CN102128643A

CN102128643A - Distributed sensing device on basis of superfine annular bipyramid optical fiber resonant cavity

Info

Publication number: CN102128643A
Application number: CN 201010593385
Authority: CN
Inventors: 董小伟; 王志军; 盛晓娟; 彭昌
Original assignee: Beijing Jiaotong University
Current assignee: Beijing Jiaotong University
Priority date: 2010-12-17
Filing date: 2010-12-17
Publication date: 2011-07-20
Anticipated expiration: 2030-12-17
Also published as: CN102128643B

Abstract

The invention relates to a distributed sensing device on the basis of a superfine annular bipyramid optical fiber resonant cavity, which belongs to the technical field of optical fiber sensing. Parts are connected in a way that a broadband light source (1) is connected with an in-line port of a 1*N coupler (3) by an opto-isolator (2), N biforked ports of the 1*N coupler (3) are respectively connected with one end of a first to the Nth sensing circuits (51, 52,......, 5N) through a first to Nth band-pass filters (41, 42,......,4N), and the other end of each of the first to the Nth sensing circuits (51, 52,......, 5N) are respectively connected with the Nth biforked ports of the 1*N coupler (6), and the in-line port of the 1*N coupler (6) is connected with a spectrum analyzer (7) and a computer (8). The first to the Nth sensing circuits (51, 52,......, 5N) are mutually connected in series by annular resonant cavities of which the radiuses have different microndimensions. Each annular resonant cavity is formed by winding and coupling a superfine annular bipyramid optical fiber. The distributed sensing device has the advantages of small size, low insertion loss, high cost performance, and simplicity and easiness in cascade connection and multiplexing.

Description

Distributed sensing device based on the fine fiber annular resonant cavity of bipyramid

Technical field

The present invention relates to a kind of distributed sensing device, belong to the technical field of Fibre Optical Sensor based on the fine fiber annular resonant cavity of bipyramid.

Background technology

Distributing optical fiber sensing is a technology of utilizing the continuation property of the optical fiber one-dimensional space to measure.Optical fiber had both been made sensing element, made transfer element again, can carry out continuous coverage to the environmental parameter along fiber distribution on whole fiber lengths, obtained measured space distribution state and time dependent information simultaneously.Distributed fiberoptic sensor has a series of outstanding advantages, is in the Fibre Optical Sensor the most potential one, can be widely used in various fields such as civil engineering, space flight, ocean, electric power, petrochemical complex, biology, medical treatment.

At present distribution type optical fiber sensing equipment mainly contains according to principle of work: based on backward scattered distributed sensing, based on the distributed sensing of polarized light time domain reflection, based on the distributed sensing of the interference of light with based on four types of the quasi-distributed sensings of Fiber Bragg Grating FBG.

Based on backward scattered distributing optical fiber sensing technology: be the rear orientation light that produces when utilizing light wave in optical fiber, to transmit, comprise Rayleigh scattering, Raman scattering and Brillouin scattering, by these rear orientation lights and measured, can realize distributing optical fiber sensing as the relation between temperature, stress, the vibration etc.This commercial measurement principle is simple, and cost is cheap relatively, can realize the measuring distance that 10km is above at present.But it needs the light source of high power, short pulse and high speed signal to amplify sampler, and its measuring accuracy and spatial resolution are subjected to the restriction of device performance and cost.

Distributing optical fiber sensing technology based on polarized light time domain reflection: be with linearly polarized light pulse coupled into optical fibres, a kind of novel sensing technology that the additional information of utilizing the scatter light polarization attitude to change along optical fiber comes parameter to external world to monitor.The advantage of this sensing technology is to have higher sensitivity, but because the statistics randomness of light pulse polarization state, controlling cost of system is higher.

Distributing optical fiber sensing technology based on the interference of light: mainly comprise Mach-Zehnder interfere type, Sa Genike interfere type, Michelson interfere type and Fabry-Perot interference type.Its principle of work is a different transmission path of utilizing interferometer to provide, and generation difference extracts interference heat transfer agent to be measured when making the light pulse of LASER Light Source output by light path to be measured and reference path from the result of interference of two paths of signals.This sensing technology is owing to adopting interference effect, and is higher to resolution to be measured and bearing accuracy, but also causes the less stable of system.

