CN101709956B - Optical fiber point diffraction phase shifting interferometry of optical plane surface shape - Google Patents
Optical fiber point diffraction phase shifting interferometry of optical plane surface shape Download PDFInfo
- Publication number
- CN101709956B CN101709956B CN2009102374268A CN200910237426A CN101709956B CN 101709956 B CN101709956 B CN 101709956B CN 2009102374268 A CN2009102374268 A CN 2009102374268A CN 200910237426 A CN200910237426 A CN 200910237426A CN 101709956 B CN101709956 B CN 101709956B
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- beam splitter
- measuring
- level crossing
- face
- 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
- Length Measuring Devices By Optical Means (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
The invention relates to an optical fiber point diffraction phase shifting interferometry of an optical plane surface shape, belonging to the field of optical measuring technique. The interferometry of the invention comprises the following steps: penetrating a beam splitter from a spheric wave for measuring the optical fiber diffraction, and refracting after reflecting on the surface of the plane mirror to be measured; reflecting the spheric wave front by the beam splitter, diffracting with the reference optical fiber, and converging with the spheric wave front of the beam splitter to generate interference; analyzing and processing the interference figure by using a standard method; measuring to obtain the surface shape of the measured plane mirror and the aberration introduced by the beam splitter; removing the plane mirror to be measured, moving the measuring optical fiber to the end surface of the reference optical fiber in the conjugate position relative to the beam splitter, and converging the spheric wave front diffracted from the reference optical fiber and the spheric wave front diffracted from the measuring optical fiber to generate interference again; measuring to obtain the aberration introduced by the beam splitter; and subtracting the measuring result obtained in step 2 from the measuring result obtained in step 1 to obtain the surface shape of the measured plane mirror. The interferometry of the invention has high precision of the measuring result of the plane surface shape, is an absolute measurement method of the plane surface shape, and extends the application range of the point diffraction interferometry.
Description
Technical field
The optical fiber point-diffraction phase-shifting interference measuring method of a kind of plane shape of optical plane of the present invention belongs to field of optical measuring technologies.
Background technology
Planar optical elements is used very extensive in optical system, and its effect mainly is turn back light path and imaging, and its flatness is usually at one below the wavelength.The surface shape measurement of optical flat generally adopts interference technique, and this just needs the reference planes of a standard as datum plane.The dressing plate that common interferometer use optics processing and manufacturing goes out is as the reference plane, always exist certain face shape, thereby having limited the accuracy of interferometer measurement plane surface shape, the accuracy of measurement of current interferometer plane surface shape can only reach λ/20～λ/50 (wavelength is 632.8nm).Far can not satisfy the demand of cutting edge technology researches such as ultraprecise processing and ultraviolet photolithographic.
The key that improves interferometric method plane surface shape measuring accuracy is to seek high-precision reference planes, and liquid level once was used as the reference plane of interferometry.Because liquid level roughly has the radius-of-curvature that equates with the earth, the maximum planes degree error of about 0.5 a meter liquid level of diameter only has λ/100.But have a lot of problems in the practical application, vibration, liquid are in the surface tension of chamber wall, and surperficial dust etc. all are to limit this method accuracy factors.
Make up the absolute method of measurement of testing flatness by the polylith flat board, for example " three plate methods " is suggested and used decades, but this method has only provided the deviation of a certain radial direction of tested plane component but not deviations from planarity on the whole plane.Many researchers attempts expanding this measuring method by rotating tested plane increase measurement data, and this method need use fitting of a polynomial to be similar to whole shape of representative, can not obtain the accurate measurement result of holomorphism equally.
We know, can produce the spherical wave of approximate ideal by means of aperture point diffraction.The size of aperture has determined the numerical aperture of diffraction light and has departed from the error of spherical wave.If hole diameter is 4 λ, then diffracted beam is when numerical aperture 0.2, and the diffraction spherical aberration in its far field is less than λ/10
4For actual measurement, it can be considered desirable corrugated with reference to sphere.End face with the flexible optical fibre fibre core replaces aperture just to constitute the optical fiber point-diffraction interferometer.
The reference spherical wave front that the some diffraction produces is dispersed, thereby naturally is suitable for measuring concave spherical surface, but can't directly apply to plane surveying.It is preceding by tested flat mirror reflects that our imagination will be put diffracted wave, then remain spherical wave front before the reflection wave, but carry the face shape information of tested level crossing, as long as the reference sphere ground roll of this spherical wave and another root optical fiber diffraction is interfered the face shape information that can obtain tested spherical mirror, this can realize by beam splitter.Though the use beam splitter can be finished with reference to the corrugated and measure converging of corrugated, the aberration of beam splitter itself has introduced error for undoubtedly the measurement of plane surface shape.Obtain plane surface shape measurement result accurately, just must accurately measure aberration that beam splitter introduces and measurement result is revised.
Summary of the invention
The objective of the invention is to have flatness error for the reference planes that solve common interferometer, cause absolute method of measurement such as limited and three flat boards of its plane surface shape accuracy of measurement can't realize the problem that holomorphism is measured, proposed a kind of optical fiber point-diffraction phase-shifting interference measuring method of plane shape of optical plane.
The present invention converges the measurement wavefront that carries tested plane minute surface shape information and reference wavefront to produce interference by introducing beam splitter.The plane surface shape measuring process was divided into for two steps: it is poor at first to measure the ripple that comprises tested plane and beam splitter, then the aberration of independent measurement beam splitter; Two pacing amounts are all used near desirable some diffraction spherical wave as the reference wavefront, to guarantee each accuracy of measuring; The face shape on tested plane can be subtracted each other by two pacing amount results and obtained.
The objective of the invention is to be achieved through the following technical solutions.
The optical fiber point-diffraction phase-shifting interference measuring method of a kind of plane shape of optical plane of the present invention realizes that the measurement mechanism of this method comprises beam splitting system, measuring optical fiber, reference optical fiber, beam splitter, imaging lens, ccd video camera, computing machine, tested level crossing; Beam splitting system comprises laser instrument, adjustable neutral density filter, 1/2 wave plate, polarizing beam splitter mirror, right-angle prism A, right-angle prism B, quarter wave plate A, quarter wave plate B, piezoelectric ceramics, polaroid A, polaroid B, microcobjective A and microcobjective B; Its concrete implementation step is:
The first step: enter the light of measuring optical fiber from beam splitting system, at measuring optical fiber end face generation diffraction; The diffraction spherical wave sees through beam splitter, turns back after the surface reflection of tested level crossing; Be the spherical wave front that carries tested plane minute surface shape information before the reflection wave, its centre of sphere be arranged in the measuring optical fiber end face by beam splitter at the formed picture point P of tested level crossing; Above-mentioned spherical wave front is reflected by beam splitter once more, forms to measure wavefront; Place reference optical fiber at picture point P about the conjugate position of beam splitter, see through beam splitter from the spherical wave of reference optical fiber end face diffraction and form reference wavefront, converge with above-mentioned measurement wavefront and interfere; Gather interferogram with ccd video camera, and handle and analyze with standard method;
Second step: remove tested level crossing, keep other optical element original positions motionless; The measuring optical fiber end face is moved to picture point P; Reflected to form the measurement wavefront from the spherical wave of measuring optical fiber end face diffraction by beam splitter; See through beam splitter formation reference wavefront from the spherical wave of reference optical fiber end face diffraction; Reference wavefront is converged with the measurement wavefront and is interfered; Gather interferogram with ccd video camera, and handle and analyze with standard method;
It is poor that the measurement result that the measurement result of the first step deducted for second step promptly obtains the ripple of tested level crossing.The plane wave front of nonnormal incidence in order to obtain the face shape of tested level crossing, needs this ripple difference is carried out pointwise correction by measuring wavefront at the incident angle of tested level crossing owing to measure wavefront and be sphere; The face shape of tested level crossing is calculated as follows:
If φ (x, y) be coordinate points in the tested level crossing that obtains by above-mentioned computing (x, the ripple of y) locating is poor, tested level crossing (x, face shape y) be F (x y), has:
F(x，y)＝λ·φ(x，y)·cos[θ(x，y)]/4π
Wherein λ is an optical wavelength, and (x is to see through light beam behind the beam splitter at (x, incident angle y) from the spherical wave front of measuring optical fiber diffraction y) to θ.
Beneficial effect
Plane surface shape measurement of the present invention be divided into two the step realize, two pacing amounts have all been utilized near desirable some diffraction spherical wave front, can guarantee the high precision of twice interferometry, also just can guarantee the precision of final plane surface shape measurement result, can be considered as a kind of absolute method of measurement of plane surface shape;
Method of the present invention realized the measurement of plane surface shape on the optical fiber point-diffraction interferometer, solved that the general point diffraction interferometer can only be measured concave spherical surface and a difficult problem that can't measurement plane, expanded the range of application of point-diffraction interference measuring method.
Description of drawings
Fig. 1 is the optical fiber point-diffraction phase-shifting interference measuring first step synoptic diagram on plane;
Fig. 2 is second step of the optical fiber point-diffraction phase-shifting interference measuring synoptic diagram on plane;
Wherein, 1-laser instrument, the adjustable neutral density filter of 2-, 3-1/2 wave plate, 4-polarizing beam splitter mirror, 5-right-angle prism A, 6-right-angle prism B, 7-1/4 wave plate A, 8-1/4 wave plate B, 9-piezoelectric ceramics, 10-polaroid A, 11-polaroid B, 12-microcobjective A, 13-microcobjective B, 14-measuring optical fiber, 15-beam splitter, the tested level crossing of 16-, 17-picture point P, 18-reference optical fiber, 19-imaging lens, 20-CCD video camera, 21-computing machine.
Embodiment
The optical fiber point-diffraction phase-shifting interference measuring method of a kind of plane shape of optical plane of the present invention, realize the measurement mechanism of this method, as shown in Figure 1 and Figure 2, comprise beam splitting system, measuring optical fiber 14, reference optical fiber 18, beam splitter 15, imaging lens 19, ccd video camera 20, computing machine 21, tested level crossing 16; Beam splitting system comprises laser instrument 1, adjustable neutral density filter 2,1/2 wave plate 3, polarizing beam splitter mirror 4, right-angle prism A5, right-angle prism B6, quarter wave plate A7, quarter wave plate B8, piezoelectric ceramics 9, polaroid A 10, polaroid B11, microcobjective A12 and microcobjective B13; Its concrete implementation step is:
The first step: as shown in Figure 1: decay by adjustable neutral density filter 2 from the linearly polarized light of laser instrument 1 outgoing, by inciding polarizing beam splitter mirror 4 behind 1/2 wave plate, the 3 adjustment polarization directions, be broken down into the mutually perpendicular two bunch polarized lights in polarization direction, a branch of measuring light that is transmitted as, a branch of reference light that is reflected into; When this two bunch polarisation during respectively by right-angle prism A5 and right-angle prism B6 reflected back polarizing beam splitter mirror 4 twice through quarter wave plate A7 and quarter wave plate B8, its polarization direction changes 90 degree separately, previous transmitted light beam will reflect, and by piezoelectric ceramics 9 realization phase shifts, and previous folded light beam is with transmission; Adjust its polarization direction by polaroid A 10, polaroid B11 respectively from two bundle crossed polarized lights of polarizing beam splitter mirror 4 outgoing, and then be coupled to measuring optical fiber 14 and reference optical fiber 18 respectively by microcobjective A12, microcobjective B13; See through beam splitter 15 from the spherical wave of the end face diffraction of measuring optical fiber 14, in the surface reflection of tested level crossing 16 and turn back; Be the spherical wave front that carries 16 shape information of tested level crossing before the reflection wave, the end face that its centre of sphere is arranged in measuring optical fiber 14 passes through beam splitter 15 at tested level crossing 16 formed picture point P17; Above-mentioned spherical wave front is reflected by beam splitter 15 once more, forms to measure wavefront; The end face of reference optical fiber 18 is positioned over the conjugate position of picture point 17 about beam splitter 15, sees through beam splitter 15 from the spherical wave of the end face diffraction of reference optical fiber 18 and forms reference wavefronts, converges with above-mentioned measurement wavefront and interferes; Realize that by computing machine 21 control piezoelectric ceramics 9 step-length is the phase shift of pi/2, phase-shift interference is received by ccd video camera 20 by imaging lens 19, and sending into computing machine 21 is that 4 steps or 5 step phase shift algorithms carry out Treatment Analysis by standard method; Can adjust the relative intensity of reference light and measuring light by rotating 1/2 wave plate 3 and polaroid A 10, polaroid 11 among Fig. 1, to reach best fringe contrast; This pacing amount result comprise the ripple difference of tested level crossing 16 and ripple that beam splitter 15 is brought into poor;
Second step: as shown in Figure 2: remove tested level crossing 16, keep other optical element original positions motionless; The end face of measuring optical fiber 14 is moved to the position of picture point P17; Reflected to form the measurement wavefront from the spherical wave of the end face diffraction of measuring optical fiber 14 by beam splitter 15; See through beam splitter 15 from the spherical wave of the end face diffraction of reference optical fiber 18 and form reference wavefronts; Reference wavefront is converged with the measurement wavefront and is interfered; Realize that by computing machine 21 control piezoelectric ceramics 9 step-length is the phase shift of pi/2, phase-shift interference is received by ccd video camera 20 by imaging lens 19, and sending into computing machine 21 is that 4 steps or 5 step phase shift algorithms carry out Treatment Analysis by standard method; Can adjust the relative intensity of reference light and measuring light by rotating 1/2 wave plate 3 and polaroid A 10, polaroid B11 among Fig. 2, to reach best fringe contrast; It is poor that this pacing amount result only comprises the ripple that beam splitter 15 brings into;
It is poor that the measurement result that the measurement result of the first step deducted for second step promptly obtains the ripple of tested level crossing 16; The face shape of tested level crossing 16 is calculated as follows:
If φ (x, y) be coordinate points in the tested level crossing 16 that obtains by above-mentioned computing (x, the ripple of y) locating is poor, tested level crossing 16 (x, face shape y) be F (x y), has:
F(x，y)＝λ·φ(x，y)·cos[θ(x，y)]/4π
Wherein λ is an optical wavelength, and (x is to see through light beam behind the beam splitter (15) at (x, incident angle y) from the spherical wave front of measuring optical fiber (14) diffraction y) to θ.
Claims (1)
1. the optical fiber point-diffraction phase-shifting interference measuring method of a plane shape of optical plane realizes that the measurement mechanism of this method comprises beam splitting system, measuring optical fiber (14), beam splitter (15), tested level crossing (16), picture point P (17), reference optical fiber (18), imaging lens (19), ccd video camera (20) and computing machine (21);
The first step: enter the concurrent spherical wave front of penetrating of gaining interest of measuring optical fiber (14) from beam splitting system and see through beam splitter (15), in the surface reflection of tested level crossing (16) and turn back; Be the spherical wave front that carries tested level crossing (16) face shape information before the reflection wave, the end face that its centre of sphere is arranged in measuring optical fiber (14) passes through beam splitter (15) at the formed picture point P of tested level crossing (16) (17); Above-mentioned spherical wave front forms and measures wavefront once more by beam splitter (15) reflection; The end face of reference optical fiber (18) is positioned over the conjugate position of picture point P (17) about beam splitter (15), sees through beam splitter (15) from the spherical wave of the end face diffraction of reference optical fiber (18) and forms reference wavefront, converges with above-mentioned measurement wavefront and interferes; Interferogram adopts standard method to handle and analyze;
Second step: remove tested level crossing (16), keep other optical element original positions motionless; The end face of measuring optical fiber (14) is moved to the position of picture point P (17); Reflected to form the measurement wavefront from the spherical wave of the end face diffraction of measuring optical fiber (14) by beam splitter (15); See through beam splitter (15) from the spherical wave of the end face diffraction of reference optical fiber (18) and form reference wavefront; Above-mentioned reference wavefront is converged with the measurement wavefront and is interfered; Interferogram adopts standard method to handle and analyze;
It is poor that the measurement result that the measurement result of the first step deducted for second step promptly obtains the ripple of tested level crossing (16);
The face shape of tested level crossing (16) is calculated as follows:
If φ (x, y) be coordinate points in the tested level crossing (16) that obtains by above-mentioned computing (x, the ripple of y) locating is poor, tested level crossing (16) (x, face shape y) be F (x y), has:
F(x，y)＝λ·φ(x，y)·cos[θ(x，y)]/4π
Wherein λ is an optical wavelength, and (x is to see through light beam behind the beam splitter (15) at (x, incident angle y) from the spherical wave front of measuring optical fiber (14) diffraction y) to θ.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102374268A CN101709956B (en) | 2009-11-06 | 2009-11-06 | Optical fiber point diffraction phase shifting interferometry of optical plane surface shape |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102374268A CN101709956B (en) | 2009-11-06 | 2009-11-06 | Optical fiber point diffraction phase shifting interferometry of optical plane surface shape |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101709956A CN101709956A (en) | 2010-05-19 |
| CN101709956B true CN101709956B (en) | 2011-01-05 |
Family
ID=42402754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009102374268A Expired - Fee Related CN101709956B (en) | 2009-11-06 | 2009-11-06 | Optical fiber point diffraction phase shifting interferometry of optical plane surface shape |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101709956B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101865670B (en) * | 2010-06-08 | 2011-11-09 | 北京理工大学 | Plane surface shape measurement method of optical fiber point-diffraction phase-shifting interferometer |
| CN102620680B (en) * | 2012-03-29 | 2014-05-28 | 中国科学院光电技术研究所 | Detecting device and method for tri-plane absolute measurement of optical surface |
| CN104181146A (en) * | 2013-05-22 | 2014-12-03 | 中国科学院光电研究院 | Multipulse laser-induced breakdown spectrum on-line detection system |
| CN105277338B (en) * | 2014-07-04 | 2018-10-26 | 中国科学院长春光学精密机械与物理研究所 | Large-numerical aperture phase shift double needle hole diffraction interferometer and its test method |
| CN114739327B (en) * | 2022-03-24 | 2022-12-30 | 中国科学院光电技术研究所 | Method for detecting coplanarity of eight spliced mirrors |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1431477A (en) * | 2003-02-14 | 2003-07-23 | 中国科学院上海光学精密机械研究所 | Spot diffraction interferometer for measuring surface shape |
-
2009
- 2009-11-06 CN CN2009102374268A patent/CN101709956B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1431477A (en) * | 2003-02-14 | 2003-07-23 | 中国科学院上海光学精密机械研究所 | Spot diffraction interferometer for measuring surface shape |
Non-Patent Citations (2)
| Title |
|---|
| Hagyong Kihm and et al.A Point-Diffraction Interferometer with Vibration-Desensitizing.《Interferometry XIII: Applications, edited by Erik L. Novak, Wolfgang Osten, Christophe Gorecki,Proc. of SPIE》.2006,第6293卷62930B-1~62930B-8. * |
| N. I. Chkhalo and et al.A source of a reference spherical wave based on a single mode optical fiber with a narrowed exit aperture.《REVIEW OF SCIENTIFIC INSTRUMENTS》.2008,033107-1~033107-5. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101709956A (en) | 2010-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101672632B (en) | Optical spherical surface shaped fiber point-diffraction phase-shifting interference measuring method | |
| CN101865670B (en) | Plane surface shape measurement method of optical fiber point-diffraction phase-shifting interferometer | |
| CN102519358B (en) | Phase-shift diffraction/interference measuring instrument and method for detecting three-dimensional shape of microsphere | |
| US7777895B2 (en) | Linear-carrier phase-mask interferometer | |
| CN101762242B (en) | Absolute interference measurement method for plane shape of optical plane | |
| CN101799279B (en) | Optical fiber point diffraction phase shift interferometry method of surface shape of large relative aperture sphere | |
| CN110017793B (en) | Double-channel anti-vibration interference measurement device and method | |
| CN101324421A (en) | Synchronous phase-shift fiso interferometer | |
| CN102289152B (en) | Optical system wave aberration detection device | |
| CN107462149B (en) | Phase-shift interferometry system and wave plate phase-shift method thereof | |
| CN108709514B (en) | A kind of compact rolling angle sensor device and measurement method | |
| CN101709956B (en) | Optical fiber point diffraction phase shifting interferometry of optical plane surface shape | |
| CN102401630B (en) | Spatial phase shift Fizeau spherical interferometer | |
| CN103245423B (en) | Light path polarized point diffraction movable phase interfere Wavefront sensor altogether | |
| CN103454712B (en) | Based on the wave plate array and preparation method thereof of pixel | |
| CN104713494B (en) | The dual wavelength tuning interference testing device and method of Fourier transformation phase shift calibration | |
| CN103344176A (en) | Octave type short coherence transient phase-shifting interferometer and measurement method used for detecting spherical topographic characteristics | |
| CN110057543B (en) | Wave surface measuring device based on coaxial interference | |
| CN202329545U (en) | Spatial phase-shifting Fizeau spherical interferometer | |
| CN101319873B (en) | Spacing phase shifter used for synchronous phase shift interferometer | |
| CN106643507B (en) | A kind of Three-coordinate measurer and method based on binary channels point-diffraction interference | |
| CN105674875B (en) | A kind of full filed low frequency heterodyne point-diffraction interferometer | |
| CN201251428Y (en) | Synchronous phase-shifting fizeau interferometer | |
| CN110160443B (en) | Optical fiber point diffraction interference device and method for transient three-coordinate measurement | |
| CN110030921B (en) | Shearing-quantity-adjustable transmission-type dual-frequency laser differential interference measuring device and method |
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 | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110105 Termination date: 20111106 |