CN103499385B - A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously - Google Patents
A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously Download PDFInfo
- Publication number
- CN103499385B CN103499385B CN201310452081.4A CN201310452081A CN103499385B CN 103499385 B CN103499385 B CN 103499385B CN 201310452081 A CN201310452081 A CN 201310452081A CN 103499385 B CN103499385 B CN 103499385B
- Authority
- CN
- China
- Prior art keywords
- semi
- frequency
- reflecting lens
- light
- transparent semi
- 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
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
The present invention relates to laser interferometry field, be specifically related to a kind of high precision double frequency and measure laser heterodyne interference phase place vibration measuring light path simultaneously, comprising: double-frequency laser source, first, second and third semi-transparent semi-reflecting lens, sample, half-wave plate, completely reflecting mirror, polarization spectroscope, first and second detector, phase tester.Lasing light emitter sends the linearly polarized light that mutually orthogonal frequency component is f1 and f2, light beam is divided into two bundles after the first semi-transparent semi-reflecting lens, through the second semi-transparent semi-reflecting lens after transmitted light is first, sample, fast shaft angle degree is the half-wave plate of 45 °, completely reflecting mirror, close light with reflected light at the 3rd semi-transparent semi-reflecting lens place and after being incident to polarization spectroscope, be divided into the two-beam respectively containing parallel and vertical component, formation first measuring-signal is received by the first detector containing after horizontal component Transmission light, formation second measuring-signal is received by the second detector containing after the reflection of vertical component light, sample vibration causes the two frequency difference to be 2 △ f, and recorded corresponding phase differential by phase tester.
Description
Technical field
The present invention relates to laser interferometry field, particularly relate to the heterodyne laser vibration measuring light path utilizing Doppler's principle to carry out measurement target movable information.Be specifically related to a kind of high precision double frequency and measure laser heterodyne interference phase place vibration measuring light path simultaneously.
Background technology
Vibration survey can reflect the dynamic perfromance of object especially high-speed moving object because of it, very important in engineering field.Since nineteen sixty, laser doppler technique, owing to having high spatial and temporal resolution in the measurements, not to contact, the advantage such as disturbance testee and getting most of the attention.Since within 1964, to have delivered the 1st section about the paper of laser Dppler veloicty measurement after, this technology is subject to each side immediately and payes attention to and carried out a large amount of theories and experimental study, achieve remarkable achievement, nowadays, laser Doppler vibration and the vibration measuring technology that developed by it have become indispensable detection method in science and technology and many industries.
At present, laser Dppler veloicty measurement many employings heterodyne laser interference light path, the frequency sent by lasing light emitter with spectroscope is that the light beam of f is divided into reference light and measures light two parts, and measure light and incide tested vibrating object surface, its reflected light produces Doppler shift Δ f.In order to determine the direction of vibration of testee, in reference path, using acousto-optic modulator to carry out shift frequency to reference light, producing the frequency offset of fd.Adopt optical element with reference to light with measure photosynthetic and thus produce and interfere, interference light is undertaken receiving by photodetector and contains the modulation signal of frequency component fd+ Δ f to signal processor output packet, sends into computing unit and demodulate Δ f after then being carried out mixing, filtering process.
Be acousto-optic modulator due to what adopt when carrying out shift frequency to reference light in said method, therefore frequency shift amount fd is general larger, is usually greater than tens of MHz magnitude.Therefore, when causing Δ f less because speed is lower, can there is the not high problem of measuring accuracy in existing heterodyne laser vialog.In addition, due to all will crystal oscillation signal be used when carrying out shift frequency to reference light in acousto-optic modulator and carry out mixing to modulation signal in signal processing, and crystal oscillator can be subject to the such environmental effects such as temperature, magnetic field, its corresponding oscillation frequency can produce error f ' and f "; thus bring error to measurement result Δ f; as Δ f and f '-f " close to time, this influence factor becomes large, thus measuring result error is increased.
Therefore, desirable to provide a kind of precision that can further improve heterodyne laser vialog, and make it also can have the laser heterodyne interference vialog of very high measurement accuracy in low-frequency vibration object fields of measurement.For this reason, the present invention proposes a kind of high precision double frequency and measure laser heterodyne interference phase place vibration measuring light path simultaneously, and adopt Method for Phase Difference Measurement demodulation Δ f signal, can solve the problem.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, provide a kind of high precision double frequency and measure laser heterodyne interference phase place vibration measuring light path simultaneously, adopt difference interference light path, good stability, and two frequency components all take part in measurement, frequency difference has changed 2 Δ f, be equivalent to measuring accuracy and improve 1 times, and adopt Method for Phase Difference Measurement demodulation frequency difference variable signal, solve the heterodyne laser vialog problem that precision is not high when low-frequency vibration object is measured conventional at present, and phase measurement can improve vibration measurement with laser precision further.
Technical solution of the present invention is:
A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously, comprising: double-frequency laser source (101), the first semi-transparent semi-reflecting lens (102), the second semi-transparent semi-reflecting lens (103), testing sample (104), half-wave plate (105), completely reflecting mirror (106), the 3rd semi-transparent semi-reflecting lens (107), polarization spectroscope (108), the first detector (109), the second detector (110), phase tester (111);
It is characterized in that: the light that double-frequency laser source (101) send has a pair mutually orthogonal linear polarization, and the frequency-splitting of two linear polarization f1 and f2 is between 100kHz-100MHz.The light that double-frequency laser source (101) send is divided into the two-beam all containing f1 and f2 frequency component by the first semi-transparent semi-reflecting lens (102), wherein reflected light is incident to the 3rd semi-transparent semi-reflecting lens (107), and transmitted light enters follow-up optical path.The fractional transmission of the second semi-transparent semi-reflecting lens (103) from the first semi-transparent semi-reflecting lens (102) light beam containing f1 and f2 frequency component, and partly reflects the light beam returned from testing sample (104) surface reflection.Due to Doppler effect, its frequency component of light beam of returning from testing sample (104) surface reflection becomes f1+ Δ f and f2+ Δ f.Half-wave plate (105) is positioned between the second semi-transparent semi-reflecting lens (103) and completely reflecting mirror (106), its fast shaft position and vertical direction are 45 °, therefore the light beam reflected from the second semi-transparent semi-reflecting lens (103) is after half-wave plate (105), all there are 90 ° of rotations in former polarized component, polarization state becomes that parallel component is f2+ Δ f and vertical component is f1+ Δ f.3rd semi-transparent semi-reflecting lens (107) will reflect from completely reflecting mirror (106) and the light beam being transmitted through it merges with the light beam reflected from the first semi-transparent semi-reflecting lens (102) and it and forms light beam.Now the parallel polarization states of light beam contains f1 and f2+ Δ f two frequency components and perpendicular polarisation state contains f1+ Δ f and f2 two frequency components.This light beam is divided into two parts by polarization spectroscope (108), received by the first detector (109) the first measuring-signal that forming frequency is f1-f2-Δ f after two frequency component transmissions of horizontal state of polarization, after two frequency component reflections of perpendicular polarisation state, received by the second detector (110) the second measuring-signal that forming frequency is f1-f2+ Δ f.Phase tester (111) receives the first and second measuring-signals, both measurements due to frequency difference change that 2 Δ f cause phase differential changes delta φ.
Principle of work of the present invention is:
Refer to accompanying drawing, double-frequency laser source (101) sends the mutually orthogonal linearly polarized light of a pair polarization, its frequency component that is parallel and vertical paper is respectively f1 and f2, light beam is divided into two parts after the first semi-transparent semi-reflecting lens (102), two parts light is all containing f1 and f2 frequency component, wherein reflected light is incident to the 3rd semi-transparent semi-reflecting lens (107), transmitted light is by being incident to testing sample (104) surface of vibration after the second semi-transparent semi-reflecting lens (103), due to Doppler effect, its frequency component of light beam of returning from testing sample (104) surface reflection becomes and becomes f1+ Δ f and f2+ Δ f respectively, it is passed through a half-wave plate (105) by after the second semi-transparent semi-reflecting lens (103) reflection, the fast shaft position of half-wave plate (105) is set to be 45 ° with vertical direction, therefore light beam is after half-wave plate (105), all there are 90 ° of rotations in former polarized component, polarization state becomes that parallel component is f2+ Δ f and vertical component is f1+ Δ f, light beam continues to incide completely reflecting mirror (106), reflected by it and be transmitted through the 3rd semi-transparent semi-reflecting lens (107), with reflected by the 3rd semi-transparent semi-reflecting lens (107) from the first semi-transparent semi-reflecting lens (102) containing f1, the light beam of f2 frequency component merges formation light beam, now parallel polarization states contains f1 and f2+ Δ f two frequency components and perpendicular polarisation state contains f1+ Δ f and f2 two frequency components, this light beam is divided into two parts after being incident to polarization spectroscope (108), received by the first detector (109) the first measuring-signal that forming frequency is f1-f2-Δ f after two frequency component transmissions of horizontal state of polarization, received by the second detector (110) the second measuring-signal that forming frequency is f1-f2+ Δ f after two frequency component reflections of perpendicular polarisation state, two-way measuring-signal is sent into phase tester (111) and is obtained the two due to frequency difference and change the phase differential changes delta φ that 2 Δ f cause, thus record the vibration velocity of testing sample (104), frequency parameter.
The advantage of the present invention compared with former technology is, two-frequency laser is adopted directly to export the component that two have certain frequency difference, avoid and adopt acousto-optic modulator to obtain the frequency shift amount of reference signal, the frequency shift amount produced with acousto-optic modulator more greatly compared with, frequency difference value of the present invention can be less, therefore also can have very high precision to the measurement of low-frequency vibration object.And two frequency components all take part in measurement in light path, frequency difference has changed 2 Δ f, is equivalent to measuring accuracy and improves 1 times.The mixing that before the phase measurement adopted avoids, technology adopts, means of filtering, signal processing is simpler, and phase measurement accuracy is higher.
Accompanying drawing explanation
Accompanying drawing is the schematic diagram that a kind of high precision double frequency of the present invention measures laser heterodyne interference phase place vibration measuring light path simultaneously.
Embodiment
Refer to accompanying drawing, double-frequency laser source (101) adopts frequency difference to be the dual-frequency transverse Zeeman laser of 3MHz, the wavelength sending a pair polarization mutually orthogonal is the linearly polarized light of 633nm, and its frequency component that is parallel and vertical paper is respectively f1 and f2, and frequency difference is 5MHz.First semi-transparent semi-reflecting lens (102) is for being coated with the k9 optical glass of semi-permeable diaphragm, and light beam is divided into two parts after (102), and two parts light is all containing f1 and f2 frequency component.Wherein reflected light is incident to the 3rd semi-transparent semi-reflecting lens (107), (107) be the product identical with (102), transmitted light is by being incident to testing sample (104) surface of vibration after the second semi-transparent semi-reflecting lens (103), (103) be also the product identical with (102), (104) adopt by the stalloy of Piezoelectric Ceramic, vibration frequency is set to 500KHz.Due to Doppler effect, its frequency component of light beam of returning from (104) surface reflection becomes and becomes f1+0.5MHz and f2+0.5MHz respectively, it is passed through the commercial half-wave plate (105) of a high precision after (103) reflection, (105) fast shaft position is set to be 45 ° with vertical direction, therefore light beam is after half-wave plate (105), all there are 90 ° of rotations in former polarized component, polarization state becomes that parallel component is f2+0.5MHz and vertical component is f1+0.5MHz.Light beam continues to incide commercial high reflection mirror (106), reflected by it and be transmitted through (107), form light beam with merging from (102) light beam containing f1, f2 frequency component of being reflected by (107), now parallel polarization states contains f1 and f2+0.5MHz two frequency components and perpendicular polarisation state contains f1+0.5MHz and f2 two frequency components.Polarization spectroscope (108) adopts ZF glass and is coated with polarization spectro deielectric-coating, this light beam is divided into two parts after being incident to (108), received by the first detector (109) the first measuring-signal that forming frequency is 3-0.5MHz after two frequency component transmissions of horizontal state of polarization, received by the second detector (110) the second measuring-signal that forming frequency is 3+0.5MHz after two frequency component reflections of perpendicular polarisation state, (109) and (110) are general commercial photodetector.Two-way measuring-signal sends into the phase tester (111) that a resolution is 0.01 degree, (111) record due to frequency difference change 1MHz cause phase differential changes delta φ, thus record the vibration frequency parameter of (104).
Claims (8)
1. high precision double frequency measures a laser heterodyne interference phase place vibration measuring light path simultaneously, comprising: double-frequency laser source (101), the first semi-transparent semi-reflecting lens (102), the second semi-transparent semi-reflecting lens (103), testing sample (104), half-wave plate (105), completely reflecting mirror (106), the 3rd semi-transparent semi-reflecting lens (107), polarization spectroscope (108), the first detector (109), the second detector (110), phase tester (111); It is characterized in that:
Double-frequency laser source (101) sends the mutually orthogonal linearly polarized light of a pair polarization, its frequency component that is parallel and vertical paper is respectively f1 and f2, light beam is divided into two parts after the first semi-transparent semi-reflecting lens (102), two parts light is all containing f1 and f2 frequency component, wherein reflected light is incident to the 3rd semi-transparent semi-reflecting lens (107), and transmitted light is by being incident to testing sample (104) surface of vibration after the second semi-transparent semi-reflecting lens (103); Due to Doppler effect, its frequency component of light beam of returning from testing sample (104) surface reflection becomes f1+ △ f and f2+ △ f respectively, reflected light is passed through a half-wave plate (105) by after the second semi-transparent semi-reflecting lens (103) reflection, the fast shaft position of half-wave plate (105) is set to be 45 ° with vertical direction, therefore light beam is after half-wave plate (105), all there are 90 ° of rotations in former polarized component, polarization state becomes that parallel component is f2+ △ f and vertical component is f1+ △ f; Light beam continues to incide completely reflecting mirror (106), reflected by it and be transmitted through the 3rd semi-transparent semi-reflecting lens (107), form light beam with merging from the light beam of the first semi-transparent semi-reflecting lens (102) containing f1, f2 frequency component of being reflected by the 3rd semi-transparent semi-reflecting lens (107), now parallel polarization states contains f1 and f2+ △ f two frequency components and perpendicular polarisation state contains f1+ △ f and f2 two frequency components; This light beam is divided into two parts after being incident to polarization spectroscope (108), received by the first detector (109) the first measuring-signal that forming frequency is f1-f2-△ f after two frequency component transmissions of horizontal state of polarization, received by the second detector (110) the second measuring-signal that forming frequency is f1-f2+ △ f after two frequency components reflection of perpendicular polarisation state, two-way measuring-signal is sent into phase tester (111) and is obtained the two due to frequency difference and change the phase differential change that 2 △ f cause
, thus record vibration velocity, the frequency parameter of testing sample (104).
2. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: the light that described double-frequency laser source (101) sends has a pair mutually orthogonal linear polarization, and the frequency-splitting of two linear polarization f1 and f2 is between 100kHz-100MHz.
3. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: the light that double-frequency laser source (101) send is divided into the two-beam all containing f1 and f2 frequency component by described first semi-transparent semi-reflecting lens (102), wherein reflected light is incident to the 3rd semi-transparent semi-reflecting lens (107), and transmitted light enters follow-up optical path.
4. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: the effect of described second semi-transparent semi-reflecting lens (103) be fractional transmission from the first semi-transparent semi-reflecting lens (102) light beam containing f1 and f2 frequency component, and the light beam containing f1+ △ f and f2+ △ f frequency component that part reflection is returned from testing sample (104) surface reflection.
5. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: its frequency component of light beam of returning from described testing sample (104) surface reflection becomes f1+ △ f and f2+ △ f due to Doppler effect.
6. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: described half-wave plate (105) is positioned between the second semi-transparent semi-reflecting lens (103) and completely reflecting mirror (106), its fast shaft position and vertical direction are 45 °, therefore the light beam reflected from the second semi-transparent semi-reflecting lens (103) is after half-wave plate (105), all there are 90 ° of rotations in former polarized component, polarization state becomes that parallel component is f2+ △ f and vertical component is f1+ △ f.
7. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: described 3rd semi-transparent semi-reflecting lens (107) will reflect from completely reflecting mirror (106) and be transmitted through the 3rd semi-transparent semi-reflecting lens (107) containing parallel component be f2+ △ f, vertical component is that the light beam of f1+ △ f to merge with the light beam that parallel component was f1, vertical component is f2 containing of reflecting from the first semi-transparent semi-reflecting lens (102) and the 3rd semi-transparent semi-reflecting lens (107) and forms light beam.
8. high precision double frequency as claimed in claim 1 measures laser heterodyne interference phase place vibration measuring light path simultaneously, it is characterized in that: described phase tester (111) receives the first and second measuring-signals, both measurements change the phase differential change that 2 △ f cause due to frequency difference
.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310452081.4A CN103499385B (en) | 2013-09-25 | 2013-09-25 | A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310452081.4A CN103499385B (en) | 2013-09-25 | 2013-09-25 | A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103499385A CN103499385A (en) | 2014-01-08 |
| CN103499385B true CN103499385B (en) | 2016-04-13 |
Family
ID=49864616
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310452081.4A Expired - Fee Related CN103499385B (en) | 2013-09-25 | 2013-09-25 | A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103499385B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606194B (en) * | 2015-12-29 | 2018-09-07 | 哈尔滨工业大学 | A kind of underwater signal real time extracting method based on laser orthogonal polarization interferometry technology |
| CN209910815U (en) * | 2018-12-25 | 2020-01-07 | 茂莱（南京）仪器有限公司 | Laser interference low frequency vibration measurer |
| CN111412936B (en) * | 2020-03-10 | 2021-08-06 | 天津大学 | Full-digital orthogonal phase shift pulse COTDR sensing device and method |
| CN114061737B (en) * | 2021-11-22 | 2022-10-28 | 燕山大学 | Double-detection heterodyne interference voice acquisition system |
| CN114172584B (en) * | 2021-12-13 | 2023-04-21 | 上海交通大学 | High-precision optical millimeter wave/terahertz transmission system and transmission method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5274436A (en) * | 1989-11-24 | 1993-12-28 | Renishaw Plc | Laser interferometer for measuring distance using a frequency difference between two laser beams |
| US5305084A (en) * | 1991-09-02 | 1994-04-19 | Mitsubishi Denki Kabushiki Kaisha | Heterodyne interferometer |
| CN201413130Y (en) * | 2009-06-22 | 2010-02-24 | 浙江理工大学 | Measuring device based on double-frequency interference principle for measuring straightness and position |
| CN102620811A (en) * | 2012-03-29 | 2012-08-01 | 中国计量科学研究院 | Novel high-precision heterodyne laser vibration measuring instrument |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10274513A (en) * | 1997-03-31 | 1998-10-13 | Nippon Telegr & Teleph Corp <Ntt> | Surface configuration measuring method and surface configuration measuring apparatus |
| JP4026760B2 (en) * | 2002-11-22 | 2007-12-26 | 株式会社小野測器 | Heterodyne interferometer |
-
2013
- 2013-09-25 CN CN201310452081.4A patent/CN103499385B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5274436A (en) * | 1989-11-24 | 1993-12-28 | Renishaw Plc | Laser interferometer for measuring distance using a frequency difference between two laser beams |
| US5305084A (en) * | 1991-09-02 | 1994-04-19 | Mitsubishi Denki Kabushiki Kaisha | Heterodyne interferometer |
| CN201413130Y (en) * | 2009-06-22 | 2010-02-24 | 浙江理工大学 | Measuring device based on double-frequency interference principle for measuring straightness and position |
| CN102620811A (en) * | 2012-03-29 | 2012-08-01 | 中国计量科学研究院 | Novel high-precision heterodyne laser vibration measuring instrument |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103499385A (en) | 2014-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103499384A (en) | Novel double-frequency laser heterodyne interference phase vibration measuring light path | |
| CN103499385B (en) | A kind of high precision double frequency measures laser heterodyne interference phase place vibration measuring light path simultaneously | |
| CN107664482B (en) | Grating measuring device | |
| CN110411335A (en) | Differential type sinusoidal phase modulation laser interference surface nanometer-displacement device and method | |
| CN105571529B (en) | A kind of laser heterodyne interference system for angle measurement without error | |
| US9587927B2 (en) | High speed high resolution heterodyne interferometric method and system | |
| CN101581576B (en) | Method for measuring straightness accuracy and position thereof based on double frequency interference principle | |
| CN101581577B (en) | Device for measuring straightness accuracy and position thereof based on double frequency interference principle | |
| CN106289499B (en) | A kind of micrometer vibrational system and micrometer method for oscillating using femtosecond laser | |
| CN110132138B (en) | Double-sweep-frequency light source ranging system and method based on cascade interferometer | |
| CN107806821B (en) | With the difference single-frequency interference signal processing unit and method of integrated four photodetectors | |
| CN103075969B (en) | Differential laser interference nano-displacement measurement method and differential laser interference nano-displacement measurement apparatus | |
| CN110646805B (en) | Frequency modulation continuous wave laser ranging system based on virtual sweep frequency light source | |
| CN109631805B (en) | Wollaston prism movable laser interference straightness and displacement simultaneous measurement device | |
| CN103439010A (en) | Wavelength measurement method and device based on laser synthesized wavelength interference principle | |
| CN111735391B (en) | Double-phase measurement type laser interference straightness and displacement simultaneous measurement device and method | |
| CN106017333B (en) | Double excitation single-frequency interference nano displacement measuring device and method based on phase-modulation | |
| CN101887126A (en) | Double-frequency laser Doppler velocity measurement method and device | |
| CN103411689B (en) | Based on optical maser wavelength direct measuring method and the device of the orthogonal line polarized light of single-frequency | |
| CN110174054A (en) | A kind of four light path laser interferometer measuration system of high stability | |
| CN101169525A (en) | Device and method for measuring liquid crystal device twist angle and optical delay-time | |
| CN201413130Y (en) | Measuring device based on double-frequency interference principle for measuring straightness and position | |
| CN107764197B (en) | A kind of optical system axial direction parameter measuring apparatus and method | |
| CN109520428A (en) | A kind of displacement measurement optical system | |
| CN102519375A (en) | Ultra-large range space measuring system and method based on light cycle and spectral domain carrier frequency |
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: 20160413 Termination date: 20160925 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |