Microscopic in-situ high-pressure pumping-pushing-detecting three-beam spectral measurement system

Abstract

The invention belongs to the field of sample ultrafast spectral optical detection, and particularly relates to a microscopic in-situ high-pressure pumping-pushing-detecting three-beam spectral measurement system, which comprises a femtosecond laser light source and a beam splitting module, wherein the femtosecond laser light source and the beam splitting module are used for splitting a fundamental frequency pulse into a pumping path, a pushing path and a detecting path which are respectively input into corresponding modulation modules; the pump light modulation module performs frequency multiplication and modulation on the pump light; the light modulation module is driven to independently tune the wavelength and introduce a first time delay; the probe light modulation module introduces a second time delay and generates super-continuous white light. The beam combining module modulates the three paths and then combines the three paths into one beam. The dual-mode detection module selects a reflection mode or a transmission mode to collect signals, and then the signal acquisition and processing module generates spectral data. And the microscopic imaging module and the detection light path partially coincide to observe the sample and the light spot in real time. According to the invention, active tracking and multi-dimensional analysis of ultrafast intermediate state dynamics in a high-voltage microcell sample are realized by combining a three-beam time sequence with high-voltage, microscopy and dual-mode detection.

Description

Technical Field

[0001] This invention belongs to the field of ultrafast optical spectroscopy detection of samples, specifically a microscopic in-situ high-pressure pump-drive-probe three-beam spectral measurement system. Background Technology

[0002] Transient spectroscopy (also known as pump-probe spectroscopy) is an ultrafast laser detection technique with femtosecond-level time resolution. It can accurately capture ultrafast dynamic processes such as molecular vibrational relaxation, charge transfer, and energy relaxation. It is a core technology for studying ultrafast photophysical and photochemical processes in materials, chemical, and biological systems, and has wide application value in cutting-edge fields such as photocatalysis, optoelectronic materials, and biophotonics.

[0003] Current mainstream femtosecond transient spectroscopy measurement schemes mostly employ dual-beam technology. This method has the limitation of a single control dimension, only achieving two-dimensional temporal control of excitation-probe. It is difficult to clearly track and detect complex processes involving multi-step relaxation, energy transfer, or multiple transient intermediate states. Furthermore, existing devices typically perform spectral acquisition under normal pressure, making it impossible to simulate and observe the ultrafast dynamics of materials under high pressure. In addition, conventional detection systems are only equipped with one type of detection module—either transmission or reflection. When dealing with different types of samples such as transparent films, opaque solids, and colloidal solutions, different equipment or disassembly and re-adjustment of the optical path are required, resulting in low detection efficiency and limited equipment versatility.

[0004] Therefore, there is an urgent need to develop an ultrafast spectroscopic measurement system that can actively track intermediate states, is compatible with high-pressure in-situ environments, and has multi-mode detection capabilities, in order to address the shortcomings of existing technologies in terms of time-series control dimensions, environmental simulation capabilities, and sample universality. Summary of the Invention

[0005] The purpose of this invention is to provide a microscopic in-situ high-pressure pump-push-probe three-beam ultrafast spectroscopic measurement system, which solves the problems of insufficient control dimensions, frequent disassembly of optical paths, and inability to achieve in-situ ultrafast detection under high pressure in traditional dual-beam single-probe mode systems. It enables multi-directional tracking and analysis of the relaxation dynamics of sample excitation intermediate state under high pressure conditions at the femtosecond scale.

[0006] The technical solution adopted by the present invention to achieve the above objectives is: a microscopic in-situ high-pressure pump-push-probe three-beam spectral measurement system, comprising:

[0007] The femtosecond laser source and beam splitting module are used to generate fundamental frequency femtosecond laser pulses and split them into pump optical path input beams, drive optical path input beams and probe optical path input beams, which are then incident on the pump optical path modulation module, drive optical path modulation module and probe optical path modulation module, respectively.

[0008] The pump optical path modulation module is connected to the pump optical path output end of the femtosecond laser source and the beam splitter module. It is used to perform wavelength conversion, energy adjustment and frequency modulation on the received pump light. The modulated pump light is output and enters the beam combiner module.

[0009] The driving optical path modulation module is connected to the output end of the driving optical path of the femtosecond laser source and the beam splitter module. It is used to independently tune the wavelength, adjust the energy and modulate the frequency of the received driving light, introduce a first time delay Δt1 relative to the pump light, and output it to the beam combiner module.

[0010] The probe optical path modulation module is connected to the probe optical path output end of the femtosecond laser source and the beam splitter module. It is used to generate supercontinuous white light as probe light, introduce a second time delay Δt2 relative to the pump light, and output it to the beam combiner module.

[0011] The beam combining module is used to spatially collinearly combine the three beams of light from the pump optical path modulation module, the drive optical path modulation module, and the probe optical path modulation module, and use them as the incident light for the dual-mode probe module.

[0012] The dual-mode detection module, located after the beam combining module, is used to focus the three beams of light after beam combining onto the sample, and to collect the reflection mode and transmission mode of the detection light signal after it has acted on the sample, and output them to the signal acquisition and processing module respectively.

[0013] The signal acquisition and processing module, connected to the dual-mode detection module, is used to acquire and process the detection light signal and generate an ultrafast dynamic spectrum.

[0014] The microscopic imaging module is used to visualize the micro-area and spot position of the sample.

[0015] The femtosecond laser source and beam splitting module include: a femtosecond laser source, a first beam splitter, and a second beam splitter;

[0016] The fundamental frequency laser pulse output by the femtosecond laser source is incident on the first beam splitter, the reflected beam of the first beam splitter constitutes the pump optical path input beam, and its transmitted beam is incident on the second beam splitter.

[0017] The transmitted beam of the second beam splitter forms the input beam of the driving optical path and is incident on the driving optical path modulation module, while its reflected beam forms the input beam of the probe optical path and is incident on the probe optical path modulation module.

[0018] The femtosecond laser source outputs a fundamental frequency light with a pulse frequency f0.

[0019] The pump optical path modulation module includes: a first reflector, a first lens, a nonlinear crystal barium β-borate, a second lens, a first neutral density filter, a first filter, and a first chopper;

[0020] The pump light input beam from the first beam splitter is reflected by the first mirror and then incident on the nonlinear crystal barium β-borate through the first lens to be frequency doubled, thereby generating pump light.

[0021] The pump light after frequency doubling passes through the second lens, through the first neutral density filter for energy adjustment, through the first filter to filter out non-target wavelength components, and through the first chopper for pulse frequency modulation. The modulated pump light is reflected by the second mirror and then output and enters the beam combining module.

[0022] The frequency of the first chopper is f1.

[0023] The driving optical path modulation module includes: an optical parametric amplifier, a second filter, a third mirror, a fourth mirror, a first optical delay line, a fifth mirror, a sixth mirror, a second chopper, and a second neutral density filter arranged sequentially.

[0024] Among them, the input beam from the driving optical path transmitted by the second beam splitter is incident on the optical parametric amplifier for wavelength tuning;

[0025] After the tuned driving light passes through the second filter to filter out stray light, it is reflected in sequence by the third and fourth mirrors and guided into the first optical delay line. By changing the optical path of the first optical delay line, a time delay Δt1 is introduced between the driving light and the pump light.

[0026] The driving light is reflected by the fifth and sixth mirrors and then enters the second chopper for frequency modulation. After being regulated by the second neutral density filter, the light is output to the beam combining module.

[0027] The detection optical path modulation module includes: a seventh reflector, a second optical delay line, a reflector group, a third neutral density filter, a variable aperture, a twelfth reflector, a thirteenth reflector, a first concave mirror, a sapphire crystal, a second concave mirror, a fourteenth reflector, and a third filter.

[0028] Among them, the probe light input beam reflected from the second beam splitter enters the second optical delay line after being reflected by the seventh mirror, and the time delay Δt2 of the probe light relative to the pump light is introduced by changing its optical path.

[0029] After being reflected sequentially by the mirror group, the delayed beam is then passed through the third neutral density filter and the variable aperture to adjust its energy and spot size, respectively.

[0030] The adjusted beam is guided by the twelfth and thirteenth reflecting mirrors and focused into the sapphire crystal by the first concave mirror to generate supercontinuous white light. After being collimated by the second concave mirror, the supercontinuous white light is output through the fourteenth reflecting mirror and the third filter in sequence and enters the beam combining module.

[0031] The frequency of the second chopper (308) is f2=f1= .

[0032] The beam combining module includes: a third beam splitter and a fourth beam splitter;

[0033] In this process, the driving light from the driving optical path modulation module and the probe light from the probe optical path modulation module are collinearly combined at the third beam splitter. The combined beam is then collinearly combined again with the pump light from the pump optical path modulation module at the fourth beam splitter, so that the three beams of pump light, driving light and probe light overlap in space and propagate along the same optical path, serving as the incident light of the dual-mode probe module.

[0034] The dual-mode detection module includes: a fifth beam splitter, a sixth beam splitter, a first reflective objective lens, a fourth filter, a fifteenth reflective mirror, a third lens, a first fiber optic probe, a second reflective objective lens, a sixteenth reflective mirror, a fifth filter, a fourth lens, and a second fiber optic probe.

[0035] The three collinear beams after being combined are transmitted sequentially through the fifth and sixth beam splitters, and then focused onto the sample by the first reflecting objective and interact with the sample.

[0036] In the reflection detection mode, the detection light reflected by the sample is collected and collimated again by the first reflective objective lens, then transmitted sequentially through the sixth beam splitter and reflected at the fifth beam splitter. The reflected detection light then passes sequentially through the fourth filter to filter out the pump light and driving light components, is reflected by the fifteenth reflector and focused by the third lens to the first fiber optic probe, and the first fiber optic probe transmits the detection light to the signal acquisition and processing module through the fiber optic cable.

[0037] In transmission detection mode, the probe light transmitted through the sample is collected and collimated by the second reflective objective lens, reflected by the sixteenth reflective mirror, filtered by the fifth filter to remove non-probe light components, and focused by the fourth lens onto the second fiber optic probe. The second fiber optic probe then transmits the probe light to the signal acquisition and processing module via optical fiber.