Quasi-distributed optical fiber sensing technology based on Fiber Bragg Grating FBG: be to utilize Fiber Bragg Grating FBG to temperature, stress, vibration, crooked, the high sensitivity of refractive index etc. is realized the sensing detection of parameter to external world, utilize the wavelength selectivity of fiber grating simultaneously, by the multiplexing distributed sensing that carries out of the grating cascade that centre wavelength is different, can increase the regional extent of detection, but because each raster unit takies certain measurement bandwidth, can not overlap each other, therefore reusable number is subjected to the restriction of wideband light source line width, system cost is with multiplexing number linear growth in addition, and the spatial resolution of detection is restricted by raster size.

Summary of the invention

Technical matters to be solved by this invention is, overcomes the deficiency that present distribution type optical fiber sensing equipment exposes, and proposes a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid.

The present invention proposes a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid, its principle of work is: the fine optical fiber of high-quality bipyramid that utilizes fusion draw, adopt from twining coupled method and make the ring resonator that radius is a micron dimension, according to the high evanescent field effect of biconical fiber, and the corresponding relation between resonator cavity transmission spectrum ripple and environment parameter of living in, by real-time monitoring ripple drift, realize sensing detection to environmental change.

The present invention solves the technical scheme of its technical matters:

The present invention proposes a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid, and this device comprises: wideband light source, optoisolator, first, second 1 * N coupling mechanism, first to N bandpass filter, first to N sense line, spectroanalysis instrument and computing machine.Connection between each device is as follows:

Wideband light source links to each other with a word port of one 1 * N coupling mechanism through optoisolator, and the N of one 1 * N coupling mechanism bifurcated port connects first bandpass filter respectively, second bandpass filter ..., the input end of N bandpass filter.

The output terminal of first bandpass filter is connected with an end of first sense line, and the output terminal of second bandpass filter is connected with an end of second sense line ..., the output terminal of N bandpass filter is connected with an end of N sense line.

First sense line, second sense line ..., the other end of N sense line links to each other with N bifurcated port of 21 * N coupling mechanism respectively.

One word port of 21 * N coupling mechanism is connected with the input end of spectroanalysis instrument, and the output terminal of spectroanalysis instrument links to each other with computing machine.

First sense line is by the one one ring resonator, the first second ring resonator cavity ..., the M ring resonator formation of connecting mutually.

Second sense line is by the 21 ring resonator, the second second ring resonator cavity ..., the 2nd M ring resonator formation of connecting mutually.

……。

The N sense line is by N one ring resonator, N second ring resonator cavity ..., the NM ring resonator formation of connecting mutually.

All ring resonators are made from twining coupling by the fine optical fiber of bipyramid, and its radius is different micron dimensions.The fine optical fiber of bipyramid is formed by the flame fusion draw.

The integer of N 〉=2, the integer of M 〉=2.

Beneficial effect of the present invention is specific as follows:

A kind of distributed sensing device of the present invention based on the fine fiber annular resonant cavity of bipyramid, made full use of the high evanescent field effect of the fine optical fiber of bipyramid, and the corresponding relation between resonator cavity transmission spectrum ripple and environment parameter of living in, by real-time monitoring ripple drift, realize sensor monitoring to environmental change.The radius of this ring resonator is a micron dimension, size is little, simple in structure, and adopt the fine optical fiber of continuous bipyramid to make from twining coupling, the transmission of sensing and signal is integrated, cascade and multiplexing convenient, compare with the ring resonator that the integrated method of present slab guide is made, it is lower to insert loss and cost.This have high sensitivity, microsize, a novel optical fiber sensing device that cost performance is higher, solved the high multiplexing cost of present distributed sensing well, and, the development that promotes Fibre Optical Sensor had important economy and social effect in the limitation of fineness, the demanding applications of spatial resolution.

Description of drawings

Fig. 1 is for adopting the distributed sensing device based on the fine fiber annular resonant cavity of bipyramid of 1 * N coupling mechanism, and N and M be 〉=structural representation of 2 integer.

Fig. 2 is for adopting the distributed sensing device based on the fine fiber annular resonant cavity of bipyramid of array waveguide grating, and N and M be 〉=structural representation of 2 integer.

Fig. 3 is for adopting the distributed sensing device based on the fine fiber annular resonant cavity of bipyramid of 1 * N coupling mechanism, and N gets 2, and M gets 2 structural representation.

Fig. 4 is for adopting the distributed sensing device based on the fine fiber annular resonant cavity of bipyramid of array waveguide grating, and N gets 256, and M gets 8 structural representation.

The structural representation of the ring resonator that Fig. 5 makes for being coupled by oneself winding of the fine optical fiber of bipyramid.

