CN113567441B - Method, system, device and storage medium for detecting nano-scale object - Google Patents
Method, system, device and storage medium for detecting nano-scale object Download PDFInfo
- Publication number
- CN113567441B CN113567441B CN202111133386.XA CN202111133386A CN113567441B CN 113567441 B CN113567441 B CN 113567441B CN 202111133386 A CN202111133386 A CN 202111133386A CN 113567441 B CN113567441 B CN 113567441B
- Authority
- CN
- China
- Prior art keywords
- light
- light intensity
- order
- expression
- intensity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
Abstract
The application relates to a detection method, equipment and storage medium for nano-scale objects, wherein the method comprises the following steps: acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of detection light; establishing a relational expression among the scattering force, the work and the first-order axial differential of the light intensity; and substituting the first-order axial differential of the light intensity of the detection light into the relational expression to obtain the scattering force and work of the object to be detected on the detection light, thereby realizing the detection of the object to be detected. The method and the device have the technical effects of high detection efficiency and high sensitivity.
Description
Technical Field
The present application relates to the field of nano-scale microscopic measurement technologies, and in particular, to a method, a system, a device, and a storage medium for detecting a nano-scale object.
Background
On the premise of continuous development of advanced micro-nano manufacturing, the integration level of various micro-nano devices is also continuously improved. However, the nanometer-scale disturbance caused by dust particles in the environment or the manufacturing process will reduce the performance of the device and even affect the whole manufacturing supply chain.
Although the atomic force microscope and the scanning tunneling microscope can provide imaging resolution on a nanometer scale or even higher, a scanning process needs to be performed on the surface of an object to be measured by using a probe, which greatly limits the application range of the atomic force microscope and the scanning tunneling microscope. The small field of view and the need for electron beam bombardment on the surface of a sample of a scanning electron microscope widely used for micro-nano characterization also limit the nondestructive detection of large-area micro-nano devices, and although many scholars wish to use multiple electron beams to increase the field of view, the physical limitation of electron repulsion is still difficult to break through.
Due to the characteristics of large field of view and low exposure, the measuring means such as a microscope based on the optical principle can realize non-contact measurement and higher measurement efficiency, but noise from the aspect of an imaging device, such as defects of an optical lens, instability of mechanical parts, shot noise and readout noise of a camera, edge roughness and line width roughness of a sample and the like, undoubtedly reduces the signal-to-noise ratio when the optical means is used for measurement.
Therefore, how to improve the robustness of the imaging system to various noises and the sensitivity to the nanometer disturbance is a key technical problem for realizing the nanometer disturbance sensing with high efficiency and low cost.
Disclosure of Invention
In view of this, the present application provides a method, a system, a device and a storage medium for detecting a nano-scale object, so as to solve the technical problems of low detection efficiency and low sensitivity of the nano-scale object.
In order to solve the above problem, in a first aspect, the present invention provides a method for detecting a nanoscale object, including:
acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of detection light;
establishing a relational expression among the scattering force, the work and the first-order axial differential of the light intensity;
and calculating to obtain the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, thereby realizing the detection of the object to be detected.
Optionally, performing finite value difference based on the intensity image to obtain a first-order axial differential of the light intensity of the probe light, specifically:
selecting an under-focused intensity image and an over-focused intensity image, and performing axial differential estimation by using a first-order central finite difference method:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is the intensity of the intensity image in the through focus,
the intensity of the intensity image that is out of focus,
is the defocus distance.
Optionally, performing finite value difference based on the intensity image to obtain a first-order axial differential of the light intensity of the probe light, specifically:
selecting intensity images corresponding to a plurality of measurement planes, and performing axial differential estimation by using high-order finite difference:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is as follows
The intensity of the intensity image of the individual measurement planes,
is as follows
The weight corresponding to each of the measurement planes,
the number of measuring planes is 2 for the defocus distancenThe number of the (C) is +1,
corresponds to 2nIn +1 measurement planesnThe value is obtained.
Optionally, a relation between the scattering force, the work and the first-order axial differential of the light intensity is established, specifically:
for a paraxial light beam propagating in the optical axis direction, rewriting a momentum flux of the paraxial light beam as an expression on light intensity;
considering only the electric dipole model, the scattering force is expressed as an expression on the momentum flux;
combining the expression of momentum flux and the expression of scattering force to obtain the expression of scattering force relative to light intensity;
only considering the transverse scattering force, and combining an expression of the scattering force on the light intensity and a light intensity transmission equation to obtain an expression of first-order axial differential of the transverse scattering force on the light intensity;
and acquiring an expression of the first-order axial differential of the light intensity related to work corresponding to the transverse scattering force based on the expression of the first-order axial differential of the transverse scattering force related to the light intensity.
