Ultra-high temporal and spatial resolution nanostructure measurement system and method combining virtual and real probes

Abstract

The present invention discloses an ultra-high spatiotemporal resolution nanostructure measurement system and method combining virtual and real probes. The system includes: a signal generation module for generating a pulse signal; a vector light field generation module for outputting radially polarized light and / or angularly polarized light based on the pulse signal; an upright objective lens for focusing the radially polarized light and / or angularly polarized light onto a pixel to be measured on a sample; a physical probe for generating a scattered light signal at the near-field position of the pixel to be measured when the vector light field generation module only outputs radially polarized light; a detection module for detecting the light signal generated by the pixel to be measured and determining the detection result of the pixel to be measured based on the light signal; and a processor for determining the nanostructure measurement result of the area to be measured based on the detection results of several pixels to be measured in the area to be measured of the sample. The embodiments of the present invention can improve the spatiotemporal resolution of measuring nanostructures and can be widely used in the field of nanostructure measurement.

Description

Technical Field

[0001] The present invention relates to the field of nanostructure measurement, and in particular to a nanostructure measurement system and method combining virtual and real probes with ultra-high temporal and spatial resolution. Background Art

[0002] With the widespread application of micro-nano devices in intelligent manufacturing, advanced materials, and biomedicine, and the rapid development of advanced manufacturing technologies, including micromachining, there is an urgent need for non-destructive measurement of nanoscale microstructures. Compared to electron microscopes, optical microscopes have advantages such as not requiring a vacuum environment, being harmless to samples, and being able to detect the optical response of materials. Therefore, optical microscopes have become an important instrument for non-destructive measurement of nanostructures.

[0003] On the one hand, the spatial resolution of traditional optical microscopes is always limited by the physical diffraction properties of light waves. For the visible light band, its lateral resolution is limited to about 200nm. This fundamental defect makes it impossible for traditional microscopes to clearly distinguish the surface morphology and structural details of nanostructures, resulting in low spatial resolution of nanostructure measurements using optical microscope systems; on the other hand, the temporal resolution of traditional optical microscopes is limited by the response speed of the detector. For example, traditional photoelectric probes combined with high-speed oscilloscopes can only achieve nanosecond-scale temporal resolution, which does not meet the current research needs on information such as the electronic energy levels and carrier dynamics of materials in nanostructures. Therefore, the temporal resolution of nanostructure measurements using optical microscope systems still needs to be improved. Summary of the Invention

[0004] In view of this, in order to solve one of the above problems, an embodiment of the present invention aims to provide an ultra-high spatiotemporal resolution nanostructure measurement system and method combining virtual and real probes, which can improve the spatiotemporal resolution of nanostructure measurements.

[0005] In one aspect, an embodiment of the present invention provides an ultra-high spatiotemporal resolution nanostructure measurement system combining virtual and real probes, comprising:

[0006] A signal generating module, configured to generate a pulse signal; the pulse signal comprises a pump pulse and a probe pulse with adjustable relative delay time;

[0007] A vector light field generating module, configured to output radially polarized light and / or angularly polarized light based on the pulse signal;

[0008] An upright objective lens, used to focus the radially polarized light and / or the angularly polarized light onto a pixel to be measured on the sample;

[0009] A physical probe, configured to generate a scattered light signal at a near-field position of the pixel to be measured when the vector light field generating module outputs only radially polarized light;

[0010] A detection module, configured to detect the optical signal generated by the pixel to be measured, and determine a detection result of the pixel to be measured based on the optical signal; the detection result includes a reflection result and / or a transmission result;

[0011] A loading platform, used for loading and moving the sample to a preset position;

[0012] The processor is used to determine the nanostructure measurement result of the area to be tested based on the detection results of a plurality of pixel points to be tested in the area to be tested of the sample.

[0013] Specifically, the signal generating module includes:

[0014] Femtosecond laser, used to generate femtosecond laser pulses;

[0015] a beam splitter, for splitting the femtosecond laser pulse into a pump pulse and a probe pulse;

[0016] A delay line, used to adjust the optical path of the probe pulse so that the relative delay time between the pump pulse and the probe pulse is adjustable;

[0017] A plurality of reflecting mirrors are used to collimate the output optical paths of the pump pulse and the detection pulse.

[0018] Specifically, the vector light field generation module includes:

[0019] A linear polarizer, used to change the polarization state of the pulse signal to obtain linearly polarized light;

[0020] The vortex half-wave plate is used to convert the linearly polarized light into radially polarized light and / or angularly polarized light.

[0021] Specifically, when the vector light field generating module outputs radially polarized light and angularly polarized light, the vector light field generating module further includes:

[0022] An annular aperture is used to modulate the radially polarized light and the angularly polarized light so that the modulated radially polarized light produces a focused focal spot of a first preset size after being focused by the upright objective lens, and the modulated angularly polarized light produces a hollow hole focused focal spot of a second preset size after being focused by the upright objective lens.

[0023] Specifically, the detection module includes a reflection detection module and / or a transmission detection module; the reflection result includes reflection wide-field imaging information and a reflection light intensity signal; the reflection detection module includes a beam splitter, a first tube lens, an image sensor, a second tube lens, a precision pinhole and a photodetector, wherein:

[0024] The beam splitter is used to split the optical signal into a first optical path and a second optical path;

[0025] The light of the first optical path passes through the first tube lens and the image sensor in sequence to obtain reflected wide-field imaging information of the pixel to be measured;

[0026] The light of the second optical path passes through the second tube lens, the precision pinhole and the photodetector in sequence to obtain a reflected confocal detection signal.

[0027] On the other hand, an embodiment of the present invention further provides a method for nanostructure measurement with ultra-high temporal and spatial resolution combining virtual and real probes, which is applied to the system described above, comprising:

[0028] Controlling the signal generating module to generate a pulse signal; the pulse signal includes a pump pulse and a detection pulse with adjustable relative delay time;

[0029] controlling the vector light field generating module to output radially polarized light and / or angularly polarized light based on the pulse signal;

[0030] Controlling the stage to load and move the sample to a preset position;

[0031] Based on the detection results of a plurality of pixels to be measured in the area to be measured of the sample acquired by the detection module, a nanostructure measurement result of the area to be measured is determined.

[0032] Specifically, the vector light field generating module includes a linear polarizer and a vortex half-wave plate; and controlling the vector light field generating module to output radially polarized light and / or angularly polarized light based on the pulse signal includes:

[0033] Setting the polarization direction of the linear polarizer to obtain linearly polarized light;

[0034] The relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light is adjusted to output radially polarized light and / or angularly polarized light.

[0035] Specifically, the detection result includes wide-field imaging information; the light intensity signal of the pixel to be measured in the area to be measured of the sample is obtained by:

[0036] Acquiring wide-field imaging information of each pixel on the sample to generate a wide-field imaging image of the sample;

[0037] determining a region of the sample to be measured according to the wide-field imaging image of the sample;

[0038] The stage is moved to move the sample to a corresponding position and detect the light signal generated by the pixel to be tested in the test area, and the light intensity signal of the pixel to be tested is determined based on the light signal.

[0039] Specifically, if the output of the vector light field generating module is radially polarized light and angularly polarized light, the light intensity signal of the pixel to be measured is determined by:

[0040] Focusing the radially polarized light onto the pixel to be measured to obtain a first light intensity signal of the pixel to be measured;

[0041] Focusing the angularly polarized light onto the pixel to be measured to obtain a second light intensity signal of the pixel to be measured;

[0042] The first light intensity signal and the second light intensity signal are subtracted according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

[0043] On the other hand, an embodiment of the present invention further provides a computer-readable storage medium storing a program executable by a processor. When the program is executed by the processor, it is used to perform the method described above.

[0044] The implementation of the embodiments of the present invention includes the following beneficial effects:

[0045] This embodiment provides an ultra-high spatiotemporal resolution nanostructure measurement system that combines virtual and real probes. The system includes a signal generation module, a vector light field generation module, an upright objective lens, a physical probe, a detection module, a stage, and a processor. On the one hand, the signal generation module is used to generate a pulse signal including a pump pulse and a detection pulse with an adjustable relative delay time. The signal generation module can measure the transmittance change or reflectivity change of the material by first exciting and then detecting. By continuously adjusting the relative delay time, the dynamic relaxation caused by the pump light can be measured and information such as the electronic energy level and carrier dynamics of the nanostructure can be obtained. The nanostructure measurement results of the sample are recorded each time the relative delay time is changed. A series of optical signals with ultra-high temporal resolution of the sample can be obtained, thereby effectively improving the spatial resolution of nanostructure measurement. On the other hand, the virtual probe formed by the physical probe or the vector light field generation module and the upright objective lens can generate extremely small-scale light fields in different forms, and use the generated light fields to achieve interaction between the light field and the sample, thereby breaking the diffraction limit and improving the spatial resolution of nanostructure measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a structural block diagram of an ultra-high temporal and spatial resolution nanostructure measurement system combining virtual and real probes provided by an embodiment of the present invention;

[0047] Figure 2 This is a structural block diagram of a signal generating module provided by an embodiment of the present invention;

[0048] Figure 3 This is a structural block diagram of a reflection signal detection module provided by an embodiment of the present invention;

[0049] Figure 4 This is a structural block diagram of a transmission signal detection module provided by an embodiment of the present invention;

[0050] Figure 5 This is a structural block diagram of a vector light field generation module provided by an embodiment of the present invention;

[0051] Figure 6 This is a flowchart of the steps of a method for measuring nanostructures with ultra-high temporal and spatial resolution by combining virtual and real probes provided by an embodiment of the present invention;

[0052] Figure 7 is a schematic diagram of a confocal imaging result provided by an embodiment of the present invention;

[0053] Figure 8 is a schematic diagram of another nanostructure measurement result provided by an embodiment of the present invention;

[0054] Figure 9 This is a structural block diagram of an ultra-high temporal and spatial resolution nanostructure measurement device combining virtual and real probes provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are provided for ease of description only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted based on the understanding of those skilled in the art.

[0056] Several terms used in this application are explained as follows:

[0057] Diffraction limit: refers to the theoretical minimum spatial resolution determined by the wave properties of light. It is a barrier that traditional optical microscopes find difficult to overcome, restricting the system's ability to resolve adjacent tiny structures and making it difficult to clearly present the details of smaller-scale nanostructures. The value of the diffraction limit is related to the wavelength of light and the numerical aperture of the objective lens. The minimum resolution achievable using a traditional objective lens in the visible light range is approximately 200nm.

[0058] Temporal resolution refers to the shortest time interval between two successive events that a microscope can distinguish. It reflects a microscope's ability to capture dynamic processes. Higher temporal resolution allows for clearer observation of the behavior of nanostructures undergoing rapid physical or chemical changes, such as the rapid transitions of electrons.

[0059] Spatial resolution is the minimum distance between two adjacent points in a sample that a microscope can distinguish. It is an important indicator of the clarity of a microscope image. Higher spatial resolution allows us to more clearly see the details of nanostructures, such as the shape, size, and arrangement of nanoparticles.

[0060] Pump-probe technology: A method for studying the dynamic processes of nanostructures. Pump light is first used to excite the sample, causing a change in its state. Then, after a certain delay, probe light is used to probe the sample. By varying the delay time, the state changes of the sample at different time points can be studied, thereby understanding the dynamic behavior of the nanostructure.

[0061] Ultrafast lasers are lasers with extremely short pulse widths (typically on the order of femtoseconds or even attoseconds). These lasers possess extremely high peak power and extremely fast timescales, enabling intense light-matter interactions in an instant. These lasers can be used to study ultrafast physical and chemical processes occurring in nanostructures, such as the rapid excitation and relaxation of electrons.

[0062] Sub-hundred nanometers: This refers to a spatial resolution between 10 and 100 nanometers. This resolution surpasses that of traditional optical microscopes. At this scale, nanostructures can be imaged and measured with remarkable precision, enabling the observation of many nanoscale features and details that are difficult to detect with traditional microscopes. This makes it widely used in nanoscience research.

[0063] like Figure 1 As shown, an embodiment of the present invention provides an ultra-high spatiotemporal resolution nanostructure measurement system combining virtual and real probes, including a signal generating module 1, a detection module, a vector light field generating module 2, an upright objective lens 3, a physical probe 4, a stage 5, an inverted objective lens 6, a beam splitter 7, a detection module and a processor, wherein:

[0064] The signal generating module 1 is used to generate a pulse signal; the pulse signal includes a pump pulse and a detection pulse with adjustable relative delay time.

[0065] The signal generation module in this embodiment of the system uses a laser pulse (pump pulse) to excite the material and then uses another laser pulse (probe pulse) with an adjustable relative delay time to measure changes in the material's transmittance or reflectivity. By continuously varying the delay time, the dynamic relaxation caused by the pump light can be measured, thereby obtaining information such as electron energy levels and carrier dynamics. By continuously adjusting the delay between the pump and probe pulses, the temporal resolution of nanostructure measurements can be improved.

[0066] The vector light field generating module 2 is configured to output radially polarized light and / or angularly polarized light based on the pulse signal.

[0067] A vector light field is output according to the input pulse signal as preparation for subsequent nanostructure measurement of the sample.

[0068] The upright objective lens 3 is used to focus the radially polarized light and / or the angularly polarized light onto the pixel to be measured on the sample.

[0069] The physical probe 4 is used to generate a scattered light signal at the near-field position of the pixel to be measured when the vector light field generating module only outputs radially polarized light.

[0070] If sample conditions are suitable, a physical probe with a nanometer-scale tip radius can be used to perform scattered near-field optical scanning imaging of nanostructured samples, achieving higher spatial resolution. The basic principle of scattered near-field optical scanning imaging is that the illuminated physical probe tip forms an enhanced light field around it, and this near-field is modified by the nearby nanostructures. This near-field interaction causes the scattered light received by the detection module in the far field to carry the local optical properties of the nanostructure, thereby improving the spatial resolution of nanostructure measurements.

[0071] The loading platform 5 is used to load and move the sample to a preset position.