Embodiment

Below in conjunction with accompanying drawing the present invention is further described.

Embodiment one, as Fig. 1, a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid comprises: wideband light source 1, optoisolator 2, first, second 1 *

N coupling mechanism

3,6, first to

N bandpass filter

41,42 ..., 4N, first to

N sense line

51,52 ..., 5N, spectroanalysis instrument 7 and computing machine 8.Connection between above-mentioned each device is as follows:

Wideband light source 1 links to each other with a word port of one 1 * N coupling mechanism 3 through optoisolator 2, the N of one 1 * N coupling mechanism 3 bifurcated port connects first bandpass filter, 41, the second bandpass filter 42 respectively ... the input end of N bandpass filter 4N, wideband light source 1 adopts Erbium-Doped Fiber Amplifier (EDFA).

The output terminal of first bandpass filter 41 is connected with an end of first sense line 51, and the output terminal of second bandpass filter 42 is connected with an end of second sense line 52 ..., the output terminal of N bandpass filter 4N is connected with the end of N sense line 5N.

First sense line 51, second sense line 52 ..., the other end of N sense line 5N links to each other with N bifurcated port of 21 * N coupling mechanism 6 respectively.

First, second 1 *

N coupling mechanism

3,6 all adopts Optical Fiber Star Couplers.

One word port of 21 * N coupling mechanism 6 is connected with the input end of spectroanalysis instrument 7, and the output terminal of spectroanalysis instrument 7 links to each other with computing machine 8, and spectroanalysis instrument 7 adopts ANDO6317.

First sense line 51 is by the one one ring resonator 511, the first second ring resonator cavitys 512 ..., the M ring resonator 51M formation of connecting mutually.

Second sense line 52 is by the 21 ring resonator 521, the second second ring resonator cavitys 522 ..., the 2nd M ring resonator 52M formation of connecting mutually.

……。

N sense line 5N is by N one ring resonator 5N1, N second ring resonator cavity 5N2 ..., the NM ring resonator 5NM formation of connecting mutually.

All ring resonators are made from twining coupling by the fine optical fiber of bipyramid, see Fig. 5, and its radius is different micron dimensions.The fine optical fiber of bipyramid is formed by the flame fusion draw.

The integer of N 〉=2, the integer of M 〉=2.

Embodiment two, and as Fig. 2, a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid comprises: wideband light source 1, optoisolator 2, first, second

array waveguide grating

3,6, the first to

N sense line

Wideband light source 1 links to each other with a word port of first array waveguide grating 3 through optoisolator 2, the N of first array waveguide grating 3 bifurcated port respectively with first sense line, 51, the second sense lines 52 ... N sense line 5N connects, and wideband light source 1 adopts LED.

First sense line 51, second sense line 52 ..., the other end of N sense line 5N links to each other with N bifurcated port of second array waveguide grating 6 respectively.

One word port of second array waveguide grating 6 is connected with the input end of spectroanalysis instrument 7, and the output terminal of spectroanalysis instrument 7 links to each other with computing machine 8, and spectroanalysis instrument 7 adopts ANDO6317.

……。

The integer of N 〉=2, the integer of M 〉=2.

Embodiment three, as Fig. 3, a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid comprises: wideband light source 1, optoisolator 2, first, second 1 * 2

coupling mechanism

3,6, first,

second bandpass filter

41,42, first,

second sense line

51,52, spectroanalysis instrument 7 and computing machine 8, the connection between above-mentioned each device is as follows:

Wideband light source 1 links to each other with a word port of the one 1 * 2 coupling mechanism 3 through optoisolator 2, and two bifurcated ports of the one 1 * 2 coupling mechanism 3 connect the input end of first bandpass filter 41 and second bandpass filter 42 respectively, and wideband light source 1 adopts Erbium-Doped Fiber Amplifier (EDFA).

The output terminal of first bandpass filter 41 is connected with an end of first sense line 51, and the output terminal of second bandpass filter 42 is connected with an end of second sense line 52.

The other end of first sense line 51, second sense line 52 links to each other with two bifurcated ports of the 21 * 2 coupling mechanism 6 respectively.

One word port of the 21 * 2 coupling mechanism 6 is connected with the input end of spectroanalysis instrument 7, and the output terminal of spectroanalysis instrument 7 links to each other with computing machine 8, and spectroanalysis instrument 7 adopts ANDO6317.

First sense line 51 is the one one ring resonator 511 of 100 μ m by radius, and radius is the first second ring resonator cavity, the 512 series connection formations mutually of 800 μ m.

