Ultra-high temporal-spatial resolution nanostructure measurement system and method combined with virtual-real probe

Abstract

The invention discloses an ultrahigh temporal-spatial resolution nanostructure measurement system and method combined with a virtual-real probe, and the system comprises a signal generation module which is used for generating a pulse signal; the vector light field generation module is used for outputting radial polarized light and / or angular polarized light based on the pulse signal; the upright objective lens is used for focusing the radial polarized light and / or the angular polarized light to a to-be-measured pixel point on the sample; the entity probe is used for generating a scattered light signal at the near-field position of the pixel point to be measured when the vector light field generation module only outputs the radial polarized light; the detection module is used for detecting an optical signal generated by the to-be-detected pixel point and determining a detection result of the to-be-detected pixel point based on the optical signal; and the processor is used for determining a nanostructure measurement result of the to-be-measured area based on the detection results of the plurality of to-be-measured pixel points in the to-be-measured area of the sample. According to the embodiment of the invention, the temporal-spatial resolution of the measurement of the nanostructure can be improved, and the method can be widely applied to 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 with ultra-high spatio-temporal resolution combining virtual and real probes. Background Art

[0002] With the wide application of micro-nano devices in the fields of intelligent manufacturing, advanced materials, biomedicine, etc., and the rapid development of advanced manufacturing technologies including microfabrication, there is an urgent need for non-destructive measurement technologies for microstructures at the nanoscale. Compared with electron microscopes, due to the advantages of optical microscopes such as no need for a vacuum environment, no damage to samples, and the ability to detect the optical response of materials, optical microscopes have become important measurement instruments for non-destructive measurement of nanostructures.

[0003] On the one hand, the spatial resolution of traditional optical microscopes has always been limited by the physical diffraction characteristics of light waves. For the visible light band, its lateral resolution is limited to about 200 nm. This fundamental defect makes it impossible for traditional microscopes to clearly resolve the surface topography features and structural details of nanostructures, resulting in low spatial resolution for measuring nanostructures using optical microscope systems. On the other hand, the time resolution of traditional optical microscopes is limited by the response speed of detectors. For example, traditional optoelectronic probes combined with high-speed oscilloscopes can only achieve time resolution at the nanosecond scale, which does not meet the current requirements for studying information such as the electronic energy levels and carrier dynamics of materials in nanostructures. Therefore, the time resolution for measuring nanostructures using optical microscope systems still needs to be improved. Summary of the Invention

[0004] In view of this, to solve one of the above problems, an object of an embodiment of the present invention is to provide a nanostructure measurement system and method with ultra-high spatio-temporal resolution combining virtual and real probes, which can improve the spatio-temporal resolution for measuring nanostructures.

[0005] On the one hand, an embodiment of the present invention provides a nanostructure measurement system with ultra-high spatio-temporal resolution combining virtual and real probes, including: A signal generation module for generating a pulse signal; the pulse signal includes a pump pulse and a probe pulse with an adjustable relative delay time; A vector light field generation module for outputting a radially polarized light and / or an azimuthally polarized light based on the pulse signal; An upright objective lens for focusing the radially polarized light and / or the azimuthally polarized light onto a pixel to be measured on the 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 a radially polarized light; A detection module for detecting the optical signal generated by the pixel to be measured and determining the 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; A stage for loading and moving the sample to a preset position; A processor for determining the measurement result of the nanostructure in the region to be measured based on the detection results of a plurality of pixels to be measured in the region to be measured of the sample.

[0006] Specifically, the signal generation module includes: A femtosecond laser for generating femtosecond laser pulses; A beam splitter for splitting the femtosecond laser pulse into a pump pulse and a probe pulse; A delay line for adjusting 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 mirrors for collimating the output optical paths of the pump pulse and the probe pulse.

[0007] Specifically, the vector optical field generation module includes: A linear polarizer for changing the polarization state of the pulse signal to obtain linearly polarized light; A vortex half-wave plate for converting the linearly polarized light into radially polarized light and / or azimuthally polarized light.

[0008] Specifically, when the vector optical field generation module outputs radially polarized light and azimuthally polarized light, the vector optical field generation module further includes: An annular aperture for modulating the radially polarized light and the azimuthally polarized light so that the modulated radially polarized light generates a first preset-size focused spot after being focused by the upright objective lens, and the modulated azimuthally polarized light generates a second preset-size hollow-hole focused spot after being focused by the upright objective lens.