Optionally, the first-order axial differential of the light intensity of the probe light and the relational expression are combined to calculate the scattering force and work of the object to be measured on the probe light, and specifically:
an expression combining the first-order axial differential of the light intensity of the probe light and the corresponding work of the transverse scattering force with respect to the first-order axial differential of the light intensity:
wherein the content of the first and second substances,
，
the wave vector is the wave vector,
in order to be the speed of light in a vacuum,
is the frequency of the electric field and is,
in order to be the laplacian operator,
in order to be the first order axial differential,
work of lateral scattering forces;
the work of calculating the transverse scattering force is as follows:
wherein the content of the first and second substances,
is an inverse Laplace operator;
and calculating to obtain the scattering force by combining the work of the transverse scattering force and the relation between the scattering force and the work:
wherein the content of the first and second substances,
in order to be able to scatter the force,
the work of transversely scattering the force is,
is a transverse gradient operator.
In a second aspect, the present application also provides a nanoscale object detection system, the system comprising:
the differential module is used for acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of the detection light;
the relational expression module is used for establishing a relational expression between the scattering force, the work and the first-order axial differential of the light intensity;
and the calculation module is used for calculating and obtaining the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, so that the detection of the object to be detected is realized.
In a third aspect, the present application provides a computer device, which adopts the following technical solution:
a computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the nano-scale object detection method when executing the computer program.
In a fourth aspect, the application provides a nanometer level object detection device, include computer equipment still includes microscopic imaging device, microscopic imaging device is used for carrying out of focus scanning along the optical axis object to the object that awaits measuring and obtains a plurality of intensity images, and will intensity image send to computer equipment is used for the object to detect.
Optionally, the microscopic imaging device includes an optical fiber port, a collimating lens, a first adjustable diaphragm, a rotatable polarizer, a first lens, a non-polarizing beam splitter and an objective lens, which are sequentially arranged, and further includes a second lens, a second adjustable diaphragm, a third lens, a fourth lens and a camera, which are sequentially arranged along a reflection light path of the non-polarizing beam splitter, and further includes an electric displacement table arranged below the objective lens.
In a fifth aspect, the present application provides a computer-readable storage medium, which adopts the following technical solutions:
a computer-readable storage medium storing a computer program which, when executed by a processor, implements the steps of the nano-scale object detection method.
The beneficial effects of adopting the above embodiment are: the invention uses work and scattering force to represent the measured object in object space, the work and scattering force are two-dimensional results, the values can represent the three-dimensional appearance of the micro-nano structure to a certain extent, and the detection of the nano object is realized according to the abnormal change or the characteristics of the nano object, thereby realizing the non-destructive non-interference far-field imaging. Because the work and the scattering force are selected to characterize the measured object, the method can be realized by means of a bright field microscope and a defocusing scanning device, has simple and easy structure, avoids the detection of an atomic force microscope and a scanning tunnel microscope by using a probe, realizes non-contact nondestructive detection, overcomes the problem of small field of view of a scanning electron microscope, and improves the detection efficiency. Meanwhile, the established relational expression among the scattering force, the work and the first-order axial differential of the light intensity is a two-dimensional Poisson equation, so that the image reconstruction is established on the electrodynamic force obtained by solving the two-dimensional Poisson equation, the robustness on system errors and random noise is good, and the sensitive detection of the nano-scale object can be realized without a complex noise reduction processing algorithm.
Drawings
FIG. 1 is a flowchart of a method according to an embodiment of a method for detecting a nanoscale object provided herein;
FIG. 2 is a schematic block diagram of an embodiment of a nanoscale object detection system provided herein;
FIG. 3 is a functional block diagram of one embodiment of a computer device provided herein;
fig. 4 is a schematic structural diagram of an embodiment of a nanoscale object detection apparatus provided in the present application.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the application and together with the description, serve to explain the principles of the application and not to limit the scope of the application.
In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
The present application provides a method, system, device, computer device and storage medium for detecting nano-scale objects, which are described in detail below.