Second sense line 52 is the 21 ring resonator 521 of 100 μ m by radius, and radius is the second second ring resonator cavity, the 522 series connection formations mutually of 800 μ m.

All ring resonators are made from twining coupling by the fine optical fiber of bipyramid, see Fig. 5.The fine optical fiber of bipyramid is formed by the flame fusion draw.

Embodiment four, as Fig. 4, a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid comprises: wideband light source 1, optoisolator 2, first, second array waveguide grating 3,6, first to

N sense line

51,52 ..., 5N, spectroanalysis instrument 7 and computing machine 8, N=256, M=8.Connection between above-mentioned each device is as follows:

Wideband light source 1 links to each other with a word port of first array waveguide grating 3 through optoisolator 2,256 bifurcated ports of first array waveguide grating respectively with first sense line, 51, the second sense lines 52 ... the 256 sense line 5256 connects, and wideband light source 1 adopts LED.

First sense line 51, second sense line 52 ..., the other end of the 256 sense line 5256 links to each other with 256 bifurcated ports of second array waveguide grating 6 respectively;

First sense line 51 is the one one ring resonator 511 of 100 μ m by radius, and radius is the first second ring resonator cavity 512 of 200 μ m ..., radius is the one or the eight ring resonator 518 series connection formations mutually of 800 μ m.

Second sense line 52 is the 21 ring resonator 521 of 100 μ m by radius, and radius is the second second ring resonator cavity 522 of 200 μ m ..., radius is the two or the eight ring resonator 528 series connection formations mutually of 800 μ m;

The 256 sense line is the 256 ring resonator 52561 of 100 μ m by radius, radius is the 256 second ring resonator cavity 52562 of 200 μ m,, radius is the 256 ring resonator 52568 series connection formations mutually of 800 μ m.

Claims

1. distributed sensing device based on the fine fiber annular resonant cavity of bipyramid, it is characterized in that, this sensing device comprises: wideband light source (1), optoisolator (2), first, second 1 * N coupling mechanism (3,6), first are to N bandpass filter (41,42,, 4N), first to N sense line (51,52,, 5N), spectroanalysis instrument (7) and computing machine (8);

Connection between described each device:

Wideband light source (1) links to each other with a word port of one 1 * N coupling mechanism (3) through optoisolator (2), N bifurcated port of one 1 * N coupling mechanism (3) connects first bandpass filter (41) respectively, second bandpass filter (42) ..., the input end of N bandpass filter (4N);

The output terminal of first bandpass filter (41) is connected with an end of first sense line (51), the output terminal of second bandpass filter (42) is connected with an end of second sense line (52),, the output terminal of N bandpass filter (4N) is connected with an end of N sense line (5N);

First sense line (51), second sense line (52) ..., the other end of N sense line (5N) links to each other with N bifurcated port of 21 * N coupling mechanism (6) respectively;

One word port of 21 * N coupling mechanism (6) is connected with the input end of spectroanalysis instrument (7), and the output terminal of spectroanalysis instrument (7) links to each other with computing machine (8);

First sense line (51) is by the one one ring resonator (511), the first second ring resonator cavity (512) ..., a M ring resonator (51M) series connection mutually constitutes;

Second sense line (52) is by the 21 ring resonator (521), the second second ring resonator cavity (522) ..., the 2nd M ring resonator (52M) series connection mutually constitutes;

…；

N sense line (5N) is by N one ring resonator (5N1), N second ring resonator cavity (5N2) ..., NM ring resonator (5NM) series connection mutually constitutes;

The integer of N 〉=2, the integer of M 〉=2.

2. a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid according to claim 1 is characterized in that:

Described wideband light source (1) is Erbium-Doped Fiber Amplifier (EDFA) or LED or other any wavelength coverage wideband light source in the optical fiber low loss window.

3. a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid according to claim 1 is characterized in that:

Described one 1 * N coupling mechanism (3) and 21 * N coupling mechanism (6) are Optical Fiber Star Couplers or array waveguide grating.

4. a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid according to claim 1 is characterized in that:

First sense line to the N sense line (51,52 ..., 5N) ring resonator in is made from twining coupling by the fine optical fiber of bipyramid, and its radius is different micron dimensions.

5. a kind of distributed sensing device based on the fine fiber annular resonant cavity of bipyramid according to claim 4 is characterized in that:

The fine optical fiber of described bipyramid is formed by the flame fusion draw.