[0009] 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 reflected light intensity signal; the reflection detection module includes a beam splitter, a first sleeve lens, an image sensor, a second sleeve lens, a precision pinhole, and a photodetector, where: The beam splitter for splitting the optical signal into a first optical path and a second optical path; The light rays of the first optical path sequentially pass through the first sleeve lens and the image sensor to obtain the reflection wide-field imaging information of the pixel to be measured; The light rays of the second optical path sequentially pass through the second sleeve lens, the precision pinhole, and the photodetector to obtain a reflection confocal detection signal.

[0010] On the other hand, an embodiment of the present invention further provides a method for measuring nanostructures with ultra-high spatio-temporal resolution by combining virtual and real probes, which is applied to the system as described above, and includes: Controlling the signal generation module to generate a pulse signal; the pulse signal includes a pump pulse and a probe pulse with adjustable relative delay time; Controlling the vector light field generation module to output radially polarized light and / or azimuthally 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 number of pixels to be measured in the area to be measured of the sample obtained by the detection module, determining the measurement result of the nanostructure in the area to be measured.

[0011] Specifically, the vector light field generation module includes a linear polarizer and a vortex half-wave plate; the controlling the vector light field generation module to output radially polarized light and / or azimuthally polarized light based on the pulse signal includes: Setting the polarization direction of the linear polarizer to obtain linearly polarized light; Adjusting the relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light to output radially polarized light and / or azimuthally polarized light.

[0012] Specifically, the detection result includes wide-field imaging information; the light intensity signal of the pixels to be measured in the area to be measured of the sample is obtained by the following method: Obtaining the wide-field imaging information of each pixel on the sample to generate a wide-field imaging image of the sample; Determining the area to be measured of the sample according to the wide-field imaging image of the sample; Moving the stage to move the sample to a corresponding position and detecting the optical signal generated by the pixels to be measured in the area to be measured, and determining the light intensity signal of the pixels to be measured based on the optical signal.

[0013] Specifically, if the output of the vector light field generation module is radially polarized light and azimuthally polarized light; the light intensity signal of the pixels to be measured is determined by the following method: Focusing the radially polarized light on the pixel to be measured to obtain a first light intensity signal of the pixel to be measured; Focusing the azimuthally polarized light on the pixel to be measured to obtain a second light intensity signal of the pixel to be measured; Subtracting the first light intensity signal and the second light intensity signal according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

[0014] On the other hand, an embodiment of the present invention also provides a computer-readable storage medium, in which a program executable by a processor is stored, and the program executable by the processor is used to execute the method as described above when executed by the processor.

[0015] Implementing the embodiments of the present invention includes the following beneficial effects: This embodiment provides a nano-structure measurement system with ultra-high spatio-temporal resolution combining 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. Among them: on the one hand, the signal generation module is used to generate a pulse signal including a pump pulse and a probe pulse with adjustable relative delay time. By the method of first excitation and then detection, it can measure the change in transmittance or reflectance of the material. 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 nano-structure can be obtained. Each time the relative delay time is changed, the nano-structure measurement result of the sample is recorded, and a series of optical signals with ultra-high temporal resolution for the sample can be obtained, thereby effectively improving the spatial resolution of measuring the nano-structure; on the other hand, through the physical probe or the virtual probe formed by the vector light field generation module and the upright objective lens, an extremely small-scale light field can be generated in different forms, and the generated light field is used to realize the interaction between the light field and the sample, so as to be able to break through the diffraction limit and improve the spatial resolution of measuring the nano-structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a structural block diagram of a nano-structure measurement system with ultra-high spatio-temporal resolution combining virtual and real probes provided by an embodiment of the present invention; Figure 2 is a structural block diagram of a signal generation module provided by an embodiment of the present invention; Figure 3 is a structural block diagram of a reflection signal detection module provided by an embodiment of the present invention; Figure 4 is a structural block diagram of a transmission signal detection module provided by an embodiment of the present invention; Figure 5 is a structural block diagram of a vector light field generation module provided by an embodiment of the present invention; Figure 6 is a step flow chart of a nano-structure measurement method with ultra-high spatio-temporal resolution combining virtual and real probes provided by an embodiment of the present invention; Figure 7 is a schematic diagram of a confocal imaging result provided by an embodiment of the present invention; Figure 8 is a schematic diagram of another nano-structure measurement result provided by an embodiment of the present invention; Figure 9It is a structural block diagram of a nanostructure measurement device with ultra-high spatio-temporal resolution that combines virtual and real probes provided by an embodiment of the present invention. Detailed implementation manners

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. For the step numbers in the following embodiments, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0018] Explanations of several terms involved in this application are as follows: Diffraction limit: It refers to the theoretical minimum value of the spatial resolution determined by the wave characteristics of light. It is an obstacle that traditional optical microscopes are difficult to break through, restricting the system's ability to resolve adjacent tiny structures and making it difficult to clearly present the details of nanostructures at smaller scales. Among them, the value of the diffraction limit is related to the wavelength of light and the numerical aperture of the objective lens. The minimum resolution that can be achieved using a traditional objective lens within the visible light range is approximately 200 nm.

[0019] Time resolution: It refers to the shortest time interval that a microscope can resolve two consecutive events. It reflects the microscope's ability to capture dynamic processes. A higher time resolution means that the behavior of nanostructures during rapid physical or chemical changes, such as the rapid transition of electrons, can be observed more clearly.

[0020] Spatial resolution: It is the minimum distance that a microscope can distinguish between two adjacent points in a sample. It is an important indicator to measure the clarity of microscope imaging. A higher spatial resolution allows us to see the detailed features of nanostructures more clearly, such as the shape, size, and arrangement of nanoparticles.

[0021] Pump-probe technique: A method for studying the dynamic processes of nanostructures. First, a pump light is used to excite the sample, changing the state of the sample. Then, after a certain time delay, a probe light is used to detect the sample. By changing the delay time, the state changes of the sample at different time points are studied to understand the dynamic behavior of nanostructures.

[0022] Ultra-fast laser: It refers to a laser with an extremely short pulse width (usually in the femtosecond or even attosecond range). This laser has extremely high peak power and an extremely fast time scale, capable of generating intense light-matter interactions instantaneously and can be used to study ultra-fast physical and chemical processes occurring in nanostructures, such as the rapid excitation and relaxation of electrons.

[0023] Sub-nanometer: It indicates that the spatial resolution is in the range of 10 - 100 nanometers. It is superior to the resolution of traditional optical microscopes. At this scale, relatively fine imaging and measurement of nanostructures can be carried out, and many nanoscale features and details that are difficult to detect with traditional microscopes can be observed. It is widely used in the field of nanoscience research.

[0024] As Figure 1 shown, an embodiment of the present invention provides a nanostructure measurement system with ultra-high spatio-temporal resolution combining virtual and real probes, including a signal generation module 1, a detection module, a vector light field generation module 2, an upright objective lens 3, a solid probe 4, a stage 5, an inverted lens 6, a beam splitter 7, a detection module, and a processor, where: The signal generation module 1 is used to generate a pulse signal; the pulse signal includes a pump pulse and a probe pulse with adjustable relative delay time.

[0025] In the signal generation module of the system in this embodiment, a material is excited by a laser pulse (pump pulse), and the transmittance or reflectance change of the material is measured by another laser pulse (probe pulse) with adjustable relative delay time. By continuously changing the delay time, the dynamic relaxation caused by the pump light can be measured, so as to obtain information such as electron energy levels and carrier dynamics. By continuously adjusting the time delay between the pump and probe pulses, the time resolution of nanostructure measurement can be improved.

[0026] The vector light field generation module 2 is used to output radially polarized light and / or azimuthally polarized light based on the pulse signal.

[0027] Output a vector light field according to the input pulse signal as a preparation for subsequent nanostructure measurement of the sample.

[0028] The upright objective lens 3 is used to focus the radially polarized light and / or azimuthally polarized light onto the pixel point to be measured on the sample.

[0029] The solid probe 4 is used to generate a scattered light signal at the near-field position of the pixel point to be measured when the vector light field generation module only outputs radially polarized light.

[0030] If the sample conditions are suitable, a nanostructure sample can be subjected to scattering-type near-field optical scanning imaging with a solid probe with a tip radius on the nanoscale to obtain higher spatial resolution. The basic principle of scattering-type near-field optical scanning imaging is: the illuminated tip of the solid probe will form an enhanced light field around it, and this near field will be changed by the nearby nanostructures. This near-field interaction will cause the scattered light received by the detection module in the far field to carry the local optical properties of the nanostructures, thereby improving the spatial resolution of nanostructure measurement.

[0031] The stage 5 is used to load and move the sample to a preset position.

[0032] In this embodiment, a precision displacement stage is used to load and move the sample, enabling extremely high positioning accuracy, repeat positioning accuracy, and stability during the sample movement process, as well as pixel-by-pixel scanning imaging of the sample.

[0033] An inverted objective lens 6 is used to focus the transmitted part of the optical signal generated by the pixel to be measured on the sample onto the detection module.

[0034] A beam splitter 7 is used to allow the reflected part of the optical signal generated by the pixel to be measured on the sample to enter the detection module.

[0035] A detection module is used to detect the optical signal generated by the pixel to be measured and determine the 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.

[0036] A processor is used to determine the measurement result of the nanostructure of the region to be measured based on the detection results of a number of pixels to be measured in the region to be measured of the sample.

[0037] Specifically, as Figure 2 shown, the signal generation module in this embodiment includes a femtosecond laser 10, a beam splitter 11, three mirrors 12, 13, 15, and a delay line 14, where: The femtosecond laser is used to generate femtosecond laser pulses.

[0038] Femtosecond laser pulses are generated by the femtosecond laser as the initial light source for subsequent pump-probe pulse signals.

[0039] The beam splitter is used to split the femtosecond laser pulses into pump pulses and probe pulses.

[0040] The femtosecond laser pulses are split into pump pulses and probe pulses by the beam splitter, where the pump pulses (ultrafast laser pulses) are used to excite the material, and the probe pulses are used to measure the change in transmittance or reflectance generated after the material is excited. Among them, when splitting the beam, the relative delay time of the two laser pulses can be kept constant, and then the relative delay time is controlled by adjusting the optical path later.

[0041] The delay line is 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.

[0042] In this embodiment, a precision delay line is used to adjust the optical path of the laser by adjusting the position of the mirror therein, thereby changing the relative delay time between the pump pulse and the probe pulse, enabling the relative delay time to change continuously, so that the dynamic relaxation caused by the pump light can be measured, and information such as the electronic energy level and carrier dynamics of the sample nanostructure can be obtained.

[0043] A plurality of reflectors for collimating the output optical paths of the pump pulse and the probe pulse.

[0044] Collimate the output optical paths of the pump pulse and the probe pulse after collimation adjustment, so that the input vector light field generation module.

[0045] In some embodiments, such as Figure 5 As shown, the vector light field generation module at least includes a linear polarizer 28 and a vortex half-wave plate 29, where: The linear polarizer is used to change the polarization state of the pulse signal to obtain linearly polarized light.

[0046] By setting the polarization direction of the linear polarizer, the passed pulse signal is converted into linearly polarized light with a specific polarization direction The vortex half-wave plate is used to convert linearly polarized light into radially polarized light and / or azimuthally polarized light.

[0047] The vortex half-wave plate in this embodiment is a liquid crystal polymer wave plate with a fast axis continuously rotating in the optical region, which can convert incident light with two specific polarization directions into radially polarized light and azimuthally polarized light respectively.

[0048] Furthermore, as Figure 5 As shown, when the vector light field generation module outputs radially polarized light and azimuthally polarized light, the vector light field generation module further includes an annular aperture 30, where: The annular aperture is used to modulate the radially polarized light and the azimuthally polarized light, so that the modulated radially polarized light generates a first preset-size focused spot after being focused by an upright objective lens, and the modulated azimuthally polarized light generates a hollow-hole focused spot with a second preset size after being focused by the upright objective lens.

[0049] Specifically, the radially polarized light can generate a focused spot with an extremely small scale after being modulated by the annular aperture and focused by the upright objective lens, and the azimuthally polarized light can generate a hollow-hole focused spot after being modulated by the annular aperture and focused by the upright objective lens, serving as the light source basis for subsequent confocal scanning imaging. Among them, the current optical diffraction limit size (i.e., the minimum spot size focused by the lens) is calculated by the scalar diffraction theory without any aperture modulation on the entire lens. However, in fact, the influence of the vector nature of light becomes larger under large NA focusing. At this time, using radially polarized light combined with an annular aperture with a very large ratio of inner diameter to outer diameter for focusing can greatly compress the spot size.

[0050] Specifically, in this embodiment, if the vector light field generation module 2 outputs radially polarized light or azimuthally polarized light, the upright objective lens 3 is used to focus the light on the sample to be measured; If the vector light field generation module 2 outputs both radially polarized light and azimuthally polarized light, the upright objective lens 3 is used to focus the vector light field output after being modulated by the annular aperture to generate a focused spot.

[0051] Specifically, the specific operation of generating the scattered light signal by using the solid probe 4 in this embodiment: when the vector light field generating module only outputs the radially polarized light, the solid probe 4 is brought close to the near-field position of the nanostructure sample, and the incident radially polarized light is focused on the tip of the solid probe 4 by using the upright objective lens 3. The illuminated tip of the solid probe 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 to be measured on the sample.

[0052] Specifically, the detection module in this embodiment includes a reflection signal detection module 8 and a transmission signal detection module 9. Among them: The reflection signal detection module 8 is used to detect the reflected light signal generated by the pixel to be measured, and determine the reflection result of the pixel to be measured based on the reflected light signal.

[0053] In this embodiment, as Figure 3 shown, the reflection signal detection module 8 includes a beam splitter 15, a first sleeve lens 16, an image sensor 17, a second sleeve lens 18, a precision pinhole 19 and a photodetector 20. Among them: The beam splitter is used to split the optical signal into a first optical path and a second optical path.

[0054] The light rays of the first optical path pass through the first sleeve lens and the image sensor in sequence to obtain the reflected wide-field imaging information of the pixel to be measured.

[0055] The light rays of the first optical path split by the beam splitter are used to roughly measure the pixel to be measured to obtain its wide-field imaging information.

[0056] The light rays of the second optical path pass through the second sleeve lens, the precision pinhole and the photodetector in sequence to obtain the reflection confocal detection signal.

[0057] The light rays of the second optical path split by the beam splitter are used to finely measure the pixel to be measured. Among them, the precision pinhole can use the confocal effect to reduce the detection spatial scale, so as to obtain the optical signal at an extremely small spatial scale at the position of the pixel to be measured.

[0058] Among them, obtaining the wide-field imaging information is used to preliminarily locate the position of the micro-nano structure, and obtaining the confocal detection signal is used to realize the high-resolution imaging measurement of the micro-nano structure.

[0059] The transmission signal detection module 9 is used to detect the transmitted light signal generated by the pixel to be measured, and determine the transmission result of the pixel to be measured based on the transmitted light signal; the structure of the transmission detection module 9 is basically the same as that of the reflection detection module 2, and only needs to first convert the optical 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.

[0060] In this embodiment, asFigure 4 As shown in the figure, the transmitted signal detection module 8 includes a vortex wave plate 21, a beam splitter 22, a first sleeve lens 23, an image sensor 24, a second sleeve lens 25, a precision pinhole 26, and a photodetector 27.

[0061] The polarization state of the optical signal collected by the inverted objective lens 6 is radially polarized or azimuthally polarized. It needs to be first converted into linearly polarized light by the vortex wave plate 21, and then collected through two optical paths of the beam splitter, using the first sleeve lens 23 and the second sleeve lens 25 respectively. The combination of the image sensor 24, the precision pinhole 26, and the photodetector 27 is used to obtain transmitted wide-field imaging information, transmitted spectral information, and transmitted confocal detection signals respectively. Among them, obtaining wide-field imaging information is used for preliminary positioning of the micro-nano structure position, obtaining spectral information is used for spectral analysis of the micro-nano structure, and obtaining confocal detection signals is used to achieve high-resolution imaging measurement of the micro-nano structure.

[0062] Implementing the embodiments of the present invention at least includes the following beneficial effects: This embodiment provides a nano-structure measurement system with ultra-high spatio-temporal resolution combining virtual and real probes. The system includes a signal generation module, a vector light field generation module, an upright objective lens, a solid probe, a detection module, a stage, and a processor. Among them: on the one hand, the signal generation module is used to generate a pulse signal including a pump pulse and a probe pulse with adjustable relative delay time. By the method of first excitation and then detection, it can measure the change in transmittance or reflectance of the material. 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 nano-structure can be obtained. Each time the relative delay time is changed, the nano-structure measurement result of the sample is recorded, and a series of optical signals with ultra-high temporal resolution for the sample can be obtained, thereby effectively improving the spatial resolution of measuring the nano-structure; on the other hand, through the virtual probe formed by the solid probe or the vector light field generation module and the upright objective lens, a light field with an extremely small scale can be generated in different forms, and the interaction between the generated light field and the sample can be realized by using the generated light field, thereby being able to break through the diffraction limit and improve the spatial resolution of measuring the nano-structure.

[0063] As Figure 6 shown, the embodiments of the present invention also provide a nano-structure measurement method with ultra-high spatio-temporal resolution combining virtual and real probes, which is applied to the above system embodiments and includes steps S100 to S400 as follows: S100: Control the signal generation module to generate a pulse signal; the pulse signal includes a pump pulse and a probe pulse with adjustable relative delay time.

[0064] By setting the relative delay time between the pump pulse and the probe pulse in the pulse signal, the process of first exciting the nanostructured sample with the pump pulse and then detecting it with the probe pulse having a relative delay time with respect to the pump pulse is realized; further, 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 levels and carrier dynamics of the nanostructured sample, and achieving high-time-resolution measurement.

[0065] S200: The vector light field generation module includes a linear polarizer and a vortex half-wave plate; control the vector light field generation module to output radially polarized light and / or azimuthally polarized light based on the pulse signal.

[0066] After adjusting the polarization state and performing polarization conversion on the pulse signal, radially polarized light and / or azimuthally polarized light is output.

[0067] Specifically, in step S200, the process of controlling the vector light field generation module to output radially polarized light and / or azimuthally polarized light based on the pulse signal includes: Set the polarization direction of the linear polarizer to obtain linearly polarized light.

[0068] Set the polarization direction of the linear polarizer so that the pulse signal passing through it is converted into linearly polarized light.

[0069] Adjust the relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light to output radially polarized light and / or azimuthally polarized light.

[0070] 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 the corresponding radially polarized light or azimuthally polarized light.

[0071] S300: Control the sample stage to load and move the sample to a preset position.

[0072] In this embodiment, by driving a precision displacement sample stage to load and move the sample, light signals are generated at each pixel point to be measured on the sample, and the generated light signals are detected and analyzed to determine the detection results of each pixel point to be measured, serving as the data basis for analyzing the nanostructure of the sample.

[0073] S400: Based on the detection results of several pixel points to be measured in the region to be measured of the sample obtained by the detection module, determine the measurement result of the nanostructure of the region to be measured.

[0074] By driving a precision displacement sample stage, light signals are generated at each pixel point to be measured on the sample, and the generated light signals are detected and analyzed, thereby determining the measurement result of the nanostructure of the region to be measured of the sample.

[0075] 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 in the following manner: S410: Obtain the wide-field imaging information of each pixel on the sample, and generate a wide-field imaging image of the sample.

[0076] First, perform an initial imaging on the nanostructure sample. Use the linear polarizer and vortex half-wave plate in the vector light field generation module to output a vector light field, and focus it onto the sample through an upright objective lens. Use the image sensor in the detection module to obtain the wide-field imaging information of each pixel on the sample, and generate a wide-field image of the sample.

[0077] S420: Determine the area to be measured of the sample according to the wide-field imaging image of the sample.

[0078] Determine the area to be measured of the sample from the wide-field imaging image of the sample, that is, the observation area of interest, and move the precision displacement stage to find the observation area.

[0079] S430: Move the stage so that the sample moves to the corresponding position and detect the optical signal generated by the pixel to be measured in the area to be measured, and determine the light intensity signal of the pixel to be measured based on the optical signal.

[0080] After determining the observation area, add an annular aperture in the vector light field generation module, rotate the vortex half-wave plate in the vector light field generation module to convert the laser pulse into radially polarized light, and make the radially polarized light pass through the upright objective lens and be focused into a focal spot with an extremely small scale, and focus it on the pixel to be measured at the current position. Use the photodetector in the signal detection module to detect the optical signal of the pixel to be measured. The precision pinhole in front of the photodetector can use the confocal effect to reduce the detection spatial scale, so as to obtain the light intensity signal with an extremely small spatial scale at this position. Further, drive the precision displacement stage to finely move the sample in the horizontal direction, record the light intensity signal of the pixel to be measured detected by the photodetector every time a position is moved, until each pixel to be measured in the area to be measured is detected, and realize scanning imaging, that is, the confocal imaging obtained by confocal scanning of the article using radially polarized light can be obtained. The same is true when imaging the sample with azimuthally polarized light. Finally, determine the light intensity signal of the pixel to be measured through the obtained confocal imaging. Figure 7 Figure (1) in is the result of confocal imaging of three adjacent gold nanoparticles using the method of this embodiment. Among them, Figure 7 the small figure in the upper right corner of the picture is the imaging of the gold nanoparticles using a scanning electron microscope; Figure 7 Figure (2) in is the result of confocal imaging of two adjacent gold nanoparticles. Among them, the small figure in the upper right corner of the picture is the imaging of the gold nanoparticles using a scanning electron microscope;Figure 7 Figure (3) therein is the result of confocal imaging of adjacent gold nanoparticles, and the small image in the upper right corner of the picture is the imaging of gold nanoparticles using a scanning electron microscope; from this, it can be obtained that by using confocal imaging, the method and system of the present invention can clearly distinguish multiple gold nanoparticles, realizing high-resolution measurement of nanostructures.

[0081] Specifically, if the output of the vector light field generation module is radially polarized light and azimuthally polarized light; the light intensity signal of the pixel to be measured is determined in the following manner: S440: Focus the radially polarized light on the pixel to be measured to obtain the first light intensity signal of the pixel to be measured.

[0082] Perform confocal imaging on the pixel to be measured through the radially polarized light to determine the light intensity signal (pixel value A(i, j)) of the pixel to be measured.

[0083] S450: Focus the azimuthally polarized light on the pixel to be measured to obtain the second light intensity signal of the pixel to be measured.

[0084] Perform confocal imaging on the pixel to be measured through the azimuthally polarized light to determine the light intensity signal (pixel value is B(i, j)) of the pixel to be measured.

[0085] S460: Subtract the first light intensity signal and the second light intensity signal according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

[0086] Define the subtraction coefficient according to the actual situation, and subtract to obtain the final light intensity signal (pixel value C(i, j) = A(i, j) - a * B(i, j), where a is the subtraction coefficient) of the pixel to be measured.

[0087] In some embodiments, after obtaining the confocal image of the sample, subtraction imaging can also be used to further improve the resolution. The principle of subtraction imaging based on the vector light field is as Figure 8 shown, where Figure 8 Figure (1) therein is the point spread function focused by the radially polarized light, Figure 8 Figure (2) therein is the point spread function focused by the azimuthally polarized light, and subtracting the two according to a certain coefficient can obtain as Figure 8The point spread function with a smaller full width at half maximum shown in FIG. (3). Obtaining a point spread function with a smaller full width at half maximum can theoretically achieve higher image resolution. Therefore, by subtracting the images obtained by confocal scanning of a nanostructure sample using radially polarized light and azimuthally polarized light according to a certain coefficient, the measurement of the nanostructure sample with higher spatial resolution can be carried out. 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 point to be measured in the area to be measured 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 azimuthally polarized light, and use the azimuthally polarized light to perform confocal scanning on each pixel point to be measured in the area to be measured 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 and is defined by oneself according to the actual situation. As Figure 8 FIG. (4) in Figure 8 is a simulated image of a nanograting structure, Figure 8 FIG. (5) and FIG. (6) in

[0088] are the images obtained by confocal scanning using radially polarized light and azimuthally polarized light respectively, Figure 9 FIG. (7) in is the image obtained by subtracting FIG. (5) and FIG. (6) according to a certain coefficient. It can be seen that the resolution of the obtained FIG. (7) is higher than that of FIG. (5). Thus, it can be seen that the spatial resolution of measuring the nanostructure can be improved by subtracting the obtained confocal images.

[0089]

[0090] As shown in

[0090] It can be seen that the content in the above method embodiments is applicable to the device embodiments of the present invention. The functions specifically implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0091] In addition, an embodiment of the present application also discloses a computer program product or a computer program. The computer program product or the computer program is stored in a computer-readable storage medium. The processor of the computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program to enable the computer device to execute the above method.

[0092] Finally, an embodiment of the present invention also 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 execute the above method when executed by the processor.

[0093] An embodiment of the present invention also provides a computer-readable storage medium, which stores a program executable by a processor. The program executable by the processor is used to implement the above method when executed by the processor. Similarly, the content in the above method embodiments is applicable to the storage medium embodiments of the present invention. The functions specifically implemented by the storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0094] It can be understood that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and their appropriate combinations. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or can be implemented as hardware, or can be implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or a non-transitory medium) and a communication medium (or a transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium 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 disc (DVD), or other optical disc storage, magnetic cassette, 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. In addition, as is well known to those of ordinary skill in the art, a communication medium generally includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0095] The above is a specific description of the preferred embodiment of the present invention. However, the present invention is not limited to the described embodiment. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An ultra-high spatio-temporal resolution nanostructure measurement system combining virtual and real probes, characterized in that, Comprising: A signal generation module for generating a pulse signal; The pulse signal includes a pump pulse and a probe pulse with an adjustable relative delay time; A vector light field generation module for outputting a radially polarized light and / or an azimuthally polarized light based on the pulse signal; An upright objective lens for focusing the radially polarized light and / or the azimuthally polarized light onto a pixel to be measured on the sample; A solid 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 a radially polarized light; A stage for loading and moving the sample to a preset position; A detection module for detecting the optical signal generated by the pixel to be measured and determining the 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; A processor for determining the measurement result of the nanostructure of the region to be measured based on the detection results of a plurality of pixels to be measured in the region to be measured of the sample.

2. The system according to claim 1, characterized in that The signal generation module includes: A femtosecond laser for generating femtosecond laser pulses; A beam splitter for splitting the femtosecond laser pulses into a pump pulse and a probe pulse; A delay line for adjusting 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 mirrors for collimating the output optical paths of the pump pulse and the probe pulse.

3. The system according to claim 1, wherein The vector light field generation module includes: A linear polarizer for changing the polarization state of the pulse signal to obtain a linearly polarized light; A vortex half-wave plate for converting the linearly polarized light into a radially polarized light and / or an azimuthally polarized light.

4. The system according to claim 3, wherein When the vector light field generation module outputs a radially polarized light and an azimuthally polarized light, the vector light field generation module further includes: An annular aperture for modulating the radially polarized light and the azimuthally polarized light so that the modulated radially polarized light generates a first preset-size focused spot after being focused by the upright objective lens, and the modulated azimuthally polarized light generates a second preset-size hollow-hole focused spot after being focused by the upright objective lens.

5. The system according to claim 1, characterized in that, 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 reflected light intensity signal; the reflection detection module includes a beam splitter, a first sleeve lens, an image sensor, a second sleeve lens, a precision pinhole, and a photodetector, wherein: The beam splitter for splitting the optical signal into a first optical path and a second optical path; The light rays of the first optical path sequentially pass through the first sleeve lens and the image sensor to obtain the reflection wide-field imaging information of the pixel to be measured; The light rays of the second optical path sequentially pass through the second sleeve lens, the precision pinhole, and the photodetector to obtain a reflection confocal detection signal.

6. A method for measuring nanostructures with ultra-high spatio-temporal resolution by combining virtual and real probes, applied to the system according to any one of claims 1 to 5, characterized in that, Comprising: Controlling the signal generation module to generate a pulse signal; The pulse signal includes a pump pulse and a probe pulse with an adjustable relative delay time; Controlling the vector light field generation module to output a radially polarized light and / or an azimuthally 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 number of pixels to be measured in the area to be measured of the sample obtained by the detection module, determine the measurement results of the nanostructure of the area to be measured.

7. The method according to claim 6, characterized in that, The vector light field generation module includes a linear polarizer and a vortex half-wave plate; controlling the vector light field generation module to output radial polarized light and / or azimuthal polarized light based on the pulse signal includes: Set the polarization direction of the linear polarizer to obtain linearly polarized light; Adjust the relationship between the fast axis direction of the vortex half-wave plate and the polarization direction of the linearly polarized light to output radial polarized light and / or azimuthal polarized light.

8. The method according to claim 7, wherein 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 the following method: Obtain the wide-field imaging information of each pixel on the sample to generate a wide-field imaging image of the sample; Determine the area to be measured of the sample according to the wide-field imaging image of the sample; Move the stage so that the sample moves to the corresponding position and detect the optical signal generated by the pixel to be measured in the area to be measured, and determine the light intensity signal of the pixel to be measured based on the optical signal.

9. The method according to claim 8, characterized in that, If the output of the vector light field generation module is radial polarized light and azimuthal polarized light; the light intensity signal of the pixel to be measured is determined by the following method: Focus the radial polarized light on the pixel to be measured to obtain the first light intensity signal of the pixel to be measured; Focus the azimuthal polarized light on the pixel to be measured to obtain the second light intensity signal of the pixel to be measured; Subtract the first light intensity signal and the second light intensity signal according to a preset coefficient to determine the light intensity signal of the pixel to be measured.

10. A computer-readable storage medium storing a program executable by a processor, characterized in that, The program executable by the processor is used to execute the method according to any one of claims 6 to 9 when executed by the processor.

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