CN107830937B - Double grating polarized point diffraction interferometer device and wavefront test method - Google Patents
Double grating polarized point diffraction interferometer device and wavefront test method Download PDFInfo
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- CN107830937B CN107830937B CN201711287015.0A CN201711287015A CN107830937B CN 107830937 B CN107830937 B CN 107830937B CN 201711287015 A CN201711287015 A CN 201711287015A CN 107830937 B CN107830937 B CN 107830937B
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- 230000003287 optical effect Effects 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 26
- 230000001427 coherent effect Effects 0.000 claims abstract description 14
- 230000010363 phase shift Effects 0.000 claims abstract description 8
- 230000010287 polarization Effects 0.000 claims description 21
- 238000003491 array Methods 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 4
- 238000009738 saturating Methods 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 claims description 2
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- 241000208340 Araliaceae Species 0.000 description 2
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 2
- 235000003140 Panax quinquefolius Nutrition 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 235000008434 ginseng Nutrition 0.000 description 2
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- 238000005530 etching Methods 0.000 description 1
Classifications
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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
- 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
- G01J2009/0223—Common path interferometry; Point diffraction interferometry
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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
- G01J2009/0261—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength by interferometric methods polarised
- G01J2009/0265—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength by interferometric methods polarised with phase modulation
Abstract
The invention discloses a kind of double grating polarized point diffraction interferometer device and wavefront test methods, including beam-splitting optical grating, the first polarizing film, point diffractive plate PDP, the second polarizing film, plane mirror, combined beam light grid, spatial Phase-shifting Method component, ccd image sensor；Double grating polarized point diffraction device is divided using beam-splitting optical grating, to realize the relevant light modulation of subsequent optical path；Total light channel structure is formed using combined beam light grid, to realize the interference of light of detection device, the collimated objective lens entrance of coherent light finally collects the spatial Phase-shifting Method interference pattern that amount of phase shift differs 90 ° into spatial Phase-shifting Method component on ccd image sensor, resolves wavefront to be measured using Phase-shifting algorithm.
Description
Technical field
The invention belongs to the technical fields of optical interferometry, and in particular to fill to using double grating polarized point diffraction interferometer
It sets, is used for point-diffraction interference dynamic Wave-front Measuring Technique.
Background technique
Point-diffraction interference technology remains the advantage of the high-resolution measurement of interferometry, in turn ensures total optical path characteristic, makes
It obtains Wave-front measurement and is provided simultaneously with high-resolution, high-precision advantage.However, such technology is still at an early stage, improvement still in need
Place.It is mainly shown as: guaranteeing to realize spatial Phase-shifting Method while optical path characteristic altogether.In order to promote phase recovery precision, generally adopt
With spatial Phase-shifting Method algorithm demodulation phase, and realizes spatial Phase-shifting Method and need to carry out Polarization Modulation to coherent light.
In currently existing scheme or polarized point diffraction plate and micro- polarization arrays are used, or are tied using Mach-Zehnder
Structure is respectively to relevant light modulation.For the former, polarized point diffraction plate is obtained by etching pin hole on polarizing film, cannot be obtained partially
The coherent light of polarization state exact vertical, so that including error in phase recovery result；As for the latter, need using a variety of optical elements
It realizes the beam splitting of coherent light and closes beam, largely destroy total light channel structure, reduce system accuracy.
Summary of the invention
In order to solve in existing point-diffraction interference technology, the problem that precision is low, error is big, the present invention provides one kind to be used for
Point-diffraction interference technology detects the double grating polarized point diffraction interferometer device of wavefront to be measured.
Realize the technical solution of the object of the invention are as follows: a kind of double grating polarized point diffraction interferometer device, including beam-splitting optical grating,
First polarizing film, point diffractive plate PDP, the second polarizing film, plane mirror, combined beam light grid；Beam-splitting optical grating is one-dimensional with combined beam light grid
Grating；
Beam-splitting optical grating is divided, and the first polarizing film, point diffractive plate PDP, the second polarizer group are at polarization type point diffractive plate；
The saturating vibration direction of first polarizing film and the second polarizing film is orthogonal, and described diffractive plate PDP is equipped with diffraction pin hole and transmission
Hole, direct light go out from the transmission of diffractive plate PDP beam orifice, carry wavefront wave difference information formation test light to be measured, diffraction light from
It puts diffractive plate PDP diffraction pin hole diffraction and goes out, form the reference light close to ideal spherical face wave through pinhole filter；Reference light is by flat
Face reflecting mirror is reflected into combined beam light grid, and reference light, into plane mirror, reaches raising with reference to light polarization with brewster angle incidence
The purpose of degree, reference light is Chong Die at combined beam light grid with test light, forms light channel structure altogether.
By combined beam light grid diffraction occurs for reference light and test light, take test light 0 grade of diffraction light and+1 grade of reference light
Diffraction light forms total optical path coherent light, and collimated objective lens entrance will on ccd image sensor into spatial Phase-shifting Method component, finally
The spatial Phase-shifting Method interference pattern that amount of phase shift differs 90 ° is collected simultaneously, and wavefront to be measured is resolved using Phase-shifting algorithm.
A kind of wavefront test method based on double grating polarized point diffraction interferometer device:
Step 1: wavefront to be measured is incident on beam-splitting optical grating (1) and is divided into 0 grade of diffraction light and+1 grade of diffraction light；
Step 2: 0 grade of diffraction light is with+1 grade of diffraction light through the first polarizing film (2), point diffractive plate PDP (3), the second polarizing film
(4) polarization type point diffractive plate is formed, diffraction light goes out from the diffraction pin hole diffraction of diffractive plate PDP (3), formed through pinhole filter
Close to the reference light of ideal spherical face wave；Direct light goes out from diffractive plate PDP (3) beam orifice transmission, and it is poor to carry wavefront wave to be measured
Information forms test light；
Step 3: reference light with brewster angle incidence into plane mirror (5), improve and refer to polarization degree, plane is anti-
It penetrates mirror (5) reference light is turned back at combined beam light grid (6), and Chong Die with test light；
Step 4: reference light and test light take the 0 grade of diffraction light and ginseng of test light by combined beam light grid (6) generation diffraction
+ 1 grade of diffraction light for examining light forms total optical path coherent light；
Step 5: the collimated objective lens entrance of coherent light finally acquires on ccd image sensor into spatial Phase-shifting Method component
90 ° of spatial Phase-shifting Method interference pattern is differed to amount of phase shift；
Step 6: wavefront to be measured is resolved using Phase-shifting algorithm:S11、S12、S13、S14Respectively
90 ° of interference pattern light distribution is differed for phase shift difference.
Compared with prior art, the present invention remarkable advantage are as follows: compared to showing using polarized point diffraction plate and micro- polarization arrays
There is scheme, the polarization state that is concerned with is vertical, and phase recovery result includes that error is smaller；Distinguish compared to using Mach-Zehnder structure
To the scheme of relevant light modulation, reduce the optical element for realizing that beam is closed in coherent light beam splitting, largely retains optical path knot altogether
Structure improves system accuracy.
Detailed description of the invention
Fig. 1 is double grating polarized point diffraction interferometer wavefront test macro.
Fig. 2 is double grating point diffraction polarization modulating system.
Fig. 3 is a diffractive plate PDP structure.
Fig. 4 is spatial Phase-shifting Method modular construction.
Fig. 5 is micro- polarization arrays structural schematic diagram.
Specific embodiment
With reference to the accompanying drawing and specific embodiment is described in further details the present invention.
As shown in Figure 1, be double grating polarized point diffraction interferometer wavefront test macro, wherein double grating polarized point diffraction interferometer
Device 100 and spatial Phase-shifting Method component 200 and ccd image sensor 300, light is by double grating polarized point diffraction interferometer device 100
Diffraction interference is carried out, forms optical path coherent light altogether, coherent light enters spatial Phase-shifting Method component 200, finally on ccd image sensor
Collect the spatial Phase-shifting Method interference pattern that amount of phase shift differs 90 °.
As shown in Fig. 2, double grating point diffraction polarization modulating system, wherein beam-splitting optical grating 1, the first polarizing film 2, point diffractive plate
PDP3, the second polarizing film 4, plane mirror 5, combined beam light grid 6.
As shown in figure 3, point diffractive plate PDP3, which is provided with beam orifice 3-1 and diffraction pin hole 3-2.
As shown in figure 4, spatial Phase-shifting Method modular construction, including the first lens 7, chessboard phase grating 8, filter 9 prolongs
Slow array group 10, third polarizing film 1, the second lens 12.
Double grating polarized point diffraction interferometer device, along the direction of light incidence be followed successively by beam-splitting optical grating 1, the first polarizing film 2,
Point diffractive plate PDP3, the second polarizing film 4, plane mirror 5, combined beam light grid 6；The beam-splitting optical grating 1 is divided, the first polarization
Piece 2, point diffractive plate PDP3, the second polarizing film 4 form polarization type point diffractive plate, the saturating vibration of the first polarizing film 2 and the second polarizing film 4
Direction is orthogonal.
Angle by the reference light plane of incidence reflecting mirror 5 of the first polarizing film 2 is Brewster's angle.
Wavefront test method based on double grating polarized point diffraction interferometer device is as follows:
Wavefront to be measured impinges perpendicularly on beam-splitting optical grating 1 and is divided into 0 grade of diffraction light and+1 grade of diffraction light, vertical incidence beam-splitting optical grating
1 light splitting angle meets the following conditions:
D sin θ=m λ
D is grating coefficient, and θ is the angle of light splitting, and m is light splitting series, and λ is wavelength.0 grade of diffraction light and+1 is taken in embodiment
Grade diffraction light, m 1.
Direct light transmits from the beam orifice 3-1 of diffractive plate PDP3 and is gone out, and carries wavefront wave difference information to be measured and forms test
Light, diffraction light go out from the diffraction pin hole 3-2 diffraction of diffractive plate PDP3, form the ginseng close to ideal spherical face wave through pinhole filter
Examine light.
Vibration direction is orthogonal thoroughly for first polarizing film 2 and the second polarizing film 4, and reference light is with brewster angle incidence into plane
Reflecting mirror 5, incidence angle and plane mirror refractive index meet:
Tan λ=n2/n1
λ is the incidence angle of reference light plane of incidence reflecting mirror, n2For plane mirror refractive index, n1For air refraction, one
As take 1.According to fresnel formula, the polarization state of incident light will be changed, under the conditions of Brewster angle incidence, the p of emergent light
Component will be suppressed, and back wave will contain only s component.Meeting this formula can realize that the secondary of reference light is polarized, and reach raising reference light
The purpose of degree of polarization.
Reflecting mirror 5 turns back reference light at combined beam light grid 6, and Chong Die with test light, and reference light and test light pass through light
Diffraction occurs for grid 6, and+1 grade of diffraction light of the 0 grade of diffraction light and reference light that take test light forms total optical path coherent light, collimated object
Mirror is incident on spatial Phase-shifting Method component 200.
In spatial Phase-shifting Method component, coherent light is through chessboard phase grating G3Light splitting, converges to L2Focal plane at.Using space
Filter SP selection (± 1, ± 1) grade diffraction light is incident on delay array group CW.CW using optical path delay amount be followed successively by λ/4,
λ/2,3 λ/4, λ wavelet piece constitute.Polarizing film P on the phase retardation and PDP of adjustment delay array2Vibration direction is consistent thoroughly,
Using saturating vibration direction and P2The polarizing film P of 45 ° of folder3。
The spatial Phase-shifting Method interference pattern that 90 ° of amount of phase shift difference will finally be collected simultaneously on ccd image sensor 300, is adopted
Wavefront to be measured is resolved with Phase-shifting algorithm:S11、S12、S13、S14Respectively phase shift difference differs 90 °
Interference pattern light distribution.
In addition, spatial Phase-shifting Method modular construction used by the technical solution of the invention patent can also be replaced with micro- polarization arrays
In generation, it is micro- polarization arrays structural schematic diagram as shown in Figure 5, the same function of realizing interferometric phase modulation.
Claims (5)
1. a kind of double grating polarized point diffraction interferometer device, it is characterised in that: described device is followed successively by along the direction of light incidence
Beam-splitting optical grating (1), the first polarizing film (2), point diffractive plate PDP (3), the second polarizing film (4), plane mirror (5), combined beam light grid
(6)；The beam-splitting optical grating (1) is divided, and the first polarizing film (2), point diffractive plate PDP (3), the second polarizing film (4) composition are inclined
The saturating vibration direction of vibration formula point diffractive plate, the first polarizing film (2) and the second polarizing film (4) is orthogonal, described diffractive plate PDP
(3) diffraction pin hole and beam orifice are equipped with；Lateral shift distance is equipped between diffraction pin hole and beam orifice；First polarizing film (2)
Near the diffraction pin hole of near point diffractive plate PDP (3), the second polarizing film (4) is leaned near the beam orifice of near point diffractive plate PDP (3),
Direct light goes out from the transmission of diffractive plate PDP (3) beam orifice, carries wavefront wave difference information formation test light to be measured, diffraction light from
It puts diffractive plate PDP (3) diffraction pin hole diffraction and goes out, form the reference light close to ideal spherical face wave through pinhole filter；Reference light warp
It crosses plane mirror (5) to be reflected into combined beam light grid (6), reference light is Chong Die at combined beam light grid (6) with test light, forms optical path altogether
Structure.