[0072] In this embodiment, a precision displacement stage is used to load and move the sample, which can achieve extremely high positioning accuracy, repeatability, and stability during the sample movement process, as well as pixel-by-pixel scanning and imaging of the sample.

[0073] The inverted objective lens 6 is used to focus the transmitted portion of the light signal generated by the pixel to be measured on the sample onto the detection module.

[0074] The beam splitter 7 is used to allow the reflected part of the light signal generated by the pixel to be measured on the sample to enter the detection module.

[0075] The detection module is used to detect the light signal generated by the pixel to be tested and determine the detection result of the pixel to be tested based on the light signal; the detection result includes a reflection result and / or a transmission result.

[0076] The processor is used to determine the nanostructure measurement result of the area to be tested based on the detection results of a plurality of pixel points to be tested in the area to be tested of the sample.

[0077] Specifically, if Figure 2 As shown, the signal generating module in this embodiment includes a femtosecond laser 10, a beam splitter 11, three reflectors 12, 13, 15 and a delay line 14, wherein:

[0078] Femtosecond laser, used to generate femtosecond laser pulses.

[0079] Femtosecond laser pulses are generated by a femtosecond laser and serve as the initial light source for subsequent pump-probe pulse signals.

[0080] A beam splitter is used to split the femtosecond laser pulse into a pump pulse and a probe pulse.

[0081] A beam splitter is used to split a femtosecond laser pulse into a pump pulse and a probe pulse. The pump pulse (ultrafast laser pulse) is used to excite the material, while the probe pulse is used to measure the change in transmittance or reflectivity of the material after the excitation. The beam splitting process allows the relative delay between the two laser pulses to remain constant, which can then be controlled by adjusting the optical path length.

[0082] The delay line is used to adjust the optical path length of the probe pulse so that the relative delay time between the pump pulse and the probe pulse can be adjusted.

[0083] In this embodiment, a precision delay line is used to adjust the position of the reflector to adjust the optical path of the laser, thereby changing the relative delay time of the pump pulse and the detection pulse, so that the relative delay time can be continuously changed, thereby measuring the dynamic relaxation caused by the pump light and obtaining information such as the electronic energy level and carrier dynamics of the sample nanostructure.

[0084] Several reflectors are used to collimate the output optical paths of the pump pulse and the detection pulse.

[0085] The output optical paths of the collimated pump pulse and the detection pulse are input into the vector light field generation module.

[0086] In some embodiments, as Figure 5 As shown, the vector light field generation module includes at least a linear polarizer 28 and a vortex half-wave plate 29, wherein:

[0087] Linear polarizer, used to change the polarization state of the pulse signal to obtain linearly polarized light.

[0088] By setting the polarization direction of the linear polarizer, the passing pulse signal is converted into linear polarized light with a specific polarization direction.

[0089] Vortex half-wave plates are used to convert linearly polarized light into radially polarized light and / or azimuthally polarized light.

[0090] The vortex half-wave plate in this embodiment is a liquid crystal polymer wave plate whose fast axis rotates continuously in the optical region, and can convert incident light in two specific polarization directions into radially polarized light and angularly polarized light respectively.

[0091] Furthermore, if Figure 5 As shown, when the vector light field generating module outputs radially polarized light and angularly polarized light, the vector light field generating module further includes an annular aperture 30, wherein:

[0092] The annular aperture is used to modulate radially polarized light and angularly polarized light so that the modulated radially polarized light produces a focused focal spot of a first preset size after being focused by the upright objective lens, and the modulated angularly polarized light produces a hollow hole focused focal spot of a second preset size after being focused by the upright objective lens.

[0093] Specifically, radially polarized light modulated by an annular aperture and focused by an upright objective lens can produce an extremely small focal spot. Angularly polarized light modulated by an annular aperture and focused by an upright objective lens can produce a hollow-hole focal spot, serving as the light source for subsequent confocal scanning imaging. The current optical diffraction limit (i.e., the minimum spot size focused by a lens) is calculated using scalar diffraction theory for the entire lens without aperture modulation. However, in reality, the vectorial properties of light can significantly impact focusing at high NAs. Therefore, using radially polarized light in combination with an annular aperture with a large ratio of inner and outer diameters can significantly reduce the focal spot size.

[0094] Specifically, in this embodiment, if the vector light field generating module 2 outputs radially polarized light or angularly polarized light, the upright objective lens 3 is used to focus the light on the sample to be measured;

[0095] If the vector light field generating module 2 outputs radially polarized light and angularly polarized light, the upright objective lens 3 is used to focus the vector light field modulated by the annular aperture to generate a focused spot.