First, as shown in fig. 1, an embodiment of the present application provides a method for detecting a nano-scale object, where the method includes:
s1, acquiring a plurality of intensity images obtained by defocusing scanning of the object to be detected along an optical axis, and performing finite numerical difference based on the intensity images to obtain first-order axial differential of light intensity of the detection light;
s2, establishing a relational expression between the scattering force, the work and the first-order axial differential of the light intensity;
and S3, calculating to obtain the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, thereby realizing the detection of the object to be detected.
The embodiment provides an imaging method for detecting a nano-scale object by using optical scattering force, and non-destructive non-interference far-field imaging is realized. The method described in this embodiment is established on the electrodynamics of a nanoscale object, and uses work and scattering force to characterize the object to be measured in an object space, the work and scattering force obtained by the solution are both two-dimensional results, the values of which can characterize the three-dimensional morphology of a micro-nano structure to a certain extent, and the detection of the nanoscale object is realized according to the abnormal changes or characteristics thereof.
Specifically, a plurality of intensity images obtained by performing out-of-focus scanning on an object to be measured along an optical axis are obtained. The intensity image can be obtained by means of a bright field microscope and a defocusing scanning device, the structure is simple and easy to implement, the atomic force microscope and the scanning tunnel microscope are prevented from utilizing a probe to detect, non-contact nondestructive detection is realized, meanwhile, the problem of small field of view of a scanning electron microscope is also solved, and the detection efficiency is improved. And then, calculating the first-order axial differential of the light intensity based on the intensity image, establishing a relational expression between the scattering force and work and the first-order axial differential of the light intensity, and further solving to obtain the scattering force and the work. Different from most existing imaging modes taking amplitude, phase and polarization states as information carriers, the invention takes scattering force and work as the information carriers to realize detection imaging, and because the established relational expression among the first-order axial differentials of the scattering force, the work and the light intensity is a two-dimensional Poisson equation, image reconstruction is established on the basis of the electrodynamic force obtained by solving the two-dimensional Poisson equation, the method has good robustness on system errors and random noise, and can realize sensitive detection of nano-scale objects without complex noise reduction processing algorithms.
In an embodiment, the first-order axial differential of the light intensity of the probe light is obtained by performing finite value difference based on the intensity image, specifically:
selecting an under-focused intensity image and an over-focused intensity image, and performing axial differential estimation by using a first-order central finite difference method:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is the intensity of the intensity image in the through focus,
the intensity of the intensity image that is out of focus,
is the defocus distance.
The first-order axial differential estimation can adopt the light intensity axial differential estimation of a biplane, namely, the axial differential of the biplane can be estimated by respectively using slightly under-focused intensity images and over-focused intensity images and applying a first-order central finite difference method.
In an embodiment, the first-order axial differential of the light intensity of the probe light is obtained by performing finite value difference based on the intensity image, specifically:
selecting intensity images corresponding to a plurality of measurement planes, and performing axial differential estimation by using high-order finite difference:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is as follows
The intensity of the intensity image of the individual measurement planes,
is as follows
The weight corresponding to each of the measurement planes,
the number of measuring planes is 2 for the defocus distancenThe number of the (C) is +1,
corresponds to 2nIn +1 measurement planesnThe value is obtained.
The intensity axial differential estimation for the multi-plane is preferred over the intensity axial differential estimation for the biplane, i.e. using 2nAnd +1 measurement planes, and performing axial differential estimation by using high-order finite difference.
Weight of
Can be derived from Taylor expansion, which can be specifically derived from the following formula:
in the above formula, the first and second carbon atoms are,
、
parameters of Taylor expansion, in this embodiment
And is and
corresponds to 2nIn +1 measurement planesnThe value is obtained.
In one embodiment, the relationship between the scattering force, work and the first order axial differential of the light intensity is established by:
for a paraxial light beam propagating in the optical axis direction, rewriting a momentum flux of the paraxial light beam as an expression on light intensity;
considering only the electric dipole model, the scattering force is expressed as an expression on the momentum flux;
combining the expression of momentum flux and the expression of scattering force to obtain the expression of scattering force relative to light intensity;
only considering the transverse scattering force, and combining an expression of the scattering force on the light intensity and a light intensity transmission equation to obtain an expression of first-order axial differential of the transverse scattering force on the light intensity;
based on the expression of the first-order axial differential of the transverse scattering force relative to the light intensity, the expression of the first-order axial differential of the work corresponding to the transverse scattering force relative to the light intensity is obtained
In particular, a scattering force is established
And their work
Axial differential to first order
The link between them is implemented as follows.
