CN1259541C - Self-mixed interference displacement sensor based on two-way laser - Google Patents
Self-mixed interference displacement sensor based on two-way laser Download PDFInfo
- Publication number
- CN1259541C CN1259541C CN 200510011230 CN200510011230A CN1259541C CN 1259541 C CN1259541 C CN 1259541C CN 200510011230 CN200510011230 CN 200510011230 CN 200510011230 A CN200510011230 A CN 200510011230A CN 1259541 C CN1259541 C CN 1259541C
- Authority
- CN
- China
- Prior art keywords
- light
- laser
- phase
- signal
- signals
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
The present invention relates to a displacement sensor based on self-mixing interference effect, which belongs to the field of laser displacement measurement. The present invention is characterized in that the displacement sensor is composed of a light source, a measuring part and a signal processing part; the present invention has a compact structure and only has one interference passage. The light source of the present invention uses a two-frequency laser; in a measuring process, two beams of orthogonal polarized light output by the two-frequency laser are detected so as to obtain two cosine signals with a phase difference of 90 DEG, and phase reversion is carried out on the two signals so as to obtain the other two cosine signals with the phase difference of 90 DEG. The phase differences of the four cosine signals are orderly 90 DEG, and the four signals are used as input signals of a quadruple circuit so as to achieve electronic subdivision. Resolution is improved by four times, and the moving directions of objects to be measured are identified. The self-mixing interference displacement sensor designed by the present invention is a displacement measuring device which has the advantages of compact and simple structure, and high resolution and performance-price ratio, and the identification of the moving directions of the objects is easily realized.
Description
Technical field
The invention belongs to Laser Measuring shift technique field.
Background technology
Laser displacement sensor is widely used, and based on the displacement transducer of interfering traditional interferometer and self-mixed interference instrument etc. is arranged.For traditional interferometer its technology maturation of two-frequency laser interferometer and be widely used for example in metering with in measuring.But the two-frequency laser interferometer complex structure, collimation requires high, costs an arm and a leg.The research of self-mixed interference displacement measuring technology is to begin to rise in 80 years, and most research all concentrates on the self-mixed interference research in the semiconductor laser.This kind displacement measuring device light path system has only a laser instrument and an extraneous reverberation (a for example catoptron).The light of laser instrument output be reflected or scattering after the return laser light resonator cavity, mix the variable power that causes laser instrument with light in the chamber, external mirror whenever moves striped of displacement lasers device variable power of half optical wavelength, and the fluctuation degree of depth of striped and traditional double beam interference system can compare.The laser power striped can be directly used in counting and realize that displacement measurement realization resolution is half wavelength this moment.Self-mixed interference more complicated in the semiconductor laser, can be divided into four kinds of light feedback levels according to the difference of feedback coefficient C: very low light level feedback (C＜＜1), low light level feedback (0.1＜C＜1), intermediate light feedback (1＜C＜4.6) and high light feedback (C＞4.6).Under low light level feedback and intermediate light feedback level, the self-mixing interference of semiconductor laser is asymmetrical class sawtooth wave shape, and the vergence direction of sawtooth wave is relevant with the moving direction of exocoel reverberation.Consider the displacement of the corresponding exocoel reverberation of each periodic group sawtooth wave half wavelength simultaneously, therefore not only can utilize class sawtooth wave realization direction to discern but also can realize the measurement of displacement.But this moment, the resolution of self-mixed interference system only was λ/2 (λ is the wavelength of laser instrument), and resolution is not high.Under intermediate light feedback level, sluggish phenomenon can appear in self-mixing interference, will bring error to counting.By contrast, can effectively realize displacement measurement under the low light level feedback level, but the feedback level of laser instrument need be controlled at low light level feedback level.If light feedback level makes laser works in low light level feedback level very because of the variation of extraneous reverberation surface reflection or scattering property, system will because of self-mixing interference for the sinusoidal signal of symmetry can not realize declaring to.If light feedback level makes laser works in intermediate light feedback level because of the improvement of extraneous reverberation surface reflection or scattering property, system will cause measuring error because of the hysteresis phenomenon of self-mixing interference this moment.
Summary of the invention
The object of the invention is to provide a kind of compact conformation, and the cost performance height need not to control the high-resolution self-mixed interference displacement sensor of light feedback level.
The present invention is characterised in that it contains:
The Lights section, it is a two-frequency laser, this two-frequency laser comprises:
Laser gain pipe, inside are filled with the HeNe mixed gas;
Tail light outgoing mirror, reflectivity is 99.8%, is positioned at the axial side of laser gain pipe;
Anti-reflection window is positioned at the axial opposite side of laser gain pipe;
Mechanical type stress bringing device, it applies a stress along the direction perpendicular to laser gain tube axis to anti-reflection window;
The main beam outgoing mirror, reflectivity is 98%, is positioned at anti-reflection window opposite side, output pairwise orthogonal polarized light, i.e. directional light and vertical light;
The transverse magnetic field generator, it applies parallel or perpendicular to the transverse magnetic field of above-mentioned stress direction to laser gain pipe;
Measure portion, referring to the exocoel catoptron is object under test; When the exocoel catoptron when laser instrument output direction of light is moved, the polarized light that incides two above it bundle quadrature will be reflected back toward laser resonant cavity to be mixed with the polarized lights of two bundle quadratures in the chamber respectively, causes that two restraint the polarized light light-intensity variation separately of quadratures.Because the polarized light of two bundle quadratures has certain mode competition with being present in same resonator cavity between the two.Mode competition makes has certain phase difference between the powertrace of polarized light of two bundle quadratures.Experimental result shows, is the Zeeman-birefraction two-frequency laser of 6.7MHz for used frequency difference in our experiment, and phase differential is about 90 degree between the feedback curve of the polarized light of its output two bundle quadratures.
Very the light intensity of the polarized light of single longitudinal mode Zeeman-birefraction two-frequency laser two bundle quadratures is expressed as under the low light level feedback level:
I
∥＝I
∥0[1+mcos()]
I
＝I
0[1+mcos(+Δ]
I
∥And I
Represent directional light and the vertical light light intensity when the light feedback exists respectively, and I
∥ 0And I
0Then represent directional light and the vertical light light intensity when unglazed feedback respectively.M is the index of modulation of light feedback.=4 π l/ λ are light beam at the exocoel caused back and forth phase differential of advancing, and wherein l is an external cavity length.The phase differential of Δ for causing because of the mode competition between two light got pi/2 for the application's the Δ of system.By above two formulas as can be known, the exocoel catoptron is the displacement of mobile half wavelength whenever, above-mentioned two light light intensity separately change a cosine striped, and two have a phase differential between striped, exocoel vertical light feedback curve when elongation is ahead of directional light, and vertical light feedback curve lags behind directional light when exocoel shortens.Two smooth feedback curves occur because of exocoel catoptron moving direction is different the two relation leading or that fall behind can realize declaring to.
Signal processing comprises:
The Wollaston prism, it is positioned at the opposite side of tail light outgoing mirror, is used for the polarized light of two bundle quadratures is separated;
Photodetector, totally two, be positioned at Wollaston prism opposite side, be used for detecting the two polarized light intensity variations of restrainting quadratures that the Wollaston prism is separated;
Differentiator, totally two, be used for the electric signal of two photodetectors is carried out differential, remove the DC component in the signal, can obtain the cosine signal that the two-way phase differential is 90 degree this moment, setting this two paths of signals is sin () and cos ();
Phase inverter, totally two, be used for being undertaken by the signal of two differentiators institute differential anti-phase, this moment obtain other two-way phase differential be 90 the degree cosine signal-sin () and-cos ();
Quadruplicated frequency circuit, be used to realize electronic fine-grained and to external world the movement of objects direction discern.The input signal of quadruplicated frequency circuit be the two paths of signals sin () of gained behind the differentiator differential and cos () and the anti-phase back of phase inverter gained two paths of signals-sin () and-cos ().This four road signal phase difference is followed successively by 90 degree, after quadruplicated frequency circuit is handled, can realize systemic resolution improve four times realize simultaneously declaring to;
Digital indicator is used for the pulse signal of the output of quadruplicated frequency circuit is carried out plus-minus counting, and displacement measurement is shown.
It is simple to the invention provides a kind of compact conformation, the cost performance height, and be easy to realize the high-resolution displacement measuring device of the differentiation of sense of displacement, see
Fig. 2.
Description of drawings
Fig. 1 is one of self-mixed interference displacement sensor embodiment of the present invention.
Fig. 2 is two of a self-mixed interference displacement sensor embodiment of the present invention.
Fig. 3 is the polarized light light intensity curve figure of two bundle quadratures in the light regeneration processes.
Fig. 4 (a) is the polarized light light intensity curve figure of two bundle quadratures; (b) be displacement curve figure after electronic fine-grained.
Embodiment
Experimental provision of the present invention (example 1) as
Shown in Figure 1,1 is the tail light outgoing mirror of HeNe laser instrument, and it is the gain tube of laser instrument that its reflectivity is generally 99.8%, 2, and inside is filled with the mixed gas of HeNe, and 3 is the anti-reflection window of laser instrument, and 4 is the main beam outgoing mirror of laser instrument, and reflectivity is generally 98%.1,2,3 and 4 have formed the main body of a HeNe laser instrument jointly, and the chamber is long to be 155mm.Light source used in the present invention is a two-frequency laser, applies a stress by 5 pairs of existing laser instrument windows 3 of mechanical type stress bringing device and produces birefringence effect.This mechanical type stress bringing device is a reinforcing ring that studs with a screw, and the degree of tightness of set screw can be regulated the size of stress.Transverse magnetic field generator 6 is placed in the laser gain pipe both sides, and it is made of jointly two blocks of permanent magnets.The transverse magnetic field direction that the transverse magnetic field generator produces is parallel or perpendicular to the direction of above-mentioned stress, the adding in magnetic field can reduce the mode competition of two frequencies in the two-frequency laser greatly to realize the output of little frequency difference.Six parts of 1-6 have been formed a birefringence-double-frequency zeeman laser device, and this laser instrument will be exported two linear orthogonal polarized lights.The frequency difference of the two-frequency laser two linear orthogonal polarized lights that this experimental provision is used is 6.7MHz.7 is the exocoel catoptron, and in actual applications, this catoptron is an object under test.Piezoelectric ceramics 8 drives catoptron 7 moving along radiation direction.7 and 8 two elements have been formed the exocoel of self-mixed interference system, and the chamber is long to be 310mm.The tail light of laser instrument through Wollaston prism 9 be divided into two the bundle quadratures polarized light, two the bundle quadratures polarized lights survey by detector 10 and 11 respectively, gained two photosignals are handled by computing machine 12.Computing machine 12 realizes collecting the function that signals collecting, signal inversion, signal differentiation, quadruplicated frequency circuit processing and measurement result show by the mode of software programming.Total system can be divided into three parts: 19 are the Lights section, and 20 for measure portion is the exocoel of self-mixed interference system, and 21 is signal processing.
The principle of the invention is as follows.Very the light intensity of the polarized light of single longitudinal mode Zeeman-birefraction two-frequency laser two bundle quadratures is expressed as under the low light level feedback level:
I
∥＝I
∥0[1+mcos()] (1)
I
＝I
0[1+mcos(+Δ)] (2)
I
∥And I
Represent directional light and the vertical light light intensity when the light feedback exists respectively, and I
∥ 0And I
0Then represent directional light and the vertical light light intensity when unglazed feedback respectively.M is the index of modulation of light feedback.=4 π l/ λ are light beam at the exocoel caused back and forth phase differential of advancing, and wherein l is an external cavity length.The phase differential of Δ for causing because of the mode competition between two light, experimental result shows, the single longitudinal mode Zeeman-birefraction two-frequency laser that for frequency difference is 6.7MHz is under the condition that the light feedback exists, and phase differential is about 90 degree between the light intensity curve of the polarized light of two bundle quadratures.Therefore the Δ of system for the application gets pi/2.
Therefore after laserresonator is returned in the polarized light feedback simultaneously of two of single longitudinal mode Zeeman-birefraction two-frequency laser output being restrainted quadratures, can directly obtain two light intensity curves of certain phase differential, for example shown in Figure 3.Last figure is the polarized light light intensity curve of two bundle quadratures among Fig. 3, and the curve of punctuating is that directional light feedback curve real point curve map then is vertical light feedback curve.Figure below is the triangular wave drive signal of piezoelectric ceramics among Fig. 3.
By above two formulas as can be known, the exocoel catoptron is the displacement of mobile half wavelength whenever, two light light intensity separately change a cosine striped, and two have a phase differential between striped, exocoel vertical light feedback curve when elongation is ahead of directional light, and vertical light feedback curve lags behind directional light when exocoel shortens.Two smooth feedback curves occur because of exocoel catoptron moving direction is different the two relation leading or that fall behind can realize declaring to.
Two light intensity signals are collected in the computing machine 12 by the capture card on the computing machine 12 among Fig. 3, remove DC component in the signal to obtain signal sin () and the cos () that the two-way phase differential is 90 degree by the two paths of signals that collects being carried out differential, then to the signal inversion behind the differential with obtain other two-way phase differential be the 90 signal-sin () that spend and-cos ().More than 4 road signal phase differences differ 90 degree successively, handle with the software program of quadruplicated frequency circuit and can realize electronic fine-grainedly, realize that systemic resolution raising four times of whiles can realize the identification of the moving direction of external cavity reflection mirror.
Experimental result after handling with the software program of quadruplicated frequency circuit as shown in Figure 4, Fig. 4 (a) and Fig. 4 (b) two figure obtain simultaneously.Fig. 4 (a) is the polarized light light intensity curve of two bundle quadratures, and the last figure of Fig. 4 (a) is the directional light light intensity curve, and Fig. 4 (a) figure below is the vertical light light intensity curve.The triangular wave of the last figure of Fig. 4 (b) is the driving voltage of piezoelectric ceramics, and Fig. 4 (b) figure below is the displacement curve that electronic fine-grained back is obtained.By Fig. 4 (a) as seen, along with the rising of piezoelectric ceramics voltage, striped from sparse to dense, this mainly is to be caused by the non-linear of piezoelectric ceramics 8.By formula 1 and formula 2 as can be known among Fig. 4 (a) each striped, in the whole uphill process of piezoelectric ceramics voltage 8, always have 15 stripeds and produce for the displacement of exocoel catoptron 7 half wavelength, the elongation of pairing piezoelectric ceramics 8 is λ/2 * 15=4746nm.But the resolution of fringe count method is lower, has only λ/2, so 4746nm is accurate inadequately.And after electronic fine-grained, in the whole uphill process of piezoelectric ceramics voltage, always have 62 count pulses, the corresponding λ of each pulse/8, so this moment, the elongation of pairing piezoelectric ceramics 8 was λ/8 * 62=4904nm, than fringe count method measurement result 4746nm, 4904nm is more accurate.From the displacement curve of Fig. 4 (b) gained as seen, displacement curve begins to change slowly in the whole uphill process of piezoelectric ceramics voltage, even variation then, and this is consistent from sparse to dense with the middle striped of Fig. 4 (a), all is by due to piezoelectric ceramics 8 non-linear.Two curves can not overlap in rising of Fig. 4 (b) displacement curve and the decline process, and this is because the hesitation of piezoelectric ceramics 8 causes.Displacement curve has two minimum value among Fig. 4 (b) simultaneously, and the two all is 0, illustrates that the application's displacement transducer has the characteristic that well makes zero.Under the long condition of different exocoels, for example exocoel is long is 285mm, 335mm, 360mm, 385mm, 410mm ... still can obtain the curve among Fig. 4 under the condition of 535mm, illustrate that the application's displacement transducer can measure bigger displacement range.Consider that single longitudinal mode HeNe laser instrument has good interference pattern, this displacement transducer institute energy measurement maximum displacement scope is half of single longitudinal mode HeNe laser instrument coherent length on the principle.
The structural representation of example 2 of the present invention as
Shown in Figure 2.11 elements of 1-11 with
11 elements of 1-11 are identical among Fig. 1, so locate no longer to repeat to introduce.13 and 14 is two differentiators, is used for two photodetectors 10 and 11 received signals are carried out differential, removes the DC component in the signal, can obtain cosine signal sin () and cos () that the two-way phase differential is 90 degree this moment.15 and 16 is phase inverter, be used for being undertaken by the signal of two differentiators institute differential anti-phase, this moment obtain other two-way phase differential be 90 the degree cosine signal-sin () and-cos ().17 is quadruplicated frequency circuit, be used to realize electronic fine-grained and to external world the movement of objects direction discern.The input signal of quadruplicated frequency circuit 17 be the two paths of signals sin () of gained behind differentiator 13 and 14 differential and cos () and phase inverter 15 and 16 anti-phase back gained two paths of signals-sin () and-cos ().This four road signal phase difference is followed successively by 90 degree, after quadruplicated frequency circuit 17 is handled, can realize systemic resolution improve four times of whiles can declare to.18 is digital indicator, is used for the pulse signal of the output of quadruplicated frequency circuit 17 is carried out plus-minus counting to show displacement measurement.Compare with the example 1 among Fig. 1, example 2 uses hardware to realize in signal processing, can improve conversion speed, reduces cost.
The designed self-mixed interference displacement sensor of the present invention is by light source, and 3 parts of measure portion and signal Processing are formed.What its system source was used is two-frequency laser, in measuring process, the polarized lights of two bundle quadratures of two-frequency laser output are surveyed can obtain the cosine signals that the two-way phase differential is 90 degree, this two paths of signals carries out the anti-phase cosine signals that other two-way phase differential is 90 degree that obtain.Four road cosine signals that phase differential is followed successively by 90 degree have been realized electronic fine-grained as the input signal of quadruplicated frequency circuit, reach resolution and improve four times, and can realize the identification to movement of objects direction to be measured.The designed self-mixed interference displacement sensor of the present invention is that a kind of compact conformation is simply compact, resolution and cost performance height, and be easy to realize the displacement measuring device of movement of objects direction identification.
Claims (1)
1, the self-mixed interference displacement sensor based on two-frequency laser comprises light source, measures and three parts of signal Processing, it is characterized in that it contains:
The Lights section, it is a single longitudinal mode Zeeman-birefraction two-frequency laser, this two-frequency laser comprises:
Laser gain pipe, inside are filled with the HeNe mixed gas;
Tail light outgoing mirror, reflectivity is 99.8%, is positioned at the axial side of laser gain pipe;
Anti-reflection window is positioned at the axial opposite side of laser gain pipe;
Mechanical type stress bringing device, it applies a stress along the direction perpendicular to laser gain tube axis to anti-reflection window;
The main beam outgoing mirror, reflectivity is 98%, is positioned at anti-reflection window opposite side, output pairwise orthogonal polarized light, directional light and vertical light;
The transverse magnetic field generator, it applies parallel or perpendicular to the transverse magnetic field of above-mentioned stress direction to laser gain pipe;
Measure portion, referring to the exocoel catoptron is object under test; When the exocoel catoptron when laser instrument output direction of light is moved, the polarized light that incides two above it bundle quadrature will be reflected back toward laser resonant cavity to be mixed with the polarized lights of two bundle quadratures in the chamber respectively, cause the polarized light light-intensity variation separately of two bundle quadratures, and between the powertrace of the polarized light of two bundle quadratures certain phase difference is arranged;
Very the light intensity of the polarized light of single longitudinal mode Zeeman-birefraction two-frequency laser two bundle quadratures is expressed as under the low light level feedback level:
I
∥＝I
∥0[1+mcos()]
I
⊥＝I
⊥0[1+mcos(+Δ)]
I
∥And I
⊥Represent directional light and the vertical light light intensity when the light feedback exists respectively, and I
∥ 0And I
⊥ 0Then represent directional light and the vertical light light intensity when unglazed feedback respectively; M is the index of modulation of light feedback; =4 π l/ λ are light beam at the exocoel caused back and forth phase differential of advancing, and wherein l is an external cavity length; The phase differential of Δ for causing because of the mode competition between two-beam, Δ gets pi/2;
Signal processing comprises:
The Wollaston prism, it is positioned at the opposite side of tail light outgoing mirror, is used for the polarized light of two bundle quadratures is separated;
Photodetector, totally two, be positioned at Wollaston prism opposite side, be used for detecting the two polarized light intensity variations of restrainting quadratures that the Wollaston prism is separated;
Differentiator, totally two, be used for the electric signal of two photodetectors is carried out differential, obtain the cosine signal that the two-way phase differential is 90 degree, setting this two paths of signals is sin () and cos ();
Phase inverter, totally two, will be undertaken by the signal of two differentiators institute differential anti-phase, obtain other two-way phase differential and be 90 degree cosine signal-sin () and-cos ();
Quadruplicated frequency circuit, realize electronic fine-grained and to external world the movement of objects direction discern; The input signal of quadruplicated frequency circuit be the two paths of signals sin () of gained behind the differentiator differential and cos () and the anti-phase back of phase inverter gained two paths of signals-sin () and-cos (); This four road signal phase difference is followed successively by 90 degree, and the input quadruplicated frequency circuit carries out electronic fine-grained;
Digital indicator is used for the pulse signal of the output of quadruplicated frequency circuit is carried out plus-minus counting, and displacement measurement is shown.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510011230 CN1259541C (en) | 2005-01-21 | 2005-01-21 | Self-mixed interference displacement sensor based on two-way laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510011230 CN1259541C (en) | 2005-01-21 | 2005-01-21 | Self-mixed interference displacement sensor based on two-way laser |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1645036A CN1645036A (en) | 2005-07-27 |
| CN1259541C true CN1259541C (en) | 2006-06-14 |
Family
ID=34875497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200510011230 Expired - Fee Related CN1259541C (en) | 2005-01-21 | 2005-01-21 | Self-mixed interference displacement sensor based on two-way laser |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1259541C (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1940692B (en) * | 2005-09-26 | 2010-05-05 | 鸿富锦精密工业（深圳）有限公司 | Photoelectric frequency-multiplication generator |
| CN100386596C (en) * | 2006-06-07 | 2008-05-07 | 清华大学 | Laser feed-back displacement sensor based on frequency locked double-frequency laser |
| CN100412502C (en) * | 2006-07-20 | 2008-08-20 | 清华大学 | Extender high-light folding feedback displacement measuring system |
| CN100541113C (en) * | 2007-05-23 | 2009-09-16 | 中国科学院光电技术研究所 | Sub nano grade double frequency laser interferometer signal subdivision system |
| CN101949685B (en) * | 2010-09-08 | 2011-11-16 | 南京师范大学 | Fiber laser self-mixing interferometer and measurement method thereof |
| CN102155916B (en) * | 2011-03-02 | 2012-10-10 | 清华大学 | System for measuring phase orthogonal double-frequency laser feedback displacement |
| CN102564321B (en) * | 2011-12-22 | 2014-02-19 | 清华大学 | Laser feedback displacement measuring method and system based on external cavity modulation and frequency stabilization |
| CN102829729B (en) * | 2012-09-04 | 2015-01-14 | 清华大学 | Method for aliasing polarizations of high-gain laser displacement sensor |
| CN104655159B (en) * | 2015-02-10 | 2017-05-24 | 深圳大学 | Sensor of orthogonal polarization laser device |
| CN104634370B (en) * | 2015-02-10 | 2017-01-25 | 深圳大学 | Laser-based sensor |
| KR102354989B1 (en) * | 2015-04-14 | 2022-01-24 | 삼성전자주식회사 | Method and apparatus for performing tile binning for path rendering |
| CN106643477B (en) * | 2017-01-16 | 2018-11-06 | 南京师范大学 | Palarization multiplexing phase modulation-type laser mixes two-dimentional interferometer and its measurement method certainly |
| CN109813227B (en) * | 2017-11-20 | 2021-01-05 | 中国人民解放军第四军医大学 | Laser cavity tuning-based multiple feedback displacement measuring device and measuring method |
| CN108775954B (en) * | 2018-06-06 | 2020-10-16 | 岭南师范学院 | Resolution-adjustable dual-wavelength LD self-mixing vibration measuring instrument and measuring method thereof |
| CN110030921B (en) * | 2019-05-14 | 2021-02-02 | 北方工业大学 | Shearing-quantity-adjustable transmission-type dual-frequency laser differential interference measuring device and method |
| CN110672011A (en) * | 2019-10-30 | 2020-01-10 | 苏州赛腾精密电子股份有限公司 | Calibration device and automatic system based on laser self-mixing interference |
-
2005
- 2005-01-21 CN CN 200510011230 patent/CN1259541C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1645036A (en) | 2005-07-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1259541C (en) | Self-mixed interference displacement sensor based on two-way laser | |
| CN100538397C (en) | Double-refraction external cavity displacement measuring system | |
| CN1333230C (en) | Laser feedback nano displaycement measuring device | |
| CN103528511A (en) | Sinusoidal phase modulation type laser self-mixing interferometer and measuring method thereof | |
| CN101261322B (en) | Double frequency He-Ne laser optical feedback distance measuring apparatus | |
| CN1595170A (en) | Self-mixed intervention Doppler velometer based on two-frequency laser | |
| CN103075969A (en) | Differential laser interference nano-displacement measurement method and differential laser interference nano-displacement measurement system | |
| CN1811365A (en) | System for detecting polarization maintaining optical fiber beat length | |
| CN102253389B (en) | He-Ne laser birefringent outer cavity feedback displacement measurement system | |
| CN1710398A (en) | Laser feed-back wave plate measuring apparatus | |
| CN1844868A (en) | Method and apparatus for measuring laser wavelength by heterodyne interference method | |
| CN100520281C (en) | Adjustable frequency difference two-frequency laser back-feed nano measuring ruler for frequency stabilizing | |
| CN1888816A (en) | Extender high-light folding feedback displacement measuring system | |
| CN1379225A (en) | Frequency-dividing self-mixing feedback-type non-contact He-Ne laser micrometer | |
| CN1304814C (en) | Self-mixed interference HeNe laser displacement transducer with direction recognition function | |
| CN101033970A (en) | Transit time testing method of fiber optic gyroscope | |
| CN1664613A (en) | Optical feedback range finder for two-frequency laser based on Zeeman-birefraction | |
| CN1851392A (en) | Laser feed-back displacement sensor based on frequency locked double-frequency laser | |
| CN1095542C (en) | Dual-vacuum chamber and dual-frequency phase measurement air refractivity interferometer | |
| CN100340869C (en) | Electro-optic double modulation polarized light laser distance measuring method and its device | |
| CN1279327C (en) | Nano laser measuring rule and subdivision method for nano measurement realization | |
| CN1892193A (en) | Method and apparatus for measuring laser wave-length using heterodyne in interference method | |
| CN110972556B (en) | Frequency response frequency band calibrating device for displacement sensor | |
| CN211697497U (en) | Time-domain optical coherence tomography system | |
| CN1308700C (en) | Electro light modulation laser distance measuring method and its device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20060614 Termination date: 20160121 |
|
| EXPY | Termination of patent right or utility model |