Claims
- 1. A device for reading sensors coherently, said device comprising:
- a single integrated optics interferometer having two arms of different length with at least one of said arms having a phase modulator, a first detector, and circuit for slaving said interferometer including a feedback control synchronous detector for controlling said slaving of said interferometer wherein a control voltage necessary for slaving said interferometer by a negative-feedback signal provides a signal to be measured in order to coherently read said sensors, wherein said phase modulator is integrated with said single interferometer and wherein said synchronous detector is directly connected to said phase modulator.
- 2. Device according to claim 1, wherein said slaving circuit comprises a generator of substantially sinusoidal voltage, connected to the interferometer and to a synchronous detector itself connected to the interferometer.
- 3. A device according to claim 1, wherein said slaving circuit further includes a means responsive to delays to be measured of a value greater than a given optical wavelength, for generating a jump voltage corresponding to interference fringe jumps.
- 4. Device according to claim 1, wherein for reading n sensors disposed in series and multiplexed coherently, said device further comprises, shunted onto a main fibre, n branches each comprising an interferometer and a detector.
- 5. Device according to claim 3, wherein the interferometer of the reading device receives a first control voltage segment varying in line with the variations in the delays to be measured and (C) controls the interference fringe jumps, and an a.c. voltage segment (V).
- 6. Device according to claim 5, wherein one arm of the interferometer comprises a modulator receiving a control voltage, and in that the other arm comprises a modulator receiving an a.c. voltage.
- 7. Device according to claim 1, wherein one arm of the interferometer comprises two modulators one of which receives an a.c. voltage with nil average value, and the other a first substantially rectangular signal, the other arm of the interferometer receiving a second substantially rectangular signal synchronous with the first, one of the substantially rectangular signals being positive, and the other negative, their amplitude having equal absolute values.
- 8. Device according to claim 1, wherein one of the arms of the interferometer comprises a modulator receiving a first substantially rectangular signal, the other arm comprising a modulator receiving a second substantially rectangular signal synchronous with the first, the average value of one of the signals being positive, and the average value of the other being negative.
- 9. A device for reading sensors coherently, said device comprising:
- a single integrated optics interferometer having two arms of different lengths with at least one of said arms having a phase modulator, a detector, and a circuit for slaving said interferometer including a feedback control means for controlling said slaving of said interferometer wherein a control voltage necessary for slaving said interferometer by a negative-feedback signal provides a signal to be measured in order to coherently read said sensors, said slaving circuit further including a means responsive to delays of a value greater than a given optical wavelength, for generating a jump voltage corresponding to interference fringe jumps.
Priority Claims (1)
Number |
Date |
Country |
Kind |
89 15876 |
Dec 1989 |
FRX |
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Parent Case Info
This application is a Continuation of application Ser. No. 07/730,954, filed on Jul. 23, 1991, now abandoned.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/FR90/00867 |
11/30/1990 |
|
|
7/23/1991 |
7/23/1991 |
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0251632 |
Jan 1989 |
EPX |
2147695 |
May 1985 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan, vol. 10, No. 15 (P-422)(2072) Jan. 21, 1986 Japanese Appln. 60-170723 (Yokokawa Hokushin Denki KK) Sep. 4, 1985. |
Continuations (1)
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Number |
Date |
Country |
Parent |
730954 |
Jul 1991 |
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