CN108401555B - Microvibration measuring instrument based on fibre-optic waveguide modulation - Google Patents
Microvibration measuring instrument based on fibre-optic waveguide modulation Download PDFInfo
- Publication number
- CN108401555B CN108401555B CN200810075197.XA CN200810075197A CN108401555B CN 108401555 B CN108401555 B CN 108401555B CN 200810075197 A CN200810075197 A CN 200810075197A CN 108401555 B CN108401555 B CN 108401555B
- Authority
- CN
- China
- Prior art keywords
- polarization
- maintaining optical
- light
- fibre
- optical fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The present invention relates to a kind of microvibration measuring instrument based on fibre-optic waveguide modulation.The measuring instrument loads high-frequency phase carrier (boc) modulated signals by polarization maintaining optical fibre waveguide modulator, using Zigzag type telescope transmitting laser and receive scattering light, that is the laser beam of light source is divided into two bundles through polarization-maintaining optical fiber beam splitter, a branch of is signal light, another beam is reference light, reference beam is launched after polarization maintaining optical fibre waveguide modulator by the first polarization maintaining optical fiber collimator, successively after the one 1/2 wave plate, the first polarization beam apparatus and the 2nd 1/2 wave plate, it is incident on the first detector and the second detector respectively using the light splitting of the second polarization beam apparatus.The present invention passes through polarization-maintaining optical fiber beam splitter, the devices such as polarization maintaining optical fibre waveguide tune device and polarization maintaining optical fiber collimator form reference path, for loading high-frequency phase carrier modulation, change modulation demodulation system, solve the problems, such as that temperature instability and the control of common vialog PZT modulation are complicated, modulated signal source circuit is simple, and normal signal source can be used.
Description
Technical field
The invention belongs to non-contact laser vibration measuring technology, especially a kind of microvibration measuring instrument based on fibre-optic waveguide modulation.
Background technology
With the development of vibration measurement with laser technology, in some specific researchs and application field, such as national security or public security department
Technology intercept, bridge exploration, precision machinery processing, aerospace field malfunction monitoring etc., not only need sometimes
It is detected at a distance, and wants to measure vibrational waveform in real time, cause vibration can further probe into
Physical mechanism, and the signal for causing vibration is restored, here it is the measurement of the remote non-contact micro-vibration of unmatched glove and guarantors
The mostly of method use of true pickup, measurement are diffusing reflection formula laser doppler techniques.
In the application of some Laser Doppler speed and vibration measuring, in order to reduce signal distortion and distortion, detection is improved
Sensitivity needs to use Phase Demodulation Method of Optic, including passive homodyne, active homodyne, phase generated carrier homodyne technique, warp
At this moment allusion quotation heterodyne and synthetic heterodyne several method usually need to introduce high-frequency phase carrier signal, traditional technology is to pass through pressure
Electroceramics heap (PZT) loads.Such as application No. is 03113478.5 patents of invention typically the reflection of reference path
Mirror adheres on PZT, drives speculum vibration to introduce phase carrier modulated signal by PZT.However, PZT is an appearance
Property load device, by temperature, humidity, stress influence, characteristic is very unstable, and drives the signal source circuit of its work
Complicated, modulating frequency is difficult more than 10KHz, this just greatly limits the frequency range of detectable vibration signal.
In addition, when measurement distance farther out, measurement angle it is larger and when without the cooperative target for increasing return light energy, due to
Receive the rapid decaying of light energy so that the signal detected is extremely faint；When measurement distance farther out when, on Scattering Targets
Spot size can be increasing, the influence of speckle is more and more obvious, and can also signal-to-noise ratio be made significantly to decline.
Existing vibration measurement with laser technology due to above, it is difficult to the technology for meeting in national security or public security department intercept,
The fields such as bridge surveys, precision machinery is processed, the malfunction monitoring of aerospace field carry out micro- shake to long distance scatter target
The dynamic demand measured and fidelity picks up.
Invention content
The purpose of the present invention is to provide it is a kind of can to long distance scatter target carry out microvibration measuring and fidelity pickup
Microvibration measuring instrument based on fibre-optic waveguide modulation.
