LD

989935

1 1 3 3 4 4 LD 6 7 10 1 3 13 13 16 0 4 5 30 31 33 33 35 35 37

38 5 40 FFT 40 40 4 4 4 44 47 48 49 51 51 5 53 54 55 56

Abstract [1] HDD (LaserDopplerVibrometer; LDV) [] HDD IC

1 4 LDV LDV He-Ne Acousto-optic modulater; AOM LDV He-Ne Laser diode ; LD 1mm [3] [4] LDV [5] FM [6]LD FM FM LDV LD FM FM 5

1 5

6 Abstract - FM LD S4V46,TOSHIBA (0) Fig..1 Fig..1 68.5nm68.57nm 5.0GHz/mA [3] 6

7 Fig.4 Lasing wavelength vs. the injection current (T=4 Fig..1LD Fig.. l LD i i m LD ν ν l Fig..3 t b Fig..4 ( c t l = c ) b l = ν (.1) c b m (1) b l Fig..5 1mm 15kHz 550Hz ν 7

8 ν =3.7GHz/mA 3mA 7.4GHz FM FM Fig..4 i 0 i Reerence mirror [ ] m khz t LD Hal-mirror l i PD Vibrating object V v [Hz] t Fig.. 8

9 Scattered light Reerence light Beat signal ν t 1 m t Fig..3 Output voltage o PD [V] Injection current Output voltage o PD Time [ µs ] Injection current [ma] Fig..4 9

10 Fig..5 ω 0 Hz E 1 ( t) t E () () E 1 t = E1 cos{ ( ω ω 0 ) ωt k0n1 ( l1 + D1 + D )} () E t E { t k n ( l + D + )} cos 0 1 D. = ω.3 k i i i 0,n 1, θ = k 0 n l n = 1, (.4) ( ) 10

11 I = E + () t E () 1 t 1 + I + I1I cos ( ω + θ ) = I t θ (.5) 0 1 I 1 = E 1 E I = (.6).6 ( ) v v v v = v cosω t (.7) 0 v 0 c + v 0 = (.8) c c v 1 c 1 c v c + v = c v = 0 (.9) λ LD 11

1 ω = π = π ( ) 1 4πv c 4πv = λ 4πv 0 = cos λ ω v t (.10).4 ω 0 ω + ω 0 [5] cos { ( ω ω ) + θ θ } 4πv 0 0 + dt 1 = cos ω 0 + cosω v t dt + θ1 θ λ 4πv 0 1 cos ω + 0t sinω vt + θ1 θ λ ω v =.11 ( ) FM FM FM.4 LD LD FM FM 3 FM 1 1

13 3 Abstract FM 0[Vp-p] 0.0910[kHz] Fig.3.1 (.10) Fig.3.1 c LD 0 [ m s] 8 c = 3 10 / 8 3 10 0 = c / λ = 4.48 10 9 670 10 14 [ Hz] 13

13 3 v = aω a (3.1) Fig.3. 500[Hz] 00[Vp-p] Fig.3.33.4 Fig.3.1 14

13 3 Fig.3. Fig.3.3 15

13 3 Fig.3.4 (3.1) 10kHz FM [8] Fig.3.5 FM ωb v = v cosω t ω cos 0 v d ω v t 16

13 3 { ω + φ} () t cos ( + ω cosω t) = dt b ω d = cos{ ω + sinω + φ} ω b t vt v d v 3. ω d 4πv 0 ω d = λ (3.3) λ LD A φ ω d d ( sin ω vt ω v ) 90 cos ( ω t), sin( ω st) s s (3.4)3.5 () t 1 ω d ω d cosω {cos ω sinω cos sinω + φ} + ω ω st = st + vt vt v v d d () t sinω t = {sin ω t + sinω t sin sinω t + φ} (3.4) 1 ω ω l s v ω v ω (3.5) v v (3.4)3.5 s + d s s + d d LPF d (3.6)3.7 I ( t) Q() t I 1 ω ω v d () t = Lowpass{ ( 3.) } = cos{ sinω t + φ} v (3.6) 17

