CN104034271B - A kind of lateral resolution reaches the interference rotation map detection method of 1nm - Google Patents

Abstract

A kind of lateral resolution reaches the interference rotation map detection method of 1nm, it is characterised in that the method devises a kind of both arms and interferes microscopic system.This system can will be presented on uniform location, so that it interferes with reference to the picture of reflecting surface with measured object.Interfere the spectrum formed or striped can map out the optical path difference at measured point.Rotation/the scanning platform of Piezoelectric Driving is installed, it is possible to achieve the transversal scanning of 1nm precision and 360 degree of rotations below measured object.By difference acquisition method, it is possible to obtain the light path projection upwards of ultrahigh resolution one-dimensional square.Then sample is rotated, gather the light path projection of sample under multiple angle, three-dimensional ultrahigh resolution image can be reconstructed.

Description

A kind of lateral resolution reaches the interference rotation map detection method of 1nm

Technical field

The present invention relates to ultrahigh resolution micro measurement technology, particularly relate to a kind of based on Michelson interferometer structure, There is the detection technique of rotation map ultrahigh resolution imaging.

Background technology

Micro-imaging technique has a wide range of applications in fields such as electronics technology, biomedicine, chemical materials.Along with science The development of technology, people are also more and more higher to the requirement of microscopic resolution.But traditional optical microphotograph resolution can be subject to The restriction of diffraction limit, is merely able to realize the resolution of submicron order, it is impossible to meet the application needs of development in science and technology.

In order to solve the problem of optical microscope diffraction limit, scientific research personnel have developed a series of ultrahigh resolution and shows Micro-system.Ultramicroscope is the ultrahigh resolution microscope being most widely used at present, and it uses electron beam to substitute light beam, right Imaging of samples.Wavelength due to electron beam is much smaller than the wavelength of visible ray, such that it is able to realize higher resolution.But The electron beam that ultramicroscope is used has a serious injury to cell, and environment must be near vacuum state, so not Living cells can be observed, this severely limits the ultramicroscope application at biomedical sector.

Scanning probe microscopy is another ultrahigh resolution microscope.Scanning probe microscopy utilizes voltage level moving stage The imaging resolution of displacement resolution alternative optical system, it is achieved high-resolution electric scanning imaging.Scanning probe microscopy Developed polytypes such as atomic force microscope, scanning electron microscope, but this kind of microscope needs that grows very much to sweep Retouch the time, be not suitable for the detection to dynamic sample.

Optical microscope aspect also has the relevant technical method breaking through diffraction limit.As late 1920s proposes, The NFM that the eighties in 20th century is just achieved, uses nano optical fibers probe, near by controlling in wavelength dimension Distance contact range gathers diffracted light signals, it is achieved that the super resolution optical scanning imagery of about 30nm.The and for example beginning of this century " the random optical reconstruction microscopy ", " photoactivation location microtechnique " of development etc., this kind of method uses the principle of local tomography, One part of pixel in the most specific activation image in Polaroid, to prevent the crosstalk between pixel, it is possible to achieve 20-30nm Super-resolution scanning imagery.But, this kind of method is in order to realize lighting of pixel in batches, and sample must use fluorescence to process, Fluorescent labeling then can produce certain toxicity to biological sample, and makes whole detection process significantly complicate.Above method is equal Need the detection time grown very much could obtain piece image, be not suitable for the detection of dynamic sample.

Additionally, also the instrument such as ellipsometer test, white light interferometer has been able in the superelevation longitudinally realizing nanometer level Resolution.This quasi-instrument utilizes the interference of light self or polarization to achieve the resolution of nanometer level, but its range of dynamic measurement The most hundreds of nanometer, and this resolution is only capable of embodying the change of sample surfaces thickness, and cannot provide higher horizontal point Resolution.

Summary of the invention

It is an object of the invention to provide a kind of lateral resolution and reach the interference rotation map detection method of 1nm, it is special Levy and be that to interfere to map in detecting system at a sample surfaces thickness including dynamic sample and realize according to the following steps :

Step (1), constructs an optical interference structure, by rotating sample, the longitudinal direction interfering thickness measure is divided Resolution Mapping Resolution is open into resolution, for realizing the interference rotation map detecting system of three-dimensional ultrahigh resolution imaging, its Include: light source (1), collimating mirror (2), beam splitter (3), the first object lens (41), the second object lens (42), computer (5), imaging are saturating Mirror (6), sensitive detection parts (7), electronic rotation/translation three-dimensional motion object stage (8) and reflecting mirror (9), wherein:

Light source (1) is laser or other white light source,

Beam splitter (3) is any one of plane mirror, dichroic mirror or prism,

First object lens (41), are positioned at length-adjustable measurement arm arm end,

Second object lens (42), are positioned at length-adjustable reference arm arm end,

Sensitive detection parts (7), use white light to make during light source to be spectrogrph, use laser to make during light source to be CCD device, described spy The outfan surveying device (7) is connected with described computer (5),

Electronic rotation/translation three-dimensional motion object stage (8), be called for short object stage (8), be positioned at described first object lens (41) just under Side, has the microcarrier chip of sample, described object stage (8) to be three layers of nested structure for installing surface attachment, and outer layer is Motor drives motion platform, centre to drive motion platform for piezoquartz, and internal layer is rotation sweep platform, and microcarrier chip is fixed On internal layer rotation sweep platform, described object stage (8), under the control of described computer (5), completes described microcarrier core The scanning of sample and rotation on sheet, to obtain the full spectral information of all spatial points of sample；

The light that light source (1) sends impinges perpendicularly on described beam splitter (3) after described collimating mirror (2) is collimated into directional light On, it is divided into transmission light and reflection light；Described transmission light converges on described microcarrier chip through described first object lens (41), by instead Again through described first object lens (41) after being emitted back towards, it is collimated into directional light, is sent to described beam splitter (3), is reflected to institute Object light is pooled after stating on imaging len (6)；Described reflection light is after described second object lens (42) are collimated into directional light, described Reflecting mirror (9) reflects, and is collimated into directional light through described second object lens (42) the most again, then after described beam splitter (3) transmission, Reference light is pooled by described imaging len (6)；Described object light and reference light coherent superposition are received by described sensitive detection parts (7), It is subsequently sent to described computer (5), is formed and interfere high-resolution spectroscopy, be called for short EO-1 hyperion；

Step (2), described a kind of lateral resolution reaches the interference rotation map detection method of 1nm, and implementation step is such as Under:

Step (2,1), adjusts measurement arm and becomes identical optical path length with reference arm, make object light and reference light interfere；

Step (2,2), described computer (5) controls described object stage (8), is adjusted to horizontal level, opens described light source (1), it is thus achieved that the EO-1 hyperion of sample；

Step (2,3), under described computer (5) controls, described object stage (8) rotates around trunnion axis, searches out reflection Anglec of rotation α of intensity maxima point, it is thus achieved that the interference EO-1 hyperion of sample under described anglec of rotation α；

Step (2,4), the described interference EO-1 hyperion that step (2,3) is obtained, carry out microcarrier chip high spectrum intervention thick Degree coding/decoding numerical solution, calculates sample radial thickness information ρ under anglec of rotation α；

Step (2,5), calculates sample mapping longitudinal coordinate y under anglec of rotation α and lateral coordinates according to the following formula X:

X=ρ × Cos α,

Y=ρ × Sin α；

Step (2,6), by radial thickness resolution ax ρ, calculates sample under anglec of rotation α according to the following formula Mapping longitudinal resolution Δ y and lateral resolution Δ x:

Δ x=Δ ρ × Cos α,

Δ y=Δ ρ × Sin α.

A kind of lateral resolution that the present invention provides reaches the interference rotation map detection method of 1nm, it is characterised in that institute State microcarrier chip high spectrum intervention thickness coding/decoding method, by numerical solution calculated thickness, measure radially or longitudinally thick Degree resolution can reach 1nm；It is further characterized in that described interference high-resolution spectroscopy is suitable for all two corrugated parts or complete The interference spectrum of any interference structure device generation of portion's coherent superposition or interference fringe.

No matter use which kind of method to obtain the one-dimensional scattergram of thickness of sample, all can be obtained by rotatable stage multiple The one-dimensional scattergram of thickness of angle shot.One-dimensional for these thickness scattergram is integrated, utilizes Radon alternative approach to get final product real Existing two dimensional surface imaging and fault information, utilize multi-angle to interfere EO-1 hyperion to reconstruct and restore 3 d surface topography information, Utilize spectrum coding method that longitudinal resolution is mapped to lateral resolution, two dimension, resolution and the one-dimensional distribution of three-dimensional reconstruction figure The resolution of figure is consistent, has the feature of 1nm ultrahigh resolution.

A kind of lateral resolution that the present invention provides reaches the interference rotation map detection method of 1nm, it is characterised in that institute Stating sample is biomolecule, biomolecule, cell, tissue, virus, microorganism, antibacterial, micro Process structure and nanometer material Any one of material.

Accompanying drawing explanation

Fig. 1 broadband light super-resolution microscope equipment structural representation

Fig. 2 laser super-resolution microscope equipment structural representation

Fig. 3 image planes difference and the mapping relations figure of interference fringe

Fig. 4 phase contrast score value and the mapping relations figure of optical path difference variable quantity

Fig. 5 angle coverage, angular resolution and the last relation rebuild between image

Fig. 6 interferes rotation map to realize the extremum principle that longitudinal resolution is changed to lateral resolution

Fig. 7 interferes the example of rotation map method reduction triangle shape nanostructured

Fig. 8 interferes rotation map to realize the General Principle that longitudinal resolution is changed to lateral resolution

Detailed description of the invention

1, system apparatus arrangements

The embodiment of the method is now illustrated by measuring the experiment of aluminium-foil paper surface topography.The invention provides one Plant EO-1 hyperion microscopic system as depicted in figs. 1 and 2, including light source 1, collimating mirror 2, beam splitter 3, reference arm object lens 42, survey Amount arm object lens 41, imaging lens 6, sensitive detection parts 7, rotation/translation stage 8, reflecting mirror 9 and computer 5.Rotate/translation loading Platform 8 uses piezoquartz to drive and realizes the translation of nm resolution, and turntable uses turbine and worm transmission.Detection when light source selects white light Device 7 needs to use spectrogrph 7a, and when light source selects laser, sensitive detection parts 7 need to use CCD7b.Reference arm or the length of measurement arm Degree can regulate.

Specific to all parts, the wideband light source of system can use broadband halogen tungsten lamp, electrical power 250W, and luminous flux 9000 flows Bright, spectral region 400nm 2500nm.Light optical fiber couples, and is transmitted to above collimating lens, and emergent light is collimated by collimating lens After be input in system.LASER Light Source uses semiconductor laser, wavelength 650nm (or other wavelength), luminous power 50mW, passes through Collimating lens is input in system after being transformed into directional light.

System uses flat field infinity camera lens, numerical aperture 0.60, operating distance 3.7-2.7mm；Eyepiece focal length 800nm. Camera lens amplification 61.5 ×.Object lens are fixed on electric elevating rack, in order to electromotive focusing.

System rotation/translation stage 8 includes translation stage and turntable two parts, and the translation stage used in it is double-deck Nested structure, outer layer is motor driven platform, and internal layer is piezoelectric drive platform.The step resolution of motor driven platform is 6 μm, The step resolution of piezoelectric drive platform is 2nm, with Close loop servo control.Turntable is fixed on piezoelectric drive platform.

2, light path detection method

System uses wideband light source or LASER Light Source illumination.When using different light sources, need to use different light paths to examine Survey method, could accurately detect the change of measured object surface thickness.

When using wideband light source, reference image can interfere with measuring picture in spectral domain, needs to use spectrogrph to make For sampler.The spectral response range of spectrogrph requires as 0.2-1.1 μm or wider, can cover comprehensively ultraviolet-visible light- Infrared band.When reference image and measure as between optical path difference less time, the frequency of interference spectrum is relatively low；When reference image and measurement When optical path difference between Xiang is bigger, the frequency of interference spectrum is higher.Trickle optical path difference change then can be presented as the change of phase place Change.As it is shown in figure 1, phase place change is the most linear with the change of optical path difference, it is possible to obtained by difference integrating method One-dimensional scattergram to thickness of sample.

When using LASER Light Source, reference image can produce interference fringe with measuring picture, needs to use CCD as receptor Part.CCD collects as shown in Figure 2, image planes alternate position spike the light and shade striped caused.When the thickness of sample measured on arm is thinning or Time thickening, the light path of corresponding point position can shorten or elongated, and the change of this light path eventually results in interference and inwardly and outwardly contracts Put.Annulus often changes a cycle, to should indicate that optical path difference has changed a wavelength.Interference circle is subtracted each other with standard annulus, Isocontour difference can be obtained.Difference and change in optical path length linear correlation.Change according to striped can deduce works as pre-test Average change in optical path length at Dian.The one-dimensional scattergram of thickness of sample can be obtained again by difference integrating method.In like manner, load is worked as When thing platform tilts, a fixing angle between measuring surface and the plane of reference, can be formed.If two planes are the most smooth, work as loading When platform moves, interference fringe also should uniform motion.And when measuring surface out-of-flatness, the athletic meeting of interference fringe forms speed and becomes Change, by detecting this velocity variations, equally obtain the one-dimensional scattergram of thickness of sample.

During use, first reference arm and measurement arm are adjusted to equal length, make reference image (such as corrugated 11 in Fig. 3) and survey Amount can successfully interfere as (such as corrugated 12 in Fig. 3) in superposition (such as corrugated 13 in Fig. 3), forms interference spectrum or interference fringe (such as interference fringe 14 circular in Fig. 3).Spectrogrph or CCD is used to collect interference spectrum or interference fringe.Interference spectrum with The relation of optical path difference is:

$\begin{array}{c}{\left|R\left(\mathrm{\λ}\right)\right|}^2={\left|\mathrm{Rs}\left(\mathrm{\λ}\right)\right|}^2+{\left|\mathrm{Rr}\left(\mathrm{\λ}\right)\right|}^2-2\·\left|\mathrm{Rs}\left(\mathrm{\λ}\right)\right|\·\left|\mathrm{Rr}\left(\mathrm{\λ}\right)\right|\·\cos \left(\frac{2\mathrm{\π\Δ}}{\mathrm{\λ}}\right)\\ ={\left|\mathrm{Rs}\left(\mathrm{\λ}\right)\right|}^2+{\left|\mathrm{Rr}\left(\mathrm{\λ}\right)\right|}^2-2\·\left|\mathrm{Rs}\left(\mathrm{\λ}\right)\right|\·\left|\mathrm{Rr}\left(\mathrm{\λ}\right)\right|\·\cos \left(\frac{4\mathrm{\πnd}}{\mathrm{\λ}}\right)\end{array}---\left(1\right)$

If reference point thickness is d₀, measuring dot thickness variable quantity is d_Δ, i.e. measuring dot thickness value is d₀+d_Δ.When thickness is thickening Time, spectrum can drift about to red end.Spectrum before change is as shown in curve 21 in Fig. 4, and the spectrum after change is then as in Fig. 4 Shown in curve 22.When thickness changes, change before with change after optical path difference be:

$\begin{array}{c}{\left|R\left(\mathrm{\λ}\right)\right|}^2{|}_{{d=d}_0}-{\left|R\left(\mathrm{\λ}\right)\right|}^2{|}_{d=d_0+d_{\mathrm{\Δ}}}\\ =-2\·\left|\mathrm{Rs}\left(\mathrm{\λ}\right)\right|\·\left|\mathrm{Rr}\left(\mathrm{\λ}\right)\right|\·\{\cos \left(\frac{{4\mathrm{\πnd}}_0}{\mathrm{\λ}}\right)-\cos [\frac{4\mathrm{\πn}(d_0+d_{\mathrm{\Δ}})}{\mathrm{\λ}}\left]\right\}\\ =-4\·\left|\mathrm{Rs}\left(k\right)\right|\·\left|\mathrm{Rr}\left(k\right)\right|\·\sin (\frac{{4\mathrm{\πnd}}_0}{\mathrm{\λ}}+\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}})\·\sin \left(\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}}\right)\end{array}---\left(2\right)$

To λ integration, eliminate λ-variable:

${\∫}_{{\mathrm{\λ}}_{\min }}^{{\mathrm{\λ}}_{\max }}|-4\·|\mathrm{Rs}\left(k\right)|\·|\mathrm{Rr}\left(k\right)|\·\sin (\frac{{4\mathrm{\πnd}}_0}{\mathrm{\λ}}+\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}})\·\sin \left(\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}}\right)|\·\mathrm{d\λ}---\left(3\right)$

Formula (3) can be split as three products:

${\∫}_{{\mathrm{\λ}}_{\min }}^{{\mathrm{\λ}}_{\max }}|-4\·|\mathrm{Rs}\left(k\right)|\·|\mathrm{Rr}\left(k\right)\left|\right|\·\mathrm{d\λ}---\left(4\right)$

${\∫}_{{\mathrm{\λ}}_{\min }}^{{\mathrm{\λ}}_{\max }}\left|\sin (\frac{{4\mathrm{\πnd}}_0}{\mathrm{\λ}}+\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}})\right|\·\mathrm{d\λ}---\left(5\right)$

${\∫}_{{\mathrm{\λ}}_{\min }}^{{\mathrm{\λ}}_{\max }}\left|\sin \left(\frac{{4\mathrm{\πnd}}_{\mathrm{\Δ}}}{2\mathrm{\λ}}\right)\right|\·\mathrm{d\λ}---\left(6\right)$

Formula (4) does not contains Δ, is considered as a constant.In formula (5), d_ΔCompare d₀The least, therefore be negligible, from And this also can regard a constant as, long-pending by the two constant is designated as constant C, it may be assumed that

$C={\∫}_{{\mathrm{\λ}}_{\min }}^{{\mathrm{\λ}}_{\max }}|-4\·|\mathrm{Rs}\left(k\right)|\·|\mathrm{Rr}\left(k\right)|\·\sin \left(\frac{{4\mathrm{\πnd}}_0}{\mathrm{\λ}}\right)|\·\mathrm{d\λ}---\left(7\right)$

Formula (6) is about d_ΔA function, be calculated as M (d_Δ), itself and formula (7) are substituted into formula (3) in the lump, abbreviation is C M (d_Δ).Due to M (d_Δ) analytic solutions the most complicated, therefore its numerical solution can be sought, result is as shown in curve 23 in Fig. 4, in left figure 21 Reflectance spectrum before corresponding thickness change, the reflectance spectrum after 22 corresponding thickness changes.Knowable to Fig. 4 right figure curve 23, thickness Variable quantity becomes the relation of approximately linear with measured value in the range of 50nm, and the resolution of thickness measure can reach 1nm.Coordinate pressure The one-dimensional scanning of level platform, the method can obtain the light path information on one-dimensional straight line at each point.Due to the existence of diffraction, It is possible that aliasing between pixel and pixel in the method.As shown in Figure 4, the spectral differences component of the method changes with thickness The relation of approximately linear is become, it is possible to utilize the mathematic interpolation between neighbor to go out adjacent differential amount, Jin Erji between amount Calculate the light path information that surface topography is corresponding.

3, reconstructing method

After obtaining one-dimensional thickness information, by object stage, sample is rotated, it is thus achieved that the light on another projecting direction Journey projection information.Object stage multiple rotary, can obtain the light path information under multiple angle.Three kinds of reconstruct sides of this Information commons Method:

1. restore fault information with Radon conversion.

2. restore 3 d surface topography information with multi-angle reconstructing method.

3. map out lateral resolution by spectrum coding method from longitudinal resolution.

Concrete grammar by Radon conversion reduction fault information is as follows.Due in the light path projection information of each angle All include the fault information of part in whole scanning plane, after sample multiple rotary, this projection information is drawn with light path information In same sinogram.According to the principle of CT imaging, sinogram meets Central slice theorem, it is possible to use anti-Radon converts Restoring sectional view from sinogram, concrete grammar includes filtered back projection or convolutional back-projection two kinds.

The concrete grammar of filtered back projection is:

1. the projection signal g (R) of each projecting direction is taken out；

2. g (R) signal carries out Fourier transform (can use fast fourier transform or other equivalent changing method) obtain To frequency-region signal；

3. the frequency-region signal after conversion is multiplied by | ρ |, variable corresponding after wherein ρ is radius r Fourier transform；

4. under pair all angles through the 3rd step process after projection signal reuse Fourier transform, by signal quantitative change Gain spatial domain；

5., according to respective angle, the spatial domain signal back projection after processing forms reconstructed results.

