CN101111739A - Fizeau interferomenter with simultaneous phase shift - Google Patents
Fizeau interferomenter with simultaneous phase shift Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J9/00—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength
- G01J9/02—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength by interferometric methods
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02015—Interferometers characterised by the beam path configuration
- G01B9/02032—Interferometers characterised by the beam path configuration generating a spatial carrier frequency, e.g. by creating lateral or angular offset between reference and object beam
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02055—Reduction or prevention of errors; Testing; Calibration
- G01B9/02056—Passive reduction of errors
- G01B9/02057—Passive reduction of errors by using common path configuration, i.e. reference and object path almost entirely overlapping
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- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02055—Reduction or prevention of errors; Testing; Calibration
- G01B9/02062—Active error reduction, i.e. varying with time
- G01B9/02064—Active error reduction, i.e. varying with time by particular adjustment of coherence gate, i.e. adjusting position of zero path difference in low coherence interferometry
- G01B9/02065—Active error reduction, i.e. varying with time by particular adjustment of coherence gate, i.e. adjusting position of zero path difference in low coherence interferometry using a second interferometer before or after measuring interferometer
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/0209—Low-coherence interferometers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/45—Multiple detectors for detecting interferometer signals
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/70—Using polarization in the interferometer
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J9/00—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength
- G01J9/02—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength by interferometric methods
- G01J2009/028—Types
- G01J2009/0292—Fizeau; Wedge
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Abstract
The tilted relationship between the reference and test mirrors (24,26) of a Fizeau interferometer is used to spatially separate the reflections (R,T) from the two surfaces. The separate beams (R, T) are filtered through a spatial polarization element (32) that provides different states of polarization to the beams. The beams (R,T) are subsequently recombined to form a substantially collinear beam that is processed using a spatial-phase-shift interferometer (44) that permits quantitative phase measurement in a single video frame. Alternatively, two beams (104,106) with orthogonal polarization are injected into the Fizeau cavity (20) at different angles, such that after reflection from the reference and test optics (24,26) they are substantially collinear. Unwanted reflections are blocked at the focal plane through the use of a circular aperture (112). Short coherence length light and a delay line (84) may be used to mitigate stray reflections, reduce measurement integration times, and implement temporal phase averaging.
Description
Related application
The present invention is based on and require the U.S. Provisional Patent Application No.60/498 of submission on August 28th, 2003,522 right of priority.
Technical field
The present invention relates to the preceding measurement of electromagnetic wave.Especially, the present invention relates to the quantitative transient measurement of the interfering beam that produces by fizeau interferometer.
Background technology
Light velocity measurement and quality identify that be important in the manufacturing of many opticses of for example data-storage laser heads.Therefore, many optical interferometric systems have been designed in order to improve accuracy and the reliability of measuring.Generally speaking, the front end interferometric measuring means that produces test and reference beam combines with the rear end optical devices, in order to the phase differential between the resolved beam.This can use different polarization state for test with reference beam such as passing through, and spatially solve them in the rear end by realizing simultaneously at front end coding (or " mark ") light beam.Alternatively, can in time change path difference between test and the reference surface,, and temporarily solve phase differential in the rear end for example by with respect to surface of another surface scan at front end.
A problem in the some problems that exist in the prior art is the suitable ability of coded reference and test beams in the measure portion of striking rope type interferometer.In U.S. Patent No. 4,872, in 755, people such as Kuchel by to simultaneously and temporary transient phase measurement adopt diverse ways to overcome this defective.By in the measure portion of interferometer, introducing optical delay devices, and the length in the gap in the length of the coherent length of selective light, delay path and the striking rope chamber dexterously, two relevant tests and reference beam and two incoherent light beams produce simultaneously.This deferred mount is used to change the path difference between the coherent light beam that is used for temporary transient phase measurement.Alternatively, can be polarized after test and reference beam produce in the measure portion of this device, and be introduced into the space analysis receptacle that is used for phase measurement simultaneously.