[0038] The microscopic imaging module includes: an LED illumination source, a seventh beam splitter, and a camera;

[0039] The illumination white light output by the LED lighting source is reflected by the seventh beam splitter and then incident on the sixth beam splitter. The illumination white light reflected by the sixth beam splitter is focused on the sample surface by the first reflective objective lens to achieve micro-area illumination.

[0040] The white illumination light reflected from the sample carries information about the sample surface morphology and the position of the light spot. The reflected white illumination light returns along the original illumination light path, passes through the first reflective objective lens, is transmitted to the sixth beam splitter, and is reflected to the seventh beam splitter. After passing through the seventh beam splitter, the reflected illumination beam is reflected sequentially by the seventeenth and eighteenth reflective mirrors to the third lens. After being focused by the third lens, it is incident on the target surface of the imaging camera, where the imaging camera captures and outputs the image.

[0041] It also includes: a high-voltage environment loading module;

[0042] The high-pressure environment loading module is located at the sample position between the first reflective objective lens and the second reflective objective lens;

[0043] The high-pressure environment loading module is a diamond anvil cell device, used to apply a controllable high-pressure environment to the sample without changing the collinear optical path of the pump light, driving light and probe light.

[0044] A measurement method for a microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system includes the following steps:

[0045] S1: A femtosecond laser pulse is generated using a femtosecond laser source and a beam splitter module, and then split into a pump optical path, a driving optical path, and a probe optical path.

[0046] S2: Modulate and delay the three beams respectively: make the pump light output from the pump light path modulation module reach the sample; make the driving light output from the driving light path modulation module independently tuned in wavelength and energy, and introduce a first time delay Δt1 relative to the pump light through the first optical delay line before reaching the sample; make the probe light path modulation module generate supercontinuous white light as the probe light, and introduce a second time delay Δt2 relative to the pump light through the second optical delay line before reaching the sample.

[0047] S3: The modulated and delayed pump light, driving light and probe light are spatially collinearly combined by the beam combining module;

[0048] S4: The three beams of light after collinear beam combining are focused onto the sample placed in the high-pressure environment loading module through the dual-mode detection module to provide a high-pressure environment for the sample;

[0049] S5: Control the first time delay Δt1 and the second time delay Δt2 so that the pump light first excites the sample, the driving light acts on the excited sample after the delay Δt1, and the probe light detects the sample state after the delay Δt2.

[0050] S6: The dual-mode detection module collects the detection light signal after it has been acted upon by the sample, and selects either the reflection mode or the transmission mode for collection based on the sample characteristics;

[0051] S7: The collected probe light signal is transmitted to the signal acquisition and processing module for spectral analysis and processing to generate an ultrafast kinetic spectrum of the sample with Δt1 and Δt2 as variables;

[0052] S8: During the measurement process, the microscopic imaging module is used to observe and monitor the sample micro-area and the focused spot of the three beams in real time to assist in the alignment of the optical path and the selection of the measurement area.

[0053] The present invention has the following beneficial effects and advantages:

[0054] 1. This invention constructs a novel "pump-push-probe" three-beam timing sequence by introducing a driving beam with independent modulation (wavelength, energy, and frequency) and precise timing control. This design enables the system to actively intervene in and monitor the evolution path of excited states, and can detect intermediate state population, relaxation, and energy transfer processes that are difficult to capture using traditional two-beam methods, providing a new multi-dimensional detection dimension for studying complex ultrafast dynamics.

[0055] 2. This invention integrates a diamond anvil cell high-pressure device with a collinear optical path and a compatible design with microscope objectives. This enables the system to perform femtosecond-resolved in-situ spectroscopic detection of minute samples (located between diamond anvil cells) under pressure environments of several gigapascals or even higher. This provides an irreplaceable technical means for studying the electronic structure, lattice dynamics, and phase transition mechanisms of materials under pressure.

[0056] 3. This invention seamlessly integrates both reflection and transmission detection modes within the same system by employing a pair of reflective objectives and a clever beam-splitting optical path design. Users can quickly switch detection modes based on the physical characteristics of the sample, such as transparency, thickness, and morphology, without disassembling or significantly adjusting the core optical path. This significantly improves equipment utilization and experimental efficiency, and enhances the system's versatility for various sample systems.

[0057] 4. This invention achieves real-time, high-resolution visualization of micron-scale sample regions within a high-pressure cavity by integrating an independent microscopic imaging module. This function can not only be used to accurately select the area to be measured, but also to intuitively monitor the spatial overlap and focused spot quality of the three beams of pump, drive, and probe, greatly reducing the alignment difficulty in high-pressure and micro-area experiments and ensuring the reliability and repeatability of measurement results.