[0096] Specifically, in this embodiment, the specific operation of using the physical probe 4 to generate a scattered light signal is as follows: when the vector light field generating module only outputs radially polarized light, the physical probe 4 is brought close to the near-field position of the nanostructured sample, and the upright objective lens 3 is used to focus the incident radially polarized light on the tip of the physical probe 4. The illuminated physical probe tip will form an enhanced light field around it to interact with the sample, and generate a scattered light signal at the near-field position of the pixel point to be measured in the sample.

[0097] Specifically, the detection module in this embodiment includes a reflection signal detection module 8 and a transmission signal detection module 9.

[0098] The reflection signal detection module 8 is used to detect the reflection light signal generated by the pixel to be measured, and determine the reflection result of the pixel to be measured based on the reflection light signal.

[0099] In this embodiment, if Figure 3 As shown, the reflected signal detection module 8 includes a beam splitter 15, a first tube lens 16, an image sensor 17, a second tube lens 18, a precision pinhole 19 and a photodetector 20, wherein:

[0100] The beam splitter is used to split the optical signal into a first optical path and a second optical path.

[0101] The light of the first optical path passes through the first sleeve lens and the image sensor in sequence to obtain reflected wide-field imaging information of the pixel to be measured.

[0102] The light of the first light path split by the beam splitter is used to roughly measure the pixel to be measured to obtain its wide-field imaging information.

[0103] The light of the second optical path passes through the second sleeve lens, the precision pinhole and the photoelectric detector in sequence to obtain a reflected confocal detection signal.

[0104] The light from the second optical path separated by the beam splitter is used to perform a detailed measurement of the pixel to be measured. The precision pinhole can use the confocal effect to reduce the spatial scale of detection, thereby obtaining an optical signal of extremely small spatial scale at the position of the pixel to be measured.

[0105] Among them, wide-field imaging information is obtained for preliminary positioning of the micro-nano structure, and confocal detection signals are obtained for achieving high-resolution micro-nanostructure imaging measurement.

[0106] The transmission signal detection module 9 is used to detect the transmission light signal generated by the pixel to be measured, and determine the transmission result of the pixel to be measured based on the transmission light signal; the structure of the transmission detection module 9 is basically the same as that of the reflection detection module 2. It only needs to convert the light signal collected by the inverted objective lens into linearly polarized light through the vortex wave plate, and the subsequent processing is basically the same as that of the reflection signal detection module.

[0107] In this embodiment, if Figure 4 As shown, the transmission signal detection module 8 includes a vortex wave plate 21 , a beam splitter 22 , a first tube lens 23 , an image sensor 24 , a second tube lens 25 , a precision pinhole 26 and a photodetector 27 .

[0108] The polarization state of the light signal collected by the inverted objective lens 6 is radial polarization or angular polarization. It needs to be converted into linearly polarized light by the vortex wave plate 21 first, and then collected by the first tube lens 23 and the second tube lens 25 through the two optical paths of the beam splitter. The image sensor 24, the precision pinhole 26 and the photodetector 27 are used to respectively obtain the transmission wide-field imaging information, the transmission spectrum information and the transmission confocal detection signal. Among them, the wide-field imaging information is used to preliminarily locate the position of the micro-nano structure, the spectrum information is used to perform spectral analysis on the micro-nano structure, and the confocal detection signal is used to achieve high-resolution imaging measurement of the micro-nano structure.

[0109] The implementation of the embodiments of the present invention may have at least the following beneficial effects:

[0110] This embodiment provides an ultra-high spatiotemporal resolution nanostructure measurement system that combines virtual and real probes. The system includes a signal generation module, a vector light field generation module, an upright objective lens, a physical probe, a detection module, a stage, and a processor. On the one hand, the signal generation module is used to generate a pulse signal including a pump pulse and a detection pulse with an adjustable relative delay time. The signal generation module can measure the transmittance change or reflectivity change of the material by first exciting and then detecting. By continuously adjusting the relative delay time, the dynamic relaxation caused by the pump light can be measured and information such as the electronic energy level and carrier dynamics of the nanostructure can be obtained. The nanostructure measurement results of the sample are recorded each time the relative delay time is changed. A series of optical signals with ultra-high temporal resolution of the sample can be obtained, thereby effectively improving the spatial resolution of nanostructure measurement. On the other hand, the virtual probe formed by the physical probe or the vector light field generation module and the upright objective lens can generate extremely small-scale light fields in different forms, and use the generated light fields to achieve interaction between the light field and the sample, thereby breaking the diffraction limit and improving the spatial resolution of nanostructure measurement.

[0111] like Figure 6 As shown, an embodiment of the present invention further provides an ultra-high spatiotemporal resolution nanostructure measurement method combining virtual and real probes, which is applied to the above system embodiment and includes steps S100 to S400 as shown below:

[0112] S100: Controlling a signal generating module to generate a pulse signal; the pulse signal includes a pump pulse and a detection pulse with adjustable relative delay time.