Therefore, people's such as Kuchel method needs the fine setting of the length of delay path, and implementing this fine setting is difficulty and expensive.In addition, the existence of two irrelevant light beams has produced the tangible bias light that may influence measurement.Therefore, still need be based on the phase measuring system of the fizeau interferometer that does not have these shortcomings.
People's such as Millerd U.S. Patent No. 6,304,330 have described a kind of back-end system, before wherein test that is produced by interferometer and reference wavefront list simultaneously at single detector or a plurality of detector array and be calibrated, be divided into wavelet, phase shifts, merging interfere and along total repacking survey to produce.If desired, light beam also can be detected on the single detector array in order.Test and reference beam after the optical system of Millerd also needs to encode.Therefore, in conjunction with front-end fizeau configuration, need overcome the same encoded question that proposes by people such as Kuchel.The invention describes a kind of new method, by this method, the output with striking rope chamber of tilt reference mirror combines with polarizer, is suitable for as U.S. Patent No. 6 with generation, carry out relevant test and the reference wavefront that space phase is measured in the system of describing in 304,330 simultaneously.
Summary of the invention
The present invention has utilized the reference of fizeau interferometer and the tilt relationship between the test mirrors, spatially to separate the reflection from two surfaces.Required as the while phase measurement, the light beam of separation filters by the spatial polarization element that the different polarization state is provided to light beam.By the light beam of recombination with formation cardinal principle conllinear, the light beam of this conllinear utilizes the spatial phase shift interferometer to handle to this light beam subsequently, and this spatial phase shift interferometer allows to carry out quantitative phase measurement in single frame of video.
Alternatively, two light beams with cross polarization are launched into striking rope chamber in different angles, make them at cardinal principle conllinear after reference and testing lens reflection.Undesired being reflected on the focal plane by using the circular hole blocking-up.Instruct as people such as Kuchel, can use the light of short-phase dry length and lag line to alleviate scattering, to reduce and measure integral number of times and carry out temporary transient phase average.
Various other purposes of the present invention and advantage are from the description of following instructions part and particularly point out novel feature will become clearer from claims.Therefore, for realizing goal of the invention as the aforementioned, the present invention by shown in the accompanying drawing of back, that describe fully and feature that particularly point out is in the claims formed in detailed description of preferred embodiment.Yet this accompanying drawing and explanation be open just can implement a kind of in the multiple mode of the present invention.
Description of drawings
Figure 1A is the synoptic diagram according to measurement mechanism of the present invention, this measurement mechanism is configured to pitch angle between use test and the reference surface and produces apart between test and the reference beam, and comprises that polaroid filter is to produce the test and the reference beam of polarization orthogonally.
Figure 1B is the synoptic diagram of polaroid filter with part of adjacent polarization orthogonally.
Fig. 1 C has to be included in another synoptic diagram of the polaroid filter of first polarization part of the part of polarization orthogonally.
Fig. 1 D is the synoptic diagram of polaroid filter, and wherein dual-aperture mask is added to the polaroid filter among Figure 1B, to stop the extra light beam that is caused by the multipath reflection between test and the reference planes.
Fig. 2 is the synoptic diagram of the spatial phase shift interferometer module commonly used that is suitable for combining with optical devices of the present invention.
Fig. 3 is the synoptic diagram of phase shifting interferometer module, wherein orthogonally the reference of polarization and test beams by lens focus to spectroscope, it is right as light beam that this spectroscope produces a plurality of sons, then, this son as light beam to be calibrated and by the phase interference sheet by lens imaging to detecting device.
Fig. 4 illustrates the spatial phase shift interferometer of the spatial-frequency carrier method of utilizing the phase change that detects test wavefront.
Fig. 5 is the schematic representation of apparatus of the optical delay line with influence input light of Fig. 1.
Fig. 6 A is the synoptic diagram of another embodiment of the present invention, this embodiment is configured to use the polarization spectroscope of operation input beam to produce apart between test and the reference beam, and comprises and be suitable for the hole from Axial Bundle that the phase shifting interferometer module is pointed in light beam on the transmitter shaft and blocking-up.
Fig. 6 B is the synoptic diagram of substitute of the polarization spectroscope of Fig. 6 A.
Fig. 7 is the schematic representation of apparatus of the optical delay line with influence input light of Fig. 6 A.
Fig. 8 is the synoptic diagram of another exemplary embodiment of the present invention, and wherein the apart between test and the reference beam is to use the combination of beamsplitter to provide.
Fig. 9 is the synoptic diagram of another exemplary embodiment of the present invention, and wherein the position in the position of polarization spectroscope and prevention hole is repositioned at other conjugate image plane in the imaging system.
Figure 10 is the synoptic diagram of optical devices, wherein lag line among Fig. 5 and polarization spectroscope and spatial phase shift interferometer among Fig. 3 test surfaces that combines and be arranged in parallel with reference surface in the fizeau interferometer structure to be characterized in.
Embodiment
Substantially, the invention reside in following idea: spatially separate the test and the reference beam that produce by striking rope type interferometer, and make each light beam pass encoded filter.By making test and reference beam produce the quadrature of polarization, but test and reference beam recombination and in the spatial phase shift interferometer, obtain handling, to realize the phase measurement of while.
For the purposes of the present invention, " pitch angle " is meant with respect to desirable parallel condition measured test and the angle between the reference surface in fizeau interferometer.Thereby the pitch angle is used on hand interferometry task that the striped of suitable resolution is provided in the present invention.
Design of the present invention with the interferometer 10 of Figure 1A as an example.The light source 12 of collimated light L is expanded by expansion lens 14, and spectroscope 16 is left in reflection, by collimation lens 18 calibrations, and the interferometer 20 of the striking Cable Structure of directive.Owing to input light L comprises level and vertical polarization, so half-wave plate 22 can be used for changing the ratio at the light of each polarization state (vertical or level).As known in the art, the light in the interferometer is reflected to produce corresponding reference and test beams R and T respectively from reference surface 24 and test surfaces 26.The reference and the test surfaces of interferometer tilt relative to each other, thereby produce reference and the test beams R that spatially separates, T, (wherein test surfaces 26 and test surfaces 24 vertical with the collimated light beam of injecting is to the collimated light beam inclination of injecting) as shown in FIG..As the result of this inclination, propagate along the light path of incident light from the light T of test surfaces 26 reflection, and after passing spectroscope 16, focus on point 28 places in the focal plane of collimation lens 18.From the light R of rear surface 24 reflection of reference eyeglass because the inclination on this surface is shifted and so focus on the difference 30 of the focal plane of collimation lens.
According to the present invention, spatial polarization filter 32 is placed on the focal plane of collimation lens 18.Shown in Figure 1B, polaroid filter 32 comprises have the different polarization component two zones of (preferably orthogonal), and these two zone locations become to make test beams T and reference beam R to transmit by different zones.Therefore since with the interaction of this polarizer, cross polarization has all taken place in each light beam.Among the embodiment in Figure 1B, polaroid filter 32 is made up of first linear polarizer regions 34 and second linear polarizer regions 36 adjacent to each other and that have a mutual vertically directed axis of polarization.In another embodiment 38, shown in Fig. 1 C, second polarizer region 36 is surrounded by first polarizer region 34 fully.Such device can be manufactured for example as patterned polarizer (can obtain from the Codixx of German Barleben).In the preferred embodiment shown in Fig. 1 D, the linear polarizer regions 34,36 among dual-aperture mask 33 and Figure 1B is used in combination, with the multipath reflection of blocking-up generation between reference and test surfaces 24,26.
In order to make interferometer to work on wide acceptance angle, the thickness of polarizer should be preferably less than 1.5 λ (NA)
2, wherein, λ is meant light wavelength, NA is meant the numerical aperture of collimation lens 18.As the skilled person will readily understand, bigger thickness will need bigger inclination, and this tends to introduce more aberration by optical system, and therefore will need bigger calibration.Be well known that the polarising means that is equal to that can use other is to replace the optical filtering shown in Figure 1B-1D, for example their axis orientation separately become to become relative to each other two quarter-wave plates of 90 degree.The combination of other birefringence and polarizer is possible equally and knows in this area.
In the rear end of interferometer 10, imaging len 40 is used for test and reference beam T, and the apart between the R is converted to the angle and separates.Polarization spectroscope 42 is used for this light beam of recombination, to produce roughly conllinear and the common wavefront that extends.This light beam is handled by spatial phase shift interferometer module 44 then.Fig. 2 illustrates polarization phase-shifting interferometer 44, wherein incident wavefront when keeping their total path through four treatment steps in succession.The first step utilization refraction, diffraction and/or the reflection beam splitting device that occur in the separation/imaging moiety 46 of interferometer produce a plurality of copy T ' of test and reference wavefront, R '.Second step was utilized phase shift section 48 to produce different relative phases between the copy of reference and test wavefront and moves.Next step combined reference that carries out in interference portion 50 and the dephased copy of test wavefront are to produce interferogram by interacting with suitable polarizer.At last, in the step in the end, the detector portion 52 with a plurality of photodetectors is used for the consequent interferogram of spatial sampling.
As the co-pending U.S. Patent application No.10/652 that is incorporated by reference at this, described in 903, being suitable for spatial phase shift interferometer module 44 of the present invention can implement with various layouts.For example, Fig. 3 illustrates an embodiment 54, and wherein the reference of polarization and test beams are focused on the beamsplitter element 58 of suitable placement by lens 56 orthogonally.This spectroscope by reflection, refraction or diffraction element produce a plurality of sons as light beam to (with reference to adding test), these a plurality of sons as light beam to be calibrated and by lens 60 by 62 imagings of interference sheet to detecting device 64.The generation phase shifts of this sheet 60 and the suitably overlapping son that is calibrated are as light beam, and the interference Figure 66 with phase shift is delivered on the detecting device 64 whereby.The birefringent wave plate that this sheet 62 comprises flat be arranged in parallel and/or adjacent layer in polarizer, as is known in the art.
The entrance area of interferometer 54 preferably inserts field stop 68, this field stop and the planar conjugate of importing pupil image plane and detecting device 64.The purpose of field stop 68 is overlapping between the child picture that is limited on the detecting device.The unconventional array that this detecting device 64 allows the high-resolution digital of the interferogram of phase shift to sample typically.This digitized interferogram is handled in a usual manner by computing machine then, is used for a kind of characterization test surface of many algorithms of knowing of phase determination with utilization.
In another embodiment 70 shown in Fig. 4, image drift interferometer in space uses the method for the spatial-frequency carrier that detects the phase change in the test wavefront.Reference and test beams are calibrated and are directed at the polarizer 72 (it can be a birefringece crystal, for example Wollaston prism, perhaps any other refraction or diffractive part) in the interferometer 70 as described above.This element 72 plays the effect of polarization spectroscope, therefore introduces the angle between corresponding wavefront and separates.This ripple is interfered and imaging on single detector 76 by polarizer 74 then.The contrast of corresponding interferogram can obtain adjusting by rotating this polarizer 74, with the reference of compensating image and the random polarization of test waves.Digitized interferogram is further handled to calculate phase place and characterization test surface by computing machine.
Another embodiment of the present invention shown in Fig. 5 80, optical delay line 84 are used to produce two light beams that separated by optical path delayed Δ L, instruct as people such as Kuchel.Input beam L guides two catoptrons 88 and 90 into by spectroscope 86, preferably along the mutually perpendicular light path that differs Δ L on length.Then, two beam reflected are redirected by spectroscope and inject fizeau interferometer shown in Figure 1, and here they all are reflected from reference surface 24 and test surfaces 26.In the focal plane of main lens 18, folded light beam is transmitted by spatial polarization filter 32, and this polaroid filter transmits test beams T and reference beam R according to selected cross polarization, as previously mentioned.Then, this test and the detected temporary transient phase shifts of reference beam, perhaps as shown in Fig. 2-4 by phase shifts and processing.