[0058] 5. This invention highly integrates functional modules such as femtosecond light source, three-channel independent modulation, timing delay, high-pressure loading, dual-mode detection, microscopic imaging, and signal processing, and uses a computer for synchronous control and data acquisition. This integrated design simplifies the operation process and enables automated, high-precision scanning and analysis of ultrafast dynamic processes in multi-parameter (pressure, time, wavelength) space. Attached Figure Description

[0059] Figure 1 Schematic diagram of the optical path structure of the present invention;

[0060] Among them, 1 is the femtosecond laser source and beam splitting module, 2 is the pump optical path modulation module, 3 is the drive optical path modulation module, 4 is the probe optical path modulation module, 5 is the beam combining module, 6 is the dual-mode detection module, 7 is the signal acquisition and processing module, 8 is the microscopic imaging module, 9 is the high-pressure environment loading module, 101 is the femtosecond laser source, 102 is the first beam splitter, 103 is the second beam splitter, 201 is the third reflecting mirror, 202 is the first lens, 203 is the nonlinear crystal barium β-borate, 204 is the second lens, and 205 is the first neutral density filter. 206 is the first filter, 207 is the first chopper, 208 is the second mirror, 301 is the optical parametric amplifier, 302 is the second filter, 303 is the third mirror, 304 is the fourth mirror, 305 is the first optical delay line, 306 is the fifth mirror, 307 is the sixth mirror, 308 is the second chopper, 309 is the second neutral density filter, 401 is the seventh mirror, 402 is the second optical delay line, 403 is the eighth mirror, 404 is the ninth mirror, 405 is the tenth mirror, and 406 is the tenth mirror. Mirror 1, 407 is the third neutral density filter, 408 is the variable aperture, 409 is the twelfth mirror, 410 is the thirteenth mirror, 411 is the first concave mirror, 412 is a sapphire crystal, 413 is the second concave mirror, 414 is the fourteenth mirror, 415 is the third filter, 501 is the third beam splitter, 502 is the fourth beam splitter, 601 is the fifth beam splitter, 602 is the sixth beam splitter, 603 is the first reflecting objective lens, 604 is the fourth filter, 605 is the fifteenth mirror, 606 is the third lens, 607... 608 is the first fiber optic probe, 609 is the second reflecting objective, 610 is the sixteenth reflecting mirror, 611 is the fifth filter, 612 is the fourth lens, 701 is the second fiber optic probe, 702 is the spectrometer, 702 is the computer processor, 801 is the LED illumination source, 802 is the seventh beam splitter, 803 is the seventeenth reflecting mirror, 804 is the eighteenth reflecting mirror, 805 is the fifth lens, 806 is the camera, 901 is the diamond anvil cell, a is the input beam of the pump optical path, b is the input beam of the drive optical path, and c is the input beam of the probe optical path. Detailed Implementation

[0061] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0062] like Figure 1 As shown, the present invention provides a microscopic in-situ high-pressure pump-push-probe three-beam spectral measurement system, comprising:

[0063] The femtosecond laser source and beam splitting module 1 are used to generate a fundamental frequency femtosecond laser pulse and split it into a pump optical path input beam a, a driving optical path input beam b and a probe optical path input beam c, which are respectively incident on the pump optical path modulation module 2, the driving optical path modulation module 3 and the probe optical path modulation module 4;

[0064] Pump optical path modulation module 2 is connected to the pump optical path output end of femtosecond laser source and beam splitting module 1. It is used to perform wavelength conversion, energy adjustment and frequency modulation on the received pump light. The modulated pump light is output and enters beam combining module 5.

[0065] The driving optical path modulation module 3 is connected to the output end of the driving optical path of the femtosecond laser source and the beam splitting module 1. It is used to independently tune the wavelength, adjust the energy and modulate the frequency of the received driving light, introduce a first time delay Δt1 relative to the pump light, and output it to the beam combining module 5.

[0066] The probe optical path modulation module 4 is connected to the probe optical path output end of the femtosecond laser source and the beam splitting module 1. It is used to generate supercontinuous white light as probe light, introduce a second time delay Δt2 relative to the pump light, and output it to the beam combining module 5.

[0067] The beam combining module 5 is used to spatially collinearly combine the three beams of light from the pump optical path modulation module 2, the drive optical path modulation module 3, and the probe optical path modulation module 4, and use them as the incident light for the dual-mode probe module 6.

[0068] The dual-mode detection module 6 is located after the beam combining module 5. It is used to focus the three beams of light after beam combining onto the sample and to collect the reflection mode and transmission mode of the detection light signal after it is applied to the sample, and output them to the signal acquisition and processing module 7 respectively.

[0069] The signal acquisition and processing module 7 is connected to the dual-mode detection module 6 and is used to acquire and process the detection light signal to generate an ultrafast dynamic spectrum.

[0070] The microscopic imaging module 8 is used to visualize the micro-area and spot position of the sample.

[0071] (I) Femtosecond Laser and Beam Splitter Module

[0072] The femtosecond laser and beam splitting module 1 includes: a femtosecond laser source 101, a first beam splitter 102, and a second beam splitter 103.

[0073] The femtosecond laser 101 outputs a fundamental frequency pulse with a center wavelength of 800 nm, a pulse width of 35 fs, and a repetition frequency of 1 kHz. This pulse is first incident on the first beam splitter 102, the reflected portion of which serves as the input beam a of the pump optical path, and the transmitted portion of which is incident on the second beam splitter 103. The transmitted portion of the pulse after passing through the second beam splitter 103 serves as the input beam b of the driving optical path, and the reflected portion serves as the input beam c of the probe optical path.