13 3 Q 1 ω ω v d () t = Lowpass{ ( 3.3) } = sin{ sinω t + φ} v (3.7) ( ) I t Q t d [3] I () t Q() t tan a I, Q φ I, Q t () t I() t jq() t S = + 3.8 t = t, 1 t = t = t + t S, S 1 ( ) S = jφ1 1 = I1 + jq1 A1 e (3.9) jφ = I + jq Ae (3.10) S = S, S 1 S, S 1 S, S 1 S, S 1 S S 1 = A A e = I 1 ( φ φ ) j 1 = ( I1 + jq1 ) ( I jq ) ( I Q I ) 1I + Q1Q + j 1 1Q ( S jφ = I jq = A e ) (3.11) 18

13 3 I Q I Q 1 1 1 φ 1 φ = tan (3.1) I1I + Q1Q φ v = 1 φ t (3.13) t 3.6 3.7 φ ω d sin ω vt ω v t φ Im. S 1 S φ 1 φ φ1 φ S 1 S Re. S Fig.3.6 19

13 3 3.3 I, Q 4 FM 0

13 3 Intererometer beat signal cos( ω b t) sin( ω b t) PD HPF COMP exclusive or b + d d LPF d d I Q Local oscillator Fig.3.5 1

4 Abstract LPF 4.1 FFT FM Fig.4.1 HPF (TTL ) [9] b 90 (Ex-OR [9] ) b + d d LPF [10] d I Q

4 Fig.4.1 3

4 Fig.4.1 130[kHz]HPF Fig4.1 a Fig.4. HPF Fig.4.3 15kHz -13dB Fig.4.3 Fig.4.1 c b [10] b Fig.4.4 Fig.4.5 00[kHz] Fig.4.5 00[mV] Fig.4.HPF 5

4 Gain[dB] -13 15kHz Frequency[kHz] Fig.4.3 HPF Fig.4.4 6

4 00kHz Fig.4.5 ( TTL ) c TTL cos( ω bt), sin( ω bt) Fig.4.6 b NOT TTL TTL 7

4 Beat signal TTL signal cosω b t sinω b t 0 Time[s] Fig.4.6 TTL 1 c TTL Fig.4.7(a)(b) Fig.4.7(a)(b) exclusive or exclusive or 8

4 cos ω b t TTL signal 1 Fig.4.7(a) sin ω b t TTL signal Fig.4.7(b) 9

4 10[Hz] Fig.13 Output o a demodulation[v] Lo,Osc=burst Lo,Osc=Cont. Time[s] Fig.4.8 LD ν l m LPF LPF N LD (DL-3149-056,SANYO, 670nm) (3) 39mA i mapp ν 8.9GHz Fig.4.9 l =430mm 1 / (1) 1 10Hz b m 30

4 15kHz 193kHz HPF LPF 35kHz16Hz i 0 i Reerence mirror [ ] m khz t LD Hal-mirror l i PD Vibrating object V v [Hz] t Fig.4.9 4.3.1 Fig.4.9 Fig.4.10 1 1 Fig.4.11 1 31

4 Output voltage o PD [V] Injection current Output voltage o PD Time [ µs ] Injection current [ma] Fig.4.10Fig.4.9 Fig.4.11 3

4 4.. 1 17510kHz Fig.4.1 LPF Hz LPF Fig.4.1 4..3 1 l = ν (4.1) c b m 33

4 ( ) m b 540kHz Fig.4.13 1 193kHz 0.1100kHz Fig.16 S/N 0dB 1/ 7.5kHz ( ) Fig.4.13 34

4 S/N[dB] Vibration requency[khz] Fig.4.14 S/N [10] 441 3. I, Q I, Q Fig.4.15 5V () πrad ()() I 5V Q 5V πrad (5.1) t 35

4 1 rad λ π v (5.) v = λ 1 1 I Q1 I1Q tan 4π t I I + Q Q 1 1 (5.3) LD 670nm () Beat signal T = π 5V T π [ rad ] () cos sin () I =0 I = 5 () Q = 5 Q = 5 T/ 5V 5 V π [ rad ] Fig4.15 36

4 4.4. 5Vp-p 15kHz LDV Fig.4.16 5kHz Fig.4.17 Fig.4.16 15kHz 37

4 Fig4.17 5kHz 15kHz5kHz LDV 1. 38

4 39

5 40 Abstract LDV LDV FFT Fig.5.1 1 FFT Fig.5.1 FFT v ν ν d c ν v = v d (5.1) 40

5 41 m v m v Vibration velocity Modulation signal Beat signal Beat signal b FFT analysis t Fig.5.1 41

5 4 ( 1) l / b m b ν = l c (5.) m l c l = ν (5.3) ν ν =13GHz 4 l = mm ) FFT FFT 1 m khz 10kHz FFT 10kHz 6.8mm/s(o-p) Fig.5. ( HM) ( M) LD Fig.5.3 Fig.5.4 ω b1 HPF 4

5 43 Mirror Reerence light Scattered light l1/ Hal-mirror Mirror Laser Diode Hal-mirror Scattered light 1 D1 l/ l3/ i m[khz] D Piezo-actuator i[ma] t Fig.5. Reerence light Scattered light 1 Scattered light optical requency ω b t ω ω b1 b 3 t 1 t 3 ν 1/ m time Fig.5.3 43

5 44 Fig.5. HM M (4) ν 1.7GHz M HM l 1=45mm l =345mml 3=445mm (1) b=315khz b3=415khz Fig.5.4 FFT Fig.5.5 HM M HM+M 1kHz 0.1mm 10kHzν 4GHz HM 100mm HM M 1.5kHz,1kHz 3mm/s 10kHz FFT 10kHz Fig.5.6 FFT 1 4 a1 a 4 peak peak 4 n= 1 = 4 a n= 1 n a n n (5) Fig.5.7 LDV 44

5 45 1.5 Injection current 61.5 [V] Output voltage o PD 1 0.5 0-0.5 Output voltage o PD 60.0 58.5 57.0 Injection current [ma] -1 55.5-5.0E-05-50 -.5E-05-5 0.0E+00 0.5E-05 5 5.0E-05 50 [ ] Time µs Fig.5.4 1.6E-0 Hal mirror + Mirror Power(arb.) 8.0E-03 Hal mirror Mirror 0.0E+00 0 100 00 300 400 500 600 Frequency[kHz] Fig.5.5Fig.5.4 45

5 46 Amp. a1 a 1 a3 34 a4 peak = Fig.5.6 Fig.5.7 4 n=1 4 n=1 an n a n 46

5 47 Fig.5. Ex-OR Fig.5.8 (DBM) HMM 750Hz1kHz HPF HMM LPF 100kHz1.1kHz 0 600kHz FFT 750Hz 1kHz Fig.5.9 750Hz 30kHz 1kHz 415kHz Triangular signal Beat signal PD HPF DBM LPF d I Local oscillator cos sin ( ω t ) b ( ω t ) b + and b d d d Fig.5.8 47

5 48 Amplitude(arb.) 750 Hz component 1 khz component Frequency o the local oscillator [khz] Fig.5.9 Fig.5. M 1kHz l 3=445mm 415kHz 35mm75mm 5mm HM M 15dB 3 Fig.5.10 Fig.5.10 5.3 48

5 49 Eq.(3) Fig.5.10 45mm 49

5 50 50

50 Abstract LDV 10Hz LD LDV LDV 1

51 45mm 1 LPF I, Q (0kHz )

James RFriend 1 1 4 53

[1] 1983pp.188-197 [] Vol.9,No.1,pp.15-19,000 [3] A.Dandridge and L.Goldberg, Current-induced requency modulation in diode lasers, Electrum.Lett., Vol.18, No.7. pp.30-304,198. [4] [5] 1999 [6] 000 [7] 1989 [8], 1999 [9] 1997 [10] Vol.8,No.1.pp.J15J3(001) [11] Proceedingso 6th Meeting on Light wave Sensing Technology, 000, pp51-58 54

[1] 14 00pp.831-83 [] 14 00pp.811 81 [3] 15 [4] Simultaneous Vibration Measurements o Two Separate Objects Using a Wavelength-Swept Optical Heterodyne Method S. Wakisaka, T. Koike, K. Nakamura and S. UehaWCU003pp.99-100 55

DBM 56

Ex-OR 57

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