2. a kind of double grating polarized point diffraction interferometer device according to claim 1, it is characterised in that: pass through the first polarizing film
(2) angle of reference light plane of incidence reflecting mirror (5) is Brewster's angle.
3. a kind of double grating polarized point diffraction interferometer device according to claim 1, it is characterised in that: double grating polarization point spreads out
Interference device is penetrated along light incident direction, spatial Phase-shifting Method component (7) or micro- polarization arrays are successively arranged after combined beam light grid (6),
Ccd image sensor (8).
4. a kind of double grating polarized point diffraction interferometer device according to claim 3, it is characterised in that: reference light and test light
Diffraction occurs by combined beam light grid (6), it is relevant that+1 grade of diffraction light of the 0 grade of diffraction light and reference light that take test light forms total optical path
Light, collimated objective lens entrance finally collect amount of phase shift difference in spatial Phase-shifting Method component (7) on ccd image sensor (8)
90 ° of spatial Phase-shifting Method interference pattern resolves wavefront to be measured using Phase-shifting algorithm.
5. based on a kind of wavefront test method of double grating polarized point diffraction interferometer device described in claim 1, feature exists
In:
Step 1: wavefront to be measured is incident on beam-splitting optical grating (1) and is divided into 0 grade of diffraction light and+1 grade of diffraction light；
Step 2 :+1 grade of diffraction light goes out from the diffraction pin hole diffraction of diffractive plate PDP (3) again after the first polarizing film (2), warp
Pinhole filter forms the reference light close to ideal spherical face wave；0 grade of diffraction light transmits from the beam orifice of diffractive plate PDP (3) and is gone out,
Wavefront wave difference information to be measured is carried after the second polarizing film (4) again and forms test light；
Step 3: reference light with brewster angle incidence into plane mirror (5), improve and refer to polarization degree, plane mirror
(5) reference light is turned back at combined beam light grid (6), and Chong Die with test light；
Step 4: reference light and test light take the 0 grade of diffraction light and reference light of test light by combined beam light grid (6) generation diffraction
+ 1 grade of diffraction light form total optical path coherent light；
Step 5: the collimated objective lens entrance of coherent light finally collects shifting into spatial Phase-shifting Method component on ccd image sensor
Phasor differs 90 ° of spatial Phase-shifting Method interference pattern；
Step 6: wavefront to be measured is resolved using Phase-shifting algorithm:S11、S12、S13、S14Respectively move
Difference differs 90 ° of interference pattern light distribution, wave numberλ is wavelength.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102095504A (en) * | 2010-12-07 | 2011-06-15 | 四川大学 | Ring common-path point diffraction interferometer based on spatial phase modulation |
| CN103245423A (en) * | 2013-04-28 | 2013-08-14 | 内蒙古工业大学 | Common-optical path polarization point diffraction phase-shift interference wavefront sensor |
| CN107024173A (en) * | 2016-02-01 | 2017-08-08 | 南京理工大学 | Use the common light path point diffraction simultaneous phase-shifting interference testing device of pinhole difiration plate |
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| JP2004184309A (en) * | 2002-12-05 | 2004-07-02 | Pulstec Industrial Co Ltd | Interferometer |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102095504A (en) * | 2010-12-07 | 2011-06-15 | 四川大学 | Ring common-path point diffraction interferometer based on spatial phase modulation |
| CN103245423A (en) * | 2013-04-28 | 2013-08-14 | 内蒙古工业大学 | Common-optical path polarization point diffraction phase-shift interference wavefront sensor |
| CN107024173A (en) * | 2016-02-01 | 2017-08-08 | 南京理工大学 | Use the common light path point diffraction simultaneous phase-shifting interference testing device of pinhole difiration plate |
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