[0074] (ii) Pump optical path modulation module

[0075] The pump optical path modulation module 2 includes a first reflector 201, a barium β-borate crystal 202, a first attenuator 203, a first filter 204, a first chopper 205, and a second reflector 206. The fundamental frequency light reflected from the first beam splitter of the femtosecond laser and beam splitter module 1 is reflected by the first reflector 201, focused onto the barium β-borate crystal 203 by the first lens 202, and then converged by the second lens 204 to generate a 400 nm parallel pump light. This pump light then sequentially passes through the first attenuator 205 for energy adjustment, the first filter 206 to filter out stray light, and the first chopper 207 to output pump light at a frequency of 500 Hz.

[0076] (III) Promoting the optical path modulation module

[0077] The driving optical path modulation module 3 includes an optical parametric amplifier 301, a second filter 302, a third reflector 303, a fourth reflector 304, a first optical delay line 305, a fifth reflector 306, a sixth reflector 307, a second chopper 308, and a second neutral density attenuator 309. The fundamental frequency light transmitted from the second beam splitter 103 of the femtosecond laser and beam splitter module 1 is tuned to the required wavelength by the optical parametric amplifier 301. The tuned beam is then filtered by the second filter 302 to remove stray light and guided by the third and fourth reflectors 303 and 304 to the first optical delay line 305. The first optical delay line 305 is used to accurately scan the time delay (Δt1) of the driving light relative to the pump light. Subsequently, the beam is guided by the fifth and sixth reflectors 306 and 307, and frequency-modulated by the second chopper 308 to output a driving light pulse with a frequency of 250 Hz. The pulse is then output after energy adjustment by the second attenuator 309.

[0078] (iv) Detector light modulation module

[0079] The probe light modulation module 4 includes a seventh reflector 401, a second optical delay line 402, eighth to eleventh reflectors 403-406, a third attenuator 407, a variable aperture 408, a twelfth reflector 409 and a thirteenth reflector 410, a first concave mirror 411, a sapphire crystal 412, a second concave mirror 413, and a fourteenth reflector 414. The fundamental frequency light reflected from the second beam splitter 103 of the femtosecond laser and beam splitter module 1 is reflected by the seventh reflector 401 into the second optical delay line 402, which is used to adjust the time delay (Δt2) of the probe light relative to the pump light. The delayed beam is guided by a group of mirrors (eighth mirror 403, ninth mirror 404, tenth mirror 405, eleventh mirror 406), and its energy and spot size are adjusted by the third attenuator 407 and the variable aperture 408. It is then guided by the twelfth to thirteenth mirrors 410 and focused onto the sapphire crystal 412 by the first concave mirror 411, producing supercontinuum white light covering 420-1100 nm. The generated white light is collimated into parallel light by the second concave mirror 413 and finally guided out by the fourteenth mirror 414.

[0080] (v) Bundle Module

[0081] The beam combining module 5 includes a third beam splitter 501 and a fourth beam splitter 502. The driving light from the driving light modulation module 3 and the probe light from the probe light modulation module 4 are first collinearly combined by the third beam splitter 501. The combined beam is then collinearly combined again by the pump light from the pump light modulation module 2 by the fourth beam splitter 502, ultimately integrating the three beams into the same spatial optical path.

[0082] (vi) Dual-mode detection module

[0083] The dual-mode detection module 6 includes: a fifth beam splitter 601, a sixth beam splitter 602, a first reflecting objective lens 603, a fourth filter 604, a fifteenth reflecting mirror 605, a third lens 606, a first fiber optic probe 607, a second reflecting objective lens 608, a sixteenth reflecting mirror 609, a fifth filter 610, a fourth lens 611, and a second fiber optic probe 612. The area between the first reflecting objective lens 603 and the second reflecting objective lens 608 is the sample area, used to place the diamond anvil cell 901 of the high-pressure environment loading module 9.

[0084] In reflection mode, the collinear beam from the beam combiner module 5 passes sequentially through the fifth and sixth beam splitters 601 and 602, and is focused onto the sample in the diamond anvil cell 901 by the first reflecting objective lens 603. After reflection, the beam passes again through the first reflecting objective lens 603 to become a parallel beam. This parallel beam passes through the sixth beam splitter 602 to the fifth beam splitter 601, where it is reflected to the fourth filter, then to the fifteenth reflecting mirror 605, and finally reflected to the third lens 606. The beam is then collected by the first fiber optic probe 607. The beam collected by the first fiber optic probe is then transmitted to the signal acquisition and processing module 7 via optical fiber.

[0085] In transmission mode, the light passing through the beam combining module 5 passes through the fifth beam splitter 601 and the sixth beam splitter 602 respectively. The transmitted portion enters the first reflecting objective lens 602 and is focused on the sample in the diamond anvil cell 901. The transmitted beam is converged into parallel light by the second reflecting objective lens 608, and then focused into the second fiber optic probe 612 by the sixteenth reflecting mirror 609, the fifth filter 610, and the second lens 611. The beam collected by the second fiber optic probe is transmitted to the signal acquisition and processing module 7 through the optical fiber.

[0086] (vii) Signal Acquisition and Processing Module

[0087] The signal acquisition and processing module 7 includes a spectrometer 701 and a computer processing unit 702. The fiber optic interface of the spectrometer 701 is connected to the output fiber of the first fiber optic probe 607 or the second fiber optic probe 612 in the dual-mode detection module 6. The spectrometer 701 performs spectral dispersion and photoelectric conversion processing on the collected light beam, and finally outputs the result to the computer processing unit 702.

[0088] (viii) Microscopic Imaging Module

[0089] The microscopic imaging module 8 includes an LED illumination source 801, a seventh beam splitter 802, a sixth beam splitter 602, a first reflecting objective lens 603, an eighteenth reflecting mirror 804, a fifth lens 805, and a camera 806. The white illumination light emitted by the LED illumination source 801 is reflected by the seventh beam splitter 802 to the sixth beam splitter 602, and then reflected by the sixth beam splitter to the first reflecting objective lens 603, where it is focused onto the sample. The reflected white illumination light returns along its original path, passing sequentially through the first reflecting objective lens 603 and the sixth beam splitter 602, and then reflected by the sixth beam splitter 602 to the seventh beam splitter 802, where it is transmitted. The transmitted white illumination light is reflected by the seventeenth and eighteenth reflecting mirrors 803 and 804 to the fifth lens 805, where it is focused onto the target surface of the camera 806.

[0090] The high-pressure environment loading module 9 is a diamond anvil cell 901. In the dual-mode detection module 6, the first reflecting objective lens 603 focuses the light beam onto the sample in the diamond anvil cell 901, and provides a high-pressure environment for the sample by adjusting the anvil spacing.

[0091] In the above embodiments, the supercontinuous white light spectrum ranges from 420 nm to 1100 nm; the driving light spectrum ranges from 240 nm to 2600 nm.

[0092] The relationship between the pulse frequency f0 of the fundamental frequency light output by the femtosecond laser source 101, the frequency f1 of the first chopper 205, and the frequency f2 of the second chopper 308 is f0=2f1=2f2.

[0093] like Figure 1 As shown, the present invention provides a measurement method for a microscopic in-situ high-pressure pump-push-probe three-beam spectroscopy measurement system, comprising the following steps:

[0094] In this invention, a femtosecond laser source 101 generates a fundamental frequency pulse, which is split into a pump optical path input beam a, a drive optical path input beam b, and a probe optical path input beam c by a first beam splitter 102 and a second beam splitter 103. Pump optical path input beam a is modulated in pump optical path modulation module 2, a drive optical path modulation module 3, and a probe optical path modulation module 4, respectively. Pump optical path input beam a is modulated in pump optical path modulation module 2 by a nonlinear crystal β-barium borate (BBO), a filter, and a chopper to produce pump light with a wavelength of 400 nm and a frequency of 500 Hz. Drive optical path input beam b is wavelength-tuned in drive optical path module 3 by an optical parametric amplifier 301 and a filter, and then introduced with a time delay Δt1 relative to the pump light by an optical delay line 305. Finally, it is modulated by a chopper 308 to produce drive light with a frequency of 250 Hz. The input beam c in the probe light path module 4 is delayed by a time delay Δt2 relative to the pump light by an optical delay line 402, and then passes through a neutral density filter 407, a variable aperture 408, a concave mirror 411, a sapphire crystal 412, and a concave mirror 413 to form supercontinuous white light as the probe light. The pump light, driving light, and probe light are collinearly combined by the beam combiner module 5 and then focused by the reflective objective lens 603 of the dual-mode probe module 6 onto the sample within the diamond anvil cell of the high-pressure environment loading module 9. The diamond anvil cell provides the sample chamber and an extreme high-pressure environment. When the pump light and driving light illuminate the sample sequentially with a time delay Δt1, the time delay Δt2 of the probe light relative to the pump light is changed to detect the sample state. After the probe light interacts with the sample, the optical signal carrying its dynamic information is collected and processed by the dual-mode probe module 6 via an optical fiber. The microscopic imaging module 7 is used to detect the spatial overlap of the pump light, driving light, and probe light, and simultaneously select the sample area for detection.

[0095] In summary, this invention presents a novel ultrafast spectroscopic measurement system by constructing a pump-push-probe three-beam timing sequence, integrating a diamond anvil cell high-pressure loading module, and fusing microscopic imaging and dual-mode detection technologies. This system not only overcomes the limitations of traditional two-beam techniques in tracking excited-state intermediate processes but also achieves in-situ, high-precision dynamic observation of micro-area samples under extreme high-pressure conditions. This invention provides crucial technical support for ultrafast dynamics research under high-pressure extreme conditions in materials science, physical chemistry, and earth sciences, and has significant scientific value and application prospects.

[0096] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0097] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system, characterized in that, include: The femtosecond laser source and beam splitting module (1) are used to generate a fundamental frequency femtosecond laser pulse and split it into a pump optical path input beam (a), a driving optical path input beam (b) and a probe optical path input beam (c), which are respectively incident on the pump optical path modulation module (2), the driving optical path modulation module (3) and the probe optical path modulation module (4). The pump optical path modulation module (2) is connected to the pump optical path output end of the femtosecond laser source and the beam splitting module (1). It is used to perform wavelength conversion, energy adjustment and frequency modulation on the received pump light. The modulated pump light is output and enters the beam combining module (5). The driving optical path modulation module (3) is connected to the output end of the driving optical path of the femtosecond laser source and the beam splitting module (1). It is used to independently tune the wavelength, adjust the energy and modulate the frequency of the received driving light, introduce a first time delay Δt1 relative to the pump light, and output it to the beam combining module (5). The probe optical path modulation module (4) is connected to the probe optical path output end of the femtosecond laser source and the beam splitting module (1) to generate supercontinuous white light as probe light, introduce a second time delay Δt2 relative to the pump light, and output to the beam combining module (5). The beam combining module (5) is used to spatially collinearly combine the three beams of light from the pump optical path modulation module (2), the driving optical path modulation module (3) and the probe optical path modulation module (4), and use them as the incident light of the dual-mode probe module (6); The dual-mode detection module (6) is located after the beam combining module (5) and is used to focus the three beams of light after beam combining onto the sample, and to collect the reflection mode and transmission mode of the detection light signal after the sample is acted upon, and output them to the signal acquisition and processing module (7) respectively. The signal acquisition and processing module (7) is connected to the dual-mode detection module (6) and is used to acquire and process the detection light signal to generate an ultrafast dynamic spectrum. The microscopic imaging module (8) is used to visualize the micro-area and spot position of the sample.

2. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The femtosecond laser source and beam splitting module (1) includes: a femtosecond laser source (101), a first beam splitter (102), and a second beam splitter (103). The fundamental frequency laser pulse output by the femtosecond laser source (101) is incident on the first beam splitter (102), the reflected beam of the first beam splitter (102) constitutes the pump optical path input beam (a), and its transmitted beam is incident on the second beam splitter (103). The transmitted beam of the second beam splitter (103) forms the input beam (b) of the driving optical path and is incident on the driving optical path modulation module (3), and its reflected beam forms the input beam (c) of the probe optical path and is incident on the probe optical path modulation module (4). The femtosecond laser source (101) outputs a fundamental frequency light pulse frequency f0.

3. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The pump optical path modulation module (2) includes: a first reflector (201), a first lens (202), a nonlinear crystal barium β-borate (203), a second lens (204), a first neutral density filter (205), a first filter (206), and a first chopper (207). Among them, the pump light input beam (a) from the first beam splitter (102) is reflected by the first mirror (201) and then incident on the nonlinear crystal barium borate (203) through the first lens (202) to perform frequency doubling and generate pump light; The pump light after frequency doubling passes through the second lens (204), through the first neutral density filter (205) for energy adjustment, through the first filter (206) to filter out non-target wavelength light components, and through the first chopper (207) for pulse frequency modulation. The modulated pump light is reflected by the second mirror (208) and output into the beam combining module (5). The frequency of the first chopper (205) is f1.

4. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The driving optical path modulation module (3) includes: an optical parametric amplifier (301), a second filter (302), a third reflector (303), a fourth reflector (304), a first optical delay line (305), a fifth reflector (306), a sixth reflector (307), a second chopper (308), and a second neutral density filter (309) arranged in sequence. Among them, the input beam (b) of the driving optical path transmitted from the second beam splitter (103) is incident on the optical parametric amplifier (301) for wavelength tuning; After the tuned driving light passes through the second filter (302) to filter out stray light, it is reflected in sequence by the third mirror (303) and the fourth mirror (304) and guided into the first optical delay line (305). By changing the optical path of the first optical delay line (305), a time delay Δt1 is introduced between the driving light and the pump light. The driving light is reflected by the fifth mirror (306) and the sixth mirror (307) and then enters the second chopper (308) for frequency modulation. After being regulated by the second neutral attenuator (309), it is output to the beam combining module (5). The frequency of the second chopper (308) is f2=f1= .

5. The microscopic in-situ high-pressure pump-push-probe three-beam spectral measurement system according to claim 1, characterized in that, The detection optical path modulation module (4) includes: a seventh reflector (401), a second optical delay line (402), a reflector group, a third neutral density filter (407), a variable aperture (408), a twelfth reflector (409), a thirteenth reflector (410), a first concave mirror (411), a sapphire crystal (412), a second concave mirror (413), a fourteenth reflector (414), and a third filter (415). Among them, the probe light input beam (c) reflected from the second beam splitter (103) enters the second optical delay line (402) after being reflected by the seventh mirror (401), and the time delay Δt2 of the probe light relative to the pump light is introduced by changing its optical path. After being reflected sequentially by the mirror group, the delayed beam is then subjected to energy and spot size adjustment by the third neutral density filter (407) and the variable aperture (408), respectively. The adjusted beam is guided by the twelfth mirror (409) and the thirteenth mirror (410), and focused by the first concave mirror (411) into the sapphire crystal (412) to generate supercontinuous white light. After being collimated by the second concave mirror (413), the supercontinuous white light is output through the fourteenth mirror (414) and the third filter (415) and enters the beam combining module (5).

6. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The beam combining module (5) includes: a third beam splitter (501) and a fourth beam splitter (502). Among them, the driving light from the driving light path modulation module (3) and the probe light from the probe light path modulation module (4) are collinearly combined at the third beam splitter (501). The combined beam is then collinearly combined again with the pump light from the pump light path modulation module (2) at the fourth beam splitter (502), so that the three beams of pump light, driving light and probe light overlap in space and propagate along the same optical path, serving as the incident light of the dual-mode probe module (6).

7. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The dual-mode detection module (6) includes: a fifth beam splitter (601), a sixth beam splitter (602), a first reflective objective lens (603), a fourth filter (604), a fifteenth reflector (605), a third lens (606), a first fiber optic probe (607), a second reflective objective lens (608), a sixteenth reflector (609), a fifth filter (610), a fourth lens (611), and a second fiber optic probe (612). Among them, the three collinear beams after beam combining are transmitted sequentially through the fifth beam splitter (601) and the sixth beam splitter (602), and then focused by the first reflecting objective (603) onto the sample and interact with the sample. In the reflection detection mode, the detection light reflected by the sample is collected and collimated again by the first reflective objective (603), then transmitted sequentially through the sixth beam splitter (602) and reflected at the fifth beam splitter (601). The reflected detection light passes sequentially through the fourth filter (604) to filter out the pump light and driving light components, is reflected by the fifteenth reflector (605) and focused by the third lens (606) to the first fiber optic probe (607). The first fiber optic probe (607) transmits the detection light to the signal acquisition and processing module (7) through the optical fiber. In the transmission detection mode, the detection light transmitted through the sample is collected and collimated by the second reflective objective (608), reflected by the sixteenth reflective mirror (609), filtered by the fifth filter (610) to remove non-detection light components, and focused by the fourth lens (611) onto the second fiber optic probe (612). The second fiber optic probe (612) transmits the detection light to the signal acquisition and processing module (7) through the fiber optic cable.

8. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, The microscopic imaging module (8) includes: an LED illumination source (801), a seventh beam splitter (802), and a camera (806). The white light emitted by the LED lighting source (803) is reflected by the seventh beam splitter (802) and then incident on the sixth beam splitter (602). The white light reflected by the sixth beam splitter (602) is focused on the sample surface by the first reflective objective lens (603) to achieve micro-area illumination. The white light reflecting off the sample carries information about the sample surface morphology and the position of the light spot. The reflected white light returns along the original illumination path, passes through the first reflecting objective (603), is transmitted to the sixth beam splitter (602), and is reflected to the seventh beam splitter (802). The reflected illumination beam passes through the seventh beam splitter (802), and is reflected sequentially by the seventeenth mirror (803) and the eighteenth mirror (804) to the third lens (805). After being focused by the third lens (805), it is incident on the target surface of the imaging camera (806), and the imaging camera (806) captures and outputs the image.

9. The microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, It also includes: a high-pressure environment loading module (9); The high-pressure environment loading module (9) is located at the sample position between the first reflective objective lens (603) and the second reflective objective lens (608); The high-pressure environment loading module is a diamond anvil cell (901), which is used to apply a controllable high-pressure environment to the sample without changing the collinear optical path of the pump light, driving light and probe light.

10. The measurement method of the microscopic in-situ high-pressure pump-push-probe three-beam spectroscopic measurement system according to claim 1, characterized in that, Includes the following steps: S1: Use a femtosecond laser source and a beam splitting module (1) to generate a fundamental frequency femtosecond laser pulse and split it into a pump optical path, a driving optical path and a probe optical path; S2: Modulate and delay the three beams respectively: make the pump light output by the pump light path modulation module (2) reach the sample; make the driving light output by the driving light path modulation module (3) be independently tuned in wavelength and energy, and reach the sample after being introduced by the first time delay Δt1 relative to the pump light through the first optical delay line (305); The probe light path modulation module (4) generates supercontinuous white light as the probe light, and the light reaches the sample after being introduced by a second time delay Δt2 relative to the pump light through the second optical delay line (402). S3: The modulated and delayed pump light, driving light and probe light are spatially collinearly combined by the beam combining module (5); S4: The three beams of light after collinear beam combining are focused onto the sample placed in the high-pressure environment loading module (9) through the dual-mode detection module (6) to provide a high-pressure environment for the sample; S5: Control the first time delay Δt1 and the second time delay Δt2 so that the pump light first excites the sample, the driving light acts on the excited sample after the delay Δt1, and the probe light detects the sample state after the delay Δt2. S6: The dual-mode detection module (6) collects the detection light signal after it has been acted upon by the sample, and selects the reflection mode or transmission mode for collection according to the sample characteristics; S7: The collected probe light signal is transmitted to the signal acquisition and processing module (7) for spectral analysis and processing to generate a sample ultrafast kinetic spectrum with Δt1 and Δt2 as variables; S8: During the measurement process, the micro-area of ​​the sample and the focused spot of the three beams of light are observed and monitored in real time through the microscopic imaging module (8) to assist in the alignment of the optical path and the selection of the measurement area.

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