A multi-mode multi-dimensional ultrafast electron microscopy device and imaging method thereof

Abstract

The application relates to an ultrafast electron microscopy imaging device and an imaging method thereof, in particular to a multi-mode multi-dimensional ultrafast electron microscopy imaging device and an imaging method thereof, and solves the problem that the existing electron microscopy imaging technical scheme cannot simultaneously meet the requirements of high time-space-energy-momentum resolution and material diversification measurement. The device comprises a sample cabin, an electron gun, a laser generation module, a secondary electron detector, a STEM detector, an in-cabin plug-in detection assembly, a plug-in camera arranged below the sample cabin, an energy filtering electron microscopy assembly, and a vacuum system; a hollow sample table is arranged in the sample cabin; at least two ultrafast pumping laser introduction windows are arranged on the cabin wall; an ultrafast detection laser introduction window is arranged on the electron gun shell; the secondary electron detector is arranged obliquely above the sample table; the STEM detector is installed on the side cabin wall of the sample cabin and located below the sample table; and the in-cabin plug-in detection assembly is arranged below the STEM detector.

Description

TECHNICAL FIELD

[0001] The present application relates to an ultrafast electron microscopy imaging device and an imaging method thereof, in particular to a multi-mode multi-dimension ultrafast electron microscopy imaging device and an imaging method thereof. BACKGROUND

[0002] As one of the most powerful tools for nanoscale structure characterization, electron microscopes, including transmission electron microscope (TEM) and scanning electron microscope (SEM), etc. TEM transmits high-energy electrons through very thin samples, and obtains the internal structure and crystallographic information of the sample according to the diffraction or transmission image formed by the scattering of electrons and atoms; SEM captures secondary electron or backscattered electron signals to obtain the surface topography and composition information of the sample. TEM and SEM can also provide imaging modes such as electron diffraction (ED), scanning transmission electron microscopy (STEM), four-dimensional scanning transmission electron microscopy (4D-STEM), and electron energy loss spectroscopy (EELS). ED technology can analyze the diffraction pattern generated by the electron beam in the crystal to reverse the atomic structure arrangement; STEM or 4D-STEM can greatly enhance the extraction capability of transmission electron in two-dimensional sample Fourier space information by converging the electron beam on the sample and scanning point by point on the sample surface to collect the convergent electron beam diffraction pattern; EELS measures the energy loss spectrum after the non-elastic scattering of electrons and sample, and is used to analyze the element composition and electronic state of the sample. Traditional electron microscopy imaging technology has very high spatial resolution, but its time resolution is usually limited by the frame rate of the recording system (such as CCD camera), and currently it can only reach milliseconds, which is difficult to capture nanosecond or even femtosecond scale dynamic processes, so the ultrafast electron microscopy imaging (UEM) technology emerges as the times require. Ultrafast electron microscopy imaging (UEM) technology combines femtosecond pump laser and electron beam detection to introduce the fourth dimension of time into the electron microscope. One of the femtosecond lasers is directed to the sample position to achieve the dynamic excitation of the sample, and the other femtosecond laser is directed to the photocathode to generate an ultrafast pulsed electron beam. The sample is excited by the light pulse and the sample state is detected by the ultrafast pulsed electron beam with precise delay to capture snapshot images of the sample at different times. The development of ultrafast electron microscopy imaging technology provides important support for the capture of atomic scale dynamic evolution process and original innovation breakthrough demand in important fields such as information technology, quantum science, materials science, and biological science.

[0003] In the research of ultrafast electron microscopy imaging technology, a key technical challenge is to develop an ultrafast electron microscopy imaging technology platform that integrates multiple detection modes and is compatible with multiple sample types, in order to meet the needs of different ultrafast dynamic information such as carrier information, real space information, reciprocal space information, structural information, energy band information, and electronic state information, and to meet the detection needs of block sample reflection imaging and thin film sample transmission imaging.

[0004] Existing ultrafast electron microscopy technology solutions are:

[0005] Document 1 (Yang D., Mohammed O. F., Zewail A. H., et al. Scanning ultrafast electron microscopy [J]. Proceedings of the National Academy of Sciences, 2010, 107(34): 14993-14998.) proposes a combination of field emission scanning electron microscope and pump-probe technology, which realizes the construction of an ultrafast scanning electron microscopy system. The ultrafast scanning electron microscope introduces a light pulse into the electron gun, so that the filament emits a photoelectron beam synchronized with the excitation light. The relative timing of the pump light and the probe electron reaching the sample is controlled by a delay-adjustable optical delay line, thereby realizing time-domain resolution. The signal generated during imaging is mainly the secondary electrons and backscattered electrons generated on the surface of the sample, and the image is recorded by a secondary electron detector and a high-sensitivity camera system to visualize the diffusion and migration dynamics of photo-generated carriers, while obtaining the diffraction (EBSD) pattern of the crystal. However, this technology can only detect the dynamic information of the surface and near-surface of the sample, and cannot realize the internal structure imaging in transmission mode. At the same time, it is not equipped with an electron energy loss spectrum (EELS) instrument or a photoluminescence detector, and lacks the ability to simultaneously obtain energy spectrum or optical signal.

[0006] Document 2 (Barantani F., Claude R., Iyikanat F., et al. Ultrafast momentum-resolved visualization of the interplay between phonon-mediated scattering and plasmons in graphite[J]. Science advances, 2025, 11(14): eadu1001.) and patent 4 (CN106645236A) show an ultrafast transmission electron microscopy imaging system combined with transmission electron microscopy, electron energy loss spectroscopy technology and pump-probe technology. First, it accelerates the ultrafast pulsed electron beam generated by optical pulse excitation to 200 kV, ensuring the high spatial resolution of the ultrafast pulsed electron beam. Second, using the electron diffraction technology and positive space imaging capability of the transmission electron microscope, the structural information and topographic information of the sample are imaged. At the same time, EELS enables the system to obtain the electronic state information of the sample. However, the 200 kV electron energy will cause damage to the sample, severely limiting the dynamic characterization of electron-sensitive materials such as perovskite materials and biological materials. In addition, the system cannot capture signals such as secondary electrons and backscattered electrons on the surface of the sample, severely lacking the ability to explore the dynamic evolution process of carriers in materials in the field of information technology and quantum science.

[0007] Document 3 (Peter S., Peter D., Christian D., and Erdmann S. Low energy nano diffraction (LEND)–A versatile diffraction technique in SEM. Ultramicroscopy, 2020, 213: 112956.) shows a low-energy nano-diffraction device, which is modified from a scanning electron microscope. It is a simple but versatile device with an energy range of 0.5 keV-30 keV. It uses a fluorescent screen and a dedicated vacuum camera to realize the "diffraction mode" in the SEM, which can be used to obtain single diffraction patterns and complete 4D-STEM diffraction patterns. However, this device does not have ultrafast electron imaging function and can only observe static information of the sample. In addition, the transmission electron diffraction pattern is measured through the observation window on the sample chamber, which has a certain angle and will introduce image distortion, which needs to be corrected by image post-processing. At the same time, this device is not equipped with an electron energy loss spectroscopy (EELS) instrument or a photoluminescence detector, lacking the ability to simultaneously obtain energy spectrum or optical signal.

[0008] In summary, the existing ultrafast electron microscopy imaging technical solutions are difficult to meet the requirements of high time-space-energy-momentum resolution and material diversification measurement when dealing with the detection of complex ultrafast dynamics information of various materials, especially in complex systems across scales and materials, lacking versatile full-range characterization technology.

[0009] Therefore, in order to realize the effective integration of various types and multi-dimensional detection of materials, it is urgent to develop a multi-mode multi-dimensional ultrafast electron microscopy imaging device integrating scanning reflection electron imaging, scanning transmission electron imaging, electron diffraction, electron energy analysis, etc. SUMMARY

[0010] The purpose of the present application is to solve the technical problems that the existing ultrafast electron microscopy imaging technical solutions are difficult to meet the requirements of high time-space-energy-momentum resolution and material diversification measurement when dealing with the detection of complex ultrafast dynamics information of various materials, especially in complex systems across scales and materials, lacking versatile full-range characterization technology, and to provide a multi-mode multi-dimensional ultrafast electron microscopy imaging device and an imaging method thereof.

[0011] To solve the above technical problems, the technical scheme adopted by the present application is:

[0012] A multi-mode multi-dimensional ultrafast electron microscopy imaging device, characterized in that:

[0013] It comprises a sample chamber, an electron gun, a laser generation module, a secondary electron detector, a STEM detector, an in-chamber plug-in detection assembly, a plug-in camera, an energy filtering electron microscope assembly, and a vacuum system.

[0014] The sample chamber is provided with a hollow intermediate sample stage for placing a sample to be measured, and at least two ultrafast pump laser introduction windows are arranged on the chamber wall.

[0015] The electron gun is installed above the sample chamber, with its electron optical axis vertically downward and located directly above the sample stage, for emitting an ultrafast pulsed electron beam to the sample to be measured. The electron gun comprises an electron gun shell. An ultrafast detection laser introduction window is arranged on the electron gun shell. In the communication cavity formed by the sealed connection of the electron gun and the sample chamber, an objective lens coaxial with the electron optical axis of the electron gun is arranged at a position between the lower end of the electron gun and the upper end of the sample chamber.

[0016] The laser generation module is arranged outside the sample chamber and the electron gun, for generating ultrafast detection laser and ultrafast pump laser.

[0017] The secondary electron detector is arranged obliquely above the sample stage in the sample chamber.

[0018] The STEM detector is installed on the side wall of the sample chamber, and the telescopic probe head of the STEM detector is horizontally arranged in the area below the sample stage in the sample chamber and can be telescopically extended between the side wall and the position directly below the sample stage;

[0019] The plug-in probe assembly in the chamber is used for ultrafast electron diffraction imaging, and includes a through-hole fluorescent screen, a through-hole mirror, and a probe camera I; the through-hole fluorescent screen and the through-hole mirror are arranged in the area below the STEM detector in the sample chamber in a manner that the former is above the latter, the through holes of the two are coaxial, and the axis is parallel to the electron optical axis of the electron gun; the probe window of the probe camera I is in the reflection light path of the through-hole mirror;

[0020] The plug-in camera and the energy filtering electron microscope assembly include an adapter part I and an energy filtering electron microscope which are sequentially arranged below the sample chamber from top to bottom, and further include a plug-in camera; the electron incident port end of the energy filtering electron microscope is sealed and fixedly connected to the opening I below the opening I arranged on the lower side wall of the sample chamber and directly below the sample stage by the adapter part I, and the inner cavities of the two are communicated; the plug-in camera is installed on the side wall of the adapter part I, and the telescopic probe end of the plug-in camera horizontally extends into the hollow part of the adapter part I and can be telescopically extended between the side wall and the position directly below the sample stage, and is used for ultrafast four-dimensional scanning transmission electron microscopy imaging and detecting the stability of the electron source, so as to correct the diffraction pattern intensity, displacement and time jitter;

[0021] The vacuum system is communicated with the inner cavities of the sample chamber and the electron gun, so that the vacuum degree meets the requirements.

[0022] Further, it is defined that the direction parallel to and opposite to the electron optical axis of the electron gun is the positive direction of the Z axis of the spatial coordinate system XYZ; the direction intersecting the Z axis and parallel to the shortening direction of the probe head of the STEM detector is the positive direction of the Y axis of the spatial coordinate system XYZ; the positive direction of the X axis of the spatial coordinate system XYZ is determined by the left-hand rule; the rotations around the parallel axes of the X axis, the Y axis and the Z axis are respectively the α rotation, the β rotation and the R rotation;

[0023] The sample stage is a hollow six-dimensional sample stage, and the sample to be measured can be moved along the X axis, the Y axis and the Z axis and can be α rotated, β rotated and R rotated;

[0024] The probe camera I is installed on the side wall of the sample chamber;

[0025] The fluorescent surface of the through-hole fluorescent screen is horizontal and upward, and the distance between the upper surface of the through-hole fluorescent screen and the sample placement surface of the sample stage in the horizontal state is 150.15 mm±7 mm; the reflection surface of the through-hole mirror is upward;

[0026] The distance between the receiving surface of the pluggable camera detector and the sample placement surface of the horizontally positioned sample stage is 327.65 mm ± 7 mm.

[0027] Furthermore, the plug-in camera and energy-filtering electron microscope assembly also includes a vacuum tube and a magnetic lens I;

[0028] The vacuum pipe is located between the sample chamber and the adapter component I; the adapter component I is sealed and fixedly connected to the sample chamber directly below the opening I through the vacuum pipe, and the electron entrance end of the energy filter electron microscope is sealed and fixedly connected to the sample chamber directly below the opening I through the vacuum pipe and the adapter component I, and the inner cavities of the two are connected.

[0029] The magnetic lens I is mounted on the outer cylindrical surface of the vacuum pipe and is used to laterally focus the transmitted electronic signal and the electronic signal to be analyzed.

[0030] Furthermore, the sample stage includes an α rotary stage, a Z displacement component, a transition component II, an R rotary stage, an X / Y displacement component, a β rotary stage, and a sample holder;

[0031] The Z-displacement component includes a Z-displacement base layer and a Z-displacement stage; the Z-displacement base layer is rotatably connected to a door set on the side wall of the sample chamber via an α-rotating stage, and can rotate α relative to the door set on the side wall of the sample chamber; the Z-displacement stage is linearly slidably connected to the Z-displacement base layer, and can slide relative to it along the Z-axis direction;

[0032] The adapter component II is fixedly connected to the lower end of the side of the Z-displacement stage away from the Z-displacement base layer, forming an L-shaped structure with the Z-displacement stage.

[0033] The R rotary stage, X / Y displacement component, β rotary stage, and sample holder are arranged sequentially from bottom to top on the upper surface of the L-shaped horizontal arm.

[0034] The rotation axis of the R rotary table is coplanar with the rotation axis of the α rotary table;

[0035] The X / Y displacement component is located in the middle of the upper surface of the R-rotation platform, and includes an X / Y displacement base layer, an X displacement platform, and a Y displacement platform arranged sequentially from bottom to top. The X / Y displacement base layer is rotatably connected to the transfer component II via the R-rotation platform and can rotate relative to the transfer component II. The X displacement platform is linearly slidably connected to the X / Y displacement base layer and can slide relative to it along the X-axis. The Y displacement platform is linearly slidably connected to the X displacement platform and can slide relative to it along the Y-axis.

[0036] The β rotating table is arranged on the Y displacement table and on one side of the Y axis positive or negative direction of the rotating axis of the R rotating table, and comprises a β rotating table bottom layer and a β rotating table top layer arranged in sequence from bottom to top; the β rotating table bottom layer is fixedly connected with the Y displacement table, and an arc cylindrical track with an axis parallel to the Y axis and coplanar with the rotating axis of the R rotating table is arranged on the upper surface of the β rotating table bottom layer; the lower surface of the β rotating table top layer is provided with a cylindrical surface matched with the arc cylindrical track, and the β rotating table top layer is rotationally connected with the β rotating table bottom layer and can swing relative to the β rotating table bottom layer to rotate by a preset angle β;

[0037] The sample support is horizontally arranged along the Y axis direction, one end of the sample support is fixedly connected to the upper surface of the β rotating table top layer, and the other end of the sample support is suspended above the rotating axis of the R rotating table; the hollow structure of the sample table is arranged from the lower surface of the adapter component II to the lower surface of the sample support and takes the rotating axis of the R rotating table as a center axis, and a plurality of sample holes spacedly arranged and penetrating up and down are arranged on the other end of the sample support to form a hollow sample table; the other end of the sample support is used for mounting a sample to be tested.

[0038] Further, the sample table further comprises an adapter component III and an adapter component IV;

[0039] The adapter component III is arranged between the X / Y displacement base layer and the upper side of the R rotating table, the X / Y displacement base layer is fixedly connected with the adapter component III, and the adapter component III and the R rotating table are rotationally connected with the adapter component II;

[0040] The adapter component IV is arranged on one side of the Y axis positive or negative direction of the rotating axis of the R rotating table between the β rotating table bottom layer and the Y displacement table; and the β rotating table bottom layer is fixedly connected with the Y displacement table through the adapter component IV.

[0041] Further, the in-cabin plug-in and pull-out detection assembly further comprises a plug-in and pull-out control assembly and a relay optical lens assembly;

[0042] The plug-in and pull-out control assembly is arranged opposite to the detection camera I on the outside of the side cabin wall of the sample cabin, and the telescopic rod of the plug-in and pull-out control assembly horizontally extends into the sample cabin; the through-hole fluorescent screen and the through-hole mirror are fixedly connected to the end of the free end of the telescopic rod, so that the plug-in and pull-out control assembly can move horizontally between the side cabin wall and the sample table below;

[0043] The through-hole mirror is a 45° through-hole mirror;

[0044] The relay optical lens assembly is in the reflection light path of the through-hole mirror, and the detection camera I and the relay optical lens assembly are arranged on the inner and outer sides of the same side cabin wall of the sample cabin respectively, and the relay optical lens assembly adjusts the beam diameter of the light signal to adapt to the detection window of the detection camera I.

[0045] Further, the electron gun further comprises, in sequence along the electron optical axis, a cathode filament, a grid electrode, an anode, a high-voltage accelerating tube, a condenser I, a condenser II and a scanning coil, which are arranged in the electron gun shell;

[0046] The superfast probe laser introduction window is a focusing lens I, which is used to focus the superfast probe laser to the cathode filament in the electron gun shell; the accelerating voltage between the grid electrode and the anode is adjustable between 0V and 30kV;

[0047] The objective lens is an electrostatic-electromagnetic compound lens;

[0048] The sample chamber wall is provided with two superfast pump laser introduction windows, which are focusing lens II and focusing lens III, respectively; the angles between the optical axes of the focusing lens II and the focusing lens III and the electron optical axis of the electron gun are 50°~70° and 70°~110°, respectively, and the two superfast pump lasers are used to focus the 50°~70° superfast pump laser and the 70°~110° superfast pump laser to the sample on the sample table.

[0049] Further, the laser generation module comprises, in sequence along the optical path, a laser, a beam splitter, a frequency doubling component and a mirror I arranged in sequence on the reflected light path of the beam splitter, and a laser pulse delay precision control assembly, a mirror II and a mirror III arranged in sequence on the transmitted light path of the beam splitter;

[0050] The laser is used to generate a superfast laser beam;

[0051] The frequency doubling component is used to convert the frequency of the superfast laser beam on the reflected light path of the beam splitter to obtain a superfast probe laser;

[0052] The focusing lens I is on the reflected light path of the mirror I, the superfast probe laser generated by the laser generation module is emitted to the focusing lens I through the mirror I, and the superfast probe laser is focused to the cathode filament in the electron gun shell through the focusing lens I;

[0053] The laser pulse delay precision control assembly is used to convert the wavelength and time of the superfast laser beam on the transmitted light path of the beam splitter to obtain a pump-probe synchronous superfast pump laser;

[0054] The focusing lens II is on the reflected light path of the mirror III;

[0055] The focusing lens III is on the optical axis of the output end of the laser pulse delay precision control assembly, and the laser pulse delay precision control assembly and the focusing lens III are respectively distributed on the two sides of the mirror II;

[0056] The mirror II is removable;

[0057] When the reflector II is working, the ultrafast pump laser of pump-probe synchronization is converted into a 50°~70° ultrafast pump laser through the reflector II and the reflector III and emitted to the focusing lens II. The focusing lens II focuses the 50°~70° ultrafast pump laser onto the sample to be tested on the sample stage.

[0058] After the reflector II is removed, the ultrafast pump laser obtained by the pump-probe synchronization through the laser pulse delay precision control component is emitted as a 70°~110° ultrafast pump laser to the focusing lens III. The focusing lens III focuses the 70°~110° ultrafast pump laser onto the sample to be tested on the sample stage.

[0059] Furthermore, it also includes a backscattered electron detector, an energy-dispersive X-ray detector, an optical navigation camera, and a plasma cleaning device, all mounted on the sample chamber via flange interfaces.

[0060] The energy-filtering electron microscope includes an energy-filtering electron microscope tube, a dipole magnet, a magnetic lens II, an energy slit, a magnetic lens III, a magnetic lens IV, a magnetic lens V, a magnetic lens VI, and a magnetic lens VII arranged sequentially along the electron optical axis within the energy-filtering electron microscope tube, and a detection camera II located outside the energy-filtering electron microscope tube with its detection window facing the electron emission port end of the energy-filtering electron microscope tube.

[0061] Meanwhile, the present invention also provides an imaging method for the above-mentioned multi-mode, multi-dimensional ultrafast electron microscopy imaging device, which is characterized by including the following steps:

[0062] Step 1: Construct a multi-mode, multi-dimensional ultrafast electron microscopy imaging device. During construction, the ultrafast detection laser introduction window on the electron gun shell is set as focusing lens I, and two ultrafast pump laser introduction windows are set on the sample chamber wall, which are focusing lenses II and III, respectively. The angles between the optical axes of focusing lenses II and III and the electron optical axis of the electron gun are 50°~70° and 70°~110°, respectively. Then, all the retractable parts in each component of the constructed multi-mode, multi-dimensional ultrafast electron microscopy imaging device are in the retracted state, and each component is in the closed state or in a non-working standby state.

[0063] Step 2: Install the sample to be tested onto the sample stage of the multi-mode multi-dimensional ultrafast electron microscopy imaging device in the standby state where all components are in the off state or non-working state in Step 1, and then close the door of the sample chamber.

[0064] Step 3: Using the vacuum system, evacuate the inner cavities of the sample chamber and electron gun in the multi-mode multi-dimensional ultrafast electron microscopy imaging device, which was closed in Step 2, so that the inner cavities of both are evacuated to and maintained at the required vacuum level.

[0065] Step 4: according to the detection requirements of the sample to be measured installed on the sample stage in step 2, select the imaging operation process from the following four imaging modes, and after each imaging mode is executed, if the imaging mode contains multiple sub-imaging modes, then after each sub-imaging mode is executed, the retractable components of each component of the multi-mode multi-dimensional ultrafast electron microscopy imaging device constructed in step 1 are in the retracted state, and each component is in the closed state or the standby state of the non-working state; the four imaging modes are:

[0066] Imaging mode A: ultrafast scanning reflection mode

[0067] The imaging operation process is:

[0068] Step A.1: the laser generating module generates ultrafast probe laser and 50°~70° ultrafast pump laser; and the ultrafast probe laser generated by the laser generating module is emitted to the focusing lens I, and the ultrafast probe laser is focused by the focusing lens I to the electron gun shell, so that the electron gun emits an ultrafast pulse electron beam to the sample to be measured; the 50°~70° ultrafast pump laser generated by the laser generating module is emitted to the focusing lens II, and the 50°~70° ultrafast pump laser is focused by the focusing lens II to the sample to be measured on the sample stage, so as to pump and excite the sample to be measured;

[0069] Step A.2: the secondary electron detector receives the secondary electrons generated by the interaction between the ultrafast pulse electron beam emitted by the electron gun to the sample to be measured and the sample to be measured pumped and excited in step A.1, to realize surface topography and carrier imaging, and complete the ultrafast scanning reflection mode;

[0070] Imaging mode B: ultrafast scanning transmission mode

[0071] The imaging mode B is divided into two sub-imaging modes: sub-imaging mode B1 and sub-imaging mode B2;

[0072] Sub-imaging mode B1: ultrafast conventional scanning transmission mode

[0073] The imaging operation process is:

[0074] Step B1.1: the laser generating module generates ultrafast probe laser and 50°~70° ultrafast pump laser; and the ultrafast probe laser generated by the laser generating module is emitted to the focusing lens I, and the ultrafast probe laser is focused by the focusing lens I to the electron gun shell, so that the electron gun emits an ultrafast pulse electron beam to the sample to be measured; the 50°~70° ultrafast pump laser generated by the laser generating module is emitted to the focusing lens II, and the 50°~70° ultrafast pump laser is focused by the focusing lens II to the sample to be measured on the sample stage, so as to pump and excite the sample to be measured;

[0075] Step B1.2: the probe head of the STEM detector is elongated to the position right below the sample stage, so that it receives the transmission electron signal I generated by the interaction between the ultrafast pulsed electron beam emitted by the electron gun to the sample to be measured in step B1.1 and the sample to be measured pumped and excited, to realize topographic imaging, and complete the ultrafast conventional scanning transmission mode;

[0076] Sub-imaging mode B2: ultrafast four-dimensional scanning transmission mode

[0077] The imaging operation process is as follows:

[0078] Step B2.1: the laser generating module generates ultrafast detection laser and 50°-70° ultrafast pumping laser; and the ultrafast detection laser generated by the laser generating module is emitted to the focusing lens I, the ultrafast detection laser is focused by the focusing lens I and introduced into the electron gun shell, so that the electron gun emits an ultrafast pulsed electron beam to the sample to be measured; the 50°-70° ultrafast pumping laser generated by the laser generating module is emitted to the focusing lens II, the 50°-70° ultrafast pumping laser is focused by the focusing lens II and introduced to the sample to be measured on the sample stage, so as to pump and excite the sample to be measured;

[0079] Step B2.2: the detection end of the plug-in camera is elongated to the position right below the sample stage, so that it receives the transmission electron signal I generated by the interaction between the ultrafast pulsed electron beam emitted by the electron gun to the sample to be measured in step B2.1 and the sample to be measured pumped and excited, to realize ultrafast four-dimensional scanning transmission electron microscopic imaging, and complete the ultrafast four-dimensional scanning transmission mode;

[0080] Imaging mode C: ultrafast electron diffraction mode

[0081] The imaging operation process is as follows:

[0082] Step C.1: the laser generating module generates ultrafast detection laser and 50°-70° ultrafast pumping laser; and the ultrafast detection laser generated by the laser generating module is emitted to the focusing lens I, the ultrafast detection laser is focused by the focusing lens I and introduced into the electron gun shell, so that the electron gun emits an ultrafast pulsed electron beam to the sample to be measured; the 50°-70° ultrafast pumping laser generated by the laser generating module is emitted to the focusing lens II, the 50°-70° ultrafast pumping laser is focused by the focusing lens II and introduced to the sample to be measured on the sample stage, so as to pump and excite the sample to be measured;

[0083] Step C.2: move the through-hole fluorescent screen and the through-hole mirror to be directly below the sample table, and extend the detection end of the plug-in camera to be directly below the sample table; use the detection camera I to capture the optical signal reflected by the through-hole mirror after the transmission electron signal I generated by the interaction between the ultrafast pulsed electron beam emitted by the electron gun in step C.1 to the to-be-tested sample and the to-be-tested sample pumped and excited in turn through the through-hole fluorescent screen and the through-hole mirror, so as to realize the imaging of the inverse spatial information of the to-be-tested sample; use the detection end of the plug-in camera to receive the transmission electron signal II passing through the central through holes of the through-hole fluorescent screen and the through-hole mirror after the transmission electron signal I generated by the interaction between the ultrafast pulsed electron beam emitted by the electron gun in step C.1 to the to-be-tested sample and the to-be-tested sample pumped and excited in turn, so as to detect the stability of the electron source, correct the intensity, displacement and time jitter of the diffraction pattern, and complete the ultrafast electron diffraction mode.

[0084] Imaging mode D: energy-filtered electron microscopy imaging mode

[0085] Then the imaging operation process is:

[0086] Step D.1: the laser generating module generates ultrafast detection laser and 70°-110° ultrafast pumping laser; and the ultrafast detection laser generated by the laser generating module is emitted to the focusing lens I, the ultrafast detection laser is focused by the focusing lens I and introduced into the electron gun shell, so that the electron gun emits an ultrafast pulsed electron beam to the to-be-tested sample; the 70°-110° ultrafast pumping laser generated by the laser generating module is emitted to the focusing lens III, the 70°-110° ultrafast pumping laser is focused by the focusing lens III and introduced to the to-be-tested sample on the sample table, so as to pump and excite the to-be-tested sample;

[0087] Step D.2: use the energy-filtered electron microscope to receive the to-be-analyzed electron signal generated by the interaction between the ultrafast pulsed electron beam emitted by the electron gun in step D.1 to the to-be-tested sample and the to-be-tested sample pumped and excited, realize energy-filtered electron microscopy imaging, and complete the energy-filtered electron microscopy imaging mode.

[0088] The beneficial effects of the present application are:

[0089] (1) The multi-mode multi-dimensional ultrafast electron microscopy imaging device of the present application solves the problem that the electron beam of a conventional electron microscope cannot directly penetrate the sample table by designing a compact six-dimensional sample table with a hollow middle, providing a general sample table for the integration of reflection and transmission imaging modes and creating basic conditions for integration; then, through novel structural design, a scanning electron microscope, an in-cabin plug-in detection assembly, a plug-in camera, an energy filtering electron microscope, an ultrafast detection laser introduction window, at least two ultrafast pumping laser introduction windows, and the general reflection and transmission sample table are integrated; compared with traditional ultrafast scanning electron microscopes or ultrafast transmission electron microscopes, it can simultaneously provide multiple imaging modes such as ultrafast scanning reflection electron imaging, ultrafast scanning transmission electron imaging, ultrafast electron diffraction imaging, and energy filtering electron microscopy imaging, has advantages such as diverse functions, high time-space-energy-momentum resolution, wide application range, and can simultaneously meet the detection needs of bulk sample reflection imaging and thin film sample transmission imaging, greatly improving the compatibility of the sample; therefore, the present application solves the technical problem that existing ultrafast electron microscopy imaging technology solutions are difficult to simultaneously meet the high time-space-energy-momentum resolution and material diversification measurement requirements when dealing with multiple material complex ultrafast dynamic information detection, especially in complex systems across scales and materials, lacking of a versatile characterization technology with variable modes. The multi-mode multi-dimensional ultrafast electron microscopy imaging device of the present application effectively improves the spatial information acquisition capability of the sample.

[0090] (2) In the multi-mode multi-dimensional ultrafast electron microscopy imaging device of the present application, an ultrafast detection laser introduction window and two ultrafast pumping laser introduction windows are preferably designed, the ultrafast detection laser introduction window is a focusing lens I, the two ultrafast pumping laser introduction windows are focusing lens II and focusing lens III respectively, and the included angles between the optical axes of focusing lens II and focusing lens III and the electron gun electron optical axis are 50°-70° and 70°-110° respectively; such design not only realizes conventional pumping-detection imaging of ultrafast laser and electron beam, but also meets the experimental requirements of laser passing through dielectric samples to realize electron modulation, and can be used for studying the interaction between light and electrons, greatly improving the flexibility of experiments and having high universality.

[0091] (3) In the multi-mode multi-dimensional ultrafast electron microscopy imaging device, the sample stage is preferably a hollow six-dimensional sample stage; the hollow design enables it to reflect and transmit universally, and can simultaneously meet the detection needs of bulk sample reflection imaging and thin film sample transmission imaging, and the compatibility of the sample is improved; and the six-dimensional design enables it to adjust the sample in six degrees of freedom, and further improves the compatibility of the sample. In addition, in the application, the acceleration voltage between the grid electrode and the anode of the electron gun is preferably controlled at 0V-30kV, so that damage to the sample caused by excessive electron energy is avoided, and thus the application can be used for dynamic characterization of electron-sensitive materials such as perovskite materials and biological materials, and the compatibility of the sample material is also greatly improved.

[0092] (4) In the multi-mode multi-dimensional ultrafast electron microscopy imaging device, a cabin plug-in detection assembly is designed, which shortens the length of the detection camera I under the condition that the size of the through-hole fluorescent screen is constant, and can collect a larger range of ultrafast electron diffraction patterns; at the same time, the through-hole fluorescent screen and the through-hole mirror are used in the middle hole of the cabin plug-in detection assembly for receiving the transmission electron signal, so that the diffraction electron and the transmission electron signal II directly passing through the center through-hole of the through-hole fluorescent screen and the through-hole mirror are respectively imaged to the detection camera I and the plug-in camera; in this way, on the one hand, the sample information is detected by using the diffraction electron; on the other hand, the transmission electron signal II directly passing through the center through-hole of the through-hole fluorescent screen and the through-hole mirror is used to monitor the jitter of the transmission electron signal in real time, and the stability of the detection electron source is realized, so that the intensity, displacement and time jitter of the diffraction pattern are corrected, and the experimental precision and the ultrafast electron imaging resolution are improved.

[0093] (5) In the multi-mode multi-dimensional ultrafast electron microscopy imaging device, a plug-in camera is designed below the sample cabin, which can be used for ultrafast four-dimensional scanning transmission electron microscopy imaging, and greatly enhances the spatial structure information resolution capability of two-dimensional samples; on the other hand, when used for ultrafast electron diffraction imaging, the transmission electron signal II directly passing through the center through-hole of the through-hole fluorescent screen and the through-hole mirror is received, the jitter of the transmission electron signal is monitored in real time, the stability of the detection electron source is realized, the intensity, displacement and time jitter of the diffraction pattern are corrected, and the experimental precision and the ultrafast electron imaging resolution are improved.

[0094] (6) In the multi-mode multi-dimensional ultrafast electron microscopy imaging device, the condenser I and the condenser II are arranged in the electron gun shell along the electron optical axis in sequence, and a double condenser electron optical system is adopted, which can balance the electron beam flux and the time and spatial resolution, and obtain the best focusing effect. BRIEF DESCRIPTION OF DRAWINGS

[0095] Figure 1is the structural schematic diagram of the embodiment of the multi-mode multi-dimension ultrafast electron microscopy imaging device of the present application (sample stage and vacuum system diagram are not shown);

[0096] Figure 2 is the structural schematic diagram of the plug-in and plug-out probe assembly in the cabin in the embodiment of the multi-mode multi-dimension ultrafast electron microscopy imaging device of the present application;

[0097] Figure 3 is the structural schematic diagram of the plug-in and plug-out camera and the energy filtering electron microscopy assembly in the embodiment of the multi-mode multi-dimension ultrafast electron microscopy imaging device of the present application;

[0098] Figure 4 is the structural schematic diagram of the sample stage of two different viewing angles in the embodiment of the multi-mode multi-dimension ultrafast electron microscopy imaging device of the present application, wherein:

[0099] (1) is the structural schematic diagram of the sample stage of the first viewing angle;

[0100] (2) is the structural schematic diagram of the sample stage of the second viewing angle;

[0101] Figure 5 is the schematic diagram of four kinds of imaging modes that can be realized by using the embodiment of the multi-mode multi-dimension ultrafast electron microscopy imaging device of the present application, wherein:

[0102] (A) is the ultrafast scanning reflection mode;

[0103] (B) is the ultrafast scanning transmission mode;

[0104] (C) is the ultrafast electron diffraction mode;

[0105] (D) is the energy filtering electron microscopy imaging mode.

[0106] The legend of the drawings is as follows:

[0107] 1-laser, 2-ultrafast laser beam, 3-beam splitter, 4-mirror IV, 5-laser pulse delay fine control component, 6-frequency doubling component, 7-ultrafast probe laser, 8-electron gun shell, 9-focusing lens I, 10-cathode filament, 11-grid electrode, 12-anode, 13-high-voltage accelerating tube, 14-collector lens I, 15-collector lens II, 16-scanning coil, 17-objective lens, 18-ultrafast pulsed electron beam, 19-focusing lens II, 20-sample chamber, 21-focusing lens III, 22-50°~70° ultrafast pump laser, 23-70°~110° ultrafast pump laser, 24-sample to be measured, 25-transmission electron signal I, 26-secondary electron, 27-secondary electron detector, 28-STEM detector, 29-detector probe, 30-chamber plug-in detection component, 31-magnetic lens I, 32-plug-in camera and energy filtering electron microscope component, 33-plug-in control component, 34-telescopic rod, 35-through-hole fluorescent screen, 36-through-hole mirror, 37-transmission electron signal II, 38-optical signal, 39-relay optical lens component, 40-detection camera I, 41-electron signal to be analyzed, 42-plug-in camera, 43-adaptor component I, 44-energy filtering electron microscope barrel, 45-dipole magnet, 46-electron beam, 47-low-energy electron beam I, 48-low-energy electron beam II, 49-magnetic lens II, 50-energy slit, 51-magnetic lens III, 52-magnetic lens IV, 53-magnetic lens V, 54-magnetic lens VI, 55-magnetic lens VII, 56-detection camera II, 57-Z displacement stage, 58-adaptor component II, 59-R rotation stage, 60-adaptor component III, 61-X / Y displacement component, 62-adaptor component IV, 63-β rotation stage, 64-sample stage hollow structure, 65-sample support, 66-sample hole, 67-mirror I, 68-mirror II, 69-mirror III. DETAILED DESCRIPTION

[0108] The application will be described in detail below with reference to the drawings and specific embodiments.

[0109] Reference Figure 1 The application is a multi-mode multi-dimensional ultrafast electron microscopy imaging device, which comprises a sample chamber 20, an electron gun, a laser generation module, a secondary electron detector 27, a STEM detector 28, a chamber plug-in detection component 30, a plug-in camera and energy filtering electron microscope component 32, and a vacuum system (not shown in the vacuum system diagram).

[0110] The sample chamber 20 is provided with a sample stage (not shown in the sample stage) in the middle for placing a sample to be measured 24. Figure 1 The sample stage is not shown in the sample stage, and the sample stage is in Figure 1Below the sample 24 to be measured, for installing the sample 24 to be measured, the cabin wall is provided with at least two ultrafast pump laser introduction windows. In the embodiment, the cabin wall of the sample cabin 20 is provided with two ultrafast pump laser introduction windows, and the two ultrafast pump laser introduction windows are focusing lens II 19 and focusing lens III 21 respectively; the angles between the optical axes of the focusing lens II 19 and the focusing lens III 21 and the electron gun electron optical axis are 50°-70° and 70°-110° respectively, and the two are respectively used for focusing and introducing the 50°-70° ultrafast pump laser 22 and the 70°-110° ultrafast pump laser 23 to the sample 24 to be measured on the sample table.

[0111] The above-mentioned electron gun is installed above the sample cabin 20, the electron optical axis thereof is vertically downward and located directly above the sample table, and is used for emitting the ultrafast pulse electron beam 18 to the sample 24 to be measured; the electron gun comprises an electron gun shell 8; the electron gun shell 8 is provided with an ultrafast detection laser introduction window; in the communication cavity formed by the sealing connection of the electron gun and the sample cabin 20, an objective lens 17 is arranged at a position between the lower end of the electron gun and the upper end of the sample cabin 20, and the optical axis of the objective lens 17 is coaxial with the electron gun electron optical axis; in the embodiment, the electron gun comprises, in addition to the electron gun shell 8, a cathode filament 10, a grid electrode 11, an anode 12, a high-voltage accelerating tube 13, a condenser lens I 14, a condenser lens II 15 and a scanning coil 16 which are sequentially arranged in the electron gun shell 8 along the electron optical axis; the ultrafast detection laser introduction window arranged on the electron gun shell 8 is focusing lens I 9, which is used for focusing and introducing the ultrafast detection laser 7 to the cathode filament 10 in the electron gun shell 8 to generate the ultrafast pulse electron beam 18; the generated ultrafast pulse electron beam 18 is accelerated by the acceleration voltage between the grid electrode 11 and the anode 12, and is propagated downward through the high-voltage accelerating tube 13, and the propagation process sequentially passes through the focusing of the double condenser lens electron optical path system of the condenser lens I 14 and the condenser lens II 15, the electron beam control of the scanning coil 16 and the focusing of the objective lens 17, and finally reaches the sample 24 to be measured to cause the interaction between the electrons and the substance. In the embodiment, the condenser lens I 14 and the condenser lens II 15 are sequentially arranged in the electron gun shell 8 along the electron optical axis, and a double condenser lens electron optical path system is adopted, so that the electron beam flux and the time and spatial resolution can be considered, and the best focusing effect can be obtained; at the same time, in order to avoid damage to the sample caused by too high electron energy, the acceleration voltage between the above-mentioned grid electrode 11 and the anode 12 is preferably adjustable in the range of 0V-30kV. In the embodiment, the above-mentioned objective lens 17 is selected as an electrostatic-electromagnetic composite lens.

[0112] The laser generation module is arranged outside the sample chamber 20 and the electron gun, and is used for generating the ultrafast probe laser 7 and the ultrafast pump laser. The laser generation module in the embodiment includes, in sequence along an optical path, a laser 1, a beam splitter 3, a frequency doubling component 6 and a mirror I 67 arranged in sequence on a reflected light path of the beam splitter 3, and a laser pulse delay fine control assembly 5, a mirror II 68 and a mirror III 69 arranged in sequence on a transmitted light path of the beam splitter 3. The laser 1 is used for generating an ultrafast laser beam 2; in the embodiment, the laser 1 is a femtosecond laser, and the generated ultrafast laser beam 2 is a femtosecond laser beam. The ultrafast laser beam 2 generated by the laser 1 is split into two ultrafast laser beams by the beam splitter 3.

[0113] The frequency doubling component 6 is used for frequency conversion of the ultrafast laser beam on the reflected light path of the beam splitter 3, to obtain the ultrafast probe laser 7; in the embodiment, the obtained ultrafast probe laser 7 is an ultraviolet femtosecond probe laser. The ultrafast probe laser 7 can also be an ultrafast probe laser of other wavebands such as visible light or near-infrared light, and other time scales such as attosecond, picosecond or nanosecond, in addition to the ultraviolet femtosecond probe laser in the embodiment. The focusing lens I 9 is on the reflected light path of the mirror I 67, the ultrafast probe laser 7 generated by the laser generation module is emitted to the focusing lens I 9 through the mirror I 67, and the focusing lens I 9 focuses the ultrafast probe laser 7 to the cathode filament 10 in the electron gun housing 8, to generate the ultrafast pulse electron beam 18.

[0114] The laser pulse delay fine control assembly 5 is used for wavelength conversion and time control of the ultrafast laser beam on the transmitted light path of the beam splitter 3, to obtain the pump-probe synchronous ultrafast pump laser; in the embodiment, the laser pulse delay fine control assembly 5 includes four mirrors IV 4 arranged in sequence along an optical path. The focusing lens II 19 is on the reflected light path of the mirror III 69; the focusing lens III 21 is on the optical axis of the output end of the laser pulse delay fine control assembly 5, and is distributed on both sides of the mirror II 68 with the laser pulse delay fine control assembly 5; the mirror II 68 is removable; according to the detection requirements of the sample 24 to be detected, the mirror II 68 is made to work or removed to guide the ultrafast pump laser of different angles to the sample 24 on the sample table, specifically:

[0115] When the mirror II 68 is working, the pump-probe synchronized ultrafast pump laser is converted into 50°~70° ultrafast pump laser 22 by the mirror II 68 and the mirror III 69 and emitted to the focusing lens II 19, and the 50°~70° ultrafast pump laser 22 is focused by the focusing lens II 19 to the sample 24 on the sample stage. After the mirror II 68 is removed, the pump-probe synchronized ultrafast pump laser obtained by the laser pulse delay precision control assembly 5 is emitted to the focusing lens III 21 as 70°~110° ultrafast pump laser 23, and the 70°~110° ultrafast pump laser 23 is focused by the focusing lens III 21 to the sample 24 on the sample stage.

[0116] As can be seen from the above, the 50°~70° ultrafast pump laser 22 and the 70°~110° ultrafast pump laser 23 generated by the laser generation module do not work at the same time, wherein the 50°~70° ultrafast pump laser 22 is used for pumping and exciting the sample 24, and then performing electron pulse detection, which is suitable for ultrafast scanning reflection mode, ultrafast scanning transmission mode, and ultrafast electron diffraction mode, etc. The 70°~110° ultrafast pump laser 23 is used for providing a periodic light field for the photonic crystal of the sample 24, which can be used for compression of electron pulses, etc., and is suitable for energy filtering electron microscopy imaging mode. In the embodiment, the 50°~70° ultrafast pump laser 22 generated by the laser generation module is 50°~70° infrared femtosecond pump laser; and the 70°~110° ultrafast pump laser 23 generated by the laser generation module is 70°~110° infrared femtosecond pump laser. In addition to being infrared femtosecond pump laser in the embodiment, the 50°~70° ultrafast pump laser 22 and the 70°~110° ultrafast pump laser 23 can also be other wavebands such as extreme ultraviolet light, ultraviolet light, visible light, near-infrared light, or infrared light, and other time scales such as attosecond, picosecond, or nanosecond ultrafast pump laser.

[0117] The above-mentioned secondary electron detector 27 is arranged obliquely above the sample stage in the sample cabin 20; in the embodiment, the secondary electron detector 27 is an E-T secondary electron detector, and the signal output end thereof extends out of the cabin wall.

[0118] The above-mentioned STEM detector 28 is installed on the side cabin wall of the sample cabin 20, and the telescopic detector probe 29 thereof is horizontally arranged in the area below the sample stage in the sample cabin 20 and can be telescopically arranged between the side cabin wall and the area directly below the sample stage. In the embodiment, the detector probe 29 of the STEM detector 28 is a semiconductor electron detector.

[0119] Referring to Figure 1 and Figure 2The in-cabin plug-in probe assembly 30 is used for ultrafast electron diffraction imaging, and includes a through-hole fluorescent screen 35, a through-hole mirror 36, and a probe camera I 40. The through-hole fluorescent screen 35 and the through-hole mirror 36 are arranged in the STEM probe 28 below the sample cabin 20 in a manner that the fluorescent surface of the former is horizontal and upward, the reflecting surface of the latter is upward, the former is above the latter, the through holes of the two are coaxial and the axis is parallel to the electron gun electron optical axis, and the two can move horizontally between the side cabin wall and the sample stage directly below. The probe window of the probe camera I 40 is in the reflected light path of the through-hole mirror 36. In this embodiment, the probe camera I 40 is installed on the side cabin wall of the sample cabin 20. The distance between the upper surface of the through-hole fluorescent screen 35 and the sample placement surface of the sample stage in the horizontal state is 150.15 mm ± 7 mm, and in this embodiment, 150.15 mm is taken. In this embodiment, in order to facilitate the movement of the through-hole fluorescent screen 35 and the through-hole mirror 36, the in-cabin plug-in probe assembly 30 preferably further includes a plug-in control assembly 33. The plug-in control assembly 33 is installed outside the side cabin wall of the sample cabin 20, and the telescopic rod 34 horizontally extends into the sample cabin 20. By fixing the through-hole fluorescent screen 35 and the through-hole mirror 36 at the free end of the telescopic rod 34, the two can move horizontally between the side cabin wall and the sample stage directly below. In this embodiment, the plug-in control assembly 33 is preferably installed opposite to the probe camera I 40 outside the side cabin wall of the sample cabin 20. In this embodiment, the in-cabin plug-in probe assembly 30 preferably further includes a relay optical lens assembly 39. The relay optical lens assembly 39 is in the reflected light path of the through-hole mirror 36, and is installed on the inner and outer sides of the same side cabin wall of the sample cabin 20, respectively, to adjust the beam diameter of the light signal through the relay optical lens assembly 39 to adapt to the probe window of the probe camera I 40. In this embodiment, the relay optical lens assembly 39 is composed of a vacuum observation window and a lens assembly. The vacuum observation window is mainly used to connect the sample cabin, pass through the optical signal, and fix the lens assembly. The lens assembly includes a convex lens I, a concave lens, and a convex lens II arranged in sequence along the light path. In this embodiment, the through-hole mirror 36 is a 45° through-hole mirror, and the optical axis of the relay optical lens assembly 39 is horizontal and coaxial with the telescopic rod 34 of the plug-in control assembly 33. The transmitted electron signal I 25 produced by the interaction between the ultrafast pulsed electron beam 18 emitted by the electron gun to the sample to be measured 24 and the sample to be measured 24 pumped and excited reaches the through-hole fluorescent screen 35. Part of the transmitted electron signal is converted into an optical signal by the through-hole fluorescent screen 35, then reflected by the through-hole mirror 36 to convert into an optical signal 38, and then captured by the probe camera I 40 after passing through the relay optical lens assembly 39, to realize the imaging of the spatial information of the sample to be measured 24. The transmitted electron signal II 37 passing through the center through hole of the through-hole fluorescent screen 35 and the through-hole mirror 36 is received by the detection end of the plug-in camera 42 to detect the stability of the electron source and correct the intensity, displacement, and time jitter of the diffraction pattern.The probe camera I 40 can be a CCD or CMOS probe camera, and the plug-in camera 42 can be a CCD, CMOS or direct electronic probe camera with plug-in function.

[0120] Referring to Figure 1 and Figure 3The plug-in camera and energy filtering electron microscope assembly 32 comprises, from top to bottom, an adapter component I 43, an energy filtering electron microscope, and a plug-in camera 42, arranged below the sample cabin 20; an opening I is arranged at a position directly below the sample stage on the lower cabin wall of the sample cabin 20; the electron entrance port end of the energy filtering electron microscope is sealed and fixed below the opening I of the sample cabin 20 through the adapter component I 43, and the inner cavities of the two are communicated; the plug-in camera 42 is installed on the side wall of the adapter component I 43, and the telescopic detection end horizontally extends into the hollow part of the adapter component I 43, can be telescoped between the side wall and the position directly below the sample stage, is used for ultrafast four-dimensional scanning transmission electron microscopy imaging and detecting the stability of the electron source, and corrects the diffraction pattern intensity, displacement and time jitter; the receiving surface of the detection end of the plug-in camera 42 is 327.65 mm ± 7 mm away from the sample placement surface of the sample stage in a horizontal state, and 327.65 mm is taken in this embodiment. In this embodiment, in order to effectively improve the response capability to weak transmission electron signals, the plug-in camera is preferably a low-energy direct electron detection camera with high quantum detection efficiency. In order to make the imaging quality better in the ultrafast electron diffraction mode and the imaging quality better and the resolution higher in the energy filtering electron microscopy mode, the plug-in camera and energy filtering electron microscope assembly 32 preferably further comprises a vacuum pipe and a magnetic lens I 31 in this embodiment; the vacuum pipe is located between the sample cabin 20 and the adapter component I 43; the adapter component I 43 is sealed and fixed below the opening I of the sample cabin 20 through the vacuum pipe, the electron entrance port end of the energy filtering electron microscope is sealed and fixed below the opening I of the sample cabin 20 through the vacuum pipe and the adapter component I 43, and the inner cavities of the two are communicated; the magnetic lens I 31 is sleeved on the outer cylindrical surface of the vacuum pipe, and is used for transverse focusing of the transmission electron signal and the to-be-analyzed electron signal 41. The energy filtering electron microscope in this embodiment comprises an energy filtering electron microscope barrel 44, a dipole magnet 45, a magnetic lens II 49, an energy slit 50, a magnetic lens III 51, a magnetic lens IV 52, a magnetic lens V 53, a magnetic lens VI 54, and a magnetic lens VII 55 arranged in the energy filtering electron microscope barrel 44 along the electron optical axis, and further comprises a detection camera II 56 arranged opposite to the electron exit port end of the energy filtering electron microscope barrel 44 and located outside the energy filtering electron microscope barrel 44.The ultrafast pulsed electron beam 18 emitted by the electron gun to the sample 24 to be measured interacts with the sample 24 to be measured which is excited by pumping to generate an electron signal 41 to be analyzed. The electron signal 41 to be analyzed passes through the opening I, the vacuum pipe, and the adapter component I 43 in turn, enters the electron entrance end of the energy filtering electron microscope, and is deflected by 70°-110° by the dipole magnet 45. As the electron energy decreases, the electron deflection radius decreases. The electron signal 41 to be analyzed is separated into electron beams 46, low-energy electron beam I 47, and low-energy electron beam II 48 arranged in order of decreasing radial size under the action of the magnetic field. Subsequently, the electron signal 41 to be analyzed passes through the energy selection of the magnetic lens II 49, the energy slit 50, the magnetic lens III 51, the magnetic lens IV 52, the magnetic lens V 53, the magnetic lens VI 54, and the magnetic lens VII 55 in turn, and is finally received by the detection camera II 56. The detection camera II 56 can be a CCD, CMOS, or direct electron detection camera.

[0121] The vacuum system is in communication with the inner cavity of the sample cabin 20 and the electron gun to meet the required vacuum degree. In this embodiment, the vacuum system includes one turbine molecular pump, one mechanical pump, and two ion pumps.

[0122] In order to provide more imaging modes and cleaning functions for the multi-mode multi-dimensional ultrafast electron microscopy imaging device, the multi-mode multi-dimensional ultrafast electron microscopy imaging device preferably further comprises a backscattered electron detector, an energy dispersive X-ray detector, an optical navigation camera, and other detectors or cameras, and an ion cleaning device and other cleaning devices, which are respectively connected to the sample cabin 20 through flange interfaces. The multi-mode multi-dimensional ultrafast electron microscopy imaging device integrates multiple reflection and transmission imaging modes such as an ultrafast scanning reflection mode, an ultrafast scanning transmission mode, an ultrafast electron diffraction mode, and an energy filtering electron microscopy imaging mode. In the reflection imaging mode, the secondary electron detector 27 and the backscattered electron detector are used to capture secondary electrons and backscattered electrons generated on the surface of the sample, to realize nanoscale resolution imaging of dynamic information on the surface of the sample, and the energy dispersive X-ray detector is used to obtain X-ray characteristic wavelengths and analyze the types and contents of elements in a micro area of the material. In the transmission imaging mode, the STEM detector 28, the in-cabin plug-in detection assembly 30, and the plug-in camera 42 are used to realize dynamic characterization of the structure of the sample, and the energy filtering electron microscope is used to realize energy-resolved imaging. In summary, the multi-mode multi-dimensional ultrafast electron microscopy imaging device can provide information in multiple dimensions such as space, time, energy, and elements of the sample in a non-equilibrium state, and effectively improves the analysis capability of the ultrafast response process of the material.

[0123] Referring to Figure 4In the middle (1) and (2), in order to be able to adjust the sample in multiple degrees of freedom, the compatibility of the sample is further improved, and in the embodiment, the above-mentioned sample table is preferably a hollow six-dimensional sample table. Definition: the direction parallel to and opposite to the electron gun electron optical axis is the positive direction of the Z axis of the spatial coordinate system XYZ; the direction intersecting the Z axis and parallel to the above-mentioned detector probe 29 shortening direction of the STEM detector 28 is the positive direction of the Y axis of the spatial coordinate system XYZ; the positive direction of the X axis of the spatial coordinate system XYZ is determined by the left-hand rule; the rotation around the axis parallel to the X axis, Y axis and Z axis is respectively α rotation, β rotation and R rotation; then the sample table in the embodiment can make the sample to be measured 24 realize movement along the X axis, Y axis and Z axis and α rotation, β rotation and R rotation.

[0124] Reference Figure 4 In the middle (1) and (2), the sample table in the embodiment includes an α rotation table, a Z displacement component, an adapter component II 58, an R rotation table 59, an X / Y displacement component 61, a β rotation table 63 and a sample holder 65.

[0125] The Z displacement component includes a Z displacement base layer and a Z displacement table 57; the Z displacement base layer is rotationally connected with the hatch on the side wall of the sample chamber 20 through an a rotation table, and can rotate a in the a direction relative to the hatch on the side wall of the sample chamber 20; the Z displacement table 57 is linearly slidably connected with the Z displacement base layer, and can slide relative to the Z displacement base layer in the Z axis direction; an adapter component II 58 is fixedly connected with the lower end of the side of the Z displacement table 57 away from the Z displacement base layer, and forms an L-shaped structure with the Z displacement table 57; an R rotation table 59, an X / Y displacement component 61, a β rotation table 63 and a sample support 65 are sequentially arranged on the upper surface of the horizontal arm of the L-shaped structure from bottom to top; the rotation axis of the R rotation table 59 is coplanar with the rotation axis of the a rotation table; the X / Y displacement component 61 is located in the middle of the upper surface of the R rotation table 59, and includes an X / Y displacement base layer, an X displacement table and a Y displacement table arranged in sequence from bottom to top; the X / Y displacement base layer is rotationally connected with the adapter component II 58 through the R rotation table 59, and can rotate a relative to the adapter component II 58; in order to facilitate processing, the sample table of the embodiment preferably further includes an adapter component III 60; the adapter component III 60 is arranged between the lower side of the X / Y displacement base layer and the upper side of the R rotation table 59, the X / Y displacement base layer is fixedly connected with the adapter component III 60, and the adapter component III 60 and the R rotation table 59 are rotationally connected with the adapter component II 58; the X displacement table is linearly slidably connected with the X / Y displacement base layer, and can slide relative to the X / Y displacement base layer in the X axis direction; the Y displacement table is linearly slidably connected with the X displacement table, and can slide relative to the X displacement table in the Y axis direction; the β rotation table 63 is arranged on the Y displacement table and located on one side of the R rotation table 59 rotation axis pointing in the Y axis positive direction or negative direction, and includes a β rotation table bottom layer and a β rotation table top layer arranged in sequence from bottom to top; the β rotation table bottom layer is fixedly connected with the Y displacement table, and the upper surface thereof is provided with an arc cylindrical track having an axis parallel to the Y axis and coplanar with the rotation axis of the R rotation table 59; in order to facilitate processing, the sample table of the embodiment preferably further includes an adapter component IV 62; the adapter component IV 62 is arranged between the β rotation table bottom layer and the Y displacement table, and located on one side of the R rotation table 59 rotation axis pointing in the Y axis positive direction or negative direction; the β rotation table bottom layer is fixedly connected with the Y displacement table through the adapter component IV 62; the lower surface of the β rotation table top layer is provided with a cylindrical surface matched with the arc cylindrical track; the β rotation table top layer is rotationally connected with the β rotation table bottom layer, and can rotate a in the β direction relative to the β rotation table bottom layer in the form of swinging with a preset angle; in the embodiment, the β rotation table 63 is a commercially available component, and the model thereof is PG-50-11206.The sample support 65 is horizontally arranged along the Y-axis direction, one end of which is fixed on the upper surface of the top layer of the β rotary table, and the other end of which is suspended above the rotation axis of the R rotary table 59. A hollow structure 64 of the sample table is arranged from the lower surface of the adapter component II 58 to the lower surface of the sample support 65, with the rotation axis of the R rotary table 59 as the central axis. A plurality of sample holes 66 are arranged on the other end of the sample support 65, which are spaced apart and vertically through, so as to form a hollow sample table, which meets the conditions of integrated transmission imaging mode. The other end of the sample support 65 is used to install the sample to be measured 24. In this embodiment, the sample to be measured 24 installed is a copper mesh sample to be measured. The sample table in this embodiment retains the α rotary table, Z displacement base layer and Z displacement table 57 of the scanning electron microscope, and the Z displacement base layer is rotatably connected to the hatch on the side wall of the sample chamber 20 through the α rotary table.

[0126] Referring to Figure 5 , the application also provides an imaging method of the above-mentioned multi-mode multi-dimensional ultrafast electron microscopic imaging device, which comprises the following steps:

[0127] Step 1: Construct a multi-mode multi-dimensional ultrafast electron microscopic imaging device, and when constructing, make the ultrafast probe laser introduction window arranged on the electron gun shell 8 be a focusing lens I 9, make two ultrafast pump laser introduction windows arranged on the wall of the sample chamber 20, and the two ultrafast pump laser introduction windows are focusing lens II 19 and focusing lens III 21 respectively, and make the included angles between the optical axes of the focusing lens II 19 and the focusing lens III 21 and the electron optical axis of the electron gun be 50°-70° and 70°-110° respectively. Then make the retractable components in each component of the constructed multi-mode multi-dimensional ultrafast electron microscopic imaging device be in the retracted state, and make each component be in the closed state or standby state in the non-working state;

[0128] Step 2: Install the sample to be measured 24 on the sample table of the multi-mode multi-dimensional ultrafast electron microscopic imaging device in which each component is in the closed state or standby state in the non-working state in step 1, and then close the hatch of the sample chamber 20;

[0129] Step 3: Use the above-mentioned vacuum system to vacuum the inner cavities of the sample chamber 20 and the electron gun of the multi-mode multi-dimensional ultrafast electron microscopic imaging device in which the hatch is closed in step 2, so as to vacuum and maintain the inner cavities at the required vacuum degree;

[0130] Step 4: According to the detection requirements of the sample 24 to be detected installed on the sample stage in Step 2, select the imaging operation process from the following four imaging modes, and after each imaging mode is executed, if the imaging mode contains multiple sub-imaging modes, then after each sub-imaging mode is executed, the retractable components of each component of the multi-mode multi-dimensional ultrafast electron microscopy imaging device constructed in Step 1 are in the retracted state, and each component is in the closed state or the standby state of the non-working state; the above-mentioned four imaging modes are:

[0131] (I) Referring to (A) in Figure 5 , imaging mode A: ultrafast scanning reflection mode

[0132] The imaging operation process is as follows:

[0133] Step A.1: The laser generating module generates ultrafast probe laser 7 and 50°~70° ultrafast pump laser 22; and the ultrafast probe laser 7 generated by the laser generating module is emitted to the above-mentioned focusing lens I 9, and the ultrafast probe laser 7 is focused by the focusing lens I 9 to be introduced into the electron gun housing 8, so that the electron gun emits an ultrafast pulse electron beam 18 to the sample 24 to be detected; the 50°~70° ultrafast pump laser 22 generated by the laser generating module is emitted to the above-mentioned focusing lens II 19, and the 50°~70° ultrafast pump laser 22 is focused by the focusing lens II 19 to be introduced into the sample 24 on the sample stage, so as to pump and excite the sample 24 to be detected;

[0134] Step A.2: The above-mentioned secondary electron detector 27 receives the secondary electrons 26 generated by the interaction between the ultrafast pulse electron beam 18 emitted by the electron gun to the sample 24 to be detected and the sample 24 to be detected pumped and excited in Step A.1, so as to realize surface topography and carrier imaging, and complete the ultrafast scanning reflection mode;

[0135] (II) Referring to (B) in Figure 5 , imaging mode B: ultrafast scanning transmission mode

[0136] The above-mentioned imaging mode B is divided into two sub-imaging modes: sub-imaging mode B1 and sub-imaging mode B2;

[0137] Sub-imaging mode B1: ultrafast conventional scanning transmission mode

[0138] The imaging operation process is as follows:

[0139] Step B1.1: the laser generating module generates the ultrafast probe laser 7 and the 50°~70° ultrafast pump laser 22; the ultrafast probe laser 7 generated by the laser generating module is emitted to the focusing lens I 9, and the focusing lens I 9 focuses the ultrafast probe laser 7 into the electron gun housing 8, so that the electron gun emits the ultrafast pulse electron beam 18 to the sample 24 to be measured; the 50°~70° ultrafast pump laser 22 generated by the laser generating module is emitted to the focusing lens II 19, and the focusing lens II 19 focuses the 50°~70° ultrafast pump laser 22 to the sample 24 on the sample table, so as to pump and excite the sample 24 to be measured;

[0140] Step B1.2: the probe head 29 of the STEM detector 28 is extended to the position directly below the sample table, and receives the transmission electron signal I 25 generated by the interaction between the ultrafast pulse electron beam 18 emitted by the electron gun to the sample 24 to be measured and the sample 24 to be measured pumped and excited, so as to realize topographic imaging and complete the ultrafast conventional scanning transmission mode;

[0141] Sub-imaging mode B2: ultrafast four-dimensional scanning transmission mode

[0142] The imaging operation process is as follows:

[0143] Step B2.1: the laser generating module generates the ultrafast probe laser 7 and the 50°~70° ultrafast pump laser 22; the ultrafast probe laser 7 generated by the laser generating module is emitted to the focusing lens I 9, and the focusing lens I 9 focuses the ultrafast probe laser 7 into the electron gun housing 8, so that the electron gun emits the ultrafast pulse electron beam 18 to the sample 24 to be measured; the 50°~70° ultrafast pump laser 22 generated by the laser generating module is emitted to the focusing lens II 19, and the focusing lens II 19 focuses the 50°~70° ultrafast pump laser 22 to the sample 24 on the sample table, so as to pump and excite the sample 24 to be measured;

[0144] Step B2.2: the detection end of the plug-in camera 42 is extended to the position directly below the sample table, and receives the transmission electron signal I 25 generated by the interaction between the ultrafast pulse electron beam 18 emitted by the electron gun to the sample 24 to be measured and the sample 24 to be measured pumped and excited, so as to realize ultrafast four-dimensional scanning transmission electron microscopic imaging and complete the ultrafast four-dimensional scanning transmission mode;

[0145] (Three) see Figure 5 (C) in the imaging mode C: ultrafast electron diffraction mode

[0146] The imaging operation process is as follows:

[0147] Step C.1: the laser generating module generates the ultrafast probe laser 7 and the 50°~70° ultrafast pump laser 22; the ultrafast probe laser 7 generated by the laser generating module is emitted to the focusing lens I 9, and the focusing lens I 9 focuses the ultrafast probe laser 7 into the electron gun housing 8, so that the electron gun emits the ultrafast pulse electron beam 18 to the sample 24 to be measured; the 50°~70° ultrafast pump laser 22 generated by the laser generating module is emitted to the focusing lens II 19, and the focusing lens II 19 focuses the 50°~70° ultrafast pump laser 22 to the sample 24 on the sample table, so as to pump and excite the sample 24 to be measured;

[0148] Step C.2: the through-hole fluorescent screen 35 and the through-hole mirror 36 are moved to be directly below the sample table, and the detection end of the plug-in camera 42 is extended to be directly below the sample table; the detection camera I 40 captures the transmission electron signal I 25 generated by the interaction between the ultrafast pulse electron beam 18 emitted by the electron gun to the sample 24 to be measured and the sample 24 to be measured pumped and excited in step C.1, and then the optical signal 38 reflected by the through-hole mirror 36 after the transmission electron signal I 25 passes through the through-hole fluorescent screen 35 and the through-hole mirror 36 in turn, so as to realize the imaging of the inverse spatial information of the sample 24 to be measured; the detection end of the plug-in camera 42 receives the transmission electron signal II 37 passing through the central through holes of the through-hole fluorescent screen 35 and the through-hole mirror 36 after the transmission electron signal I 25 generated by the interaction between the ultrafast pulse electron beam 18 emitted by the electron gun to the sample 24 to be measured and the sample 24 to be measured pumped and excited in step C.1, so as to detect the stability of the electron source, correct the intensity, displacement and time jitter of the diffraction pattern, and complete the ultrafast electron diffraction mode;

[0149] (Four) see Figure 5 (D) in the imaging mode D: energy filtering electron microscopy imaging mode

[0150] Then the imaging operation process is:

[0151] Step D.1: the laser generating module generates the ultrafast probe laser 7 and the 70°~110° ultrafast pump laser 23; the ultrafast probe laser 7 generated by the laser generating module is emitted to the focusing lens I 9, and the focusing lens I 9 focuses the ultrafast probe laser 7 into the electron gun housing 8, so that the electron gun emits the ultrafast pulse electron beam 18 to the sample 24 to be measured; the 70°~110° ultrafast pump laser 23 generated by the laser generating module is emitted to the focusing lens III 21, and the focusing lens III 21 focuses the 70°~110° ultrafast pump laser 23 to the sample 24 on the sample table, so as to pump and excite the sample 24 to be measured;

[0152] Step D.2: The energy-filtered electron microscopy is realized by using the above-mentioned energy-filtered electron microscope to receive the analyzed electron signal 41 generated by the interaction between the ultrafast pulsed electron beam 18 emitted by the electron gun in step D.1 and the pumped sample 24 to be measured, and the energy-filtered electron microscopy mode is completed.

[0153] In summary, the multi-mode multi-dimensional ultrafast electron microscopy device of the present application can work in four imaging modes: ultrafast scanning reflection mode, ultrafast scanning transmission mode, ultrafast electron diffraction mode and energy-filtered electron microscopy mode, and can realize precise measurement of different ultrafast dynamic information such as sample surface / interface carrier information, real space information, reciprocal space information, structure information, energy band information and electronic state information, respectively. The multi-mode multi-dimensional ultrafast electron microscopy device of the present application integrates and couples multiple ultrafast electron imaging functions, can perform multi-mode, multi-dimensional high-resolution electron dynamics detection, and can generate and measure attosecond electron pulses, which has broad research and application prospects.

Claims

1. A multi-mode multi-dimension ultrafast electron microscopy device, characterized in that: comprising a sample chamber (20), an electron gun, a laser generation module, a secondary electron detector (27), a STEM detector (28), an in-chamber plug-in probe assembly (30), a plug-in camera and energy filtering electron microscope assembly (32), and a vacuum system; the sample chamber (20) is provided with a hollow six-dimensional sample stage, and two ultrafast pumping laser introduction windows are arranged on the chamber wall; the electron gun is installed above the sample chamber (20), and the electron optical axis is vertically downward and located directly above the sample stage; the electron gun comprises an electron gun shell (8) and a cathode filament (10), a grid electrode (11), an anode (12), a high-voltage accelerating tube (13), a condenser lens I (14), a condenser lens II (15), and a scanning coil (16) arranged in the electron gun shell (8) in sequence along the electron optical axis; an ultrafast detection laser introduction window is arranged on the electron gun shell (8); an objective lens (17) coaxial with the electron optical axis of the electron gun is arranged in the communication cavity formed by the sealed connection of the electron gun and the sample chamber (20) at a position between the lower end of the electron gun and the upper end of the sample chamber (20); the laser generation module is arranged outside the sample chamber (20) and the electron gun, and is used for generating an ultrafast detection laser (7), a 50°-70° ultrafast pumping laser (22), and a 70°-110° ultrafast pumping laser (23); the ultrafast detection laser introduction window is a focusing lens I (9), which is used for focusing the ultrafast detection laser (7) to the cathode filament (10) in the electron gun shell (8); the acceleration voltage between the grid electrode (11) and the anode (12) is adjustable between 0V and 30kV; the objective lens (17) is an electrostatic and electromagnetic composite objective lens; the two ultrafast pumping laser introduction windows are a focusing lens II (19) and a focusing lens III (21), respectively; the angles between the optical axes of the focusing lens II (19) and the focusing lens III (21) and the electron optical axis of the electron gun are 50°-70° and 70°-110°, respectively, and the focusing lens II (19) and the focusing lens III (21) are used for focusing the 50°-70° ultrafast pumping laser (22) and the 70°-110° ultrafast pumping laser (23) to the sample (24) to be measured on the sample stage, respectively; the secondary electron detector (27) is arranged obliquely above the sample stage in the sample chamber (20); the STEM detector (28) is installed on the side chamber wall of the sample chamber (20), and the telescopic probe head (29) of the STEM detector (28) is horizontally located below the sample stage in the sample chamber (20) and can be telescoped between the side chamber wall and the area directly below the sample stage. ​ ​ ​ ​ ​ ​ ​ ​ ​ The in-cabin plug-in detection assembly (30) comprises a through-hole fluorescent screen (35), a through-hole mirror (36), and a detection camera I (40); the through-hole fluorescent screen (35) and the through-hole mirror (36) are arranged below the STEM detector (28) in the sample cabin (20) in a manner that the former is above the latter, the through holes of the two are coaxial, and the axis is parallel to the electron optical axis of the electron gun, and the through-hole fluorescent screen (35) and the through-hole mirror (36) can move horizontally between the side cabin wall and the position directly below the sample table; the detection window of the detection camera I (40) is in the reflection light path of the through-hole mirror (36); The plug-in camera and energy filtering electron microscope assembly (32) comprises an adapter component I (43) and an energy filtering electron microscope arranged in the sample cabin (20) from top to bottom, and further comprises a plug-in camera (42); the electron incident port end of the energy filtering electron microscope is sealed and fixedly connected to the opening I directly below the lower cabin wall of the sample cabin (20) by the adapter component I (43), and the inner cavities of the two are communicated; the plug-in camera (42) is installed on the side wall of the adapter component I (43), and the telescopic detection end of the plug-in camera (42) horizontally extends into the hollow part of the adapter component I (43), and can be telescoped between the side wall and the position directly below the sample table; The vacuum system is communicated with the inner cavities of the sample cabin (20) and the electron gun.

2. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 1, wherein: Definition: the direction parallel to and opposite to the electron optical axis of the electron gun is the positive direction of the Z-axis of the spatial coordinate system XYZ; the direction intersecting the Z-axis and parallel to the shortening direction of the detector probe (29) of the STEM detector (28) is the positive direction of the Y-axis of the spatial coordinate system XYZ; the positive direction of the X-axis of the spatial coordinate system XYZ is determined by the left-hand rule; the rotations around the parallel axes of the X-axis, the Y-axis and the Z-axis are α rotation, β rotation and R rotation, respectively; The sample table can move the sample (24) to be tested along the X-axis, the Y-axis and the Z-axis, and can rotate the sample (24) to be tested by α rotation, β rotation and R rotation; The detection camera I (40) is installed on the side cabin wall of the sample cabin (20); The fluorescent surface of the through-hole fluorescent screen (35) is horizontal and upward, and the distance between the upper surface thereof and the sample placing surface of the sample table in the horizontal state is 150.15 mm±7 mm; the reflection surface of the through-hole mirror (36) is upward; The distance between the receiving surface of the detection end of the plug-in camera (42) and the sample placing surface of the sample table in the horizontal state is 327.65 mm±7 mm.

3. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 2, wherein: The plug-in camera and energy filtering electron microscope assembly (32) further comprises a vacuum pipeline and a magnetic lens I (31). The vacuum pipe is located between the sample cabin (20) and the adapter component I (43); the adapter component I (43) is sealed and fixed to the opening I of the sample cabin (20) through the vacuum pipe, the electron incident port end of the energy filtering electron microscope is sealed and fixed to the opening I of the sample cabin (20) through the vacuum pipe and the adapter component I (43), and the inner cavities of the two are communicated; The magnetic lens I (31) is sleeved on the outer cylindrical surface of the vacuum pipe and is used for transverse focusing of the transmission electron signal and the to-be-analyzed electron signal (41).

4. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 3, wherein: The sample table comprises an alpha rotating table, a Z displacement component, an adapter component II (58), an R rotating table (59), an X / Y displacement component (61), a beta rotating table (63) and a sample support (65); The Z displacement component comprises a Z displacement base layer and a Z displacement table (57); the Z displacement base layer is rotationally connected with a cabin door arranged on the side cabin wall of the sample cabin (20) through the alpha rotating table and can be alpha-rotated relative to the cabin door arranged on the side cabin wall of the sample cabin (20); The Z displacement table (57) is linearly and slidably connected with the Z displacement base layer and can slide relative to the Z displacement base layer along the Z-axis direction; The adapter component II (58) is fixed to the lower end of the side of the Z displacement table (57) away from the Z displacement base layer and forms an L-shaped structure with the Z displacement table (57); The R rotating table (59), the X / Y displacement component (61), the beta rotating table (63) and the sample support (65) are sequentially arranged on the upper surface of the horizontal arm of the L-shaped structure from bottom to top; The rotating axis of the R rotating table (59) is coplanar with the rotating axis of the alpha rotating table; The X / Y displacement component (61) is located in the middle of the upper surface of the R rotating table (59) and comprises an X / Y displacement base layer, an X displacement table and a Y displacement table which are sequentially arranged from bottom to top; the X / Y displacement base layer is rotationally connected with the adapter component II (58) through the R rotating table (59) and can be R-rotated relative to the adapter component II (58); the X displacement table is linearly and slidably connected with the X / Y displacement base layer and can slide relative to the X / Y displacement base layer along the X-axis direction; the Y displacement table is linearly and slidably connected with the X displacement table and can slide relative to the X displacement table along the Y-axis direction; The beta rotating table (63) is arranged on the Y displacement table and located on one side of the R rotating table (59) rotating axis pointing to the Y-axis positive direction or negative direction, and comprises a beta rotating table bottom layer and a beta rotating table top layer which are sequentially arranged from bottom to top; the beta rotating table bottom layer is fixed with the Y displacement table and the upper surface thereof is provided with an arc cylindrical track having an axis parallel to the Y-axis and coplanar with the rotating axis of the R rotating table (59); the lower surface of the beta rotating table top layer is provided with a cylindrical surface matched with the arc cylindrical track; the beta rotating table top layer is rotationally connected with the beta rotating table bottom layer and can be beta-rotated in a swing form by a preset angle relative to the beta rotating table bottom layer; The sample support (65) is horizontally arranged along the Y-axis direction, one end of which is fixed to the upper surface of the beta rotating table top layer and the other end of which is suspended above the rotating axis of the R rotating table (59); A hollow structure (64) is arranged in the sample stage with the rotation axis of the R-rotating stage (59) as the central axis, and a plurality of sample holes (66) are arranged on the other end of the sample holder (65) to form a hollow sample stage; the other end of the sample holder (65) is used to install the sample (24) to be tested.

5. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 4, wherein: The sample stage further comprises an adapter component III (60) and an adapter component IV (62); The adapter component III (60) is arranged between the X / Y displacement base layer and the R-rotating stage (59) above, the X / Y displacement base layer is fixedly connected with the adapter component III (60), and the adapter component III (60) and the R-rotating stage (59) are rotationally connected with the adapter component II (58); The adapter component IV (62) is arranged between the β-rotating stage bottom layer and the Y displacement stage and located on one side of the Y-axis positive direction or negative direction of the rotation axis of the R-rotating stage (59); the β-rotating stage bottom layer is fixedly connected with the Y displacement stage through the adapter component IV (62).

6. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 3, wherein: The in-cabin plug-in detection assembly (30) further comprises a plug-in control assembly (33) and a relay optical lens assembly (39); The plug-in control assembly (33) is arranged opposite to the detection camera I (40) outside the side cabin wall of the sample cabin (20), and the telescopic rod (34) horizontally extends into the sample cabin (20); the through-hole fluorescent screen (35) and the through-hole mirror (36) are fixedly connected at the free end of the telescopic rod (34), so that the plug-in control assembly (33) can move horizontally between the side cabin wall and the position directly below the sample stage; The through-hole mirror (36) is a 45° through-hole mirror; The relay optical lens assembly (39) is in the reflection light path of the through-hole mirror (36) and is arranged on the inner and outer sides of the same side cabin wall of the sample cabin (20) with the detection camera I (40) respectively, and the relay optical lens assembly (39) adjusts the beam diameter of the light signal to adapt to the detection window of the detection camera I (40).

7. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to any one of claims 1 to 6, wherein: The laser generation module comprises a laser (1), a beam splitter (3), a frequency doubling component (6) and a mirror I (67) arranged in the reflection light path of the beam splitter (3) in sequence, and a laser pulse delay precision control assembly (5), a mirror II (68) and a mirror III (69) arranged in the transmission light path of the beam splitter (3) in sequence; The laser (1) is used to generate an ultrafast laser beam (2); The frequency doubling component (6) is used to convert the frequency of the ultrafast laser beam in the reflection light path of the beam splitter (3) to obtain an ultrafast detection laser (7); The laser generation module comprises a laser (1), a beam splitter (3), a frequency doubling component (6) and a mirror I (67) arranged in the reflection light path of the beam splitter (3) in sequence, and a laser pulse delay precision control assembly (5), a mirror II (68) and a mirror III (69) arranged in the transmission light path of the beam splitter (3) in sequence; The focusing lens I (9) is in the reflection light path of the mirror I (67), the ultrafast probe laser (7) generated by the laser generation module is emitted to the focusing lens I (9) through the mirror I (67), and the ultrafast probe laser (7) is focused into the cathode filament (10) in the electron gun shell (8) through the focusing lens I (9); The laser pulse delay precision control assembly (5) is used for wavelength conversion and time control on the ultrafast laser beam in the transmission light path of the beam splitter (3), and the pump-probe synchronous ultrafast pump laser is obtained. The focusing lens II (19) is in the reflection light path of the mirror III (69); The focusing lens III (21) is on the optical axis of the output end of the laser pulse delay precision control assembly (5), and the laser pulse delay precision control assembly (5) is distributed on the two sides of the mirror II (68) respectively. The mirror II (68) is removable. When the mirror II (68) works, the pump-probe synchronous ultrafast pump laser is converted into 50°-70° ultrafast pump laser (22) through the mirror II (68) and the mirror III (69) and is emitted to the focusing lens II (19), and the 50°-70° ultrafast pump laser (22) is focused into the sample (24) on the sample stage through the focusing lens II (19). After the mirror II (68) is removed, the pump-probe synchronous ultrafast pump laser obtained by the laser pulse delay precision control assembly (5) is emitted to the focusing lens III (21) as 70°-110° ultrafast pump laser (23), and the 70°-110° ultrafast pump laser (23) is focused into the sample (24) on the sample stage through the focusing lens III (21).

8. The multi-mode multi-dimensional ultrafast electron microscopy imaging device according to claim 7, characterized in that: It further comprises a backscattered electron detector, an energy dispersive X-ray detector, an optical navigation camera and a plasma cleaning device which are respectively installed on the sample cabin (20) through flange interfaces; The energy filtering electron microscope comprises an energy filtering electron microscope column (44), a dipole magnet (45), a magnetic lens II (49), an energy slit (50), a magnetic lens III (51), a magnetic lens IV (52), a magnetic lens V (53), a magnetic lens VI (54) and a magnetic lens VII (55) which are sequentially arranged in the energy filtering electron microscope column (44) along the electron optical axis, and further comprises a detection camera II (56) which is opposite to the electron exit port end of the energy filtering electron microscope column (44) and is located outside the energy filtering electron microscope column (44).

9. An imaging method of the multi-mode multi-dimensional ultrafast electron microscopy device according to any one of claims 1 to 8, characterized in that, The steps include: Step 1: constructing a multi-mode multi-dimensional ultrafast electron microscopy imaging device; then making the retractable components in each component of the constructed multi-mode multi-dimensional ultrafast electron microscopy imaging device be in the retracted state, and making each component be in the closed state or the standby state in the non-working state; Step 2: install the sample to be tested (24) on the sample stage of the multi-mode multi-dimensional ultrafast electron microscopic imaging device in which each component is in the closed state or standby state of non-working state in step 1, and then close the cabin door of the sample cabin (20); Step 3: use the vacuum system to vacuum the inner cavities of the sample cabin (20) and the electron gun in the multi-mode multi-dimensional ultrafast electron microscopic imaging device with the cabin door closed in step 2, so that the inner cavities are vacuumed and maintained at the required vacuum degree; Step 4: according to the detection requirements of the sample to be tested (24) installed on the sample stage in step 2, select the imaging operation process from the following four imaging modes, and after each imaging mode is executed, when the imaging mode contains multiple sub-imaging modes, after each sub-imaging mode is executed, the retractable components of each component of the multi-mode multi-dimensional ultrafast electron microscopic imaging device constructed in step 1 are in the retracted state, and each component is in the closed state or standby state of non-working state; the four imaging modes are: Imaging mode A: ultrafast scanning reflection mode Then its imaging operation process is: Step A.1: make the laser generating module generate ultrafast detection laser (7) and 50°~70° ultrafast pumping laser (22); and make the ultrafast detection laser (7) generated by the laser generating module emit to the focusing lens I (9), focus the ultrafast detection laser (7) into the electron gun housing (8) through the focusing lens I (9), so that the electron gun emits an ultrafast pulse electron beam (18) to the sample to be tested (24); make the 50°~70° ultrafast pumping laser (22) generated by the laser generating module emit to the focusing lens II (19), focus the 50°~70° ultrafast pumping laser (22) to the sample to be tested (24) on the sample stage through the focusing lens II (19), to pump and excite the sample to be tested (24); Step A.2: use the secondary electron detector (27) to receive the secondary electrons (26) generated by the interaction between the ultrafast pulse electron beam (18) emitted by the electron gun to the sample to be tested (24) and the sample to be tested (24) pumped and excited in step A.1, to realize surface topography and carrier imaging, and complete the ultrafast scanning reflection mode; Imaging mode B: ultrafast scanning transmission mode The imaging mode B is divided into two sub-imaging modes: sub-imaging mode B1 and sub-imaging mode B2; Sub-imaging mode B1: ultrafast conventional scanning transmission mode Then its imaging operation process is: Step B1.1: the laser generating module generates the ultrafast probe laser (7) and the 50°~70° ultrafast pump laser (22); the ultrafast probe laser (7) generated by the laser generating module is emitted to the focusing lens I (9), the ultrafast probe laser (7) is focused by the focusing lens I (9) and introduced into the electron gun shell (8), so that the electron gun emits the ultrafast pulse electron beam (18) to the sample (24) to be measured; the 50°~70° ultrafast pump laser (22) generated by the laser generating module is emitted to the focusing lens II (19), the 50°~70° ultrafast pump laser (22) is focused by the focusing lens II (19) and introduced to the sample (24) to be measured on the sample table, so as to pump and excite the sample (24) to be measured; Step B1.2: the detector probe (29) of the STEM detector (28) is elongated to the position directly below the sample table, so as to receive the transmission electron signal I (25) generated by the interaction between the ultrafast pulse electron beam (18) emitted by the electron gun to the sample (24) to be measured and the sample (24) to be measured pumped and excited in step B1.1, so as to realize topographic imaging and complete the ultrafast conventional scanning transmission mode; Sub-imaging mode B2: ultrafast four-dimensional scanning transmission mode Then the imaging operation process is: Step B2.1: the laser generating module generates the ultrafast probe laser (7) and the 50°~70° ultrafast pump laser (22); the ultrafast probe laser (7) generated by the laser generating module is emitted to the focusing lens I (9), the ultrafast probe laser (7) is focused by the focusing lens I (9) and introduced into the electron gun shell (8), so that the electron gun emits the ultrafast pulse electron beam (18) to the sample (24) to be measured; the 50°~70° ultrafast pump laser (22) generated by the laser generating module is emitted to the focusing lens II (19), the 50°~70° ultrafast pump laser (22) is focused by the focusing lens II (19) and introduced to the sample (24) to be measured on the sample table, so as to pump and excite the sample (24) to be measured; Step B2.2: the detection end of the plug-in camera (42) is elongated to the position directly below the sample table, so as to receive the transmission electron signal I (25) generated by the interaction between the ultrafast pulse electron beam (18) emitted by the electron gun to the sample (24) to be measured and the sample (24) to be measured pumped and excited in step B2.1, so as to realize ultrafast four-dimensional scanning transmission electron microscopic imaging and complete the ultrafast four-dimensional scanning transmission mode; Imaging mode C: ultrafast electron diffraction mode Then the imaging operation process is: Step C.1: the laser generating module generates an ultrafast probe laser (7) and a 50°~70° ultrafast pump laser (22); the ultrafast probe laser (7) generated by the laser generating module is emitted to the focusing lens I (9), the ultrafast probe laser (7) is focused by the focusing lens I (9) and introduced into the electron gun shell (8), so that the electron gun emits an ultrafast pulse electron beam (18) to the sample (24) to be measured; the 50°~70° ultrafast pump laser (22) generated by the laser generating module is emitted to the focusing lens II (19), the 50°~70° ultrafast pump laser (22) is focused by the focusing lens II (19) and introduced to the sample (24) to be measured on the sample table, so as to pump and excite the sample (24) to be measured; Step C.2: the through-hole fluorescent screen (35) and the through-hole mirror (36) are moved directly below the sample table, and the detection end of the plug-in camera (42) is extended directly below the sample table; the detection camera I (40) is used to capture the transmission electron signal I (25) generated by the interaction between the ultrafast pulse electron beam (18) emitted by the electron gun to the sample (24) to be measured and the sample (24) to be measured pumped and excited in step C.1, and then the transmission electron signal I (25) passes through the through-hole fluorescent screen (35) and the through-hole mirror (36) in turn, the optical signal (38) reflected by the through-hole mirror (36), so as to realize the imaging of the inverse space information of the sample (24) to be measured; the detection end of the plug-in camera (42) receives the transmission electron signal II (37) passing through the center through holes of the through-hole fluorescent screen (35) and the through-hole mirror (36) after the transmission electron signal I (25) generated by the interaction between the ultrafast pulse electron beam (18) emitted by the electron gun to the sample (24) to be measured and the sample (24) to be measured pumped and excited in step C.1, so as to detect the stability of the electron source, correct the intensity, displacement and time jitter of the diffraction pattern, and complete the ultrafast electron diffraction mode; Imaging mode D: energy filtering electron microscopy imaging mode Then the imaging operation process is: Step D.1: the laser generating module generates an ultrafast probe laser (7) and a 70°~110° ultrafast pump laser (23); the ultrafast probe laser (7) generated by the laser generating module is emitted to the focusing lens I (9), the ultrafast probe laser (7) is focused by the focusing lens I (9) and introduced into the electron gun shell (8), so that the electron gun emits an ultrafast pulse electron beam (18) to the sample (24) to be measured; the 70°~110° ultrafast pump laser (23) generated by the laser generating module is emitted to the focusing lens III (21), the 70°~110° ultrafast pump laser (23) is focused by the focusing lens III (21) and introduced to the sample (24) to be measured on the sample table, so as to pump and excite the sample (24) to be measured; Step D.2: The energy-filtering electron microscope receives the ultrafast pulsed electron beam (18) emitted by the electron gun in step D.1 and the interaction between the ultrafast pulsed electron beam (18) and the pumped sample (24) to generate the electron signal (41) to be analyzed, and realizes energy-filtering electron microscopy imaging, and completes the energy-filtering electron microscopy imaging mode.

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