The concrete grammar of convolutional back-projection is:

1. the projection signal g (R) of each projecting direction is taken out；

2. g (R) signal R-L filter function or S-L filter function are carried out convolution.Wherein the expression formula of R-L function is:

(wherein ρ₀For cut-off frequency)

${\mathrm{\ρ}}_0^2[2\sin c\left({2\mathrm{\ρ}}_{0}R\right)-{\sin c}^2\left({\mathrm{\ρ}}_{0}R\right)]---\left(8\right)$

The expression formula of S-L function is: (whereinρ₀For cut-off frequency)

$\frac{-2}{{\mathrm{\π}}^2{T}^2({4n}^2-1)}---\left(9\right)$

3., according to respective angle, the signal back projection after processing forms reconstructed results.

According to the principle of Radon conversion, reconstruct the resolution of image by longitudinal resolution, scanning resolution and rotation point Resolution together decides on.The relation between resolution and angle coverage and the angular resolution of image of rebuilding is as it is shown in figure 5, (a) For the relation between angle coverage and reconstruction resolution, along with the increase of angle, rebuild resolution and gradually step up, on 140 ° of left sides The right side is the most undistorted；B () is angular resolution and the relation rebuild between resolution, along with the increasing of angle sorting amount Greatly, rebuild resolution and gradually step up, the most undistorted at about 1-2 °.It can be seen that the method is passed through Resolution after frequency domain transform corresponds to image radial resolving power in polar diagram, and the angle rotated is spaced corresponding angle Resolution.If the angle rotated is enough fine, the lateral resolution of the image of reconstruction can reach identical with radial resolving power Level, thus break through the restriction of diffraction limit.

Restoring the concrete grammar of 3 d surface topography information as shown in Figure 6 with multi-angle reconstructing method, (a) is corresponding original Corrugated, (b) is the corrugated that the maximum angle of reflective light intensity is corresponding, and (c) is the maximum position that the maximum angle of reflective light intensity is corresponding Putting corrugated, (d) is the line on the maximum position corrugated that the angle of all reflective light intensities maximum is corresponding in (c), after being reconstruction Corrugated pattern.First rotatable stage, selects the angle (α, β, γ, δ as in Fig. 6) that some reflective light intensities are maximum.To carry Thing platform rotates respectively to this angle, and carries out one-dimensional scanning, it is thus achieved that the reflective light intensity information under this angle and optical path difference information.Profit The one-dimensional reflective light intensity curve as shown in curve 1 in Fig. 6 is drawn out respectively by this information.Then find in reflective light intensity curve Go out maximum point, and at maximum, calculate the light path (as shown in curve 2 in Fig. 6) at this point.Optical path length is plotted in light In strong maximum position (as shown in curve 3 in Fig. 6) in, during reconstruct, for each angle, marked the line segment of light path (as 3 in Fig. 6,4,5,6) rotate through respective angle (such as α, β, γ, δ), obtain postrotational plan-position (in Fig. 6 7、8、9、10).Finally, all plan-positions are connected, the cross-section morphology (as shown in Fig. 6 11) of the most reducible measured object.

In figure 6, the line segment corresponding to different rotary angle represents by different line styles).Rotation platform turns over difference Angle, search out several angles that reflective light intensity is maximum, and calculate its optical path difference, this optical path difference can represent under this angle Reflective surface and the distance of the plane of reference, both can be obtained by bounding method, it is also possible to obtained by difference method.During reconstruct, first First determine the centre point of a reconstruct image, then describe its pattern successively with continuous line segment.Wherein, the intensity proportional of light is reflected In line segment length, light path is proportional to the distance of line segment and centre point.Each angle draws a line segment, and these line segments are even the most at last Pick up, the cross-section morphology of the most reducible measured object.

In order to multi-angle reconstructing method is better described, the equilateral triangle nanometer here by Eample Analysis length of side 23nm is micro- Structure demonstrates the reduction process of this algorithm.The numerical aperture assuming object lens is 0.60, and its aerial angular aperture is 74 degree. During rotation, the anglec of rotation is shown with relation such as Fig. 7 (a) of intensity of reflected light.Search out angle of reflection maximum point therein, Fig. 7 A, in (), maximum point is-60 degree points and+60 degree points；Then object stage is turned to the two angle, and in Fig. 7 (b), b1 turns over Having turned-60 degree, b2 has overturn 60 degree；Transversal scanning is carried out under the two angle.Optical path difference is recorded with anti-during transversal scanning Penetrate shown in light intensity such as Fig. 7 (c).Light intensity at scanning is reached c1 and c2 portion markings in part i.e. Fig. 7 (c) of more than threshold value For active position, and record the light path at this point, then the light path of active position is marked at the reconstruct as shown in Fig. 7 (d) In the figure of face, as shown in d1, d2 in Fig. 7 (d).D1 finally turns over-60 degree, and d2 turns over 60 degree, then synthesizes, obtains such as Fig. 7 (e) Shown sample sections pattern.

Using multi-angle reconstructing method, the thickness change that light path detects is corresponding to reconstructing the radial resolving power of image, smart Degree is better than 2nm, by polar coordinate system to the conversion of cartesian coordinate system, corresponding with light intensity extreme value place from radial resolving power Δ ρ Angle, θ can map out the longitudinal resolution Δ y and lateral resolution Δ x of cartesian coordinate system:

Δ y=Δ ρ × Sin θ (10)

Δ x=Δ ρ × Cos θ (11)

Illustrating, the radial resolving power Δ ρ that formula (7) obtains is 2nm, and angle, θ as corresponding in light intensity extreme value place is 60 degree, then its X-direction resolution can reach 1nm.

By spectrum coding method, longitudinal resolution being mapped to lateral resolution, it is desirable to use broadband illumination, analytic expression uses Fourier transform processing spectrum, it is thus achieved that the frequency information of spectrum, as shown in Figure 8.From Fig. 8 (a) it can be seen that optical path difference is the biggest, The frequency of reflectance spectrum is the highest；Optical path difference is the least, and the frequency of reflectance spectrum is the lowest.By object rotation alpha angle in Fig. 8 (a), and will be anti- Penetrate after the spectrum transverse axis wave number of light represents, carry out Fourier transform and can obtain the frequency spectrum as shown in Fig. 8 (b), Mei Gepin Rate point represents a thickness, the interference spectrum of object 1,2,3 as the most corresponding in Fig. 8 (b) intermediate frequency spectrum peak value 1,2,3.Utilize loading The spinfunction of platform realizes the longitudinal resolution conversion to lateral resolution, specifically comprises the following steps that

1. object stage is rotated a certain angle, make to be formed between the plane of reference and measuring surface the angle of α；

2. use spectrometer measurement reflectance spectrum, and by spectrum transform to wave-number domain；

3. reflectance spectrum is carried out Fourier transform, it is thus achieved that each frequency component amplitude signal；

4. it is directly proportional to optical path difference due to the frequency of reflectance spectrum, such that it is able to parse different longitudinal position from frequency Pixel Information；

5., due to the existence of angle between measuring surface and the plane of reference, lateral attitude can be extrapolated by lengthwise position:

(wherein lateral attitude, x position, y is lengthwise position)

X=y/tan α (12)

Therefore, when anglec of rotation difference, it is possible to obtain different lateral resolutions.When the anglec of rotation up to or over During α, lateral resolution can meet or exceed longitudinal resolution, thus realizes horizontal super-resolution imaging.

Claims (7)

1. a lateral resolution reaches the interference rotation map detection method of 1nm, it is characterised in that be to include tested at one Sample realizes in interior interference rotation map detecting system according to the following steps:

Step (1), constructs an optical interference structure, by rotating sample, the longitudinal resolution interfering thickness measure Mapping Resolution is open into resolution, for realizing the interference rotation map detecting system of three-dimensional ultrahigh resolution imaging, wherein wraps Include: light source (1), collimating mirror (2), beam splitter (3), the first object lens (41), the second object lens (42), computer (5), imaging len (6), sensitive detection parts (7), electronic rotation/translation three-dimensional motion object stage (8) and reflecting mirror (9), wherein:

Light source (1) is laser or other white light source,

Beam splitter (3) is any one of plane mirror, dichroic mirror or prism,

First object lens (41), are positioned at length-adjustable measurement arm arm end,

Second object lens (42), are positioned at length-adjustable reference arm arm end,

Sensitive detection parts (7), use white light to make during light source to be spectrogrph, use laser to make during light source to be CCD device, described detector The outfan of part (7) is connected with described computer (5),

Electronic rotation/translation three-dimensional motion object stage (8), is called for short object stage (8), is positioned at immediately below described first object lens (41), Having the microcarrier chip of sample, described object stage (8) for installing surface attachment is three layers of nested structure, and outer layer is motor Driving motion platform, centre to drive motion platform for piezoquartz, internal layer is rotation sweep platform, in microcarrier chip is fixed on On layer rotation sweep platform, described object stage (8), under the control of described computer (5), completes on described microcarrier chip The scanning of sample and rotation, to obtain the full spectral information of all spatial points of sample；

The light that light source (1) sends impinges perpendicularly on described beam splitter (3) after described collimating mirror (2) is collimated into directional light, point Become transmission light and reflection light；Described transmission light converges to, on described microcarrier chip, be reflected back toward through described first object lens (41) Again through described first object lens (41) after Laiing, it is collimated into directional light, is sent to described beam splitter (3), is reflected to described one-tenth Object light is pooled after picture lens (6) is upper；Described reflection light is after described second object lens (42) are collimated into directional light, by described reflection Mirror (9) reflects, and is collimated into directional light through described second object lens (42) the most again, then after described beam splitter (3) transmission, by institute State imaging len (6) and pool reference light；Described object light and reference light coherent superposition are received by described sensitive detection parts (7), then It is sent to described computer (5), is formed and interfere high-resolution spectroscopy, be called for short EO-1 hyperion；

Step (2), described a kind of lateral resolution reaches the interference rotation map detection method of 1nm, and implementation step is as follows:

Step (2.1), adjusts measurement arm and becomes identical optical path length with reference arm, make object light and reference light interfere；

Step (2.2), described computer (5) controls described object stage (8), is adjusted to horizontal level, opens described light source (1), Obtain the EO-1 hyperion of sample；

Step (2.3), under described computer (5) controls, described object stage (8) rotates around trunnion axis, searches out reflective light intensity Anglec of rotation α of maximum point, it is thus achieved that the interference EO-1 hyperion of sample under described anglec of rotation α；

Step (2.4), the described interference EO-1 hyperion that step (2.3) is obtained, carry out microcarrier chip high spectrum intervention thickness and compile Code/decoded value solves, and calculates sample radial thickness information ρ under anglec of rotation α；

Step (2.5), calculates sample mapping longitudinal coordinate y under anglec of rotation α and lateral coordinates x according to the following formula:

X=ρ × Cos α,

Y=ρ × Sin α；

Step (2.6), by radial thickness resolution ax ρ, calculates sample mapping under anglec of rotation α according to the following formula Longitudinal resolution Δ y and lateral resolution Δ x:

Δ x=Δ ρ × Cos α,

Δ y=Δ ρ × Sin α.

A kind of lateral resolution the most as claimed in claim 1 reaches the interference rotation map detection method of 1nm, it is characterised in that Microcarrier chip high spectrum intervention thickness coding/decoding method described in step (2), calculates radial thickness by numerical solution, Measure radial thickness resolution ax ρ and reach 1nm.

A kind of lateral resolution the most as claimed in claim 1 or 2 reaches the interference rotation map detection method of 1nm, its feature It is to restore fault information with Radon conversion.

A kind of lateral resolution the most as claimed in claim 1 or 2 reaches the interference rotation map detection method of 1nm, its feature It is to interfere EO-1 hyperion reconstruct to restore 3 d surface topography information by multi-angle.

A kind of lateral resolution the most as claimed in claim 1 or 2 reaches the interference rotation map detection method of 1nm, its feature It is, by spectrum coding method, longitudinal resolution is mapped to lateral resolution.

A kind of lateral resolution the most as claimed in claim 1 reaches the interference rotation map detection method of 1nm, it is characterised in that Described interference high-resolution spectroscopy is suitable for any interference structure device of all two part or all of coherent superposition in corrugated and produces Interference spectrum or interference fringe.

A kind of lateral resolution the most as claimed in claim 1 reaches the interference rotation map detection method of 1nm, it is characterised in that Described sample is in biomolecule, biomolecule, cell, tissue, virus, antibacterial, micro Process structure and nano material Any one.