Realize that the technical solution of the object of the invention is：A kind of microvibration measuring instrument based on fibre-optic waveguide modulation, passes through
Polarization maintaining optical fibre waveguide modulator loads high-frequency phase carrier (boc) modulated signals, using Zigzag type telescope transmitting laser and receives scattered
Penetrate light, i.e. the laser beam of light source is divided into two bundles through polarization-maintaining optical fiber beam splitter, and a branch of is signal light, and another beam is reference light,
Reference beam is launched after polarization maintaining optical fibre waveguide modulator by the first polarization maintaining optical fiber collimator, passes through the one 1/2 wave successively
After piece, the first polarization beam apparatus and the 2nd 1/2 wave plate, it is incident on the first spy respectively using the light splitting of the second polarization beam apparatus
Survey device and the second detector；Signal light is sent out from the second polarization maintaining optical fiber collimator, passes through the 3rd 1/2 wave plate, first successively
It is projected in remote scattering target by Zigzag type telescope after polarization beam apparatus and quarter wave plate, and is collected and scattered by telescope
Light, the signal light being collected into are reflected into the second polarization beam apparatus after quarter wave plate by the first polarization beam apparatus, by this
Two polarization beam apparatus, which are divided into two bundles, to be incident on respectively on the first detector and the second detector.
Compared with prior art, the present invention its remarkable advantage is：(1) pass through polarization-maintaining optical fiber beam splitter, polarization maintaining optical fibre waveguide
The devices such as device and polarization maintaining optical fiber collimator composition reference path is adjusted to change modulation for loading high-frequency phase carrier modulation
Demodulation mode solves the problems, such as that the temperature instability of common vialog PZT modulation and control are complicated, modulating signal source
Circuit is simple, and normal signal source can be used.(2) it by the use of Zigzag type telescope, increases and receives signal light
Intensity, reduce the influence of speckle, measurement distance made to greatly increase, improve signal light intensity, to improve system
Signal-to-noise ratio.(3) using narrow-linewidth polarization-maintaining fiber laser as light source, in conjunction in polarization spectro light path elimination system
It is unstable caused by polarization decay.
Present invention is further described in detail below in conjunction with the accompanying drawings.
Description of the drawings
Attached drawing is the composition and light path schematic diagram for the microvibration measuring instrument modulated the present invention is based on fibre-optic waveguide.
Specific implementation mode
In conjunction with attached drawing, the present invention is based on the microvibration measuring instrument of fibre-optic waveguide modulation, pass through polarization maintaining optical fibre waveguide modulator 4
High-frequency phase carrier (boc) modulated signals are loaded, modulated signal complicated with the unstability and control that solve the problems, such as PZT modulation
Source circuit is simple, and normal signal source can be used.Laser is emitted using Zigzag type telescope 14 and receives scattering light, i.e.,
The laser beam of light source 1 is divided into two bundles through polarization-maintaining optical fiber beam splitter 2, and a branch of is signal light, and another beam is reference light, ginseng
It examines light beam after polarization maintaining optical fibre waveguide modulator 4 to be launched by the first polarization maintaining optical fiber collimator 5, passes through the one 1/2 successively
After wave plate 6, the first polarization beam apparatus 8 and the 2nd 1/2 wave plate 10, it is divided and distinguishes using the second polarization beam apparatus 12
It is incident on the first detector 11 and the second detector 13；Signal light is sent out from the second polarization maintaining optical fiber collimator 3, is passed through successively
It crosses after the 3rd 1/2 wave plate 7, the first polarization beam apparatus 8 and quarter wave plate 9 and remote scattering target is projected by telescope 14
It on 15, and is diffused by the collection of telescope 14, the signal light being collected into is after quarter wave plate 9 by the first polarization point
Beam device 8 is reflected into the second polarization beam apparatus 12, is divided into two bundles by second polarization beam apparatus 12 and is incident on the first spy respectively
It surveys on device 11 and the second detector 13.Signal light and reference light form interference pattern on two detectors 11,12 surfaces.
In system, polarization maintaining optical fibre waveguide modulator 4 combines demodulator circuit for the reduction of micro-vibration signal.
Wherein, light source 1 is narrow linewidth linearly polarized light fibre laser.Polarization-maintaining optical fiber beam splitter 2, fibre-optic waveguide modulator 4,
First polarization maintaining optical fiber collimator 5 and the second polarization maintaining optical fiber collimator 3 are polarization-preserving optical fibre device.In order to meet remote survey
The requirement of amount needs to increase signal light intensity；Speckle in order to reduce Scattering Targets influences, and needs to reduce on Scattering Targets and gather
The size of focus；Consider that the convenience of system bulk and operation, the present invention are received using heavy caliber Zigzag type telescope 14
The back scattered signal light of scattering, is greatly improved signal light intensity, reduces the influence of speckle, is to improve
The signal-to-noise ratio of system.
In the Testing of Feeble Signals of interference-type equipment, the phase noise of light source is impossible to ignore, when optical path difference is more than one
When determining degree, phase noise may be constructed the main body of noise.When light source selects not at that time, signal is usually submerged in these
In noise.In the present invention, light source 1, which uses, has ultra-narrow laser linewidth (＜ 1KHz) single-frequency polarization-maintaining fiber laser,
Due to its coherence length with overlength, the phase noise being successfully reduced in system.
In the Testing of Feeble Signals of interference-type, when reference light and signal light power ratio are more than 10, intensity noise is also not
It may ignore, equally may be constructed the main body of noise.The present invention is by using two-way balancing method almost by the intensity of light source
Noise has been down to shot noise (this Earth noise) level, eliminates the intensity noise of light source.
When Scattering Targets vibrate, reflected signal light generates Doppler frequency shift, signal light with reference to after the interference of light
Frequency displacement size can be converted into the variation of photo-current intensity, the variation of frequency displacement can be demodulated using Phase Demodulation Method of Optic, to
Reduce the vibrational waveform of Scattering Targets.
Optical fiber laser exports laser center wavelength 1554nm, and line width is less than 1KHz, and laser power is more than 20mW, tool
There is stable polarization state；Polarization-maintaining optical fiber beam splitter 2 is the beam splitter of high splitting ratio, to ensure the utilization rate of signal light；
Polarization maintaining optical fiber collimator 1 is located at the imaging surface center of telescope.
It is 0.87A/W that photodetector, which selects InGaAs-PIN detectors, 1310nm responsivenesses,.Two detector knots
It closes subtraction circuit and forms two-way balance master system, efficiently reduce the intensity noise of light source.Telescope using
The Maksutov of bore 100mm, focal length 1000mm-Cassegrain's formula (abbreviation horse-cassette) catadioptric astronomical telescope,
Its focal length characteristic keeps the hot spot in long distance scatter target smaller, reduces the influence of speckle.
Claims (3)
1. a kind of microvibration measuring instrument based on fibre-optic waveguide modulation, it is characterised in that：Pass through polarization maintaining optical fibre waveguide
Device (4) loads high-frequency phase carrier (boc) modulated signals, using Zigzag type telescope (14) transmitting laser and receives scattering light,
I.e. the laser beam of light source (1) is divided into two bundles through polarization-maintaining optical fiber beam splitter (2), and a branch of is signal light, and another beam is ginseng
Light is examined, reference beam is launched after polarization maintaining optical fibre waveguide modulator (4) by the first polarization maintaining optical fiber collimator (5), according to
It is secondary after the one 1/2 wave plate (6), the first polarization beam apparatus (8) and the 2nd 1/2 wave plate (10), using second
The first detector (11) and the second detector (13) are incident in polarization beam apparatus (12) light splitting respectively；Signal light is from
Two polarization maintaining optical fiber collimators (3) are sent out, and pass through the 3rd 1/2 wave plate (7), the first polarization beam apparatus (8) and 1/4 successively
It is projected in remote scattering target (15) by Zigzag type telescope (14) after wave plate (9), and by telescope (14)
Scattering light is collected, the signal light being collected into is reflected into second after quarter wave plate (9) by the first polarization beam apparatus (8)
Polarization beam apparatus (12) is divided into two bundles by second polarization beam apparatus (12) and is incident on the first detector (11) respectively
On the second detector (13).
2. the microvibration measuring instrument according to claim 1 based on fibre-optic waveguide modulation, it is characterised in that：Light source
(1) it is narrow linewidth linearly polarized light fibre laser.
3. the microvibration measuring instrument according to claim 1 based on fibre-optic waveguide modulation, it is characterised in that：Polarization-maintaining
Fiber optic splitter (2), fibre-optic waveguide modulator (4), the first polarization maintaining optical fiber collimator (5) and the second polarization maintaining optical fibre are accurate
Straight device (3) is polarization-preserving optical fibre device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810075197.XA CN108401555B (en) | 2008-04-11 | 2008-04-11 | Microvibration measuring instrument based on fibre-optic waveguide modulation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810075197.XA CN108401555B (en) | 2008-04-11 | 2008-04-11 | Microvibration measuring instrument based on fibre-optic waveguide modulation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108401555B true CN108401555B (en) | 2012-09-26 |
Family
ID=63078646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200810075197.XA Active CN108401555B (en) | 2008-04-11 | 2008-04-11 | Microvibration measuring instrument based on fibre-optic waveguide modulation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108401555B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114137251A (en) * | 2021-11-16 | 2022-03-04 | 安徽大学 | Integrated multipurpose laser Doppler current measuring instrument |
| CN114518180A (en) * | 2022-01-21 | 2022-05-20 | 北京航空航天大学 | Temperature and amplitude remote measuring system and method based on laser dispersion spectrum |
| CN114813576A (en) * | 2022-04-19 | 2022-07-29 | 浙江大学 | Self-adaptive all-fiber laser ultrasonic measuring instrument |
-
2008
- 2008-04-11 CN CN200810075197.XA patent/CN108401555B/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114137251A (en) * | 2021-11-16 | 2022-03-04 | 安徽大学 | Integrated multipurpose laser Doppler current measuring instrument |
| CN114137251B (en) * | 2021-11-16 | 2024-01-16 | 安徽大学 | Integrated multipurpose laser Doppler flow velocity measuring instrument |
| CN114518180A (en) * | 2022-01-21 | 2022-05-20 | 北京航空航天大学 | Temperature and amplitude remote measuring system and method based on laser dispersion spectrum |
| CN114518180B (en) * | 2022-01-21 | 2022-12-09 | 北京航空航天大学 | Temperature and amplitude remote measuring system and method based on laser dispersion spectrum |
| CN114813576A (en) * | 2022-04-19 | 2022-07-29 | 浙江大学 | Self-adaptive all-fiber laser ultrasonic measuring instrument |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107576341B (en) | Device and method for eliminating polarization fading in OFDR (offset frequency domain digital radiography) | |
| CN101634571B (en) | Optical pulse raster distributed fiber sensing device | |
| US8467067B2 (en) | Dynamic light-scattering measuring apparatus using low-coherence light source and light-scattering measuring method of using the apparatus | |
| CN105606194B (en) | A kind of underwater signal real time extracting method based on laser orthogonal polarization interferometry technology | |
| US20200318949A1 (en) | Displacement sensor for frequency modulation continuous wave laser interference optical fiber and displacement detection method therefor | |
| CN105784101B (en) | Based on optical fiber weak reflection spot battle array Fizeau interference distributed vibration sensing systems and method | |
| CN108534686B (en) | Zero-drift-free heterodyne laser Doppler measurement optical fiber light path and measurement method | |
| CN103616165A (en) | Optical fiber loss measuring system | |
| CN102027346B (en) | Device for spatially resolved temperature measurement | |
| CN106989904A (en) | A kind of measuring method of polarization maintaining optical fibre extinction ratio | |
| CN109959403A (en) | A kind of many reference amounts large capacity sensor-based system | |
| CN108401555B (en) | Microvibration measuring instrument based on fibre-optic waveguide modulation | |
| CN106441083B (en) | Laser feedback interferometer | |
| CN109085601B (en) | High-speed model speed continuous measuring device and method for ballistic target | |
| CN104180832A (en) | Distributed orthogonal vector disturbance sensing system based on four-core optical fiber | |
| US6710860B1 (en) | Method of aligning a bistatic dopple sensor apparatus | |
| CN107064539A (en) | A kind of big visual field photon Doppler speed measuring device and method | |
| CN113960631B (en) | Radar system | |
| CN105393106B (en) | Device for measuring scattering of a sample | |
| CN107121071B (en) | Two-dimensional displacement measurer and measurement method | |
| Tosi et al. | Performance analysis of a noncontact plastic fiber optical fiber displacement sensor with compensation of target reflectivity | |
| JPS63118624A (en) | Optical fiber measuring device and method | |
| CN101561317B (en) | System for measuring the influence of object to polarization state of transmitted beams with high precision and automation | |
| CN110487186A (en) | A kind of optical fiber distance measuring device of high sensitivity | |
| CN212904428U (en) | Detection assembly and device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR03 | Grant of secret patent right | ||
| DC01 | Secret patent status has been lifted | ||
| DC01 | Secret patent status has been lifted |