(1) For a paraxial beam propagating along the z direction, its electric field under a scalar approximation can be expressed as:
wherein the content of the first and second substances,
which is indicative of the electric field,
which represents the strength of the electric field,
in order to be the amplitude value,
as an initial phase, the phase of the phase,
is wave vector
The z-direction component of (a).
While
And in the imaging space of the microscope with larger transverse magnification
The momentum flux of the paraxial light beam
Can be rewritten as:
wherein the content of the first and second substances,
in order to be a transverse gradient operator,
in order to be a background refractive index,
in order to be a magnetic permeability in a vacuum,
in order to be the speed of light in a vacuum,
，
is the frequency of the electric field and is,
，
which is indicative of the field strength of the magnetic field,
is a complex vector expression of the electric field and the magnetic field.
Then the process of the first step is carried out,
；
the complex vector expression of the electric field and the magnetic field is used as an intermediate quantity, and after the complex vector expression of the electric field and the magnetic field is expressed as an expression related to light intensity, the scattering force can be conveniently expressed as the expression related to the light intensity in the follow-up process.
(2) For being located at
The scattering force can be expressed by the following equation if only the electric dipole model is considered as the non-magnetic micro isolated object of (1):
wherein the content of the first and second substances,
is the extinction cross section of a micro object.
With the conclusion in (1), i.e., the complex vector expression of the electric and magnetic fields, the above equation can be further written as:
the above expression is the expression of the scattering force and the light intensity;
apparently, the scattering force
Can be decomposed into:
transverse scattering force
And longitudinal scattering force
。
(3) For describing the scattering power of any nanoscale object, the extinction cross-section of the polymeric object is taken into account not only to contain the independent influence of the individual objects, using
To represent the extinction cross-section of an arbitrary system, only the lateral scattering forces in (2) are considered
As the scattering force sought in this example, the following light intensity transmission equation is combined:
the lateral scattering force can be derived
Axial differential to first order
The relation of (1):
according to the mechanics theory, it can be considered that the lateral scattering force
Work in accordance with it
Satisfy the requirement of
Thus, there are:
wherein the content of the first and second substances,
is a transverse Laplace operator;
the above equation is a relation of work with respect to the first order axial differential of light intensity.
To facilitate the calculation of partial differential, a constant term is used
In the relation of the work multiplied by the lateral scattering force, it is defined as the work in the imaging system, i.e.:
then there is a change in the number of,
；
accordingly, scattering forces in imaging systems
。
In an embodiment, the scattering power and work of the object to be measured on the probe light are calculated by combining the first-order axial differential of the light intensity of the probe light and the relational expression, specifically:
an expression combining the first-order axial differential of the light intensity of the probe light and the corresponding work of the transverse scattering force with respect to the first-order axial differential of the light intensity:
wherein the content of the first and second substances,
，
the wave vector is the wave vector,
in order to be the speed of light in a vacuum,
is the frequency of the electric field and is,
in order to be the laplacian operator,
in order to be the first order axial differential,
work of lateral scattering forces;
the work of calculating the transverse scattering force is as follows:
wherein the content of the first and second substances,
is an inverse Laplace operator;
and calculating to obtain the scattering force by combining the work of the transverse scattering force and the relation between the scattering force and the work:
wherein the content of the first and second substances,
in order to be able to scatter the force,
the work of transversely scattering the force is,
is a transverse gradient operator.
Using the first order axial differential obtained in step S1 based on the relational expression obtained in step S2
Solving work
Then, based on the obtained work
Further resolving the scattering power
。
Solving the work according to the relation obtained in the step S2
The specific implementation process is as follows: using the first order axial differential obtained in step S1
And using Neumann boundary conditions to solve the standard Poisson equation in step S2:
can obtain transverse scattering power
：
Wherein the content of the first and second substances,
is the inverse laplacian operator.
Work of transverse scattering force obtained by the above formula
And the relational expression in step S2
A difference operation is performed to further solve the scattering force.
After the scattering force and the work are obtained, the work and the scattering force are used for representing the measured object in the object space, the obtained work and the scattering force are two-dimensional results, the values of the work and the scattering force can represent the three-dimensional morphology of the micro-nano structure to a certain extent, and the detection of the nano object is realized according to the abnormal change or the characteristics of the micro-nano structure.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
The present embodiment further provides a system for detecting a nano-scale object, where the system for detecting a nano-scale object corresponds to the method for detecting a nano-scale object in the foregoing embodiments one to one. As shown in fig. 2, the nano-scale object detection system includes:
the differential module 401 is configured to obtain a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and perform finite numerical difference based on the intensity images to obtain a first-order axial differential of light intensity of the probe light;
a relational expression module 402 for establishing a relational expression between the scattering force, work and the first-order axial differential of the light intensity;
the calculating module 403 is configured to calculate, according to the first-order axial differential of the light intensity of the probe light and the relational expression, a scattering force and work of the object to be detected on the probe light, so as to implement detection of the object to be detected.
For specific limitations of the nano-scale object detection system, reference may be made to the above limitations of the nano-scale object detection method, which are not described herein again. The modules in the nano-scale object detection system can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
As shown in fig. 3, based on the above nano-scale object detection method, the present application also provides a computer device, which may be a mobile terminal, a desktop computer, a notebook, a palmtop computer, a server, or other computing devices. The computer device comprises a processor 10, a memory 20 and a display 30. FIG. 3 shows only some of the components of the computer device, but it is to be understood that not all of the shown components are required to be implemented, and that more or fewer components may be implemented instead.
The storage 20 may in some embodiments be an internal storage unit of the computer device, such as a hard disk or a memory of the computer device. The memory 20 may also be an external storage device of the computer device in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the computer device. Further, the memory 20 may also include both an internal storage unit and an external storage device of the computer device. The memory 20 is used for storing application software installed in the computer device and various data, such as program codes installed in the computer device. The memory 20 may also be used to temporarily store data that has been output or is to be output. In one embodiment, the memory 20 stores a nano-scale object detection program 40, and the nano-scale object detection program 40 can be executed by the processor 10, so as to implement the nano-scale object detection method according to the embodiments of the present application.
The processor 10 may be, in some embodiments, a Central Processing Unit (CPU), a microprocessor or other data Processing chip, which is used to run program codes stored in the memory 20 or process data, such as performing a nano-scale object detection method.
The display 30 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch panel, or the like in some embodiments. The display 30 is used for displaying information at the computer device and for displaying a visual user interface. The components 10-30 of the computer device communicate with each other via a system bus.
In one embodiment, when the processor 10 executes the nano-scale object detection program 40 in the memory 20, the following steps are implemented:
acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of detection light;
establishing a relational expression among the scattering force, the work and the first-order axial differential of the light intensity;
and calculating to obtain the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, thereby realizing the detection of the object to be detected.
This embodiment still provides a nanometer level object detection equipment, include computer equipment still includes microscopic imaging equipment, microscopic imaging equipment is used for carrying out of focus scanning along the optical axis object to the object that awaits measuring and obtains a plurality of intensity images, and will intensity image send to computer equipment is used for the object to detect.
In an embodiment, as shown in fig. 4, the microscopic imaging apparatus includes an optical fiber port 1, a collimating lens 2, a first adjustable diaphragm 3, a rotatable polarizer 4, a first lens 5, a non-polarizing beam splitter 6, an objective lens 7, a second lens 11, a second adjustable diaphragm 12, a third lens 13, a fourth lens 14, and a camera 15, which are sequentially disposed along a reflection light path of the non-polarizing beam splitter, and further includes an electric displacement stage 8 disposed below the objective lens.
With reference to fig. 4, the present embodiment is based on a microscopic imaging system with a 4f system and an axially defocused scanning device. The 4f system, i.e. the optical 4f system, is a special optical system with wide application, and when two coherent polarized lights are input, the input lights generate a diffraction spectrum on a screen through an optical device, such as a cosine grating, a transform plane, and the like. The precise horizontal moving cosine grating can continuously change the phase difference of the diffraction orders of the two beams of light, thereby achieving the purpose of subtracting or adding the diffraction light intensity. In the microscope system, input light from an optical fiber port 1 is collimated by a collimating lens 2, the diameter of the light beam is adjusted by a first adjustable diaphragm 3, a rotatable polarizer 4 positioned behind the first adjustable diaphragm 3 is used for controlling the polarization direction of parallel light beams, and then the parallel light beams are converged on the back focal plane of an objective lens 7 again by a first lens 5, so that the illumination light beams on a sample can be seen as plane waves. An electric displacement table 8 with sub-10 nm step precision is used for placing a sample and realizing defocusing scanning, scattered light of the sample is captured by an objective lens 7, is reflected by a non-polarizing beam splitter 6 and then is converged by a second lens 11, and a second adjustable diaphragm 12 positioned on the focal plane of the second lens 11 can filter out the stray light. The 4f system composed of the third lens 13 and the fourth lens 14 can further improve the image magnification, the imaging plane of the camera 15 is placed on the back focal plane of the 4f system, and a series of intensity images are acquired by controlling the electric displacement platform 8.
The present embodiment also provides a computer-readable storage medium having a nano-scale object detection program stored thereon, which when executed by a processor, implements the steps of:
acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of detection light;
establishing a relational expression among the scattering force, the work and the first-order axial differential of the light intensity;
and calculating to obtain the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, thereby realizing the detection of the object to be detected.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above.
Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application.
Claims (8)
1. A method for detecting a nano-scale object, comprising:
acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of detection light;
establishing a relational expression among the scattering force, the work and the first-order axial differential of the light intensity;
calculating to obtain the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, thereby realizing the detection of the object to be detected;
the method comprises the following steps of establishing a relational expression among scattering force, work and first-order axial differential of light intensity, wherein the relational expression specifically comprises the following steps:
for a paraxial light beam propagating in the optical axis direction, the momentum flux of the paraxial light beam is rewritten into an expression on the light intensity
Rewritten as the light intensity expression:
wherein, in the step (A),
is a complex vector expression of the electric field and the magnetic field,
which represents the strength of the electric field,
which is indicative of the field strength of the magnetic field,
in order to be a background refractive index,
in order to be a magnetic permeability in a vacuum,
in order to be the speed of light in a vacuum,
in order to detect the light intensity of the light,
，
as an initial phase, the phase of the phase,
is wave vector
A z-direction component of;
considering only the electric dipole model, the scattering force is expressed as an expression for the momentum flux, which is:
，
an extinction cross section of a tiny object;
combining the expression of momentum flux and the expression of scattering force to obtain the expression of scattering force relative to light intensity;
only considering the transverse scattering force, and combining an expression of the scattering force on the light intensity and a light intensity transmission equation to obtain an expression of first-order axial differential of the transverse scattering force on the light intensity;
acquiring an expression of the first-order axial differential of the work related to the light intensity corresponding to the transverse scattering force based on the expression of the first-order axial differential of the transverse scattering force related to the light intensity;
wherein, combine the first order axial differential of the light intensity of probing light and the relational expression, calculate and obtain the scattering power and the merit of the object to be measured to probing light, specifically do:
an expression combining the first-order axial differential of the light intensity of the probe light and the corresponding work of the transverse scattering force with respect to the first-order axial differential of the light intensity:
wherein the content of the first and second substances,
，
the wave vector is the wave vector,
is the frequency of the electric field and is,
in order to be the laplacian operator,
in order to be the first order axial differential,
work of lateral scattering forces;
the work of calculating the transverse scattering force is as follows:
wherein the content of the first and second substances,
is an inverse Laplace operator;
and calculating to obtain the scattering force by combining the work of the transverse scattering force and the relation between the scattering force and the work:
wherein the content of the first and second substances,
in order to be able to scatter the force,
the work of transversely scattering the force is,
is a transverse gradient operator.
2. The method for detecting a nanoscale object according to claim 1, wherein finite numerical difference is performed based on the intensity image to obtain a first-order axial differential of light intensity of the detection light, specifically:
selecting an under-focused intensity image and an over-focused intensity image, and performing axial differential estimation by using a first-order central finite difference method:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is the intensity of the intensity image in the through focus,
the intensity of the intensity image that is out of focus,
is the defocus distance.
3. The method for detecting a nanoscale object according to claim 1, wherein finite numerical difference is performed based on the intensity image to obtain a first-order axial differential of light intensity of the detection light, specifically:
selecting intensity images corresponding to a plurality of measurement planes, and performing axial differential estimation by using high-order finite difference:
wherein the content of the first and second substances,
in order to detect the light intensity of the light,
to detect the first axial differential of the light intensity of the light,
is as follows
The intensity of the intensity image of the individual measurement planes,
is as follows
The weight corresponding to each of the measurement planes,
the number of measuring planes is 2 for the defocus distancenThe number of the (C) is +1,
corresponds to 2nIn +1 measurement planesnThe value is obtained.
4. A nanoscale object detection system, comprising:
the differential module is used for acquiring a plurality of intensity images obtained by performing out-of-focus scanning on an object to be detected along an optical axis, and performing finite numerical difference on the basis of the intensity images to obtain first-order axial differential of light intensity of the detection light;
the relational expression module is used for establishing a relational expression between the scattering force, the work and the first-order axial differential of the light intensity;
the calculation module is used for calculating and obtaining the scattering force and work of the object to be detected on the detection light by combining the first-order axial differential of the light intensity of the detection light and the relational expression, so that the detection of the object to be detected is realized;
the method comprises the following steps of establishing a relational expression among scattering force, work and first-order axial differential of light intensity, wherein the relational expression specifically comprises the following steps:
for a paraxial light beam propagating in the optical axis direction, the momentum flux of the paraxial light beam is rewritten into an expression on the light intensity
Rewritten as the light intensity expression:
wherein, in the step (A),
is a complex vector expression of the electric field and the magnetic field,
which represents the strength of the electric field,
which is indicative of the field strength of the magnetic field,
in order to be a background refractive index,
in order to be a magnetic permeability in a vacuum,
is in vacuumThe speed of the light is such that,
in order to detect the light intensity of the light,
，
as an initial phase, the phase of the phase,
is wave vector
A z-direction component of;
considering only the electric dipole model, the scattering force is expressed as an expression for the momentum flux, which is:
，
an extinction cross section of a tiny object;
combining the expression of momentum flux and the expression of scattering force to obtain the expression of scattering force relative to light intensity;
only considering the transverse scattering force, and combining an expression of the scattering force on the light intensity and a light intensity transmission equation to obtain an expression of first-order axial differential of the transverse scattering force on the light intensity;
acquiring an expression of the first-order axial differential of the work related to the light intensity corresponding to the transverse scattering force based on the expression of the first-order axial differential of the transverse scattering force related to the light intensity;
wherein, combine the first order axial differential of the light intensity of probing light and the relational expression, calculate and obtain the scattering power and the merit of the object to be measured to probing light, specifically do:
an expression combining the first-order axial differential of the light intensity of the probe light and the corresponding work of the transverse scattering force with respect to the first-order axial differential of the light intensity:
wherein the content of the first and second substances,
，
the wave vector is the wave vector,
is the frequency of the electric field and is,
in order to be the laplacian operator,
in order to be the first order axial differential,
work of lateral scattering forces;
the work of calculating the transverse scattering force is as follows:
wherein the content of the first and second substances,
is an inverse Laplace operator;
and calculating to obtain the scattering force by combining the work of the transverse scattering force and the relation between the scattering force and the work:
wherein the content of the first and second substances,
in order to be able to scatter the force,
the work of transversely scattering the force is,
is a transverse gradient operator.
5. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the nanoscale object detection method of any one of claims 1 to 3 when executing the computer program.
6. A nanoscale object detection device comprising the computer device of claim 5, and further comprising a microscopic imaging device for performing out-of-focus scanning on an object to be detected along an optical axis to obtain a plurality of intensity images, and sending the intensity images to the computer device for object detection.
7. The nanoscale object detection device according to claim 6, wherein the microscopic imaging device comprises an optical fiber port, a collimating lens, a first adjustable diaphragm, a rotatable polarizer, a first lens, a non-polarizing beam splitter, an objective lens, a second adjustable diaphragm, a third lens, a fourth lens, a camera, and an electric displacement table, wherein the optical fiber port, the collimating lens, the first adjustable diaphragm, the rotatable polarizer, the first lens, the non-polarizing beam splitter, the objective lens, the second adjustable diaphragm, the third lens, the fourth lens, the camera, the third lens, the fourth lens, the camera, the electric displacement table, and the electric displacement table are sequentially arranged below the objective lens.
8. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, implements the steps of the nano-scale object detection method according to any one of claims 1 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111133386.XA CN113567441B (en) | 2021-09-27 | 2021-09-27 | Method, system, device and storage medium for detecting nano-scale object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111133386.XA CN113567441B (en) | 2021-09-27 | 2021-09-27 | Method, system, device and storage medium for detecting nano-scale object |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113567441A CN113567441A (en) | 2021-10-29 |
| CN113567441B true CN113567441B (en) | 2021-12-28 |
Family
ID=78174755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111133386.XA Active CN113567441B (en) | 2021-09-27 | 2021-09-27 | Method, system, device and storage medium for detecting nano-scale object |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113567441B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115479544B (en) * | 2022-09-22 | 2023-11-10 | 南京理工大学 | Micro-structure line width microscopic nondestructive measurement method based on translation difference |
| CN116045852B (en) * | 2023-03-31 | 2023-06-20 | 板石智能科技(深圳)有限公司 | Three-dimensional morphology model determining method and device and three-dimensional morphology measuring equipment |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5445011A (en) * | 1993-09-21 | 1995-08-29 | Ghislain; Lucien P. | Scanning force microscope using an optical trap |
| US6098031A (en) * | 1998-03-05 | 2000-08-01 | Gsi Lumonics, Inc. | Versatile method and system for high speed, 3D imaging of microscopic targets |
| CN100398057C (en) * | 2006-07-14 | 2008-07-02 | 浙江大学 | Dispersion compensating method and system for optically coherent chromatographic imaging |
| KR101045059B1 (en) * | 2009-06-17 | 2011-06-29 | (주)나노포커스 | Afm scanning method and afm scanning system |
| CN101608904B (en) * | 2009-07-21 | 2011-09-14 | 清华大学 | Multifunction three-dimensional displacement and topography laser interferometry system |
| CN104345438A (en) * | 2014-10-29 | 2015-02-11 | 南京理工大学 | Light intensity transmission phase microscope system based on electronic control zoom lens and method thereof |
| CN108917651B (en) * | 2018-07-06 | 2020-12-04 | 中国科学院光电技术研究所 | Super-resolution three-dimensional shape measurement method based on optical tweezers medium microspheres |
-
2021
- 2021-09-27 CN CN202111133386.XA patent/CN113567441B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113567441A (en) | 2021-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113567441B (en) | Method, system, device and storage medium for detecting nano-scale object | |
| Pan | Bias error reduction of digital image correlation using Gaussian pre-filtering | |
| Ferreras Paz et al. | Solving the inverse grating problem by white light interference Fourier scatterometry | |
| Wang et al. | Single-shot isotropic differential interference contrast microscopy | |
| Holenstein et al. | High-resolution traction force microscopy on small focal adhesions-improved accuracy through optimal marker distribution and optical flow tracking | |
| Falldorf et al. | Digital holography and quantitative phase contrast imaging using computational shear interferometry | |
| Hazlett et al. | Epifluorescence-based three-dimensional traction force microscopy | |
| Lu et al. | Quantitative phase imaging camera with a weak diffuser | |
| de Groot et al. | Does interferometry work? A critical look at the foundations of interferometric surface topography measurement | |
| Zhang et al. | Influence of some recording parameters on digital holographic particle image velocimetry | |
| Alexander et al. | Precise measurements in digital holographic microscopy by modeling the optical train | |
| Memarzadeh et al. | Noninterferometric tomographic reconstruction of 3D static and dynamic phase and amplitude objects | |
| An et al. | Measurement to radius of Newton’s ring fringes using polar coordinate transform | |
| Ogundana et al. | Automated detection of planes in 3-D point clouds using fast Hough transforms | |
| Maire et al. | Experimental inversion of optical diffraction tomography data with a nonlinear algorithm in the multiple scattering regime | |
| Falldorf et al. | Advanced wave field sensing using computational shear interferometry | |
| Li et al. | In-lab in-line digital holography for cloud particle measurement experiment | |
| Shi et al. | Introducing virtual DIC to remove interpolation bias and process optimal patterns | |
| Burla et al. | Fourier descriptors for defect indication in a multiscale and multisensor measurement system | |
| Gunjala et al. | Optical transfer function characterization using a weak diffuser | |
| Endres et al. | Measurement comparison of goniometric scatterometry and coherent Fourier scatterometry | |
| Lei et al. | Nano‐level position resolution for particle tracking in digital in‐line holographic microscopy | |
| Suresh et al. | Similarity evaluation of 3D topological measurement results using statistical methods (Rising Researcher) | |
| Vladimirov et al. | Real-time study of high-cycle fatigue damage using the averaged speckle dynamics | |
| Kuś et al. | Scanning errors in holographic tomography |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |