A k-space angular resolved transient grating scattering spectroscopy system

Abstract

The present application relates to a kind of K space angle resolving transient parametric scattering spectrum measurement system, belong to microelectronic and semiconductor device field.The system includes: femtosecond laser, first beam splitting unit, electric delay table, beam combining unit, first objective, displacement table, second objective, dichroic beam splitter, continuous laser, signal collimating filter lens group, second beam splitting unit, spectrometer and beam analyzer, and parametric scattering signal light wave is excited by the timing adjustable femtosecond pump light excitation sample on displacement table, signal is collimated filter lens group, 50:50 optical splitting unit and is transmitted to spectrometer and beam analyzer in parallel, realizes parametric scattering K space dispersion and two-dimensional momentum distribution synchronous real-time measurement, solves the defect that traditional test equipment cannot complete microcavity parametric scattering momentum imaging and ultrafast time resolution measurement synchronously.

Description

Technical Field

[0001] This invention relates to the field of microelectronics and semiconductor device technology, and in particular to a K-space angle-resolved transient parametric scattering spectroscopy measurement system. Background Technology

[0002] In VCSEL microcavities, excitons are strongly coupled with cavity photons to form exciton polaritons. The parametric scattering process of these polaritons is the core physical mechanism for generating coherent polariton lasing and all-optical nonlinear modulation. Polariton parametric scattering satisfies the conservation of energy and momentum. Pump-state polariton scattering generates signal-state and idle-state quasi-particles. The momentum spatial distribution, ultrafast relaxation dynamics, and dispersion evolution of this process are key characterization objects for studying the device mechanism.

[0003] Current commercial and laboratory-scale testing optical paths have several limitations: 1. Traditional angle-resolved spectroscopic equipment can only acquire dispersion curves at fixed time intervals, and cannot introduce time-tunable seed pulses to adjust parametric scattering gain, making it difficult to study the modulation law of coherent seed injection on scattering dynamics; 2. Conventional transient time-resolved spectroscopic equipment lacks synchronous K-space momentum imaging capability, and can only acquire the time-varying integral light intensity, making it impossible to distinguish wave vectors in different planes. 3. The scattering lifetime difference of position polaritons; 4. The optical path of the separate real space imaging, spectral acquisition and momentum imaging requires multiple lens switching and sample movement. The repeated assembly and adjustment error of the optical path is large and the test efficiency is extremely low, and synchronous parallel acquisition cannot be achieved; 5. The lack of coaxial integration design of femtosecond pump pulse and continuous microscopic illumination makes it difficult to locate the nanoscale light emission area of ​​VCSEL microcavity, resulting in strong stray light interference and poor signal-to-noise ratio of weak parametric scattering signal.

[0004] Existing technology discloses a K-space angle-resolved transient spectroscopy and lifetime testing system. This system achieves separation of the excitation light incident path and the signal light collection path through the coordinated operation of a beam splitter, a lens focusing system, and a spectrometer. A parallel beam is formed by a focal aperture plate and a second focusing lens and enters the spectrometer, while an imaging device and a photon counter module are simultaneously introduced to acquire angle-resolved spectral and transient lifetime data. This approach has the following problems: the system only outputs a single signal to the spectrometer, lacks parallel beam splitting, is a general-purpose microcavity photoluminescence test, lacks a dedicated optical path for parametric scattering, and cannot distinguish the three-state momentum matching relationship. Therefore, it can only observe uncontrolled spontaneous scattering and cannot study all-optical modulation, polariton switching, or other similar situations. Summary of the Invention

[0005] This invention provides a K-space angle-resolved transient parametric scattering spectroscopy measurement system that can solve the problem that existing technologies cannot simultaneously complete the characterization of polariton parametric scattering momentum distribution, intrinsic optical properties, and ultrafast dynamic evolution.

[0006] To achieve the above objective, according to a first aspect of the present invention, a K-space angle-resolved transient parametric scattering spectroscopy measurement system is provided, the scattering spectroscopy measurement system comprising: A femtosecond laser is used to output femtosecond excitation pulses; a first beam splitter unit is disposed on the output optical path of the femtosecond laser to split the femtosecond excitation pulses into a main pump beam and a seed trigger beam; an electric delay stage is disposed on the optical path of the seed trigger beam to adjust the time delay of the seed trigger beam relative to the main pump beam; a beam combiner unit is used to combine the seed trigger beam delayed by the electric delay stage with the main pump beam to output a combined excitation beam; a first objective lens is disposed on the optical path of the combined excitation beam, and the combined excitation beam is incident on the first objective lens and focused by the first objective lens onto the sample to excite the sample to generate parametric scattering signal light; a displacement stage is used to carry the sample and drive the sample to move relative to the focused spot of the first objective lens; a second objective lens is paired with the first objective lens and disposed on the same optical axis to collect the parametric scattering signal light emitted from the sample; a dichroic beam splitter is used to split the dichroic beam. A beam mirror is positioned at the rear end of the second objective lens to transmit the parametric scattered signal light; a continuous laser, whose output beam is reflected by the dichroic beam splitter and incident on the sample along the optical axes of the first and second objectives, is used to non-resonantly excite the sample to characterize its intrinsic optical properties; a signal collimating filter lens group is positioned on the transmission path of the dichroic beam splitter to convert the diverging parametric scattered signal light into a parallel beam and to spatially filter the parallel beam to remove stray light; a second beam splitting unit is positioned at the rear end of the signal collimating filter lens group to split the collimated and filtered parallel beam into a first probe beam and a second probe beam; a spectrometer is positioned on the optical path of the first probe beam to acquire K-space angular-resolved dispersive spectra; and a beam analyzer is positioned on the optical path of the second probe beam to acquire two-dimensional K-space momentum distribution images.

[0007] Compared with existing technologies, this invention uses a time-tunable femtosecond pump light to excite a zinc oxide microcavity sample on a displacement stage to generate parametric scattering signal light waves. The signal is then transmitted in parallel to a spectrometer and beam analyzer via a collimating filter lens group and a 50:50 beam splitter, achieving simultaneous real-time measurement of parametric scattering K-space dispersion and two-dimensional momentum distribution. In a single test, this system not only outputs the wavelength energy evolution information of scattered photons but also visually presents the particle occupancy distribution of polaritons in different momentum spaces. Simultaneously, it relies on the He-Cd non-resonant excitation branch to fully acquire the intrinsic optical spectral characteristics of the microcavity. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the system structure provided in one embodiment of the present invention. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Example 1 According to one embodiment of the present invention, such as Figure 1As shown, a K-space angle-resolved transient parametric scattering spectroscopy measurement system is provided. The system includes: a femtosecond laser 21 for outputting femtosecond excitation pulses; a first beam splitting unit 3 disposed on the output optical path of the femtosecond laser 21 for splitting the femtosecond excitation pulses into a main pump light and a seed trigger light; an electrically driven delay stage 22 disposed on the optical path of the seed trigger light for adjusting the time delay of the seed trigger light relative to the main pump light; a beam combining unit 8 for combining the seed trigger light delayed by the electrically driven delay stage 22 with the main pump light to output a combined excitation light; a first objective lens 9 disposed on the optical path of the combined excitation light, the combined excitation light being incident on the first objective lens 9 and focused onto the sample by the first objective lens 9 to excite the sample to generate parametric scattering signal light; a displacement stage 10 for carrying the sample and driving the sample to move relative to the focused spot of the first objective lens 9; and a second objective lens 11 paired with the first objective lens 9 and disposed on the same optical axis for collecting the parametric scattering signal light emitted from the sample. The sample is equipped with: a parametric scattered signal light; a dichroic beam splitter 12, which is disposed at the rear end of the second objective lens 11 and is used to transmit the parametric scattered signal light; a continuous laser 20, whose output beam is reflected by the dichroic beam splitter 12 and then incident on the sample along the optical axis of the first objective lens 9 and the second objective lens 11, for non-resonant excitation of the sample to characterize the intrinsic optical properties of the sample; a signal collimating filter lens group, disposed in the transmission path of the dichroic beam splitter 12, for converting the divergent parametric scattered signal light into a parallel beam and spatially filtering the parallel beam to remove stray light; a second beam splitting unit 15, disposed at the rear end of the signal collimating filter lens group, for splitting the collimated and filtered parallel beam into a first probe beam and a second probe beam; a spectrometer 18, disposed in the optical path of the first probe beam, for acquiring K-space angular-resolved dispersive spectra; and a beam analyzer 19, disposed in the optical path of the second probe beam, for acquiring two-dimensional K-space momentum distribution images.

[0012] In this embodiment, the femtosecond laser 21 is a Ti:sapphire femtosecond laser with a repetition frequency of 80MHz, an output center wavelength of 810nm, and a pulse width of 250fs; the first beam splitting unit 3 is a 70:30 beam splitter, wherein 70% of the transmitted component is used as the main pump light and 30% of the reflected component is used as the seed trigger light; the second beam splitting unit 15 is a 50:50 beam splitter.

[0013] A femtosecond excitation pulse is incident on a 70:30 beam splitter, which splits the femtosecond beam into two paths: 70% transmitted light serves as the main pump beam, and 30% reflected light serves as the time-adjustable seed trigger beam. The main pump beam passes sequentially through the third mirror 4 and the fourth mirror 5. The time-adjustable seed trigger beam is directly introduced into the motorized delay stage 22. The delay stage is equipped with a first mirror 6 and a second mirror 7, both of which are high-reflectivity reflectors. The motorized delay stage 22 is driven by an electric controller to linearly move the first mirror 6 and the second mirror 7, changing the total optical path of the seed beam and continuously adjusting the relative time difference between the seed pulse and the main pump pulse. After optical path delay, the seed trigger beam is reflected by the beam combiner unit 8 and coaxially combined with the main pump beam transmitted from the 70:30 beam splitter 3. The beam combiner unit 8 is a reflector.

[0014] In another specific embodiment, before the femtosecond excitation pulse is incident on the 70:30 beam splitter 3, it needs to pass through the fifth reflecting mirror 1 to complete the optical path redirection. The fifth reflecting mirror 1 is a plane high-reflection mirror.

[0015] In another specific embodiment, before the femtosecond excitation pulse is incident on the 70:30 beam splitter 3, it needs to pass through the first adjustable aperture 2, which is used to perform spatial filtering on the femtosecond excitation pulse to remove stray light at the edge of the beam. The aperture of the first adjustable aperture 2 can be continuously adjusted in the range of 50~500μm.

[0016] The combined main pump beam and seed trigger beam are incident on the first objective lens 9, which is a 50x focusing objective lens. The first objective lens 9 focuses the combined double-pulse beam into a 2.5μm×2.5μm micro-spot, illuminating the microcavity sample on the displacement stage 10. The displacement stage has a minimum movement accuracy of 1 micrometer and can support micro-nano optical samples such as zinc oxide nanoribbons and VCSEL vertical cavities, achieving precise positioning of the micro-area to be measured. The double-pulse beam resonates and excites excitons inside the sample, generating polariton parametric scattering signal light waves, which are collected by the paired second objective lens 11. Both the first objective lens 9 and the second objective lens 11 are long working distance achromatic microscope objectives with a magnification of 50x, ensuring efficient collection of excitation and scattering signals from the microcavity sample.

[0017] The dichroic beam splitter 12 is used to receive the parametric scattered signal light wave output from the second objective lens 11, and simultaneously receive the continuous excitation light output from the continuous laser 20 below, wherein the continuous laser 20 is a CW He-Cd laser; the output beam of the continuous laser 20 is incident on the dichroic beam splitter 12, and after being reflected by the mirror, it is transmitted downward along the collection and focusing optical path to the zinc oxide microcavity sample, which is used to carry out non-resonant excitation of the zinc oxide microcavity and realize the individual characterization of the intrinsic optical properties of the microcavity; the dichroic beam splitter 12 has high reflectivity to the 810nm femtosecond pump light and high transmittance to the parametric scattered signal light in the visible light band, and transmits the scattered signal light wave radiated by the sample backward to the signal collimating filter lens group.

[0018] It should be noted that the dichroic beam splitter 12 can also reflect the He-Cd laser, and the optical path can be switched back and forth by replacing the dichroic mirror.

[0019] The signal collimating and filtering lens group includes a first focusing lens 13 and a second adjustable aperture 14. The divergent parametric scattered signal light wave passing through the dichroic beam splitter 12 is incident on the first focusing lens 13 and converted into a standard parallel K-space beam. The parallel beam passes through the second adjustable aperture 14 to complete the stray light filtering. The aperture can be continuously adjusted in the range of 50~500μm to filter out diffuse reflection from the semiconductor substrate and residual pump stray light, which greatly improves the signal-to-noise ratio of the weak parametric scattered signal. The filtered pure parallel beam is incident on the 50:50 beam splitter. After the parallel K-space signal light wave is incident perpendicularly, it is evenly split into two paths and transmitted in parallel to the spectrometer 18 and the beam analyzer 19.

[0020] In this embodiment, the 50:50 and 70:30 beam splitters are high-quality, low-loss fused silica substrate beam splitters, reducing beam splitting loss in the free-space optical path and ensuring efficient transmission of weak scattering signals. The second focusing lens 17 and the third focusing lens 16 both have a focal length of 150mm. The 50:50 beam splitter operates at a wavelength of 350–700nm. The first objective lens 9 and the second objective lens 11 are near-infrared and near-ultraviolet objectives with a magnification of 50% and infinity correction, respectively.

[0021] The beam analyzer 19 has a built-in imaging camera for acquiring two-dimensional momentum K-space distribution images, enabling visualization and addressing of the sample scattering region. The spectrometer 18 is equipped with a built-in monochromatic spectral module and a picosecond photon counter. The monochromatic spectral module has a wavelength resolution of 0.1 nm, and the overall spectral accuracy of the instrument is 0.5 nm. The photon counter has a time measurement accuracy of up to 5 picoseconds, capable of separating the pump state, signal state, and idle state monochromatic light in the parametric scattering process, and acquiring real-time occupancy distribution and picosecond-level ultrafast relaxation lifetime information of the multi-particle system. During measurement, the target wavelength monochromatic signal light can be filtered through the adjustable slit of the spectrometer, while a pump reference light is introduced into the discrimination photodetector. The light pulse is converted into an electrically triggered signal and input to the photon counting data acquisition and analysis terminal, simultaneously completing the fitting of monochromatic photodynamic curves under different time sequences.

[0022] It should be noted that the spectrometer has a built-in monochromatic spectroscopy module to split the scattered signal, separate the scattered light of a single energy state and couple it to a 5 picosecond high-precision photon counter. Combined with the timing scanning parameters of the motorized delay stage, it synchronously collects particle relaxation lifetime and photon correlation statistics under different pump-seed timing differences, and fully obtains the evolution law of parametric scattering dynamics.

[0023] The K-space angle-resolved transient parametric scattering spectroscopy measurement system of this invention generates parametric scattering signal light waves by exciting a zinc oxide microcavity sample on a time-adjustable dual-pulse femtosecond excitation stage. The signal is transmitted in parallel to a spectrometer and a beam analyzer via a collimating filter lens group and a 50:50 beam splitter, achieving simultaneous real-time measurement of parametric scattering K-space dispersion and two-dimensional momentum distribution. During a single test, this system not only outputs the wavelength energy evolution information of scattered photons but also visually presents the particle occupancy distribution of polaritons in different momentum spaces. Simultaneously, it fully acquires the intrinsic optical spectral characteristics of the microcavity using a He-Cd non-resonant excitation branch. By using a monochromatic beam splitter paired with a 5-picosecond high-precision photon counter, the relaxation lifetimes of different energy states in the parametric scattering multi-particle system can be analyzed in real time. Combined with an electrically delayed optical path, sub-picosecond-level scattering dynamics modulation characterization is achieved, providing researchers with complete microcavity particle evolution data, including intrinsic optics, momentum distribution, and ultrafast dynamics. This significantly supports the mechanism analysis and device optimization design of ultra-low-power polariton micro / nano lasers.

[0024] Example 2 According to the above technical solution, the present invention can start the femtosecond laser 21 and the continuous laser 20 at different times. One embodiment of the present invention is as follows: an 80MHz Ti:sapphire femtosecond laser outputs a femtosecond excitation pulse, which, after being adjusted by the fifth reflecting mirror 1 and the first adjustable aperture 2, is incident on a 70:30 beam splitter; the transmitted seed trigger light enters the electrically delayed optical path composed of the first reflecting mirror 6 and the second reflecting mirror 7; the electrically delayed stage 22 is adjusted to change the time delay between the seed trigger light and the main pump pulse; the two beams are coaxially combined by the beam combining unit 8; the combined double pulse is focused by a 50x focusing objective lens to irradiate the zinc oxide microcavity sample 10; and polariton parametric scattering signal light waves are generated through two-photon resonance excitation; the parametric scattering signal light waves radiated upwards by the sample... The emitted signal light wave is collected by the second objective lens 11, passes through the dichroic beam splitter 12, and is converted into a parallel K-space beam by the first focusing lens 13. After passing through the second adjustable aperture 14 to filter out stray light, it reaches the 50:50 beam splitter. The beam splitter splits the signal light into two paths for simultaneous acquisition. One path is sent to the beam analyzer 19, which outputs a two-dimensional K-space momentum distribution map in real time. Combined with the displacement stage, it realizes rapid addressing and positioning of the micron-level microcavity test area. The other path is sent to the high-resolution spectrometer 18 to collect K-space angular-resolved dispersive spectra at different scattering angles, which directly reflects the multi-particle momentum occupancy state of the exciton-photon coupling system inside the microcavity.

[0025] Another implementation involves turning on only the continuous laser 20 to characterize the intrinsic optical properties of the microcavity independently. The non-resonant excitation light is reflected downwards by the dichroic beam splitter 12 to illuminate the sample, and the intrinsic spectrum of the sample without pump disturbance is collected independently. The resulting parametric reflected signal light wave passes through the second objective lens 11, also through the dichroic beam splitter 12, and then through the first focusing lens 13. After the stray light is filtered out by the second adjustable aperture 14, it reaches the 50:50 beam splitter. The beam splitter splits the signal light into two paths for simultaneous acquisition. One path is sent to the beam analyzer 19, and the other path is sent to the high-resolution spectrometer 18.

[0026] Example 3 Compared to Embodiment 1, this embodiment makes the following changes: the main pump light reflected from the first beam-splitting unit 3 is directly directed towards the optical axis of the first objective lens 9 and the second objective lens 11 and incident on the sample. Therefore, it is unnecessary to place the fifth reflecting mirror 1 between the femtosecond laser 21 and the first beam-splitting unit 3, and it is unnecessary to place the second folding high-reflection mirror group between the main pump light and the first objective lens 9, thereby simplifying the overall system structure.

[0027] Example 4 Compared with Embodiments 1 and 2, this embodiment makes the following changes: A second focusing lens 17 is provided between the second beam splitting unit 15 and the spectrometer 18 to focus and couple the first probe beam to the spectrometer 18. A third focusing lens 16 is provided between the second beam splitting unit 15 and the beam analyzer 19 to focus and couple the second probe beam to the beam analyzer 19.

[0028] In the several embodiments provided by this invention, it should be understood that the disclosed methods and apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0029] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can be physically comprised separately, or two or more units can be integrated into one unit. The integrated unit described above can be implemented in hardware or in the form of hardware plus software functional units.

[0030] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A K-space angle-resolved transient parametric scattering spectroscopy measurement system, characterized in that, The scattering spectroscopy measurement system includes: A femtosecond laser (21) is used to output femtosecond excitation pulses; The first beam splitting unit (3) is disposed on the output light path of the femtosecond laser (21) and is used to split the femtosecond excitation pulse into the main pump light and the seed trigger light. An electric delay stage (22) is set in the optical path of the seed trigger light to adjust the time delay of the seed trigger light relative to the main pump light; The beam combining unit (8) is used to combine the seed trigger light delayed by the electric delay stage (22) with the main pump light to output the beam combining excitation light; The first objective lens (9) is disposed in the optical path of the combined excitation light. The combined excitation light is incident on the first objective lens (9) and focused onto the sample by the first objective lens (9) to excite the sample to generate parametric scattering signal light. A displacement stage (10) is used to carry the sample and drive the sample to move relative to the focusing spot of the first objective lens (9); The second objective lens (11) is paired with the first objective lens (9) and set on the same optical axis to collect the parametric scattered signal light emitted from the sample; Dichroic beam splitter (12), the dichroic beam splitter (12) is disposed at the rear end of the second objective lens (11) and is used to transmit the parametric scattered signal light; A continuous laser (20) outputs a beam that is reflected by the dichroic beam splitter (12) and then incident on the sample along the optical axis of the first objective lens (9) and the second objective lens (11) to perform non-resonant excitation on the sample in order to characterize the intrinsic optical properties of the sample. The signal collimating filter lens group is set on the transmission light path of the dichroic beam splitter (12) to convert the divergent parametric scattered signal light into a parallel beam and to perform spatial filtering on the parallel beam to filter out stray light. The second beam splitting unit (15) is disposed at the rear end of the signal collimating filter lens group and is used to split the collimated and filtered parallel beam into a first probe beam and a second probe beam. A spectrometer (18) is placed in the optical path of the first probe beam to collect K-space angle-resolved dispersive spectra; A beam analyzer (19) is set on the optical path of the second probe beam to acquire a two-dimensional K-space momentum distribution image.

2. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 1, characterized in that, The electric delay stage (22) includes: The first folding high-reflection mirror group is fixedly installed on the moving platform of the electric delay stage (22); The first high-reflection mirror group includes a first reflector (6) and a second reflector (7); the seed trigger light is introduced into the first high-reflection mirror group through the first reflector (6), and the moving platform is linearly moved by electronic control to change the horizontal position of the second reflector (7), thereby changing the total transmission optical path of the seed trigger light and thus continuously adjusting the relative time delay of the seed trigger light relative to the main pump light.

3. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 2, characterized in that, A second high-reflection mirror group is also provided in the optical path of the main pump light. The second high-reflection mirror group is used to direct the transmission direction of the main pump light toward the first objective lens (9). The second high-reflection mirror group includes a third mirror (4) and a fourth mirror (5). The main pump light is introduced into the second high-reflection mirror group through the third mirror (4). By adjusting the position of the fourth mirror (5), the main pump light is reflected and then coincides with the optical axis of the first objective lens (9) and the second objective lens (11).

4. A K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 2 or 3, characterized in that, A fifth reflector (1) is also provided between the femtosecond laser (21) and the first beam splitter (3). The fifth reflector (1) is used to redirect the optical path of the femtosecond excitation pulse so that the femtosecond excitation pulse is incident on the first beam splitter (3) at a preset angle.

5. A K-space angle-resolved transient parametric scattering spectroscopy measurement system according to any one of claims 2-4, characterized in that, A first adjustable aperture (2) is also provided between the femtosecond laser (21) and the first beam splitting unit (3). The first adjustable aperture (2) is used to perform spatial filtering on the femtosecond excitation pulse to remove stray light at the edge of the beam.

6. A K-space angle-resolved transient parametric scattering spectroscopy measurement system according to any one of claims 1-5, characterized in that, The signal collimating filter lens group includes: The first focusing lens (13) is used to convert the divergent parametric scattered signal light into a parallel K-space beam. The second adjustable aperture (14) is disposed at the rear end of the first focusing lens (13) and is used to perform spatial filtering on the parallel K-space beam.

7. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 6, characterized in that, It also includes: The second focusing lens (17) is disposed between the second beam splitting unit (15) and the spectrometer (18) for focusing and coupling the first detection beam to the spectrometer (18). A third focusing lens (16) is disposed between the second beam splitting unit (15) and the beam analyzer (19) for focusing and coupling the second probe beam to the beam analyzer (19).

8. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 1, characterized in that, The femtosecond laser (21) is a Ti:sapphire femtosecond laser with a repetition frequency of 80MHz, an output center wavelength of 810nm, and a pulse width of 250fs.

9. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 1, characterized in that, The first beam splitting unit (3) is a 70:30 beam splitter, wherein 70% of the transmitted component is used as the main pump light and 30% of the reflected component is used as the seed trigger light.

10. The K-space angle-resolved transient parametric scattering spectroscopy measurement system according to claim 1, characterized in that, The second beam splitting unit (15) is a 50:50 beam splitter.

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