a) (b) Fig. 4.1: FBG (a) (b) (25 ) (a-1) (b-1) (a-2) (b-2) Fig. 4.2: FBG (a-1, 2) (b-1, 2) (16.3 )
4 15 (a) (b) Fig. 4.3: FBG (a) (b) (17.2 ) FBG Fig.4.3
16 5 5.1 Fig.2.1 1 V p p Mirror from laser E2 f Half Mirror Photo Detector E1 Function generator Oscilloscope Fig. 5.1: 8 Hz 15 khz 8 Hz 10 khz φ (2.13) φ φ (1)(2)(3) LDV
5 17 Fig. 5.2: i (1) (2) (3) [rad.] Fig. 5.3: 5.2 5.2.1 Fig.5.4 19.90 MHz (SAW) PZT 10 khz φ 6 V p p 50 nm SAW 10 khz 10 khz 1 ms A sin φa cos φ A = A 2 (sin 2 φ + cos 2 φ) Fig.5.5 10 khz 19.90 MHz
5 18 Fig. 5.4: (: SAW (19.90 MHz)) Fig. 5.5: SAW (19.90 MHz)
5 19 5.2.2 10 khz 19.90 MHz 10 khz6 V p p -48.6 dbm 50 nm Fig. 5.6 Fig. 5.6: SAW (19.90 MHz)
20 6 LDV 6.1 Fig. 6.1 FBG (1) (2) Faraday Rotator Laser ω 10 GHz Phase Modulator ω Circulator 3 db Coupler 10 GHz Amp. f 10 GHz Oscillator (3) f ω (4) 10 GHz ω Polarized wave Controller Sample Circulator Faraday Rotator FC connector 3 db Coupler Local Oscillator 9 GHz 10GHz P.D. beat DBM DC2 GHz Fig. 6.1: EOM FBG LDV Fig. 6.2
6 LDV 21 Fig. 6.2: EOM FBG LDV()
6 LDV 22 Fig. 6.3 1547.04 nm FBG Fig. 4.3-19 dbm f B f B f B Fig. 6.3: 6.2 3 db 3 db Fig. 6.4 Fig. 6.4: 3 db
6 LDV 23 3 db 2 1 3 4 3 db(50 )
24 7 LDV 7.1 1 GHz SAW (Fig. 7.1) Fig. 7.1: (1 GHz) 7.2 f B =1 GHz f B + ν 1 2 J 0 J 1 A 20 khz PZT LDV hold Fig. 7.2Fig. 7.3 1 2 Fig. 7.3 FBG 10 GHz FC 10 GHz 10 GHz 1 GHz
7 LDV 25 Fig. 7.2: PZT (20kHz) Fig. 7.3: PZT (10kHz)
7 LDV 26 1 2 0 1 7.3 SAW SAW φ = 160µm SAW 20 MHz 100 µm 20 Fig. 7.4 0.01 mm Fig. 7.4: SAW (19.90 MHz)(a)28.46V p p (b)56.92v p p
27 8 φ φ SAW 200 LDV 10kHz 20 khz LDV 1 2 0 1 LDV SAW 19.90 MHz 0.01 mm SAW
28 9 LDV J n (x) x a 0
29 10 FM
30 [1],,1976.10,Tokyo [2],,1987.4,Tokyo [3],,1986.7,Tokyo [4],,2000.2,Tokyo [5] Y.Yeh,H.Z.Cummins.Localized Fluid Flow Measurements with An He-Ne Laser Spectrometer.Apl.Phys.Let,Vol. 4,No. 10,1964 [6] H.Z.Cummins,N.Knable.Single Sideband Modulation of Coherent Light by Bragg Reflection from Acoustical Waves.Proc.IEEE,p.1264;Septempber [7],2001.2 [8],2003.2 [9],,2005.2 [10],,2001.2 [11],,2003.2 [12] SAW,,2002.2
31
32 A ν = ν 0 + ν = ν 0 + 2V 0 λ sin ωt (A.1) 2V 0 λ m f = 2V 0 λf = 4πV 0 λω (A.2) (f ) p sin(α + β) = sin α cos β + cos α sin β (A.3) i = I c sin(ωt + m f sin pt) = I c [sin ωt cos(m f sin pt) + cos ωt sin(m f sin pt)] (A.4) cos(m f sin pt) sin(m f sin pt) cos(m f sin pt) = J 0 (m f ) + 2J 2 (mf) cos(2pt) + sin(m f sin pt) = 2J 1 (m f ) sin pt + 2J 3 (m f ) sin(3pt) + (A.5) (A.6) sin α cos β = 1 {sin(α + β) + sin(α β)} 2 (A.7) cos α sin β = 1 {sin(α + β) sin(α β)} 2 (A.8) (A.4) i = I c [J 0 (m f ) sin ωt+j 1 (m f ){sin(ω+p)t sin(ω p)t}+2j 2 (m f ){sin(ω+2p)t sin(ω 2p)t}+ ] (A.9) np(n ) J n
A 33 0 1 J 0 (x) J 1 (x) m f = x (A.2) a 0 Fig. A.1 Fig. A.1: