JPH0991583A - Wavelength division multiplexing optical fiber sensor array system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the wavelength division multiplex optical fiber sensor array system which can suppress power division loss and performs proper demodulation processing even if the number of channels increases. SOLUTION: The wavelength division multiplex optical fiber sensor array system is provided with light sources LD1, LD2, and LD3 which output plural light wavelengths λ1, λ2, and λ3, a device A for transmission having an optical multiplexer demultiplexer MD1 which multiplexes the light wavelengths, an optical fiber sensor array B which is connected to the device A for transmission and has an optical multiplexer demultiplexer MD2, transmission type optical fiber sensors S1, S2, and S3 connected to the optical multiplexer demultiplexer MD2, and an optical multiplexer demultiplexer MD3 connected to the transmission type optical fiber sensors S1, S2, and S3, and a device C for reception which is connected to this optical fiber sensor array B and has an optical multiplexer demultiplexer MD4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing optical fiber sensor array system used for a remote measurement system or the like.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
"Fiber Optic Michelson Ar
ray With Passive Eliminat
ionOf Polarization Fading
And Source Feedback Isol
ation ”8th Optical FiberS
ensors Conference, January
29-31.1992, P.I. 69-72.

FIG. 2 is a schematic view of such a conventional transmission type optical fiber sensor time division multiplexing (TDM) three channel array system. The optical fiber sensor array system according to this conventional technique includes a laser LD, an optical pulse gate GT, transmission optical fibers F1 and F2, and an optical coupler CP.
1, CP2, time delay fiber D, transmission type optical fiber sensors S1, S2, S3, O / E converter OE, demultiplexer DMX, and demodulator DTC.

The light output from the LD is converted into an optical pulse by the GT. This optical pulse is input to the optical fiber sensor array by the transmission optical fiber F1. The optical pulse input to CP1 is split into two optical pulses, one of which is input to the transmission optical fiber sensor S1 and the other of which is input to the optical coupler CP2 after the time delay of the time delay fiber D.

The optical pulse input to the optical coupler CP2 is 2
One optical pulse is branched, one is input to the transmission optical fiber sensor S2, and the other is input to the transmission optical fiber sensor S3 after being delayed by the time delay fiber D. Each pulse input to the transmissive optical fiber sensors S1, S2, S3 is given a reception signal from the sensor, and is output from the array by the same operation as when the sensor is input.

That is, each pulse is time-divided with a delay interval of 2D. This optical pulse train is sent to the O / E converter OE by the transmission optical fiber F2 and converted into an electric pulse train by the O / E converter OE. The electrical pulse train is subjected to channel separation and interpolation processing by the demultiplexer DMX, and the sensing signal is demodulated for each channel by the demodulator DTC.

[0007]

However, the above-mentioned conventional wavelength division multiplexing optical fiber sensor array system has a problem that the demultiplexer for pre-demodulation processing is required to have high speed as the number of channels increases. . In addition, as the number of channels increases, there is a problem that the power division loss, which is the ratio of the power of the input light and the optical power returned from the optical fiber sensor, increases, making demodulation processing difficult.

The present invention eliminates the above problems and can suppress power division loss even if the number of channels increases.
It is an object of the present invention to provide a wavelength division multiplexing optical fiber sensor array system capable of performing appropriate demodulation processing.

[0009]

In order to achieve the above object, the present invention provides: (1) In a wavelength division multiplexing optical fiber sensor array system, a light source for outputting a plurality of light wavelengths (λ1, λ2, λ3) LD1, LD2, LD3) and a transmitting device (A) having an optical multiplexing means (MD1) for multiplexing the light wavelengths.
And an optical fiber sensor array (B) connected to the transmitting device (A) and having an optical multiplexing / demultiplexing means, and an optical fiber sensor array (B) connected to the optical fiber sensor array (B) and having an optical demultiplexing means. A receiving device (C) is provided.

Therefore, even if the number of channels increases,
Power division loss can be suppressed, and appropriate demodulation processing can be performed. (2) In the wavelength division multiplexing optical fiber sensor array system, light sources (LD1, LD2, LD3) that output a plurality of optical wavelengths (λ1, λ2, λ3) and optical multiplexing means (MD1) that multiplexes the optical wavelengths. A transmitting device (A) having
And a transmission type optical fiber sensor (S1, S2, S3) connected to the transmitting device (A) and connected to the optical demultiplexing means (MD2).
And this transmission type optical fiber sensor (S1, S2, S3)
An optical fiber sensor array (B) having an optical multiplexing means (MD3) connected to the optical fiber sensor array and a receiving device connected to the optical fiber sensor array (B) and having an optical demultiplexing means (MD4). It is provided.

Therefore, in addition to the effect of (1) above, since wavelength multiplexing is performed unlike the prior art, there is no need to pulse light, and there is no need to perform channel separation / interpolation processing by DMX. Therefore, the limitation of the number of channels does not occur due to the limit of the speed of the demultiplexer.

Further, since the power division of the optical fiber sensor is independent for each wavelength, the level deterioration due to the power division loss of the light can be easily compensated. (3) In the wavelength division multiplexing optical fiber sensor array system, light sources (LD1, LD2, LD3) that output a plurality of optical wavelengths (λ1, λ2, λ3) and an optical multiplexing means (MD1) that multiplexes the optical wavelengths. And this optical multiplexing means (MD
1) A transmitting device (A) having an optical coupler (CP) connected to it, and an optical multiplexing / demultiplexing means (MD5) connected to the transmitting device (A) and a reflection type optical fiber sensor ( S11, S12, S13), and an optical fiber sensor array (B) and a receiving device (C) connected to the optical coupler (CP) and having optical demultiplexing means (MD6). It was done.

Therefore, in addition to the effect of (2) above, the system configuration can be simplified. (4) In the wavelength division multiplexing optical fiber sensor array system, light sources (LD1, LD2, LD3) that output a plurality of optical wavelengths (λ1, λ2, λ3) and optical multiplexing means (MD1) that multiplexes the optical wavelengths. And this optical multiplexing means (MD
1) A transmitting device (A) having an optical pulse gate (GT) connected to it, and an optical demultiplexing device (MD7) connected to this transmitting device (A) and this optical demultiplexing device. Transmission type optical fiber sensor (S2) connected to (MD7)
1, S22, S23, S24, S25, S26, S2
7, S28, S29) and this transmission type optical fiber sensor (S21, S22, S23, S24, S25, S26,
S27, S28, S29) optical multiplexing means (M
An optical fiber sensor array (B) having D8), and being connected to the optical fiber sensor array (B),
A receiving device (C) having an optical demultiplexing means (MD9) is provided.

Therefore, although the number of sensors is 9, the demultiplexer can maintain the same high speed as in the case of 3 channels, and the optical power division loss is the same as in the case of 3 channels. It can be reduced. (5) In the wavelength division multiplexing optical fiber sensor array system, light sources (LD1, LD2, LD3) that output a plurality of optical wavelengths (λ1, λ2, λ3) and optical multiplexing means (MD1) that multiplexes the optical wavelengths. And this optical multiplexing means (MD
1) A transmitting device (A) having an optical pulse gate (GT) connected to the optical pulse gate (GT) and an optical coupler (CP) connected to the optical pulse gate (GT), and connected to the transmitting device (A) At the same time, the optical multiplexing / demultiplexing means (MD10) and the reflection type optical fiber sensors (S31, S32, S33, S3)
4, 35, 36, 37, 38, 39) and a receiving device (C) connected to the optical coupler (CP) and having optical demultiplexing means (MD11). ) And are provided.

Therefore, in addition to the effect of the above (4), the system configuration can be simplified.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
It is a block diagram of the wavelength division multiplexing optical fiber sensor array system which shows an Example. As shown in this figure, this wavelength division multiplexing optical fiber sensor array system includes a transmitting device A, an optical fiber sensor array B, and a receiving device C.
And three light sources LD1, LD2 and LD3 having output wavelengths of λ1, λ2 and λ3, respectively, and an optical multiplexer / demultiplexer MD.
1, MD2, MD3, MD4, transmission optical fiber F1,
F2, 3-channel transmission type optical fiber sensor S1, S
2, S3, O / E converters OE1, OE2, OE3, and three demodulators DTC1, DTC2, DTC3.

The operation of the first embodiment of the present invention will be described below. Continuous lights of wavelengths λ1, λ2, and λ3 output from the light sources LD1, LD2, and LD3, respectively, are optical multiplexer / demultiplexer MD1.
Is combined into a continuous light λ123. λ123
Is transmitted to the optical multiplexer / demultiplexer MD2 by the transmission optical fiber F1. The optical multiplexer / demultiplexer MD2 sets λ123 to λ1,
The wavelengths are demultiplexed into λ2 and λ3, which are applied to three-channel transmission type optical fiber sensors S1, S2 and S3, respectively.

Each transmission type optical fiber sensor S1, S2, S
3 gives the received signals as information to λ1, λ2, and λ3, respectively, and outputs them to the optical multiplexer / demultiplexer MD3. The optical multiplexer / demultiplexer MD3 multiplexes λ1, λ2, and λ3 again, and outputs λ123.
To the optical fiber F2 for transmission. This λ123
Is again λ1, λ2, λ3 by the optical multiplexer / demultiplexer MD4.
Demultiplexed into the light of each, O / E converter OE1, OE
2, give to OE3. OE1, OE2, OE3 convert λ1, λ2, λ3 into electricity, and the three demodulators DTC1, DTC2, DTC3 demodulate the signal of each optical fiber sensor.

With this configuration, unlike the prior art, since wavelength multiplexing is performed, there is no need to pulse light, and there is no need to perform channel separation / interpolation processing by DMX. Therefore, the limitation on the number of channels does not occur due to the limit of the speed of the demultiplexer.

Further, since the power division of the optical fiber sensor is independent for each wavelength, it is easy to compensate for the level deterioration due to the power division loss of light. Next, a second embodiment of the present invention will be described. FIG. 3 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a second embodiment of the present invention.

As shown in this figure, this wavelength division multiplexing optical fiber sensor array system comprises a transmitting device A, an optical fiber sensor array B, and a receiving device C, and the wavelengths of output light are λ1 and λ2, respectively. , Three light sources L of λ3
D1, LD2, LD3, optical multiplexers / demultiplexers MD1, MD5, M
D6, optical coupler CP, transmission optical fiber F, three-channel reflective optical fiber sensors S11, S12, S13,
O / E converters OE1, OE2, OE3, three demodulators D
It is composed of TC1, DTC2 and DTC3.

The operation of the second embodiment of the present invention will be described below. The wavelength λ output from the light sources LD1, LD2, LD3
The continuous lights of 1, λ2 and λ3 are multiplexed by the optical multiplexer / demultiplexer MD1 to become continuous light λ123. Continuous light λ123 is
After passing through the optical coupler CP, it is transmitted to the optical multiplexer / demultiplexer MD5 by the transmission optical fiber F. Optical multiplexer / demultiplexer MD5
Demultiplexes the continuous light λ123 into wavelengths λ1, λ2, λ3,
Reflective optical fiber sensors S11, S12, S1
Give to 3.

Each reflection type optical fiber sensor S11, S1
2, S13 give the received signals as information to the wavelengths λ1, λ2 and λ3, respectively, and return them to the optical multiplexer / demultiplexer MD5 by reflection. The optical multiplexer / demultiplexer MD5 has wavelengths λ1, λ2, λ
3 is recombined, transmitted as a continuous light λ123 through the transmission optical fiber F, and reaches the optical coupler CP. This continuous light λ
The light 123 is given to the optical multiplexer / demultiplexer MD6 by the optical coupler CP, and is again demultiplexed into lights of wavelengths λ1, λ2, and λ3.
The wavelengths λ1, λ2, and λ3 are O / E converters OE1 and OE1, respectively.
Converted to electricity by OE2 and OE3, demodulator DTC
The signals of the respective optical fiber sensors are demodulated by 1, DTC2 and DTC3.

With this construction, the second embodiment is
The same effects as in the first embodiment can be obtained. next,
A third embodiment of the present invention will be described. FIG. 4 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a third embodiment of the present invention.

As shown in this figure, this wavelength division multiplexing optical fiber sensor array system comprises a transmitting device A, an optical fiber sensor array B, and a receiving device C, and the wavelengths of output light are λ1 and λ2, respectively. , Three light sources L of λ3
D1, LD2, LD3, optical multiplexer / demultiplexers MD1, MD7, M
D8, MD9, optical pulse gate GT, transmission optical fibers F1, F2, 9-channel transmission type optical fiber sensor S
21, S22, S23, S24, S25, S26, S2
7, S28, S29, O / E converters OE1, OE2, O
E3, three demultiplexers DMX1 to DMX3, 9
It is composed of two demodulators DTC1 to DTC9.

The operation of the third embodiment of the present invention will be described below. The wavelength λ output from the light sources LD1, LD2, LD3
The continuous lights of 1, λ2 and λ3 are multiplexed by the optical multiplexer / demultiplexer MD1 to become continuous light λ123. Optical pulse gate GT
Pulse the continuous light λ 123. This optical pulse is transmitted to the optical multiplexer / demultiplexer MD7 by the transmission optical fiber F1, and the wavelengths λ1, λ2, λ3 are transmitted by the optical multiplexer / demultiplexer MD7.
Is divided into pulses. The wavelength λ1 is used for the transmission type optical fiber sensors S21, S22 and S23, the wavelength λ2 is used for the transmission type optical fiber sensors S24, S25 and S26, the wavelength λ3 is used for the transmission type optical fiber sensors S27, S28 and S29. It is input by the action.

Each transmission type optical fiber sensor gives the received signal as information to the inputted pulse and outputs them to the optical multiplexer / demultiplexer MD8. The optical multiplexer / demultiplexer MD8 has wavelengths λ1 and λ
The optical pulse trains of 2 and λ3 are combined again and given to the transmission optical fiber F2 as an optical pulse train of continuous light λ123. This continuous light λ123 is again output by the optical multiplexer / demultiplexer MD9.
The optical pulse trains having the wavelengths λ1, λ2, and λ3 are demultiplexed, and are supplied to the O / E converters OE1, OE2, and OE3. O /
With the E converters OE1, OE2, OE3, wavelengths λ1,
λ2 and λ3 are converted into electric pulse trains, channels are selected and interpolated by the demultiplexers DMX1 to DMX3 in the same manner as in the conventional technique, and the signals of the optical fiber sensors are demodulated by DTC1 to DTC9.

As described above, according to the third embodiment, the number of sensors is 9 channels, but the high speed of the demultiplexer can be maintained at the same high speed as in the case of 3 channels of the prior art. In addition, the optical power division loss is 3
It was possible to reduce it like the case of the channel. Next, a fourth embodiment of the present invention will be described.

FIG. 5 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a fourth embodiment of the present invention. As shown in this figure, this wavelength division multiplexing optical fiber sensor array system comprises a transmitting device A, an optical fiber sensor array B, and a receiving device C, and the output light wavelengths are λ1, λ2, and λ3, respectively. Three light sources LD1,
LD2, LD3, optical multiplexer / demultiplexers MD1, MD10, MD1
1, optical pulse gate GT, optical coupler CP, transmission optical fiber F, 9-channel reflective optical fiber sensor S3
1, S32, S33, S34, S35, S36, S3
7, S38, S39, O / E converters OE1, OE2, O
E3, three demultiplexers DMX1 to DMX3, 9
It is composed of two demodulators DTC1 to DTC9.

The operation of the fourth embodiment of the present invention will be described below. The wavelength λ output from the light sources LD1, LD2, LD3
The continuous lights of 1, λ2 and λ3 are multiplexed by the optical multiplexer / demultiplexer MD1 to become continuous light λ123. Optical pulse gate GT
Pulse the continuous light λ 123. This optical pulse is transmitted to the optical multiplexer / demultiplexer MD10 by the transmission optical fiber F, and the wavelengths λ1, λ2, and λ2 are transmitted by the optical multiplexer / demultiplexer MD10.
It is demultiplexed into pulses of λ3.

The wavelength λ1 corresponds to the reflection type optical fiber sensor S31.
And S32 and S33, the wavelength λ2 is input to the reflective optical fiber sensors S34, S35 and S36, and the wavelength λ3 is input to the reflective optical fiber sensors S37, S38 and S39 by the same operation as in the conventional technique. Each reflective optical fiber sensor S3
1, S32, S33, S34, S35, S36, S3
7, S38 and S39 give the received signal as information to the inputted pulse, and reflect them to the optical multiplexer / demultiplexer MD.
Return to 10.

The optical multiplexer / demultiplexer MD10 has wavelengths λ1, λ2, λ.
The optical pulse train of No. 3 is recombined, given to the transmission optical fiber F as an optical pulse train of continuous light λ123, and reaches the optical coupler CP. The continuous light λ123 is transmitted to the optical multiplexer / demultiplexer MD11.
Are again demultiplexed into optical pulse trains of wavelengths λ1, λ2, and λ3, which are given to O / E converters OE1, OE2, and OE3. The wavelengths .lamda.1, .lamda.2, .lamda.3 are converted into electric pulse trains by the O / E converters OE1, OE2, OE3, the channels are selected and interpolated by the demultiplexers DMX1 to DMX3 in the same manner as in the conventional technique, and the demodulators DTC1 to DTC1.
The signal of each optical fiber sensor is demodulated by the DTC 9.

With this configuration, the fourth embodiment can achieve the same effects as the third embodiment.
The present invention is not limited to the above embodiment,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0034]

As described in detail above, according to the present invention, the following effects can be achieved. (1) According to the first aspect of the invention, even if the number of channels increases, the power division loss can be suppressed, and appropriate demodulation processing can be performed.