[0113] By setting the relative delay time between the pump pulse and the probe pulse in the pulse signal, the nanostructured sample is first excited by the pump pulse and then detected by the probe pulse with a relative delay time relative to the pump pulse. Furthermore, by continuously changing the relative delay time, the dynamic relaxation caused by the pump light can be measured, thereby obtaining information such as the electronic energy level and carrier dynamics of the nanostructured sample, achieving high time resolution measurement.

[0114] S200: The vector light field generating module includes a linear polarizer and a vortex half-wave plate; and the vector light field generating module is controlled to output radially polarized light and / or angularly polarized light based on a pulse signal.

[0115] The pulse signal is polarized and converted to output radially polarized light and / or angularly polarized light.

[0116] Specifically, in step S200, the process of controlling the vector light field generating module to output radially polarized light and / or angularly polarized light based on the pulse signal includes:

[0117] Set the polarization direction of the linear polarizer to obtain linearly polarized light.

[0118] Set the polarization direction of the linear polarizer so that the pulse signal passing through it is converted into linearly polarized light.

[0119] The relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light is adjusted to output radially polarized light and / or angularly polarized light.

[0120] Adjust the positional relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light so that the fast axis direction of the vortex half-wave plate and the incident polarization direction are at a specific angle, thereby outputting corresponding radially polarized light or angularly polarized light.

[0121] S300: Control the stage to load and move the sample to a preset position.

[0122] In this embodiment, the precision displacement stage is driven to load and move the sample so that each pixel point on the sample that needs to be measured generates a light signal and the generated light signal is detected and analyzed to determine the detection result of each pixel point to be measured, which serves as the data basis for analyzing the nanostructure of the sample.

[0123] S400: Determine a nanostructure measurement result of the area to be tested based on detection results of a plurality of pixels to be tested in the area to be tested of the sample acquired by the detection module.

[0124] By driving the precision displacement stage, each pixel point on the sample that needs to be measured generates a light signal and the generated light signal is detected and analyzed to determine the nanostructure measurement results of the sample area to be measured.

[0125] Specifically, in step S400, the detection result includes wide-field imaging information, and the light intensity signal of the pixel to be measured is obtained by:

[0126] S410: Acquire wide-field imaging information of each pixel on the sample to generate a wide-field imaging image of the sample.

[0127] First, the nanostructured sample is imaged initially. The linear polarizer and vortex half-wave plate in the vector light field generation module are used to output the vector light field, which is focused onto the sample through an upright objective lens. The image sensor in the detection module is used to obtain wide-field imaging information of each pixel on the sample to generate a wide-field image of the sample.

[0128] S420: Determine the area of ​​the sample to be tested according to the wide-field imaging image of the sample.

[0129] The area of ​​the sample to be measured, that is, the observation area of ​​interest, is determined from the wide-field imaging image of the sample, and the precision displacement stage is moved to find the observation area.

[0130] S430: moving the stage to move the sample to a corresponding position and detecting the light signal generated by the pixel to be tested in the test area, and determining the light intensity signal of the pixel to be tested based on the light signal.

[0131] After determining the observation area, an annular aperture is added to the vector light field generation module. The vortex half-wave plate in the vector light field generation module is rotated to convert the laser pulse into radially polarized light. This radially polarized light is then focused to an extremely small focal spot by the upright objective lens, and then onto the pixel to be measured at the current location. The light signal from the pixel to be measured is detected by a photodetector in the signal detection module. A precision pinhole located in front of the photodetector uses the confocal effect to reduce the spatial scale of detection, thereby obtaining a light intensity signal of the extremely small spatial scale at that location. Furthermore, the sample is finely moved horizontally by driving a precision displacement stage. The light intensity signal of the pixel to be measured detected by the photodetector is recorded with each position movement until every pixel in the target area is detected, achieving scanning imaging. This results in a confocal image obtained by confocal scanning of the object using radially polarized light. The same principle applies when imaging the sample using angularly polarized light. Finally, the light intensity signal of the pixel to be measured is determined from the resulting confocal image. Figure 7 The results of confocal imaging of gold nanoparticles with a diameter of about 80 nanometers using the method of this embodiment are shown in FIG. Figure 7 Figure (1) is the result of confocal imaging of three adjacent gold nanoparticles, where the small picture in the upper right corner is the imaging of gold nanoparticles using a scanning electron microscope; Figure 7Figure (2) is the result of confocal imaging of two adjacent gold nanoparticles, where the small picture in the upper right corner is the imaging of gold nanoparticles using a scanning electron microscope; Figure 7 Figure (3) is the result of confocal imaging of adjacent gold nanoparticles, where the small picture in the upper right corner of the picture is the imaging of gold nanoparticles using a scanning electron microscope; it can be seen that under the use of confocal imaging, the method and system of the present invention can clearly distinguish multiple gold nanoparticles and achieve high-resolution measurement of nanostructures.

[0132] Specifically, if the output of the vector light field generation module is radially polarized light and angularly polarized light, the light intensity signal of the pixel to be measured is determined by the following method:

[0133] S440: Focusing the radially polarized light onto the pixel to be measured to obtain a first light intensity signal of the pixel to be measured.

[0134] Confocal imaging is performed on the pixel to be measured using radially polarized light to determine the light intensity signal (pixel value A(i, j)) of the pixel to be measured.

[0135] S450: Focusing the azimuthally polarized light onto the pixel to be measured to obtain a second light intensity signal of the pixel to be measured.

[0136] The pixel to be measured is confocally imaged by angularly polarized light to determine the light intensity signal of the pixel to be measured (the pixel value is B(i, j)).

[0137] S460: Subtract the first light intensity signal from the second light intensity signal according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

[0138] Define the subtraction coefficient according to the actual situation, and perform subtraction to obtain the final light intensity signal of the pixel to be measured (pixel value C(i, j) = A(i, j) - a*B(i, j), where a is the subtraction coefficient).

[0139] In some embodiments, after obtaining a confocal image of a sample, subtraction imaging can be used to further improve the resolution. Figure 8 As shown, Figure 8 Figure (1) in the figure is the point spread function of radially polarized light focusing. Figure 8 Figure (2) is the point spread function of the angular polarized light focus. Subtracting the two by a certain coefficient can obtain the following: Figure 8The point spread function with a smaller half-width at half-maximum is shown in Figure (3). In theory, obtaining a point spread function with a smaller half-width at half-maximum can achieve higher image resolution. Therefore, by using radially polarized light and angularly polarized light to perform confocal scanning of nanostructured samples and subtracting the images obtained by a certain coefficient, nanostructured samples can be measured with higher spatial resolution. The specific operation of image subtraction is as follows: first adjust the vortex half-wave plate in the vector light field module to adjust the incident pulsed laser to radially polarized light, and use the radially polarized light to perform confocal scanning on each pixel to be tested in the test area to obtain image A, where the pixel value of the i-th row and j-th column of image A is A(i, j), then adjust the vortex half-wave plate to adjust the incident pulsed laser to angularly polarized light, and use the angularly polarized light to perform confocal scanning on each pixel to be tested in the test area to obtain image B, where the pixel value of the i-th row and j-th column of image B is B(i, j), then the pixel value of the i-th row and j-th column of the subtracted image C is C(i, j) = A(i, j)-a*B(i, j), where a is the subtraction coefficient, which can be defined according to actual conditions. Figure 8 Figure (4) is a simulated image of the nano-grating structure. Figure 8 Figures (5) and (6) are images obtained by confocal scanning using radially polarized light and angularly polarized light, respectively. Figure 8 Figure (7) is an image obtained by subtracting Figure (5) and Figure (6) according to a certain coefficient. It can be seen that the resolution of Figure (7) is higher than that of Figure (5). Therefore, it can be seen that the spatial resolution of nanostructure measurement can be improved by performing subtraction imaging on the obtained confocal image.

[0140] like Figure 9 As shown, an embodiment of the present invention provides an ultra-high temporal and spatial resolution nanostructure measurement device combining virtual and real probes, comprising:

[0141] at least one processor;

[0142] at least one memory for storing at least one program;

[0143] When at least one program is executed by at least one processor, the at least one processor implements the above method.

[0144] Among them, the memory is a non-transient computer-readable storage medium that can be used to store non-transient software programs and non-transient computer executable programs. The memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory optionally includes a remote memory remotely arranged relative to the processor, and these remote memories can be connected to the processor via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0145] It can be seen that the contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0146] In addition, embodiments of the present application further disclose a computer program product or computer program, which is stored in a computer-readable storage medium. A processor of a computer device can read the computer program from the computer-readable storage medium and execute the computer program, causing the computer device to perform the above-described method.

[0147] Finally, an embodiment of the present invention further provides a computer-readable storage medium, in which a program executable by a processor is stored. The program executable by the processor is used to perform the above method when executed by the processor.

[0148] An embodiment of the present invention further provides a computer-readable storage medium storing a program executable by a processor. When executed by the processor, the program is used to implement the above-described method. Similarly, the contents of the above-described method embodiment are applicable to the present storage medium embodiment. The functions implemented by the present storage medium embodiment are the same as those of the above-described method embodiment, and the beneficial effects achieved are also the same as those achieved by the above-described method embodiment.

[0149] It will be appreciated that all or some of the steps and systems disclosed above may be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0150] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An ultra-high temporal and spatial resolution nanostructure measurement system combining virtual and real probes, characterized in that: include: A signal generating module, used for generating a pulse signal; The pulse signal includes a pump pulse and a detection pulse with adjustable relative delay time; A virtual probe is composed of a vector light field generating module and an upright objective lens; the vector light field generating module is used to output radially polarized light and / or angularly polarized light based on the pulse signal; The upright objective lens is used to focus the radially polarized light and / or angularly polarized light to the pixel to be measured on the sample; the vector light field generation module includes: a linear polarizer, used to change the polarization state of the pulse signal to obtain linearly polarized light; a vortex half-wave plate, used to convert the linearly polarized light into radially polarized light and / or angularly polarized light; when the vector light field generation module outputs radially polarized light and angularly polarized light, the vector light field generation module also includes: an annular aperture, used to modulate the radially polarized light and the angularly polarized light, so that the modulated radially polarized light produces a focusing spot of a first preset size after being focused by the upright objective lens, and the modulated angularly polarized light produces a hollow hole focusing spot of a second preset size after being focused by the upright objective lens; A physical probe, configured to generate a scattered light signal at a near-field position of the pixel to be measured when the vector light field generating module outputs only radially polarized light; A loading platform, used for loading and moving the sample to a preset position; an inverted objective lens, used to focus the transmitted portion of the light signal generated by the pixel to be measured onto the detection module; A beam splitter, used for directing the reflected portion of the optical signal generated by the pixel to be measured into a detection module; A detection module, configured to detect the optical signal generated by the pixel to be measured, and determine a detection result of the pixel to be measured based on the optical signal; the detection result includes a reflection result and / or a transmission result; The processor is used to determine the nanostructure measurement result of the area to be tested based on the detection results of a plurality of pixel points to be tested in the area to be tested of the sample.

2. The system according to claim 1, wherein: The signal generating module includes: Femtosecond laser, used to generate femtosecond laser pulses; a beam splitter, for splitting the femtosecond laser pulse into a pump pulse and a probe pulse; A delay line, used to adjust the optical path of the probe pulse so that the relative delay time between the pump pulse and the probe pulse is adjustable; A plurality of reflecting mirrors are used to collimate the output optical paths of the pump pulse and the detection pulse.

3. The system according to claim 1, wherein: The detection module includes a reflection detection module and / or a transmission detection module; the reflection result includes reflection wide-field imaging information and a reflection light intensity signal; the reflection detection module includes a beam splitter, a first tube lens, an image sensor, a second tube lens, a precision pinhole and a photodetector, wherein: The beam splitter is used to split the optical signal into a first optical path and a second optical path; The light of the first optical path passes through the first tube lens and the image sensor in sequence to obtain reflected wide-field imaging information of the pixel to be measured; The light of the second optical path passes through the second tube lens, the precision pinhole and the photodetector in sequence to obtain a reflected confocal detection signal.

4. A method for measuring nanostructures with ultra-high temporal and spatial resolution by combining virtual and real probes, applied to the system according to any one of claims 1 to 3, characterized in that: include: Controlling the signal generating module to generate a pulse signal; The pulse signal includes a pump pulse and a detection pulse with adjustable relative delay time; controlling the vector light field generating module to output radially polarized light and / or angularly polarized light based on the pulse signal; Controlling the stage to load and move the sample to a preset position; Based on the detection results of a plurality of pixels to be measured in the area to be measured of the sample acquired by the detection module, a nanostructure measurement result of the area to be measured is determined.

5. The method according to claim 4, characterized in that The vector light field generating module includes a linear polarizer and a vortex half-wave plate; and controlling the vector light field generating module to output radially polarized light and / or angularly polarized light based on the pulse signal includes: Setting the polarization direction of the linear polarizer to obtain linearly polarized light; The relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light is adjusted to output radially polarized light and / or angularly polarized light.

6. The method according to claim 5, characterized in that The detection result includes wide-field imaging information; the light intensity signal of the pixel to be measured in the area to be measured of the sample is obtained by: Acquiring wide-field imaging information of each pixel on the sample to generate a wide-field imaging image of the sample; determining a region of the sample to be measured according to the wide-field imaging image of the sample; The stage is moved to move the sample to a corresponding position and detect the light signal generated by the pixel to be tested in the test area, and the light intensity signal of the pixel to be tested is determined based on the light signal.

7. The method according to claim 6, characterized in that If the output of the vector light field generating module is radially polarized light and angularly polarized light, the light intensity signal of the pixel to be measured is determined by: Focusing the radially polarized light onto the pixel to be measured to obtain a first light intensity signal of the pixel to be measured; Focusing the angularly polarized light onto the pixel to be measured to obtain a second light intensity signal of the pixel to be measured; The first light intensity signal and the second light intensity signal are subtracted according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

8. A computer-readable storage medium storing a program executable by a processor, characterized in that: The processor-executable program is used to perform the method according to any one of claims 4 to 7 when executed by the processor.

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