Use short coherent source to cause suppressing among the embodiment 80 in Fig. 5 by the reflection of eyeglass rather than test and reference surface generation.The length of adjusting lag line 84 with produce with striking rope chamber 20 in identical path delay, make reference beam R and test beams T transitory phase dry doubling and in spatial phase shift interferometer 44 interference fringe of generation high-contrast.Therefore, the false reflection from the imaging eyeglass significantly reduces.In addition, wideband light source is owing to its short coherent length makes it can select the different surfaces of testing lens to be used for independently measuring, and this different surfaces is the preceding and rear surface of test board for example.Use the another one advantage that broadband light produced to be, usually the rotation frosted glass that is used in the fizeau interferometer in order to the light beam that produces spatial independence can be removed, and therefore produces the higher brightness level and need correspondingly short integral time on detecting device.Can obtain repeatedly to measure and to be averaged to the random phase deviation,, be instructed in 903 the patented claim so that the residual error that depends on phase place in the minimizing system is No.10/652 as sequence number.
Interferometric measuring means 80 also provides the advantage that is better than the disclosed systems of people such as Kuchel.Because behind optical filtering 32 of the present invention, have only two light beams to keep interfering, this obtains the interference figure of higher contrast.All that reflectivity that import wave plate 92 is used to reference and test target also can be provided in conjunction with the contrast of adjusting pattern with near consistent.At last, lag line can combine with piezoelectricity or other scanning elements 94 systematically to introduce little phase shifts in lag line, make a plurality of phase diagrams can be averaged to reduce the error that depends on phase place in the last phase diagram, perhaps use traditional temporary transient phase shifts for the application of using large-scale fizeau interferometer, in this was used, it was impossible moving with reference to the piezoelectricity of eyeglass.
It should be noted that the light beam that is produced by lag line 84 also can be polarized to have the polarization of quadrature, although this feature is not necessary for implementing the present invention.For this purpose, spectroscope need be the spectroscope of polarization, and need be incorporated into such as the other polarizer of wave plate 94 and 98 in the light path of two light beams of the catoptron 88 that points to lag line respectively and 90.As one of ordinary skill in the art will readily recognize that this structure allows all light among the input beam L to transmit towards striking rope chamber, improves energy efficiency whereby and further lowers demand integral time.
Fig. 6 A has shown another embodiment of the present invention 100, and polarization spectroscope 102 is placed in the input channel, and to produce two input beams 104 and 106, these two light beams have the polarization of quadrature and spatially are shifted relative to each other to be opened.These two light beams are injected the striking rope chamber 20 of the reference surface 24 with inclination.Select the separation of two light beams to make advisably and win light beam 104, and second light beam 106 is reflected and leaves the light beam 110 of orientation of its axis interferometer with formation from the light beam 108 of reference surface reflection to be formed on pointing space phase shifting interferometer 44 on the axis.Therefore, hole 112 can be used to block the reflection of second light beam 106 (light beam 110), and transmits the reflection of first light beam 116 (light beam 108).Test surfaces 26 similarly reflects first input beam 104 and leaves the light beam 114 by hole 112 blocking-up of axis with formation, and reflects second input beam 106 to be formed on the light beam 116 by hole 112 transmission on the axis.Light beam 108 and 116 conllinear and polarization substantially orthogonally.Therefore, they can be handled by spatial phase shift interferometer module 44 subsequently.This embodiment has the advantage that need not introduce polarization spectroscope at the interferometer imaging moiety.Lose light in the light beam that shortcoming is blocked by the hole element.
Fig. 6 B has shown another embodiment of the present invention, and the embodiment among this embodiment and Fig. 6 A is closely related.Polarization spectroscope 102 in the input of installing uses diffraction grating 118, expansion lens 14 and polarization filter mask 120 structures.These combination of elements have produced the input beam 104 and 108 of polarization orthogonally, and then, these input beams are introduced in the striking rope chamber of inclination of Fig. 6 A.
Fig. 7 has shown closely-related another embodiment 130 with the embodiment shown in Fig. 6 A.The input beam 104 of polarization and 106 produces from short-phase dry length light source 82, the use that combines with optical delay line 84 of this short-phase dry length light source.Input beam L is divided into two light beams by polarization spectroscope 86 in lag line, as above described with reference to the embodiment among the figure 5 80.Therefore, two light beams are encoded by cross polarization, and light beam 104 has been introduced other light delay Δ L in its light path.In addition, spectroscope 86 also is used for producing apart on the light beam 104 and 106 that points to striking rope chamber.In lag line from catoptron 88 and 90 the reflection after, two light beams are guided striking rope chamber into by the spectroscope with proper angle 86 between two light beams, to realize the undesired reflection needed apart of blocking-up, as top described with reference to the embodiment among the figure 6A 90 from each light beam.Expansion lens 14 is used for light beam coupling to striking rope chamber.This embodiment has all advantages of aforementioned two embodiment 80 and 90.Main shortcoming is the additional complexity of light loss and device.
Fig. 8 has shown another embodiment of the present invention 140, and the input beam 104 of wherein cross polarization and 106 utilizes the light path of separating to produce.The light L of light source is divided into two light beams 104,106 of polarization orthogonally by polarization spectroscope 142, and then, these light beams are drawn towards striking rope chamber.Catoptron 144 is used to provide enforcement the present invention necessary apart.
Those skilled in the art here describe and claims defined in principle of the present invention and category in, various other changes in details, step and the parts that can be described.For example, the position of polarization spatial filtering mirror 32 can be reorientated by using a series of transmission eyeglasses among Figure 1A.A series of transmission eyeglasses can be used for the polarization spectroscope 42 and other conjugate image planes to imaging system, the position of blocking hole 112 of the embodiment of relocation clock 6A, as shown in Figure 9.Similarly, as shown in Figure 10, lag line among Fig. 5 and polarization spectroscope can combine with the spatial phase shift interferometer among Fig. 3 and be arranged to the test surfaces that parallels with reference surface in the fizeau interferometer structure to be characterized in.
Therefore, although illustrate and described the present invention here to be considered to the most practical and most preferred embodiment, but be well known that, in category of the present invention, can depart from these details, the present invention is not limited to disclosed details, but consistent, so that comprise any and all method that is equal to and products with the gamut of claim.
Claims (33)
1. optical devices that are connected to the spatial phase shift interferometer module, be used to be characterized in the test surfaces that is provided with an angle of inclination with respect to reference surface in the optics cavity, wherein input beam is reflected to produce corresponding test and reference beam by described test and reference surface, and these optical devices comprise:
Be used to produce the device of the apart between described test and the reference beam;
Be used for device with each described test of self-orthogonal polarization state polarization and reference beam; And
Be used for eliminating the described apart between this test and the reference beam and be used for producing the device of its combination at collimated light beam.
2. optical devices as claimed in claim 1, wherein, the described device that is used to produce the apart between described test and the reference beam comprises the described pitch angle between this test and the reference surface; And the described device that wherein is used for described test of polarization and reference beam comprises the polaroid filter with two polarizers that produce orthogonal polarization state.
3. optical devices as claimed in claim 2, wherein, one in the described polarizer by another encirclement in described two polarizers.
4. optical devices as claimed in claim 1 also comprise optical delay line, two light beams that this optical delay line works and temporarily separates with the predetermined light paths delay to produce described input beam.
5. optical devices as claimed in claim 4 also comprise being used to change described optical path delayed device.
6. optical devices as claimed in claim 2 also comprise optical delay line, two light beams that this optical delay line works and temporarily separates with the predetermined light paths delay to produce described input beam.
7. optical devices as claimed in claim 6 also comprise being used to change described optical path delayed device.
8. optical devices as claimed in claim 1, wherein, the described device that is used for eliminating the described apart between this test and the reference beam and is used for producing at collimated light beam its combination comprises imaging device and polarization spectroscope, this imaging device is converted into the angle with described apart to be separated, this polarization spectroscope should test and the reference beam recombination to produce described collimated light beam.
9. optical devices as claimed in claim 1, wherein, the described device that is used to produce the apart between this test and the reference beam comprises spectroscope, this spectroscope works to described input beam and produces two light beams that spatially separate, make described light beam each produce light beam on the axle that points to along the optical axis of described spatial phase shift interferometer module from described test and reference surface reflection back and point to leave its described optical axis from Axial Bundle.
10. optical devices as claimed in claim 9, wherein, the described device that is used for this test of polarization and reference beam is included in the polarizer of described spectroscope.
11. optical devices as claimed in claim 9 comprise that also transmitting described axle goes up light beam and block described hole from Axial Bundle.
12. optical devices as claimed in claim 9 also comprise optical delay line, this optical delay line works to described input beam and has described two light beams that spatially separate that predetermined light paths postpones therebetween to produce.
13. optical devices as claimed in claim 12 also comprise being used to change described optical path delayed device.
14. optical devices as claimed in claim 1, wherein, the described device that is used to produce the apart between this test and the reference beam comprises spectroscope and catoptron, this spectroscope works to described input beam with catoptron and produces two light beams that spatially separate, make described light beam each produce light beam on the axle that points to along the optical axis of described spatial phase shift interferometer module from described test and reference surface reflection back and point to leave its described optical axis from Axial Bundle.
15. optical devices as claimed in claim 14, wherein, the described device that is used for this test of polarization and reference beam is included in the polarizer of described spectroscope.
16. optical devices as claimed in claim 14 comprise that also transmitting described axle goes up light beam and block described hole from Axial Bundle.
17. method by the optical devices characterization test surface that is connected to the spatial phase shift interferometer module, wherein, described test surfaces is provided with an angle of inclination with respect to the reference surface in the optics cavity, and input beam is reflected to produce corresponding test and reference beam by described test and reference surface, and this method may further comprise the steps:
Produce the apart between described test and the reference beam;
Should test and reference beam with each self-orthogonal polarization state polarization;
Eliminate the described apart between this test and the reference beam and in collimated light beam, produce its combination; And
In this spatial phase shift interferometer module, handle described collimated light beam to carry out phase measurement.
18. method as claimed in claim 17, wherein, the described step that produces the apart between this test and the reference beam is by utilizing the described pitch angle between this test and reference surface to carry out; And wherein the described step of this test of polarization and reference beam is undertaken by polaroid filter, and this polaroid filter comprises two polarizers that produce orthogonal polarization state.
19. method as claimed in claim 18, wherein, one in the described polarizer by another encirclement in described two polarizers.
20. method as claimed in claim 17 also comprises the step that optical delay line is provided, two light beams that this optical delay line works and temporarily separates with the predetermined light paths delay to produce described input beam.
21. method as claimed in claim 20 also comprises being used to change described optical path delayed device.
22. method as claimed in claim 17, wherein, the described step of eliminating this apart between this test and the reference beam and produce its combination in collimated light beam comprises: utilize imaging device that described apart is converted into the angle and separate, and utilize polarization spectroscope should test and the reference beam recombination to produce described collimated light beam.
23. method as claimed in claim 17, wherein, the described step that produces the apart between this test and the reference beam is undertaken by spectroscope, this spectroscope works to produce two light beams that spatially separate to described input beam, makes that light beam and sensing leave its described optical axis from Axial Bundle on the axle that points to along the optical axis of described spatial phase shift interferometer module producing from described test and reference surface reflection back for each of described light beam.
24. method as claimed in claim 23, wherein, the described of this test of polarization and reference beam is to be undertaken by the polarizer in the described spectroscope.
25. method as claimed in claim 23 also comprises providing and transmits the step that described axle is gone up light beam and blocked described hole from Axial Bundle.
26. method as claimed in claim 23 also comprises the step that optical delay line is provided, this optical delay line works to described input beam and has described two light beams that spatially separate that predetermined light paths postpones therebetween to produce.
27. method as claimed in claim 26 also comprises the step that is provided for changing described optical path delayed device.
28. method as claimed in claim 17, wherein, the described step that produces the apart between this test and the reference beam is undertaken by spectroscope and catoptron, this spectroscope works to described input beam with catoptron and produces two light beams that spatially separate, make described light beam each produce light beam on the axle that points to along the optical axis of described spatial phase shift interferometer module from described test and reference surface reflection back and point to leave its described optical axis from Axial Bundle.
29. method as claimed in claim 28, wherein, the described step of this test of polarization and reference beam is to be undertaken by the polarizer in the described spectroscope.
30. method as claimed in claim 28 also comprises providing and transmits the step that described axle is gone up light beam and blocked described hole from Axial Bundle.
31. optical devices are used for characterizing the test surfaces relative with the reference surface of optics cavity, comprising:
Optical delay line, two light beams that it works and temporarily separate with the predetermined light paths delay to produce input beam;
Be used for device with described two light beams of each self-orthogonal polarization state polarization;
Be used for that described two light beams projection is had the test beams of orthogonal polarization state and the device of reference beam to described optics cavity with generation;
Be used to produce the device of a plurality of copies of this test and reference beam;
Be used between the described copy of this reference and test beams, producing the device that different relative phases moves;
Be used for should reference and the described copy of test beams in conjunction with to produce the device of interferogram; And
Be used to detect device with the described interferogram of spatial sampling.
32. optical devices as claimed in claim 31 also comprise being used to change described optical path delayed device.
33. optical devices as claimed in claim 31, wherein, described input beam has the coherent length less than the twice of the length of described optics cavity.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US2005/002923 WO2006080923A1 (en) | 2005-01-27 | 2005-01-27 | Simultaneous phase-shifting fizeau interferometer |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2009101747444A Division CN101694369B (en) | 2005-01-27 | 2005-01-27 | Fizeau interferometer with simultaneous phase shifting |
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| Publication Number | Publication Date |
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| CN101111739A true CN101111739A (en) | 2008-01-23 |
| CN100552375C CN100552375C (en) | 2009-10-21 |
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| CN (1) | CN100552375C (en) |
| WO (1) | WO2006080923A1 (en) |
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| CN102576209A (en) * | 2009-10-08 | 2012-07-11 | 布鲁塞尔大学 | Off-axis interferometer |
| CN102853761A (en) * | 2012-08-28 | 2013-01-02 | 广州华工百川科技股份有限公司 | Space phase shifter |
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| US3849003A (en) * | 1970-03-25 | 1974-11-19 | Philips Corp | Interferometer apparatus for measuring the roughness of a surface |
| US4594003A (en) * | 1983-07-20 | 1986-06-10 | Zygo Corporation | Interferometric wavefront measurement |
| DE10130902A1 (en) * | 2001-06-27 | 2003-01-16 | Zeiss Carl | Interferometer system, method for recording an interferogram and method for providing and producing an object with a target surface |
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| WO2005089299A2 (en) * | 2004-03-15 | 2005-09-29 | Zygo Corporation | Interferometer having an auxiliary reference surface |
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| CN103328921A (en) * | 2011-01-25 | 2013-09-25 | 麻省理工学院 | Single-shot full-field reflection phase microscopy |
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Also Published As
| Publication number | Publication date |
|---|---|
| WO2006080923A1 (en) | 2006-08-03 |
| CN100552375C (en) | 2009-10-21 |
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