(2) According to the invention described in claim 2, in addition to the effect of (1) above, since wavelength multiplexing is performed unlike the prior art, it is not necessary to pulse light, and channel separation and separation by DMX is performed. There is no need for interpolation processing. Therefore, the limitation on the number of channels does not occur due to the limit of the speed of the demultiplexer.

Further, since the power division of the optical fiber sensor is independent for each wavelength, the level deterioration due to the power division loss of light can be easily compensated. (3) According to the invention of claim 3, in addition to the effect of (2), the system configuration can be simplified. (4) According to the invention described in claim 4, the number of sensors is 9 channels, but the high speed of the demultiplexer can be maintained as high as that of 3 channels.
The optical power division loss can be reduced as in the case of 3 channels.

(5) According to the invention described in claim 5, in addition to the effect of (4), the system configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a time-division multiplexing 3-channel array system of a conventional transmission type optical fiber sensor.

FIG. 3 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a second embodiment of the present invention.

FIG. 4 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a third embodiment of the present invention.

FIG. 5 is a block diagram of a wavelength division multiplexing optical fiber sensor array system showing a fourth embodiment of the present invention.

[Explanation of symbols]

A transmitter device B optical fiber sensor array C receiver device LD1, LD2, LD3 light source MD1, MD2, MD3, MD4, MD5, MD6, M
D7, MD8, MD9, MD10, MD11 Optical multiplexer / demultiplexer F1, F2, F Transmission optical fiber S1, S2, S3, S21, S22, S23, S24,
S25, S26, S27, S28, S29 Transmission type optical fiber sensor S11, S12, S13, S31, S32, S33, S
34, S35, S36, S37, S38, S39 Reflective optical fiber sensor OE1, OE2, OE3 O / E converter DTC1 to DTC9 Demodulator CP Optical coupler GT Optical pulse gate DMX1 to DMX3 Demultiplexer

Claims (5)

[Claims] 1. A wavelength division multiplexing optical fiber sensor array system, comprising: (a) a light source for outputting a plurality of light wavelengths, and a transmitting device having an optical multiplexing means for multiplexing the light wavelengths, and (b) An optical fiber sensor array that is connected to the transmitting device and that has optical multiplexing / demultiplexing means; and (c) a receiving device that is connected to the optical fiber sensor array and that has optical demultiplexing means. Characteristic wavelength division multiplexing optical fiber sensor array system. 2. A wavelength division multiplexing optical fiber sensor array system comprising: (a) a light source for outputting a plurality of light wavelengths; and a transmission device having an optical multiplexing means for multiplexing the light wavelengths, and (b) An optical fiber sensor which is connected to the transmitting device and which has optical demultiplexing means, a transmission type optical fiber sensor connected to the optical demultiplexing means, and an optical multiplexing means connected to the transmission type optical fiber sensor. A wavelength division multiplexing optical fiber sensor array system comprising: an array; and (c) a receiving device that is connected to the optical fiber sensor array and has optical demultiplexing means. 3. In a wavelength division multiplexing optical fiber sensor array system, (a) a light source for outputting a plurality of optical wavelengths, an optical multiplexing means for multiplexing the optical wavelengths, and an optical coupler connected to the optical multiplexing means. And (b) an optical fiber sensor array having an optical multiplexing / demultiplexing means and a reflection type optical fiber sensor, and (c) connected to the optical coupler. And a receiving device having an optical demultiplexing means, and a wavelength division multiplexing optical fiber sensor array system. 4. A wavelength division multiplexing optical fiber sensor array system, comprising: (a) a light source for outputting a plurality of optical wavelengths, an optical multiplexing means for multiplexing the optical wavelengths, and (b) connected to the optical multiplexing means. A transmitting device having an optical pulse gate for: (c) an optical demultiplexing unit connected to the transmitting device; and a transmission type optical fiber sensor connected to the optical demultiplexing unit, (d) An optical fiber sensor array having optical multiplexing means connected to the transmissive optical fiber sensor, and (e)
A wavelength division multiplex optical fiber sensor array system comprising: a receiving device connected to the optical fiber sensor array and having an optical demultiplexing means. 5. In a wavelength division multiplexing optical fiber sensor array system, (a) a light source for outputting a plurality of optical wavelengths, an optical multiplexing means for multiplexing the optical wavelengths, and (b) connected to the optical multiplexing means. An optical pulse gate having: (c) an optical coupler connected to the optical pulse gate;
(D) An optical fiber sensor array having an optical multiplexing / demultiplexing means and a reflection type optical fiber sensor while being connected to the transmitting device, and (e) an optical fiber demultiplexing means connected to the optical coupler. A wavelength division multiplex optical fiber sensor array system, comprising: