CN104613902B - Laser interference system for displacement straight line degree measurement - Google Patents
Laser interference system for displacement straight line degree measurement Download PDFInfo
- Publication number
- CN104613902B CN104613902B CN201410746892.XA CN201410746892A CN104613902B CN 104613902 B CN104613902 B CN 104613902B CN 201410746892 A CN201410746892 A CN 201410746892A CN 104613902 B CN104613902 B CN 104613902B
- Authority
- CN
- China
- Prior art keywords
- light beam
- light
- angle
- prism
- wedge
- 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
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
The present invention relates to a kind of laser interference system for displacement straight line degree measurement, optical interference means and phase detection device between the angle of wedge prism moved comprising lasing light emitter, with measured piece, the light reflecting device positioned at the angle of wedge prism side, the opposite side positioned at the angle of wedge prism and the lasing light emitter.Wherein, lasing light emitter produces the incident beam of frequency stabilization, and incident beam is in the presence of optical interference means, pass twice through angle of wedge prism, and it is corresponding twice by the angle of wedge and light reflecting device reflection, phase detection device is finally transfused to, the linearity of measured piece is determined with the variable quantity of phase difference.It is an advantage of the invention that：It is simple in construction, measurement accuracy is high, can be widely applied to the geometric sense accurate measurement in the fields such as military project, space flight and Digit Control Machine Tool and the foundation of mete-wand.
Description
The application is the divisional application for the Chinese patent application 201110310757.7 submitted on October 14th, 2011.
Technical field
The present invention relates to a kind of Technology of Precision Measurement, more particularly to a kind of laser interference system for displacement straight line degree measurement
System.
Background technology
In the high-tech areas such as military project, space flight, Digit Control Machine Tool, accurate benchmark metering and geometric sense accurate measurement have non-
The e measurement technology of often important effect, particularly linearity, increasingly attracts people's attention.
When authorizing Sommargren et al. United States Patent (USP) No.4,787,747 and disclosing a kind of measurement mechanical device and advance
The interference system of linearity, the document is in entirety by reference comprising herein.In the interference system that the United States Patent (USP) discloses
In system, two partially reflecting mirrors (partial retroreflector) are employed to reflect two bunch light beams respectively.By
In the optical axis spacing separated by a distance that need to be set equal to be separated by between two bunch light beams in the horizontal direction of speculum, because
This adds the difficulty of interference system debugging.
The content of the invention
The present invention be directed to the interference system of existing straight line degree measurement to debug the problem of difficult, it is proposed that it is straight that one kind is used for displacement
The laser interference system of dimension measurement, simple in construction and debugging are convenient.
The technical scheme is that：A kind of laser interference system for displacement straight line degree measurement, including lasing light emitter, phase
Level detecting apparatus, optical interference means, angle of wedge prism, light reflecting device, lasing light emitter produce the first light beam and incide optical interference means,
Reference signal is produced to phase detection device simultaneously, and optical interference means are located at angle of wedge prism side, in angle of wedge prism and lasing light emitter
Between, light reflecting device is located at the opposite side of angle of wedge prism, and angle of wedge prism moves with measured piece, and the optical interference means connect
After receiving the first light beam caused by lasing light emitter, parallel the third and fourth light beam for inciding angle of wedge prism, the third and fourth light are produced
Shu Yici returns to the optical interference means, the light by angle of wedge prism and light reflecting device along with incident path identical path
Interference device produces parallel the 5th light for inciding the angle of wedge prism again respectively from the third and fourth light beam of the return
Beam and the 6th light beam, the 5th light beam and the 6th light beam are successively by angle of wedge prism and light reflecting device edge and incident identical path
The optical interference means are returned to, the optical interference means produce second light from the 5th light beam and the 6th light beam of return
Beam enters phase detection device, and the described 3rd to the 6th four articles of light beams incide position one square of composition of the angle of wedge prism
Four summits of shape, wherein the incoming position of the 3rd and the 5th light beam forms two summits of the side of the rectangle, institute
Two summits of the opposite side of the incoming position composition rectangle of the 4th and the 6th light beam are stated, phase detection device receives laser
The reference signal in source and the second light beam from optical interference means input, are calculated according to the variable quantity of the phase difference of two components
Export the linearity of measured piece.
The lasing light emitter produces the first light beam and reference signal, and the first light beam includes two components, described two component tools
There is different frequencies and linear polarization is mutually orthogonal, the frequency of the reference signal corresponds to the frequency of described two components
Difference.
The lasing light emitter produces the first light beam, and the first light beam produces the line of two different frequencies by the optical interference means
Polarized component, the linear polarization of described two components is mutually orthogonal, the reference that the lasing light emitter provides to phase detection device
Signal on the basis of signal.
The optical interference means include polarization splitting prism, quarter-wave plate, corner cube, and polarization splitting prism is from the
The first light beam is simultaneously received, first light beam is decomposed into and is parallel to each other and the 7th orthogonal light beam and the 8th light beam are from the second face
Project, it is the 3rd light beam and the 4th light beam that the 7th light beam and the 8th light beam, which incide outgoing on quarter-wave plate, the 3rd light beam
With the 4th light beam by angle of wedge prism incidence to light reflecting device, successively through angle of wedge prism, four after light emitting devices reflects
/ mono- wave plate incides the polarization splitting prism, and the 9th light beam is projected from the 3rd face after polarization splitting prism processing, should
9th light beam is reflected into the tenth light beam parallel with the 9th light beam and not on sustained height, the tenth light beam through corner cube
The polarization spectroscope is incided through the 3rd face, the tenth light beam is decomposed into by the polarization splitting prism to be parallel to each other and orthogonal
11 light beams and the 12nd light beam project from the second face, and the quarter-wave plate receives the 11st light beam and the 12nd light beam projects
5th light beam and the 6th light beam, the 5th light beam and the 6th light beam are anti-through the light through on angle of wedge prism incidence to light reflecting device
The polarization splitting prism is incided from the second face by angle of wedge prism, quarter-wave plate successively after injection device reflection, it is inclined through this
Projected after the Amici prism that shakes processing with the second light beam of synthesis from the first face.Second face, quarter-wave plate, angle of wedge prism
With the centerline axis parallel of wedge angle reflective mirror or be located along the same line, and the quarter-wave plate is located at the polarization spectro rib
Between mirror and the angle of wedge prism；The centerline axis parallel in the corner cube and the 3rd face is located along the same line；First face
It is symmetrical along the central axis of the polarization splitting prism with the 3rd face.The polarization splitting prism is by two pieces of right-angle prisms along a right angle
While being bonded, one layer of polarization beam splitter is coated with cemented surface, the merging and beam splitting of light are carried out on the polarization beam splitter.
The phase detection device includes：The polarizer, mix two quadrature components and the generation the 13rd of second light beam
Light beam；Photoelectric detector, receive the 13rd light beam and produce electric measurement signal；Phasometer receives electric measurement signal and electricity is joined
Examine signal and calculate the linearity of output measured piece.
The angle of wedge prism is the two-sided angle of wedge or the one side angle of wedge, and the light reflecting device is the wedge supporting with angle of wedge prism
Corner reflector, the angle of wedge of the one side angle of wedge prism is 1 °, and the angle of wedge of the wedge angle reflective mirror is close to one side angle of wedge prism
The half of the angle of wedge.
The beneficial effects of the present invention are：The present invention is used for the laser interference system of displacement straight line degree measurement, needed for system
Optics is few, it is simple in construction, easy to use, be easy to produce and process, cost it is relatively low.Further, since light channel structure is to two
Frequency component is symmetrical, when temperature or machinery change produce various influences to optical element, will all act on two light simultaneously
Frequency component, the change of phase difference between them will not be caused, so as to reduce the possibility for producing error, so system is steady
Fixed, high resolution, fully achieves high-precision measurement index, especially suitable for geometric sense accurate measurement and mete-wand
Establish, positioning or calibration including the metering of the accurate benchmark such as military project, space flight, various Digit Control Machine Tools and three-coordinates measuring machine,
Positioning measurement of grating ruling workbench and various measurement and positioning workbench etc..
Brief description of the drawings
Fig. 1 is the structural representation of laser interference system embodiment 1 that the present invention is used for displacement straight line degree measurement；
Fig. 2 is the light path plane expansion signal for the laser interference system embodiment 1 that the present invention is used for displacement straight line degree measurement
Figure；
Fig. 3 is the four symmetrical light path of space for the laser interference system embodiment 1 that the present invention is used for displacement straight line degree measurement
Profile；
Fig. 4 is the four symmetrical light path of space for the laser interference system embodiment 1 that the present invention is used for displacement straight line degree measurement
Sectional view；
Fig. 5 is the structural representation of laser interference system embodiment 2 that the present invention is used for displacement straight line degree measurement.
Embodiment
Fig. 1 be according to the structural representation of the laser interference system of a preferred embodiment of the present invention, including lasing light emitter 1,
Optical interference means 100, angle of wedge prism 10, light reflecting device 11, phase detection device 110.
Wherein the optical interference means 100 include polarization splitting prism 2, quarter-wave plate 9, corner cube 8.Phase-detection
Device includes polarizer 12, photoelectric detector 13 and phasometer 14.
Lasing light emitter 1 uses double-frequency laser, and the one side of lasing light emitter 1 provides polarization splitting prism 2 incident light of frequency stabilization
Beam 15, the light beam contains the component that two frequencies are different and linear polarization is mutually orthogonal, while also provides one to phasometer 14
The sinusoidal electric reference signal 68 of individual stabilization, the frequency of the reference signal 68 are equal to the difference on the frequency of two components of lasing light emitter 1.
Polarization splitting prism 2 is located at caused by lasing light emitter 1 in the light path of incident beam.Polarization splitting prism 2 for example by
Two pieces of right-angle prisms are bonded, and are coated with one layer of polarization beam splitter in adhesive surface, the appropriate area of prism facets 4 and prism facets 6 is equal
It is coated with anti-reflection film, adhesive surface is equivalent to polarization spectroscope therefore referred to as polarization light-dividing surface 3, prism facets 4 symmetrical with polarization light-dividing surface 3
Reflectance coating is coated with the appropriate area of prism facets 5, it is to make incident from prism facets 4 and separated by polarization light-dividing surface 3 that it, which is acted on,
The mutually orthogonal two light beams in polarization direction are emitted after the reflection of prism facets 4 and prism facets 5 from prism facets 6, in corner cube
8th, under the collective effect of wedge angle reflective mirror 11 and quarter-wave plate 9, light beam passes twice through angle of wedge prism 10, is finally reflected back rib
Minute surface 6 is simultaneously synthesized all the way by polarization light-dividing surface 3, is emitted from prism facets 4.
Quarter-wave plate 9 is located at the side of prism facets 6 and in parallel, and its effect is will to pass twice through quarter-wave
The light beam of piece 9 changes into circularly polarized light beam, or the circularly polarized light for passing twice through quarter-wave plate is changed into line in turn
Polarised light.
Corner cube 8 is arranged on the side of prism facets 5 and its axis is vertical with prism facets 5.Corner cube 8 and prism facets 5
Central axis be parallel to each other, be preferably placed on same straight line.Corner cube 8 reflects back the light beam being emitted from prism facets 5,
And incident beam is parallel to each other and not in a height with the reflected beams.
Angle of wedge prism 10 and light reflecting device 11 are successively set on behind quarter-wave plate 9, and flat with prism facets 6
OK；Angle of wedge prism 10 is used to reflect light beam incident before and after angle of wedge prism 10, and incides angle of wedge prism 10 twice
Preceding surface and four light beams on 10 preceding surface of angle of wedge prism returned to by light reflecting device 11 twice form the rectangle of coincidence,
And in left and right distribution, i.e., the light beam positioned at the same side is derived from same light beam, and there is identical frequency (to be such as located therein the light of side
Beam 22, light beam 55, light beam 22A, light beam 55A are derived from a light beam, and light beam 23, light beam 54, light beam positioned at other side
23A, light beam 54A are derived from another light beam).Angle of wedge prism 10 moves with measured piece, when measured piece shifts so that pass through wedge
The optical path of angle prism 10 changes, so as to cause the change of tested optical path difference；Light reflecting device 11 is fixed setting, its
Effect is light beam of the reflection from angle of wedge prism 10.It is pointed out that in this manual, square is considered as the one of rectangle
Individual special case.
The polarizer 12 be arranged in parallel with prism facets 4, and it is with being polarized in two orthogonal beams for making to be emitted from prism facets 4 that it, which is acted on,
The unidirectional quadrature component of polarization axle of device 12 is by so as to form interfering beam.
Photoelectric detector 13 receives the light beam from the polarizer 12 and produces electric measurement signal input phase meter 14, phasometer
14 are used for measuring phase difference between above-mentioned electric measurement signal and foregoing electric reference signal, the change of the phase difference with because of angle of wedge rib
Optical path difference caused by the skew of mirror 10 is directly proportional.
Although the angle of wedge prism in Fig. 1 is one side angle of wedge prism, the present invention does not make restriction to this, the angle of wedge rib
Mirror equally can be, for example, double wedge angle prism.
In the preferred embodiment shown in Fig. 1, light reflecting device 11 can be but be not limited to wedge angle reflective mirror.
In the preferred embodiment shown in Fig. 1, when angle of wedge prism is one side angle of wedge prism, the angle of wedge of wedge angle reflective mirror is about
For the half of the one side angle of wedge prism angle of wedge；When the angle of wedge corner angle are double wedge angle prism, the angle of wedge of wedge angle reflective mirror is about
For a quarter of the angle of wedge of double wedge angle prism.
In the preferred embodiment shown in Fig. 1, the angle of wedge of one side angle of wedge prism is preferably 1 °, now the wedge of wedge angle reflective mirror
Angle is close to 0.5 °.
Fig. 2 is the light path plane expanded schematic diagram according to the laser interference system of a preferred embodiment of the present invention.
The light beam 15 for carrying out self-excitation light source 1 incides polarization splitting prism 2 from prism facets 4, while carrying supply-reference letter
Numbers 68 arrive phasometer 14.The polarization light-dividing surface 3 of polarization splitting prism 2 is coated with polarization beam splitter, by two beam polarization directions mutually just
The p light 16 for the parallel plane of incidence handed over and the s light 17 in vertical incidence face separate.Two light beams reflect by prism facets 4 and prism facets 5
Afterwards, polarization splitting prism 2, i.e. light beam 20 and 21 are projected from prism facets 6.
Light beam 20 and 21 changes into circularly polarized light beam 22 and 23 respectively after quarter-wave plate 9, and light beam 22 and 23 passes through
Crossing 70A and the 70B refraction of angle of wedge prism 10 turns into light beam 24 and 25, reflects to form light beam 26 and 27 by 70C and 70D.
Light beam 26 and 27 is obtained light beam 26A and 27A after face 71A and the 71B reflection of wedge angle reflective mirror 11, after 70C and 70D refractions
Light beam 24A and 25A are formed into angle of wedge prism 10, reflects to form light beam 22A and 23A by 70A and 70B.Light beam 22A and
23A changes into polarization direction and former 20 and 21 mutually orthogonal linearly polarized light of incident beam after again passing by quarter-wave plate 9
28 and 29, light beam 28 and 29 enters polarization splitting prism 2, after prism facets 4 and prism facets 5 reflect, merges in polarization light-dividing surface 3
Into light beam 32.
Turn into light beam 35 after being reflected after the injection polarization splitting prism 2 of light beam 32 by corner cube 8, due to corner cube 8
Characteristic, light beam 32 and light beam 35 are parallel to each other, but not in a height.
The incident polarization Amici prism 2 again of light beam 35, it is orthogonal to be divided into two beam polarization directions on polarization light-dividing surface 3
Light beam 51 and 50, they come from incident beam 20 and 21 respectively.Light beam 51 and 50 turns into after prism facets 4 and prism facets 5 reflect
The outgoing polarization Amici prism 2 of light beam 53 and 52, then turn into light beam 55 and 54 by quarter-wave plate 9, again the incident angle of wedge
The preceding surface of prism, they and the light beam 22 and 23 on the incident preceding surface of angle of wedge prism collectively forms positive square for the first time, it is and left
Right distribution, i.e., symmetrical per side, i.e., the two-way light beam of the same side is same frequency.Light beam 55 and 54 is by angle of wedge prism 10
Face 70A and 70B refraction turn into light beam 57 and 56, reflect to form light beam 59 and 58 by face 70C and 70D, it is anti-by the angle of wedge
Penetrate after the face 71A and 71B reflection of mirror 11 obtain light beam 59A and 58A (wherein face 71A and 71B be respectively perpendicular to light beam 59A and
58A), enter angle of wedge prism 10 after face 70C and 70D refraction, form light beam 57A and 56A, reflected by face 70A and 70B
To form light beam 55A and 54A, they also collectively form square with the light beam 22A and 23A that return to the preceding surface of angle of wedge prism for the first time
Shape, and the rectangle with being made up of light beam 22,23,55 and 54 overlaps.Light beam 55A and 54A turn after again passing by quarter-wave plate 9
Polarization direction and the mutually orthogonal linearly polarized light 61 and 60 of former incident beam 52 and 53 are melted into, light beam 61 and 60 enters polarization spectro
Prism 2, after prism facets 4 and prism facets 5 reflect, polarization light-dividing surface 3 is reached, after transmission and reflection, is merged into light beam 64.
Light beam 64 turns into electric measurement signal 67, together entered with electric reference signal 68 by being received after the polarizer 12 by photoelectric detector 13
Applying aspect meter 14, to measure the phase difference between sinusoidal electric measurement signal and sinusoidal electric reference signal.
The specific calculating process of phase difference will be described using with reference to figure 3 and Fig. 4 below.
So-called two-frequency laser interferometer, refer to be formed using the laser beam that two beam frequencies are different and polarization direction is orthogonal
The interferometer of interference effect.This two beams laser beam is respectively by the different interfere arm of interferometer, so as to be carried in Returning beam
Have different optical phase information, when two beam laser merge once again, will be formed beat frequency interference measurement optical signal, make its with from
The reference signal of lasing light emitter carries out phase bit comparison, then can obtain phase differenceAnd two optical path difference Δ l between interfere arm it is following
Linear relationship：
Here λ is laser center wavelength,It can be measured by phasometer, it is possible thereby to determine optical path difference Δ l.If
Optical path difference Δ l is as caused by displacement, then thus can measure shift length.
In the interference system of the present invention, the light beam of each frequency component have passed through identical geometry distance, but light
Journey nl (n be light path in medium refraction index, l be light after geometry distance) whether the identical position depending on angle of wedge prism.
When angle of wedge prism shifts with measured piece, two frequency components in angle of wedge prism and in atmosphere after length will send out
Changing so that the respective light path nl of two frequency components changes, and causes the phase difference between them to change.
As it was previously stated, the light f of two different frequencies1And f2In the incidence of the angle of wedge prism space is formed with Exit positions
Four symmetrical light paths.If f1Light beam is respectively T, Q in the incoming position that goes out of angle of wedge prism, f2Light beam goes out incident position angle of wedge prism
Put respectively R, S.No matter whether measured body shifts, and position T, Q, R, S of 4 light paths are constant, and they form one
The individual length of side be b rectangle, such as Fig. 3.When angle of wedge prism produces offset d with testee, 4 luminous points are still within original
Position, and 4 light spot positions before offseting on angle of wedge prism offset by d.If from perpendicular to the side of angle of wedge prism cross-section
To observation, i.e., observed along the direction in Fig. 3 shown in arrow A, light beam f12 light paths do not shift relatively before light path court
Extreme direction in the angle of wedge to offset, i.e., the distance that light beam undergoes in glass reduces；On the other hand, light beam f22 light path courts
The direction skew of angle of wedge outer end, i.e., the distance that light beam undergoes in glass adds, and sees Fig. 4.
Because 4 light paths are centrosymmetric, the absolute value of respective offset is equal, is set to d.When angle of wedge prism is by glass
(if air replaces with vacuum or other media, derivation here is still when glass is made and the medium outside prism is air
Set up), both dielectric constants are inconsistent.So although total geometry distance that the light beam of two frequencies passes through keeps constant,
It is that optical path but changes.As shown in figure 4, in angle of wedge prism cross-section, light beam f1Inwardly skew, that is, the glass road passed through
Journey is reduced, that is, light path is reduced, light beam f2Outwards skew, that is, the glass path increase passed through, that is, light path increase.Due to
4 optical path Centers are symmetrical, and the absolute value of their offset geometry distance is equal, therefore caused corresponding optical path difference is absolute
Value is also equal.Assuming that the absolute value for the geometry distance variable quantity that light beam passes through angle of wedge prism is l, α is the wedge of angle of wedge prism
Angle, then：
L=d sin α (2)
Here l is directly related with optical path difference Δ l.Because the light beam of each frequency passes through angle of wedge prism for all 4 times, two in addition
The change in optical path length one of frequency be on the occasion of and another is negative value, so total optical path difference Δ l and l relation are：
Δ l=8l (ng- nair) (3)
Here ngAnd nairIt is the refractive index of glass and air respectively.If the refractive index of glass is 1.5, the refractive index of air
About 1.00027 (can approximate value be 1.0), then both differences are about 0.5 times, so
Δ l=4l=4d sin α (4)
Thus obtain：
Because α can be predefined, λ is laser center wavelength, therefore when by between measurement signal and reference signal
Phase bit comparison measures the phase place change of optical path differenceAfterwards, you can the straight line offset d of angle of wedge prism is determined according to formula (5).
For single frequency laser interferometer, two laser beams that beam frequency is identical but polarization direction is orthogonal are respectively by interference
The different interfere arm of instrument, so as to carry different optical phase information in Returning beam, when two beam laser merge once again,
Interferometry optical signal will be formed, detects its phase, then can obtain the phase difference as shown in formula (1)With two interfere arms it
Between optical path difference Δ l linear relationship.Its follow-up derivation is same as above.
A kind of concrete structure of laser interference system is described in superincumbent preferred embodiment.On it is pointed out that
The concrete structure that face provides is merely exemplary of the invention not for limiting.Clearly for ordinary skill in the art
For personnel, the present invention can also be realized using the laser interference system of other structures, as long as two beam different frequencies can be made
Light incide angle of wedge prism surface four road light beams 22,23,54 and 55 or so distribution, i.e., per side two-way light beam from together
Light beam, there is same frequency, and this four roads light beam forms four summits of a rectangle.
Fig. 5 shows the structural representation of the linearity interferometer measuration system according to another preferred embodiment of the invention.
As shown in figure 5, the interferometer measuration system includes lasing light emitter 1, optical interference means 400, can rotated with measured piece (not shown)
Angle of wedge prism (being made up of prism 45A and 45B), light reflecting device (being made up of speculum 70A and 70B) and phase detection device
110。
In Figure 5, the light beam 120 for carrying out self-excitation light source enters optical interference means 400, and the light beam 120 includes two frequencies not
With or identical but mutually orthogonal linear polarization component.The frequency of two components is assumed in the present embodiment, therefore
Need to provide reference signal 11 to phase detection device 110.
Optical interference means 400 divide incident beam 120 to correspond to different frequencies respectively and inciding on angle of wedge prism
Two light beams 36,37.Light beam 36,37 forms the directive light reflecting device of light beam 38 and 39 after angle of wedge refraction by prism, and anti-through light
Injection device forms the light beam 38A and 39A for being reflected back angle of wedge prism, is formed there after refraction into optical interference means 400
Light beam 36A and 37A.Two beam frequencies of return different light beam 36A and 37A are transformed to light beam 52,53 simultaneously by optical interference means 400
Angle of wedge prism is again incident on, wherein, 36,37,52 and 53 incoming position on angle of wedge prism of light beam is positioned at rectangle
Four summits.Enter laser interference device 400 after the refraction of reflection and angle of wedge prism of the light beam 52,53 through light reflecting device,
Light beam 80 is synthesized into there and delivers to phase detection device 110 to detect the change of phase difference.
Such as Fig. 5, for the initial position of angle of wedge prism, two mutually perpendicular components in polarization direction that light beam 80 includes have
One initial optical path difference, with the translation of angle of wedge prism in the z-direction, any transverse shifting in the x-direction will be in the two components
Between introduce change in optical path length, so as to cause the phase difference between two components to change.
In phase detection device 110, relative to the polarization direction of two components in 45 degree polarizers 81 set by light
Beam 80 is converted to light beam 82, and the interference of two polarized components then is converted into electric signal 85 by photodetector 83.Phasometer
90 are extracted phase place change to obtain straight line degrees of data from electric signal 85.As described above, when two polarized components of light beam 120
, it is necessary to provide reference signal 11 from light source 1 to phasometer 90 during with different frequencies.
In the present embodiment, optical interference means 400 employ the internal structure different from embodiment illustrated in fig. 2.It is specific and
Speech, as shown in figure 5, the optical interference means 400 of the present embodiment include shear plate (shear plate) 160, half-wave plate 290, combination
The polarization spectroscope 40 (polarizing beamsplitter) and right-angle prism 47 that are integrated, light shifter 72 and four/
One wave plate 44.
Conversion process of the light beam in optical interference means 400 is described below.
Such as Fig. 5, the light beam 120 from light source 1 is incided on shear plate 160, is separated into the He of light beam 31 of vertical polarization
The light beam 30 of horizontal polarization.For light beam 31 by half-wave plate 290, polarization direction is rotated by 90 degrees has phase so as to be formed with light beam 30
With the light beam 33 of polarization direction.Light beam 30 and 33 enters spectroscope 40 and transmits the formation He of light beam 34 respectively through polarizing coating 42
35.Light beam 34 and 35 is by quarter-wave plate 44 and is respectively converted into circularly polarized light beam 36 and 37.
As described above, the light beam 36,37 being emitted from optical interference means 400 is transformed to light through angle of wedge prism and light reflecting device
Optical interference means 400 are returned after beam 36A and 37A.
Then, in optical interference means 400, light beam 36A and 37A is by quarter-wave plate 44 and to be respectively converted into line inclined
Shake light beam 34A and 35A.The be split polarizing coating 42 of mirror 40 of light beam 34A and 35A reflexes to right-angle prism 47, through right-angle prism
47 reflections form light beam 50 and 51 respectively.Light shifter 72 exchanges the position of light beam 50 and 51, forms light beam 50A and 51A.Adjust
Light beam 50A and 51A after changing is respectively converted into circularly polarized light beam 52 and 53 through quarter-wave plate 44, leaves optical interference means
400 are emitted to angle of wedge prism, wherein, 36,37,52 and 53 incoming position on angle of wedge prism of light beam is located at the four of a rectangle
Individual summit.
As described above, light beam is formed respectively after the refraction of reflection and angle of wedge prism of the light beam 52,53 through light reflecting device
52A and 53A is simultaneously again introduced into laser interference device 400.
Then, in optical interference means 400, light beam 52A and 53A is by quarter-wave plate 44 and to be respectively converted into line inclined
Shake light beam 50B and 51B.Light shifter 72 exchanges light beam 50B and 51B position, forms light beam 60 and 61.Light beam 60 and 61 passes through
The transmission of the polarizing coating 42 of polarization spectroscope 40 forms light beam 62 and 63 respectively, wherein, light beam 62 is converted to through half-wave plate 290
The polarization direction linearly polarized light 64 vertical with light beam 63.Light beam 62 and 63 is synthesized light beam 80 and delivers to phase by shearing piece 160
Detection means 110.
The above-mentioned preferred embodiment of the present invention can be applied to the interferometry of high-precision linearity, and in such occasion, α is not
Need to select very big, such as 1 ° can be set to, and b may be selected to be 10mm, be currently available that the resolution ratio of phasometer is easy to reach
To 0.01 °, therefore the minimum resolution for measuring straight line offset d is about 2.4 nanometers.If use the phase that resolution ratio is 0.003 °
Meter, then straight line offset d minimum resolution can reach about 0.8 nanometer.It can be seen that done according to the laser of present pre-ferred embodiments
Interferometer compared with prior art, can reach higher resolution ratio.
The principle and spirit of the present invention are set forth by preferred embodiment above.Swashed in superincumbent description with double frequency
Exemplified by optical interferometer, but it is noted that the principle of the present invention can equally be well applied to single-frequency laser interference system, such
In interference system, lasing light emitter produces that two beam frequencies are identical and laser beam that polarization direction is orthogonal.For above-mentioned preferred embodiment,
Only need to make the layout shown in Fig. 1 some changes during applied to single-frequency laser interference system, for example, lasing light emitter 1 without again to
Phasometer 14 provides electric reference signal, and phasometer will determine phase place change according to light beam 67As for light path part (i.e. in Fig. 1
Optical interference means 100, angle of wedge prism 10 and light reflecting device 11) structure then without change.
Claims (5)
1. a kind of laser interference system for displacement straight line degree measurement, it is characterised in that including lasing light emitter（1）, phase-detection
Device（110）, optical interference means（400）, angle of wedge prism（45A, 45B）, light reflecting device（70A, 70B）, lasing light emitter produces the
One light beam（120）Optical interference means are incided, while produce reference signal（11）To phase detection device, optical interference means are located at
Angle of wedge prism side, between angle of wedge prism and lasing light emitter, light reflecting device is located at the opposite side of angle of wedge prism, angle of wedge prism with
Measured piece moves together, and the optical interference means receive the first light beam caused by lasing light emitter（120）Afterwards, generation is parallel incides wedge
Third and fourth light beam of angle prism（36,37）, the third and fourth light beam passes through angle of wedge prism successively and light reflecting device is formed
5th and the 6th light beam（36A, 36B）, the 5th and the 6th light beam edge returns to the light with incident path identical path and done
Relate to device, the optical interference means produce and parallel incide the angle of wedge prism again respectively from the described 5th with the 6th light beam
7th and the 8th light beam（52,53）, the 7th light beam and the 8th light beam successively by angle of wedge prism and light reflecting device along with
Incident identical path returns to the optical interference means, and the optical interference means produce the from the 7th light beam and the 8th light beam
Two light beams（80）Into phase detection device, the three, the four, the 7th and the 8th light beam（36,37,52,53）Incide institute
The position for stating angle of wedge prism forms four summits of a rectangle, wherein the incoming position of the 3rd and the 7th light beam forms institute
Two summits of the side of rectangle are stated, the incoming position of the 4th and the 8th light beam forms two of the opposite side of the rectangle
Summit, phase detection device receive the reference signal of lasing light emitter（11）With the second light beam inputted from the optical interference means
（80）, the linearity for exporting measured piece is calculated according to the variable quantity of the phase difference of two components.
2. it is used for the laser interference system of displacement straight line degree measurement as claimed in claim 1, wherein, the optical interference means bag
Include shear plate（160）, half-wave plate（290）, the polarization spectroscope that is combined into one（40）And right-angle prism（47）, light shifter
（72）And quarter-wave plate（44）, the shear plate is by the first light beam incident thereon（120）It is separated into vertical polarization
9th light beam（31）With the tenth light beam of horizontal polarization（30）, the 9th light beam is by half-wave plate rear polarizer direction by rotation 90
Spend so as to form the 11st light beam that there is identical polarization direction with the tenth light beam（33）, the described tenth and the 11st light beam
Into the polarization spectroscope（40）And the ten two the 13rd light beam is formed respectively（34,35）, the 12nd and the 13rd light
Beam is by the quarter-wave plate and is respectively converted into third and fourth light beam（36,37）, from the angle of wedge prism
With the 5th and the 6th light beam of light reflecting device（36A, 37A）By the quarter-wave plate and it is respectively converted into the 14th He
15 light beams（34A, 35A）, the 14th and 15 light beam reflexes to the right-angle prism by the polarization spectroscope, through institute
State right-angle prism reflection and form the 16th and 17 light beams respectively（50,51）, the light shifter is by the described 16th and 17
Light-beam position is exchanged to form the 18th and 19 light beams（50A, 51A）, the 18th and 19 light beam through described four/
One wave plate is respectively converted into the 7th and the 8th light beam, reflection and the angle of wedge of the 7th and the 8th light beam through light reflecting device
Returning beam is formed respectively after the refraction of prism（52A, 53A）, it is by the quarter-wave plate and is respectively converted into line
Light beam（50B, 51B）, the light shifter exchanges the linearly polarized light beam position（60,61）, the line after the exchange of position
Light beam is through the polarization spectroscope（40）Transmission forms the 20th and the 21st light beam respectively（62,63）, wherein, it is described
20th light beam is converted to the linearly polarized light of polarization direction and the 21st beam orthogonal through the half-wave plate, and by institute
State shearing piece and the two is synthesized into second light beam.
3. be used for the laser interference system of displacement straight line degree measurement as claimed in claim 1, wherein, the lasing light emitter produces the
One light beam and reference signal, the first light beam include two components, and described two components have different frequencies and linear polarization side
To mutually orthogonal, the frequency of the reference signal corresponds to the difference on the frequency of described two components.
4. be used for the laser interference system of displacement straight line degree measurement as claimed in claim 1, wherein, the lasing light emitter produces the
One light beam, the first light beam produce the linear polarization component of two different frequencies by the optical interference means, described two components
Linear polarization is mutually orthogonal, signal on the basis of the reference signal that the lasing light emitter provides to phase detection device.
5. it is used for the laser interference system of displacement straight line degree measurement as claimed in claim 1, wherein, the phase detection device
Including：Polarizer, mix two quadrature components of second light beam and produce the 13rd light beam；Photoelectric detector, described in reception
13rd light beam simultaneously produces electric measurement signal；Phasometer receives electric measurement signal and electric reference signal and calculates output measured piece
Displacement linearity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410746892.XA CN104613902B (en) | 2011-10-14 | 2011-10-14 | Laser interference system for displacement straight line degree measurement |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110310757.7A CN102506764B (en) | 2011-10-14 | 2011-10-14 | Laser interference system for displacement linearity measurement |
| CN201410746892.XA CN104613902B (en) | 2011-10-14 | 2011-10-14 | Laser interference system for displacement straight line degree measurement |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110310757.7A Division CN102506764B (en) | 2011-10-14 | 2011-10-14 | Laser interference system for displacement linearity measurement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104613902A CN104613902A (en) | 2015-05-13 |
| CN104613902B true CN104613902B (en) | 2018-04-06 |
Family
ID=53148463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410746892.XA Expired - Fee Related CN104613902B (en) | 2011-10-14 | 2011-10-14 | Laser interference system for displacement straight line degree measurement |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104613902B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107270837B (en) * | 2016-04-07 | 2020-05-26 | 大族激光科技产业集团股份有限公司 | Drilling machine spindle deflection test system and method |
| CN108489424A (en) * | 2018-04-13 | 2018-09-04 | 上海理工大学 | Laser interference system for roll angle and straight line degree measurement |
| CN109781034B (en) * | 2019-01-22 | 2020-11-10 | 上海理工大学 | Micro-roll angle and linearity synchronous high-precision measurement interferometer and measurement method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4787747A (en) * | 1987-11-13 | 1988-11-29 | Zygo Corporation | Straightness of travel interferometer |
| US4807997A (en) * | 1987-11-12 | 1989-02-28 | Zygo Corporation | Angular displacement measuring interferometer |
| CN1071005A (en) * | 1992-09-17 | 1993-04-14 | 清华大学 | Double-frequency laser alignment measurement method and alignment measurement interferometer thereof |
| CN1335483A (en) * | 2001-08-31 | 2002-02-13 | 清华大学 | Tumble angle measuring method and measurer |
| JP3751928B2 (en) * | 2002-10-16 | 2006-03-08 | 石川県 | Laser interferometer and measuring apparatus using the same |
| CN101650166A (en) * | 2008-08-15 | 2010-02-17 | 上海理工大学 | Laser interference system used for measuring micro roll angle |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6762845B2 (en) * | 2001-08-23 | 2004-07-13 | Zygo Corporation | Multiple-pass interferometry |
-
2011
- 2011-10-14 CN CN201410746892.XA patent/CN104613902B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4807997A (en) * | 1987-11-12 | 1989-02-28 | Zygo Corporation | Angular displacement measuring interferometer |
| US4787747A (en) * | 1987-11-13 | 1988-11-29 | Zygo Corporation | Straightness of travel interferometer |
| CN1071005A (en) * | 1992-09-17 | 1993-04-14 | 清华大学 | Double-frequency laser alignment measurement method and alignment measurement interferometer thereof |
| CN1335483A (en) * | 2001-08-31 | 2002-02-13 | 清华大学 | Tumble angle measuring method and measurer |
| JP3751928B2 (en) * | 2002-10-16 | 2006-03-08 | 石川県 | Laser interferometer and measuring apparatus using the same |
| CN101650166A (en) * | 2008-08-15 | 2010-02-17 | 上海理工大学 | Laser interference system used for measuring micro roll angle |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104613902A (en) | 2015-05-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102506764B (en) | Laser interference system for displacement linearity measurement | |
| CN101650166B (en) | Laser interference system used for measuring micro roll angle | |
| US4859066A (en) | Linear and angular displacement measuring interferometer | |
| US6806960B2 (en) | Compact beam re-tracing optics to eliminate beam walk-off in an interferometer | |
| US4883357A (en) | Dual high stability interferometer | |
| WO2016123812A1 (en) | Laser heterodyne interference linearity measuring apparatus and method having six-degrees-of-freedom detection | |
| CN102353325B (en) | Four-axial four-subdivision interferometer | |
| CN107664482B (en) | Grating measuring device | |
| CN104634283A (en) | Laser heterodyne interference linearity measuring device and laser heterodyne interference linearity measuring method with six-degree-of-freedom detection | |
| CN108489424A (en) | Laser interference system for roll angle and straight line degree measurement | |
| CN101629810B (en) | Optical doubling frequency laser interference measurement system and optical doubling frequency laser interference measurement method for displacement of special geometric point | |
| CN109631805B (en) | Wollaston prism movable laser interference straightness and displacement simultaneous measurement device | |
| US9036155B2 (en) | Six-axis four-subdividing interferometer | |
| CN100570276C (en) | The two-dimensional transversal zeeman double-frequency laser linearity/coaxiality measurement mechanism | |
| CN110174054A (en) | A kind of four light path laser interferometer measuration system of high stability | |
| JPH07101166B2 (en) | Interferometer | |
| CN104613902B (en) | Laser interference system for displacement straight line degree measurement | |
| CN106123769A (en) | The differential planar mirror laser interference device of without error | |
| JPH07239208A (en) | Device for measuring application of interference | |
| CN1036292C (en) | Two-frequency laser collimation measuring method and interferometer | |
| TWI224351B (en) | Apparatus for detecting displacement of two-dimensional motion | |
| CN109781034B (en) | Micro-roll angle and linearity synchronous high-precision measurement interferometer and measurement method | |
| CN86107252B (en) | Measuring device of refraction index of air | |
| CN202274859U (en) | Laser interferometer system for displacement straightness measurement | |
| Zhou et al. | An angular displacement interferometer based on total internal reflection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180406 Termination date: 20181014 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |