Compensation four optical axis displacement laser interferometer calibration method and the devices of pattern
Technical field
The invention belongs to laser measuring technique field, relate generally to a kind of laser interferometer calibration method and device.
Background technology
Laser interferometry displacement of the lines technology is the standard assay techniques that precision is very high, be widely used in the fields such as accurate and ultraprecise machining, microelectronics equipment, nanometer technology industrial equipment and defence equipment, in order to ensure the accuracy of laser interferometer measurement displacement of the lines, need scientific and effective linear displacement laser interferometer calibration method and device.The general thinking of lubber-line displacement laser interferometer adopts the higher linear displacement laser interferometer of accuracy class to calibrate, and when both precision are close, is namely called comparison.In actual alignment work, linear displacement laser interferometer has suitable precision mostly, is thus realized by comparison the calibration of linear displacement laser interferometer.At present, the general calibration steps of linear displacement laser interferometer has parallel type, face-to-face formula and common light path type (Liao Chengqing, Zhu little Ping, Wang Weichen, Du Hua. the research of laser interferometer length measurement precision calibration steps. modern surveying and laboratory room managing, 2005,1:6-7).
Fig. 1 is parallel type laser interferometer calibrating installation structural representation, canonical measure mirror and be calibrated and measure mirror and be arranged on same movable platform, and when sports platform moves, the light paths of two cover laser interferometer measurement light beams increase and reduction simultaneously.Place because two cover laser interferometer are parallel, two-way light is affected by environment similar, and air refraction is less to two-way influence of light, but due to the vertical range between two-way light comparatively large, therefore during two cover laser interferometer calibrations, Abbe error is larger.
Fig. 2 is face-to-face formula laser interferometer calibrating installation structural representation, canonical measure mirror and being calibrated measures that mirror is aspectant is arranged on sports platform, its advantage is that two cover laser interferometer measurement beam axis can tune to almost on same measurement axis, both Abbe errors are very little, shortcoming is because the near-end of an interferometer is another far-end, not etc., the interference by environment is not different, and the light path impact of air refraction on two cover laser interferometer is inconsistent for both light paths.
2011, China National Measuring Science Research Inst. sets up domestic first 80 meters of large length laser interfering meter measuring device (Leng Yu states, Tao Lei, Xu Jian. based on two-frequency laser interferometer system accuracy and the analysis of Influential Factors of 80m measurement mechanism. metering and measuring technology, 2011, 38 (9): 47-49), accepted standard device puts parallel for the long distance two-frequency laser interferometer of three Agilent5530 types, become three path laser interferometers, the laser interferometer be calibrated is placed in the middle of them, thus carry out calibration calibration, this scheme belongs to the derivative schemes of parallel type calibration steps, and measure owing to adopting three road light simultaneously, therefore can compensating measure time Abbe error, but put owing to being that three laser instruments are parallel, therefore three road sign locating tab assembly light locus are far away, the measurement electrical distance every road sign locating tab assembly electrical distance being calibrated laser interferometer is also far away, all optical paths are different by the impact of environment, air refraction is inconsistent on all optical path impacts, cause calibration measurement result inaccurate.
Fig. 3 is common light path type laser interferometer calibrating installation structural representation, and light path type becomes 90 degree turn back modes unlike two laser instruments with receiver with parallel type laser interferometer calibrating installation altogether, and two cover laser interferometer share interference mirror group and measure mirror.Because two cover laser interferometer share an interference mirror group and measure mirror, cannot determine that the interference mirror group shared belongs to standard laser interferometer component with measurement mirror or belongs to and be calibrated standard laser interferometer component, therefore, not that on denotation, two calibrations of overlapping laser interferometer are calibrated.
1985, Dr-Ing H.-H.Schussler makes full use of space distribution (Dr-Ing H.-H.Schussler.Comparison andcalibration oflaser interferometer systems.Measurement, 1985,3 (4): 175-184), multipair linear displacement laser interferometer is carried out common light path calibration.Owing to just increasing the quantity of light path laser interferometer altogether, institute also has the shortcoming of common light path type laser interferometer calibrating installation above-mentioned in this approach.
Summary of the invention
For Abbe error larger in above-mentioned existing linear displacement laser interferometer calibrating installation, serious air refraction inconsistency be not that on denotation, two cover laser interferometer carry out the problem of calibrating, the present invention proposes and have developed compensation four optical axis displacement laser interferometer calibration method and the devices of pattern, this invention makes canonical measure light beam and is calibrated laser interferometer measurement beam orthogonal apart from very little, thus the impact of Abbe error, reduction air refraction inconsistency can be reduced, and be that on denotation, two cover laser interferometer are calibrated.
Object of the present invention is achieved through the following technical solutions:
The compensation four optical axis displacement laser interferometer calibration method of a kind of pattern, the method step is as follows:
(1) the output light of standard laser interferometer laser instrument forms through four axle hollow laser interference mirror groups four the canonical measure light beams be parallel to each other, article four, canonical measure light beam incides on the level crossing of interstitial hole with four-prism incline distribution form, after being reflected back toward four axle hollow laser interference mirror groups with the part light of level crossing displacement information in every bar canonical measure light beam, according to four interference signals corresponding respectively with four canonical measure light beams obtained from four axle hollow laser interference mirror groups, four shift values that the level crossing that can obtain interstitial hole moves along canonical measure beam direction, the remainder light of every bar canonical measure light beam is transmitted on four light-beam position detectors through there being the level crossing of interstitial hole,
(2) the output light being calibrated laser interferometer laser instrument is calibrated laser interferometer measurement light beam through being calibrated the formation of laser interferometer interference mirror group, be calibrated the intermediate throughholes of laser interferometer measurement light beam through four axle hollow laser interference mirror groups, parallel with four canonical measure light beams, and it is equal with the distance of every bar canonical measure light beam, be calibrated laser interferometer measurement light beam to incide and be calibrated on laser interferometer catoptron, after being reflected back toward and being calibrated laser interferometer interference mirror group, according to from being calibrated the interference signal obtained in laser interferometer interference mirror group, can obtain being calibrated the shift value that laser interferometer catoptron moves along canonical measure beam direction,
Article (3) four, canonical measure light beam is respectively (x with the original incident position coordinates being calibrated laser interferometer measurement light beam respective on the target mirror plane of incidence
1, y
1), (x
2, y
2), (x
3, y
3), (x
4, y
4) and (x
5, y
5), on the target mirror plane of incidence, the original incident position coordinates of every bar measuring beam is after the coordinate displacement (x, y) of two-dimensional directional, and the displacement measurement caused because of target mirror reflecting surface shape characteristic is respectively function z
1(x
1+ x, y
1+ y), z
2(x
2+ x, y
2+ y), z
3(x
3+ x, y
3+ y), z
4(x
4+ x, y
4+ y) and z
5(x
5+ x, y
5+ y);
(4) sports platform along in canonical measure beam direction reciprocatory movement with in the derivative displacement perpendicular to random two-dimensional direction in canonical measure beam plane, with at the uniform velocity or non-at the uniform velocity sampling rate, synchronized sampling standard laser interferometer four is measured shift value and is calibrated laser interferometer measurement shift value, is respectively S
1, S
2, S
3, S
4and S
5the synchronizing detection of four light-beam position detectors is to the derivative coordinate displacement value of four canonical measure beam and focus two-dimensional directional on the target mirror plane of incidence, ask for four coordinate displacement values arithmetic mean (x ', y ') as the derivative coordinate displacement value of every bar measuring beam, the displacement measurement errors that target mirror reflecting surface shape characteristic causes is compensated to and measures in shift value, obtain S
1-z
1(x
1+ x ', y
1+ y '), S
2-z
2(x
2+ x', y
2+ y '), S
3-z
3(x
3+ x ', y
3+ y '), S
4-z
4(x
4+ x', y
4+ y ') and S
5-z
5(x
5+ x ', y
5+ y '), get S
1-z
1(x
1+ x ', y
1+ y '), S
2-z
2(x
2+ x ', y
2+ y '), S
3-z
3(x
3+ x', y
3+ y ') and S
4-z
4(x
4+ x ', y
4+ y ') mean value and S
5-z
5(x
5+ x ', y
5+ y ') poor, obtain some sampled measurements error amounts.
The compensation four optical axis displacement laser interferometer calibrating installations of a kind of pattern, comprise standard laser interferometer laser instrument and four be configured in the receiver that can receive on standard laser interferometer interference signal position, four receivers are connected with standard laser interferometer signal disposal system by wire respectively; Standard laser interferometer laser instrument output light path is configured with can allowing of intermediate throughholes and is calibrated the four axle hollow standard laser interference mirror groups that laser interferometer measurement light beam passes; Four axle hollow standard laser interference mirror group side arrangement guide rails, sports platform is fitted on guide rail, sports platform is provided with the level crossing of interstitial hole, install in level crossing interstitial hole and be calibrated laser interferometer catoptron, be calibrated laser interferometer catoptron and form by the level crossing of interstitial hole the target mirror that the coplanar and relative position of the plane of incidence fixes; Four light-beam position detector configuration are having after the level crossing regional transmission of interstitial hole, and lay respectively on four parallel standards measuring beam transmitted light paths; Be calibrated laser interferometer interference mirror group and be calibrated laser interferometer laser instrument in four axle hollow standard laser interference mirror group opposite sides configurations, described in be calibrated laser interferometer interference mirror group and be positioned at and be calibrated on laser interferometer laser instrument output light path; Being calibrated laser interferometer receiver is configured on the position that can receive and be calibrated laser interferometer interference signal, and wire will be calibrated laser interferometer receiver and be calibrated laser interferometer signal disposal system and be connected.
The present invention has following characteristics and good result:
(1) compared with parallel type laser interferometer calibrating installation, owing to being calibrated the intermediate throughholes of laser interferometer measurement light beam by four axle hollow laser interference mirror groups, the vertical range be calibrated between laser interferometer measurement optical axis and parallel standards optical axis is shorter, both light paths are more close, and therefore during two cover laser interferometer calibrations, Abbe error is very little.
(2) compared with face-to-face formula laser interferometer calibrating installation, in the plane perpendicular to four canonical measure light beams, in the square area be made up of at this plane projection point four canonical measure light beams, article four, canonical measure light beam and to be calibrated laser interferometer measurement light beam very little by the degree difference of environmental interference, the air refraction mean value of four canonical measure light beams is close to the air refraction value being calibrated laser interferometer measurement light beam.
(3) light path type laser interferometer calibrating installation is compared together, shares interference mirror group and measures mirror, standard laser interferometer component and to be calibrated standard laser interferometer component ownership clear and definite, is that on denotation, two cover laser interferometer are calibrated.
(4) four light-beam position detectors can measure four canonical measure light beam relative target catoptrons deriving displacement perpendicular to random two-dimensional direction in canonical measure beam plane, after the derivative displacement of generation, the measurement displacement error that target mirror mirror surface pattern causes compensates in linear movement measuring result, ensures the accuracy of linear movement measuring value.
Accompanying drawing explanation
Fig. 1 is parallel type laser interferometer calibrating installation structural representation
Fig. 2 is face-to-face formula laser interferometer calibrating installation structural representation
Fig. 3 is for being total to light path type laser interferometer calibrating installation structural representation
Fig. 4 is the compensation four optical axis displacement laser interferometer calibrating installation structural representations of pattern
Fig. 5 is by the level crossing of interstitial hole and hot spot position distribution schematic diagram on the plane of incidence being calibrated the target mirror that laser interferometer catoptron forms
In figure: 1 standard laser interferometer laser instrument, 2 four axle hollow standard laser interference mirror groups, 3, 4, 5, article 6 four, parallel standards measuring beam, 7 level crossings having an interstitial hole, 8, 9, 10, 11 standard laser interferometer receivers, 12 standard signal disposal systems, 13 are calibrated laser interferometer laser instrument, 14 are calibrated laser interferometer interference mirror group, 15 are calibrated laser interferometer measurement light beam, 16 intermediate throughholes, 17 are calibrated laser interferometer catoptron, 18 are calibrated laser interferometer receiver, 19 are calibrated laser interferometer signal disposal system, 20 sports platforms, 21 guide rails, 22, 23, 24, 25 4 light-beam position detectors, 26, 27, 28, article 29 4, parallel standards measuring beam facula position, 30 are calibrated laser interferometer beam and focus position.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the invention is described in further detail.
The compensation four optical axis displacement laser interferometer calibrating installations of a kind of pattern, comprise standard laser interferometer laser instrument 1 and four be configured in the receiver 8,9,10,11 that can receive on standard laser interferometer interference signal position, four receivers 8,9,10,11 are connected with standard laser interferometer signal disposal system 12 by wire respectively; Standard laser interferometer laser instrument 1 output light path is configured with can allowing of intermediate throughholes 16 and is calibrated the four axle hollow standard laser interference mirror groups 2 that laser interferometer measurement light beam 15 passes; Four axle hollow standard laser interference mirror group 2 side arrangement guide rails 21, sports platform 20 is fitted on guide rail 21, sports platform 20 is provided with the level crossing 7 of interstitial hole, install in level crossing 7 interstitial hole and be calibrated laser interferometer catoptron 17, be calibrated laser interferometer catoptron 17 and form the fixing target mirror of the coplanar and relative position of the plane of incidence by the level crossing 7 of interstitial hole; Four light-beam position detectors 22,23,24,25 are configured in after level crossing 7 regional transmission of interstitial hole, and lay respectively on four parallel standards measuring beams 3,4,5,6 transmitted light path; Be calibrated laser interferometer interference mirror group 14 in four axle hollow standard laser interference mirror group 2 opposite sides configurations and be calibrated laser interferometer laser instrument 13, described in be calibrated laser interferometer interference mirror group 14 and be positioned at and be calibrated on laser interferometer laser instrument 13 output light path; Being calibrated laser interferometer receiver 18 is configured on the position that can receive and be calibrated laser interferometer interference signal, and wire will be calibrated laser interferometer receiver 18 and be calibrated laser interferometer signal disposal system 19 and be connected.
Described four parallel standards measuring beams 3,4,5,6 are with to be calibrated laser interferometer measurement light beam 15 all vertical with the target mirror plane of incidence.
The intermediate throughholes 16 of four described axle hollow standard laser interference mirror groups 2 comprises arbitrary shape, and number is one or more.
Described every bar parallel standards measuring beam 3,4,5,6 and be calibrated laser interferometer measurement light beam 15 had the level crossing 7 of interstitial hole respectively and be calibrated laser interferometer catoptron 17 reflect once or once more than.
The described laser interferometer catoptron 17 that is calibrated comprises level crossing, prism of corner cube, right-angle prism.
The compensation four optical axis displacement laser interferometer calibration method of a kind of pattern, the method step is as follows:
(1) the output light of standard laser interferometer laser instrument 1 forms through four axle hollow laser interference mirror groups 2 four the canonical measure light beams 3 be parallel to each other, 4, 5, 6, article four, canonical measure light beam 3, 4, 5, 6 incide on the level crossing 7 of interstitial hole with four-prism incline distribution form, after being reflected back toward four axle hollow laser interference mirror groups 2 with the part light of level crossing 7 displacement information in every bar canonical measure light beam, according to obtain from four axle hollow laser interference mirror groups 2 with four canonical measure light beams 3, 4, 5, 6 four corresponding respectively interference signals, the level crossing 7 of interstitial hole can be obtained along canonical measure light beam 3, 4, 5, four shift values of 6 direction motions, the remainder light of every bar canonical measure light beam is transmitted to four light-beam position detectors 22 through there being the level crossing 7 of interstitial hole, 23, 24, on 25,
(2) the output light being calibrated laser interferometer laser instrument 13 is calibrated laser interferometer measurement light beam 15 through being calibrated the formation of laser interferometer interference mirror group 14, be calibrated the intermediate throughholes 16 of laser interferometer measurement light beam 15 through four axle hollow laser interference mirror groups 2, with four canonical measure light beams 3, 4, 5, 6 is parallel, and it is equal with the distance of every bar canonical measure light beam, be calibrated laser interferometer measurement light beam 15 to incide and be calibrated on laser interferometer catoptron 17, after being reflected back toward and being calibrated laser interferometer interference mirror group 14, according to from being calibrated the interference signal obtained in laser interferometer interference mirror group 14, can obtain being calibrated laser interferometer catoptron 17 along canonical measure light beam 3, 4, 5, the shift value of 6 direction motions,
Article (3) four, canonical measure light beam 3,4,5,6 and the original incident position coordinates that is calibrated laser interferometer measurement light beam 15 respective on the target mirror plane of incidence are respectively (x
1, y
1), (x
2, y
2), (x
3, y
3), (x
4, y
4) and (x
5, y
5), on the target mirror plane of incidence, the original incident position coordinates of every bar measuring beam is after the coordinate displacement (x, y) of two-dimensional directional, and the displacement measurement caused because of target mirror reflecting surface shape characteristic is respectively function z
1(x
1+ x, y
1+ y), z
2(x
2+ x, y
2+ y), z
3(x
3+ x, y
3+ y), z
4(x
4+ x, y
4+ y) and z
5(x
5+ x, y
5+ y);
(4) sports platform 20 along in canonical measure light beam 3,4,5,6 direction reciprocatory movement with in the derivative displacement perpendicular to random two-dimensional direction in canonical measure light beam 3,4,5,6 plane, with at the uniform velocity or non-at the uniform velocity sampling rate, synchronized sampling standard laser interferometer four is measured shift value and is calibrated laser interferometer measurement shift value, is respectively S
1, S
2, S
3, S
4and S
5the synchronizing detection of four light-beam position detectors 22,23,24,25 is to the derivative coordinate displacement value of four canonical measure light beams 3,4,5,6 hot spot two-dimensional directional on the target mirror plane of incidence, ask for four coordinate displacement values arithmetic mean (x ', y ') as the derivative coordinate displacement value of every bar measuring beam, the displacement measurement errors that target mirror reflecting surface shape characteristic causes is compensated to and measures in shift value, obtain S
1-z
1(x
1+ x ', y
1+ y '), S
2-z
2(x
2+ x ', y
2+ y '), S
3-z
3(x
3+ x ', y
3+ y '), S
4-z
4(x
4+ x ', y
4+ y ') and S
5-z
5(x
5+ x ', y
5+ y '), get S
1-z
1(x
1+ x ', y
1+ y '), S
2-z
2(x
2+ x ', y
2+ y '), S
3-z
3(x
3+ x ', y
3+ y ') and S
4-z
4(x
4+ x ', y
4+ y ') mean value and S
5-z
5(x
5+ x ', y
5+ y ') poor, obtain some sampled measurements error amounts.
Canonical measure beam and focus position 26, 27, 28, 29 is four parallel standards measuring beams 3 successively respectively, 4, 5, 6 positions inciding the level crossing 7 of interstitial hole, being calibrated laser interferometer beam and focus position 30 is be calibrated the position that laser interferometer measurement light beam 15 incidence is calibrated laser interferometer catoptron 17, can find out that being calibrated laser interferometer beam and focus position 30 is in canonical measure beam and focus position 26 from position distribution, 27, 28, the center point of 29, i.e. four parallel standards measuring beams 3, 4, 5, 6 will be calibrated laser interferometer measurement light beam 15 is clamped in center.