A device and method for detecting energy carrier dissipation behavior in thermal insulation materials

Abstract

The application discloses a device and method for detecting energy carrier dissipation behavior in thermal insulation materials, which comprises: a laser emission module for emitting a laser beam; a first filter for separating the laser beam; a supercontinuum beam forming device for processing the second laser beam; a phase delay line for phase delaying the first laser beam; the wavelength range of the supercontinuum beam is wider than that of the pump beam; a second filter for combining the supercontinuum beam and the pump beam, and then irradiating the surface of the sample and being transmitted by the sample; a photodetector collects the transmitted beam; a controller controls the delay time change of the phase delay line once, receives the transmitted beam once, processes each transmitted beam, obtains the corresponding time-resolved broadband spectral coherent anti-Stokes shift, and extracts the longitudinal optical phonon dephasing process of the sample according to the anti-Stokes shift. Multimodal coherent phonon detection of the sample is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coherent vibration imaging technology, and in particular to a device and method for detecting energy carrier dissipation behavior in thermal insulation materials. BACKGROUND

[0002] A thermal barrier coating is an important material for ensuring the stability of key components in high-temperature environments. The core is to block the damage caused by heat radiation, conduction and convection of high-temperature environments to the material below the coating through the high-temperature resistance and low-thermal-conductivity characteristics of the thermal barrier coating itself. In order to reduce the influence of residual thermal stress caused by the difference in thermal expansion coefficient between the components of the coating material, a certain amount of graphite soft phase is often added to improve the crack propagation resistance and thermal shock resistance of the thermal barrier coating material. Therefore, the study of the thermal transport process of graphite material is a key content to ensure and improve the reliability of thermal insulation coatings. The core problem of the study of the thermal transfer performance of graphite sheets is that a large amount of graphene absorbs external energy and then dissipates heat energy through vibration relaxation when developing to a thermal equilibrium state. This process occurs in a very small time, space and energy scale, which is difficult to detect directly, which directly hinders the research progress of fundamentally improving the performance of ultra-high temperature graphite composite thermal insulation coating materials. SUMMARY

[0003] The present application provides a device and method for detecting energy carrier dissipation behavior in thermal insulation materials to solve the problem that the longitudinal optical phonon of the material is difficult to detect in the related art.

[0004] According to an aspect of the present application, a device for detecting energy carrier dissipation behavior in thermal insulation materials is provided, comprising:

[0005] A laser emission module for emitting a laser beam;

[0006] A first filter located on the transmission path of the laser beam for separating the laser beam to form a first laser beam and a second laser beam;

[0007] An ultra-continuous beam forming device located on the transmission path of the second laser beam for processing the second laser beam to form an ultra-continuous beam;

[0008] A phase delay line located on the transmission path of the first laser beam for phase delaying the first laser beam to form a pump beam; the wavelength range of the ultra-continuous beam is wider than the wavelength range of the pump beam;

[0009] A second filter located on the transmission paths of the ultra-continuous beam and the pump beam for combining the ultra-continuous beam and the pump beam to form a combined beam; the combined beam is irradiated to the surface of a sample to form a transmitted beam by being transmitted by the sample;

[0010] A photodetector is used to collect the transmitted light beam;

[0011] The controller is electrically connected to the phase delay line and the photodetector, respectively, and is used to control the delay time of the phase delay line to change once, receive the transmitted beam once, process each transmitted beam, obtain the corresponding time-resolved broadband coherent anti-Stokes frequency shift, and normalize and extract the longitudinal optical phonon decoherence process of the sample based on the different time-resolved broadband coherent anti-Stokes frequency shifts.

[0012] According to one embodiment of the present invention, the controller controls the delay time variation interval of the phase delay line to be greater than or equal to 0.04 ps and less than n*10. 3 ps, where n is a natural number greater than 0 and less than 10.

[0013] According to one embodiment of the present invention, the laser emission module includes:

[0014] A laser used to emit an initial laser beam;

[0015] A first polarization device is located on the transmission path of the initial laser beam and is used to polarize the initial laser beam to form a first polarized beam.

[0016] A pair of chirped prisms is located on the transmission path of the first polarized beam and is used to broaden the time spectrum of the first polarized beam to form a time-spectrum broadened laser beam.

[0017] According to one embodiment of the present invention, the device further includes a second polarizing device located on the transmission path of the transmitted beam, for processing the transmitted beam to form a second polarized beam, wherein the polarization direction of the second polarizing device is the same as that of the first polarizing device.

[0018] According to one embodiment of the present invention, the supercontinuum beam forming device includes: a nonlinear photonic crystal fiber and a third filter for processing the second laser beam to form a supercontinuum beam.

[0019] According to one embodiment of the present invention, it further includes: a focusing objective lens group and an imaging objective lens group;

[0020] The focusing objective lens group is located on the transmission path of the combined beam and is used to process the combined beam to form a focused beam and focus it onto the surface of the sample.

[0021] The imaging objective lens group is located on the transmission path of the transmitted beam and is used to collect the transmitted beam.

[0022] According to one embodiment of the present invention, it further includes: at least one fourth filter located on the transmission path of the transmitted beam, for filtering the transmitted beam to form a combined beam and forming a signal beam; the photodetector is used to acquire the signal beam.

[0023] According to one embodiment of the present invention, the sample includes one of multilayer graphene and carbon nanotubes.

[0024] According to one embodiment of the present invention, the center wavelength of the laser beam is 800nm, the first filter is a 785nm narrowband filter, and the second filter is a 785nm narrowband filter.

[0025] According to one embodiment of the present invention, the third filter is a 780nm long-pass filter.

[0026] According to one embodiment of the present invention, the fourth filter is a 785nm short-pass filter.

[0027] According to one embodiment of the present invention, the supercontinuum wavelength range is 780nm to 1050nm; the pump light wavelength is 785nm.

[0028] According to one embodiment of the present invention, the power of the supercontinuum wavelength and the power of the pump wavelength are both 1 ± 0.1 mW.

[0029] According to another aspect of the invention, a method for detecting the energy dissipation behavior of energy carriers in thermal insulation materials is also proposed, implemented based on the detection device for the energy dissipation behavior of energy carriers in thermal insulation materials according to any embodiment of the present invention, the method comprising:

[0030] The i-th phase delay time of the phase delay line is configured for the i-th time to obtain the i-th transmitted beam of the sample;

[0031] By combining the time-resolved method to process the i-th transmitted beam, the i-th curve corresponding to the i-th transmitted beam is obtained. The i-th curve is the curve corresponding to the light intensity and the anti-Stokes frequency shift.

[0032] Obtain the first i-th light intensity value and the first i-th waveform corresponding to the first anti-Stokes frequency shift range in the i-th curve;

[0033] Compare the first i-1 light intensity value and the first i-1 waveform corresponding to the first anti-Stokes frequency shift range in the i-1 curve;

[0034] If the first i optical intensity value is close to the first i - 1 optical intensity value, the first i waveform is a peak, and the first i - 1 waveform is a trough; then traverse the first i optical intensity value to the first N optical intensity values corresponding to the first anti-Stokes frequency shift range in the i-th to N-th curves, perform normalization, and extract the longitudinal optical phonon decoherence process of the sample;

[0035] where 1 < i < N, both i and N are integers, the first anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to longitudinal optical phonons; the optical intensity value corresponding to the first anti-Stokes frequency shift range in the (N + 1)-th curve is close to the optical intensity value corresponding to the second anti-Stokes frequency shift range, and the second anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to G phonons.

[0036] According to an embodiment of the present invention, the phase delay times of configuring the phase delay line for the 1st to Nth times increase sequentially, and the phase delay time of configuring the phase delay line for the 1st time is 0 ps.

[0037] The technical solution of the embodiment of the present invention is as follows: a laser beam is emitted by a laser emission module; then the laser beam is separated by a first filter to form a first laser beam and a second laser beam; then the second laser beam is processed by a supercontinuum beam forming device to form a supercontinuum beam; then the first laser beam is phase-delayed by a phase delay line to form a pump beam; the wavelength range of the supercontinuum beam is wider than the wavelength range of the pump beam; then the supercontinuum beam and the pump beam are combined by a second filter to form a combined beam; finally, the combined beam is irradiated onto the surface of the sample, and is transmitted by the sample to form a transmitted beam; then the transmitted beam is collected by a photodetector; finally, the controller controls the delay time of the phase delay line to change once, receives the transmitted beam once, and processes each transmitted beam to obtain the corresponding time-resolved wide-spectrum coherent anti-Stokes frequency shift, and normalizes and extracts the longitudinal optical phonon decoherence process of the sample according to different time-resolved wide-spectrum coherent anti-Stokes frequency shifts. In this way, multimodal coherent phonon detection of the sample can be achieved.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 This is a schematic diagram of the structure of the detection device for the energy carrier dissipation behavior in the thermal insulation material proposed in the embodiments of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of a device for detecting the energy dissipation behavior of a thermal insulation material according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of a sample of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the sample thickness of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention.

[0044] Figure 5 This is a schematic diagram of the sample Raman frequency shift of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the inverse Stokes frequency shift of a sample in a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention.

[0046] Figure 7 yes Figure 6 A magnified view of part A in the middle;

[0047] Figure 8 This is a schematic diagram showing the anti-Stokes frequency shift of a sample and its comparison with the Raman frequency shift in related technologies, based on a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention.

[0048] Figure 9 This is a longitudinal optical phonon dephase process diagram of a sample from a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] Ultrafast optics is an effective means of directly probing the ultrafast dynamics of phonons. Currently, the main techniques for detecting ultrafast vibrational relaxation of phonons in graphene are stimulated Raman scattering (SR) and coherent anti-Stokes Raman scattering (CARS), based on the four-wave mixing principle. These two techniques can achieve coherent vibrational enhancement detection by matching the phonon energy levels of graphene with pulsed lasers. The difference between these two techniques lies in the fact that stimulated Raman scattering extracts the signal based on the intensity change of the incident light, i.e., stimulated Raman enhancement and stimulated Raman attenuation. The frequency of the signal light remains constant, and noise caused by non-resonant electronic responses can be avoided. In contrast, coherent anti-Stokes Raman scattering is based on the principle of coherent enhancement of anti-Stokes scattering in the material. Its signal light exhibits a blue shift compared to the probe light, requiring filtering to obtain the signal light.

[0052] Existing methods for studying graphene using coherent anti-Stokes Raman spectroscopy mainly involve matching the G-mode phonon energy levels of graphene with two narrowband pulsed lasers to achieve detection. While this method can achieve coherent vibrational enhancement detection, it has the drawback of only being able to extract the phonon response of a single mode of graphene at a time. This makes it difficult to achieve in-depth structural and optical information by detecting the entire Raman spectrum of graphene, as is possible with spontaneous Raman spectroscopy.

[0053] Therefore, this invention proposes a device and method for detecting the energy dissipation behavior of energy carriers in thermal insulation materials. One beam of incident light is broadened through a photonic crystal fiber, and then broadband excitation of multilayer graphene is achieved using the pulsed stimulated Raman principle. This is followed by detection using a narrowband beam, and finally, time-resolved techniques are applied to remove electronic non-resonant background noise from the signal, thus realizing the detection of multimodal coherent phonons in multilayer graphene. Based on this, not only can the intrinsic mechanism of graphene's nonlinear response be explored through the phonon peak intensity ratio, but the multi-phonon coherent dephasing process of the material can also be extracted simultaneously, revealing its ultrafast-scale energy dissipation characteristics.

[0054] The following is a detailed description of the detection device for energy carrier dissipation behavior in thermal insulation materials proposed in the embodiments of the present invention.

[0055] Figure 1 This is a schematic diagram of the structure of the detection device for the energy dissipation behavior of the heat carrier in the thermal insulation material proposed in an embodiment of the present invention. Figure 1 As shown, the detection device 100 for energy carrier dissipation behavior in thermal insulation materials includes: a laser emission module 101, a first filter 102, a supercontinuum beam forming device 103, a phase delay line 104, a second filter 105, a photodetector 106, and a controller 107.

[0056] The system includes a laser emission module 101 for emitting a laser beam 201; a first filter 102 located on the transmission path of the laser beam 201 for separating the laser beam 201 to form a first laser beam 202 and a second laser beam 203; a supercontinuum beam forming device 103 located on the transmission path of the second laser beam 203 for processing the second laser beam 203 to form a supercontinuum beam 204; a phase delay line 104 located on the transmission path of the first laser beam 202 for phase delaying the first laser beam 202 to form a pump beam 205; the wavelength range of the supercontinuum beam 204 is wider than that of the pump beam 205; and a second filter 105 located on the supercontinuum beam 204. Along the transmission path of the pump beam 205, the supercontinuum beam 204 and the pump beam 205 are combined to form a combined beam 206. The combined beam 206 irradiates the surface of the sample 108 and is transmitted by the sample 108 to form a transmitted beam 207. The photodetector 106 is used to collect the transmitted beam. The controller 107 is electrically connected to the phase delay line 104 and the photodetector 106 respectively, and is used to control the delay time of the phase delay line 104. Each change in the delay time results in the reception of one transmitted beam 207. The controller processes each transmitted beam 207 to obtain the corresponding time-resolved broadband coherent anti-Stokes frequency shift. Based on the different time-resolved broadband coherent anti-Stokes frequency shifts, the longitudinal optical phonon decoherence process of the sample is normalized and extracted.

[0057] It is understandable that by setting the wavelength range of the supercontinuum beam 204 to be wider than that of the pump beam 205, after the combined beam 206 acts on the sample 108, the multimodal phonon spectrum of the sample 108 can be detected through the transmitted beam 207. Furthermore, the longitudinal optical phonon decoherence process of the sample 108 can be extracted through the multimodal phonon spectrum. The obtained longitudinal optical phonon decoherence process has a longer time, meaning that the detection of multiphonon peaks of the sample 108 is achieved, and the longitudinal optical phonon peaks of the sample 108 exhibit a significant resonance enhancement effect. This is of great significance for coherent Raman studies of the sample and applications of phonon energy dissipation. According to one embodiment of the present invention, the wavelength range of the supercontinuum beam is 780 nm to 1050 nm; the pump beam wavelength is 785 nm.

[0058] It should be noted that the delay time of the phase delay line 104 can be controlled by the controller 107 to obtain multiple transmitted beams 207. Finally, by processing each transmitted beam 207, the corresponding time-resolved broadband coherent anti-Stokes frequency shift can be obtained. Based on the different time-resolved broadband coherent anti-Stokes frequency shifts, the longitudinal optical phonon decoherence process of the sample is normalized and extracted.

[0059] Specifically, the controller 107 first configures the phase delay time of the phase delay line (preferably 0 ps) to obtain the first transmitted beam of sample 108; the first transmitted beam is processed using a time-resolved method to obtain a first curve corresponding to the first transmitted beam, which is a curve corresponding to light intensity and anti-Stokes frequency shift; the first light intensity value and first waveform corresponding to the first anti-Stokes frequency shift range in the first curve are obtained; the controller 107 second configures the phase delay time of the phase delay line (preferably 0.3 ps) to obtain the second transmitted beam of sample 108; the second transmitted beam is processed using a time-resolved method to obtain a second curve corresponding to the second transmitted beam, which is a curve corresponding to light intensity and anti-Stokes frequency shift; the first light intensity value and first waveform corresponding to the first anti-Stokes frequency shift range in the second curve are obtained. The first 2 light intensity value and the first 2 waveform are compared with the first 1 light intensity value and the first 1 waveform corresponding to the first anti-Stokes frequency shift range in the first curve. If the first 2 light intensity value is close to the first 1 light intensity value, the first 2 waveform is a peak and the first 1 waveform is a trough. Then, the first 2 light intensity value to the first N light intensity value corresponding to the first anti-Stokes frequency shift range in the second to Nth curves are traversed and normalized to extract the longitudinal optical phonon decoherence process of the sample. Where N is an integer, the first anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to the longitudinal optical phonon. The light intensity value corresponding to the first anti-Stokes frequency shift range in the N+1th curve is close to the light intensity value corresponding to the second anti-Stokes frequency shift range, and the second anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to the G phonon.

[0060] It needs to be explained that when the first 2 light intensity value is close to the first 1 light intensity value, and the first 2 waveform is a peak while the first 1 waveform is a trough, it indicates that electronic noise is suppressed and the phonon effect begins to appear. Therefore, the controller 107 can continue to configure the phase delay time of the phase delay line for the third time (preferably 0.5 ps) to obtain the third transmitted beam of sample 108. By combining the time-resolved method with the processing of the third transmitted beam, a third curve corresponding to the third transmitted beam is obtained. The third curve is the curve corresponding to the light intensity and the anti-Stokes frequency shift. The controller 107 can continue to configure the phase delay time of the phase delay line for the fourth time (preferably 0.9 ps) to obtain the fourth transmitted beam of sample 108. This is further combined with time-resolved processing. The fourth transmitted beam is processed using a time-resolved method to obtain a fourth curve corresponding to it. This fourth curve represents the relationship between light intensity and anti-Stokes frequency shift. This process is repeated until the phase delay time of the (N+1)th phase delay line is configured, resulting in the (N+1)th transmitted beam of sample 108. The (N+1)th transmitted beam is then processed using a time-resolved method to obtain the (N+1)th curve corresponding to it. This (N+1)th curve represents the relationship between light intensity and anti-Stokes frequency shift. The light intensity value corresponding to the first anti-Stokes frequency shift range in the (N+1)th curve is close to the light intensity value corresponding to the second anti-Stokes frequency shift range, which is the anti-Stokes frequency shift range corresponding to the G phonon. In other words, when the G phonon and the longitudinal optical phonon (LOZO' mode phonon) in the corresponding light intensity and anti-Stokes frequency shift curve of the transmitted beam can no longer be distinguished, it indicates that the longitudinal optical phonon has decayed. Therefore, the phase delay time configuration of the phase delay line can be stopped, and the acquisition of the transmitted beam 207 can be stopped.

[0061] After obtaining curves 2 to N, the longitudinal optical phonon intensity and the corresponding delay time can be extracted from each curve to fit the longitudinal optical phonon decoherence process.

[0062] Specifically, when the controller 107 configures the phase delay time of the phase delay line from the 2nd to the Nth time, the phase delay time can be shortened in areas where the longitudinal optical phonon signal is weak, for example, by 0.1 ps, to avoid missing the critical point where electrons and phonons play a dominant role. Conversely, the phase delay time can be extended in areas where the longitudinal optical phonon signal is strong, for example, by 0.5 ps. In one embodiment, the controller 107 controls the phase delay line's delay time variation interval to be greater than or equal to 0.04 ps and less than n*10. 3 ps, where n is a natural number greater than 0 and less than 10. This helps reduce the amount of computation.

[0063] In the above example, if the first two optical intensity values are close to the first one optical intensity value, but the first two waveforms are troughs and the first one waveform is a trough; then continue to configure the phase delay time of the phase delay line for the third time (preferably 0.5 ps) to obtain the third transmitted beam of sample 108; combine the time-resolved method to process the third transmitted beam to obtain the third curve corresponding to the third transmitted beam, and the third curve is the curve corresponding to the optical intensity and the anti-Stokes frequency shift; continue to configure the phase delay time of the phase delay line for the fourth time (preferably 0.9 ps) to obtain the fourth transmitted beam of sample 108; combine the time-resolved method to process the fourth transmitted beam to obtain the fourth curve corresponding to the fourth transmitted beam, and the fourth curve is the curve corresponding to the optical intensity and the anti-Stokes frequency shift; and so on, until the first i optical intensity value is close to the first i - 1 optical intensity value, the first i waveform is a peak, and the first i - 1 waveform is a trough; then use the i-th curve as the starting curve for the appearance of the longitudinal optical phonon signal. Finally, use the i-th curve to the N-th curve as the original data for extracting the longitudinal optical phonon decoherence process, where 1 < i < N, and both i and N are integers.

[0064] In the above embodiment, the first filter 102 can be a 785 nm narrow-band filter; the second filter 105 can be a 785 nm narrow-band filter, and the photodetector 106 can be a CCD or a COMS camera.

[0065] Figure 2 It is a schematic structural diagram of a detection device for the dissipation behavior of energy carriers in a thermal insulation material proposed by an embodiment of the present invention. According to an embodiment of the present invention, as Figure 2 shown, the laser emission module 101 includes: a laser 109 for emitting an initial laser beam; a first polarization device 110 located on the transmission path of the initial laser beam for polarizing the initial laser beam to form a first polarized beam; and a chirped prism pair group 111 located on the transmission path of the first polarized beam for temporally and spectrally broadening the first polarized beam to form a temporally and spectrally broadened laser beam.

[0066] It can be understood that by performing polarization processing and temporally and spectrally broadening processing on the initial laser beam, it is beneficial to present the longitudinal optical phonon mode of sample 108. Among them, the laser 109 can be a femtosecond laser. Exemplarily, it can be a titanium sapphire oscillator with a central wavelength of 800 nm and a frequency of 30 fs. The initial laser beam emitted by the laser 109 can be a polarized beam. To ensure the polarization of the laser beam, the first polarization device 110 can be used to optimize the polarization of the initial laser beam. The first polarization device 110 can be a Glan-Taylor prism. The chirped prism pair group 111 can be two triangular prisms.

[0067] According to an embodiment of the present invention, as Figure 2As shown, the device 100 further includes a second polarizing device 112 located on the transmission path of the transmitted beam, used to process the transmitted beam to form a second polarized beam, wherein the polarization direction of the second polarizing device 112 is the same as that of the first polarizing device 110.

[0068] Understandably, the use of the second polarizing device 112 ensures that the transmitted beam collected by the photodetector 106 is free from reflected or scattered light, reducing noise during subsequent processing of the transmitted beam. The second polarizing device 112 can also be a Glan Taylor prism.

[0069] According to one embodiment of the present invention, such as Figure 2 As shown, the supercontinuum beam forming device 103 includes a nonlinear photonic crystal fiber 113 and a third filter 114 for processing the second laser beam to form a supercontinuum beam. The third filter 114 can be a 780nm long-pass filter.

[0070] According to one embodiment of the present invention, such as Figure 2 As shown, the device also includes: a focusing objective lens group 115 and an imaging objective lens group 116;

[0071] The focusing objective lens group 115 is located on the transmission path of the combined beam and is used to process the combined beam to form a focused beam and focus it onto the surface of the sample 108.

[0072] Imaging objective lens group 116 is located on the transmission path of the transmitted beam and is used to collect the transmitted beam.

[0073] The focusing objective group 115 can be a 50x objective lens, and the imaging objective group 116 can be a 40x objective lens. The use of the focusing objective group 115 ensures the focusing of the combined beam incident on the sample 108, thus guaranteeing light intensity and resulting in better signal strength during subsequent processing of the transmitted beam. The imaging objective group 116 further concentrates the transmitted beam, making it easier to collect.

[0074] According to one embodiment of the present invention, such as Figure 2 As shown, the device 100 further includes: at least one fourth filter 117 located on the transmission path of the transmitted beam, used to filter the transmitted beam to form a signal beam; and a photodetector 106 used to collect the signal beam.

[0075] Thus, by setting the fourth filter 117, it is beneficial to filter out the combined beam mixed in the transmitted beam, reduce the noise of the transmitted beam, and prevent it from affecting the processing and recognition of the longitudinal optical phonon signal in the later stage.

[0076] Among them, the fourth filter 117 can be a 785nm short-pass filter.

[0077] As Figure 2 shown, the device 100 further includes a plurality of mirrors 118 for adjusting the direction of light, and a polarizer 119. By setting the polarizer 119 on the initial path of the ultrasonic continuous beam transmission, the polarization of the ultrasonic continuous beam can be ensured. Similarly, by setting the polarizer 119 on the initial path of the pump beam transmission, the polarization of the pump beam can be ensured.

[0078] According to an embodiment of the present invention, the power of the supercontinuum light wavelength and the power of the pump light wavelength are both 1 ± 0.1 mW, so as to ensure that the sample 108 will not be damaged.

[0079] According to an embodiment of the present invention, the sample 108 includes one of multi-layer graphene and carbon nanotubes.

[0080] According to another aspect of the invention, a method for detecting the dissipation behavior of energy carriers in a thermal insulation material is also proposed, which is realized based on the detection device for the dissipation behavior of energy carriers in the thermal insulation material according to any embodiment of the present invention. The method includes:

[0081] Configuring the phase delay time of the phase delay line for the i-th time to obtain the i-th transmitted beam of the sample;

[0082] Processing the i-th transmitted beam by combining the time-resolved method to obtain the i-th curve corresponding to the i-th transmitted beam, and the i-th curve is a curve corresponding to the light intensity and the anti-Stokes frequency shift;

[0083] Obtaining the first i light intensity value and the first i waveform corresponding to the first anti-Stokes frequency shift range in the i-th curve;

[0084] And comparing with the first i-1 light intensity value and the first i-1 waveform corresponding to the first anti-Stokes frequency shift range in the (i - 1)-th curve;

[0085] If the first i light intensity value is close to the first i-1 light intensity value, the first i waveform is a peak, and the first i-1 waveform is a trough; then traverse the first i light intensity value to the first N light intensity values corresponding to the first anti-Stokes frequency shift range in the i-th to N-th curves, and perform normalization to extract the longitudinal optical phonon decoherence process of the sample;

[0086] where 1 < i < N, both i and N are integers, the first anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to longitudinal optical phonons; the light intensity value corresponding to the first anti-Stokes frequency shift range in the (N + 1)-th curve is close to the light intensity value corresponding to the second anti-Stokes frequency shift range, and the second anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to G phonons.

[0087] According to one embodiment of the present invention, the phase delay time of the phase delay line is increased sequentially from the first to the Nth configuration, and the phase delay time of the first configuration is 0 ps.

[0088] The following example uses multilayer graphene to illustrate the effectiveness of the detection method for energy carrier dissipation behavior in thermal insulation materials proposed in this invention.

[0089] Figure 3 This is a schematic diagram of a sample of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sample thickness of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the sample Raman frequency shift of a device for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention.

[0090] Multilayer graphene is prepared on a clean glass slide surface (e.g., by mechanical exfoliation). Figure 3 As shown), the thickness was measured using an atomic force microscope, as indicated by the image. Figure 4 As shown, the test area has a thickness of 10 nm, corresponding to approximately 30 layers. Figure 4 (a) is a diagram of the area under test under an atomic force microscope. Figure 4 (b) is along Figure 4 The thickness measured by the coordinate line X (μm) in (a) is noteworthy. Since the signal intensity is proportional to the square of the graphene thickness, the resulting phenomena and enhancement effects of this invention exist for both thinner and thicker multilayer graphene. After the multilayer graphene was exfoliated, its basic properties were characterized using Raman microscopy. The area circled by the white solid line represents the detection area in this example. Figure 5 The initial Raman spectrum of the multilayer graphene shows the initial phonon characteristics of the sample. The shape of the 2D peak indicates that it is an AB stacked structure, and the missing D peak indicates that the material has an extremely low concentration of intrinsic defects and good lattice integrity.

[0091] This invention is based on a broadband coherent anti-Stokes Raman spectrometer, and the optical path is as follows: Figure 2As shown, the femtosecond laser is generated by a Ti:sapphire oscillator 109 and tuned to a center wavelength of 800 nm at 30 fs. The laser first passes through a Glan Taylor prism 110 to optimize polarization, and then through a pair of prisms 111 to optimize chirp, thereby achieving better broadening of the nonlinear photonic crystal fiber. The pump beam is then separated by a 785 nm narrowband filter 102. The reflected laser is fed into the nonlinear photonic crystal fiber 113 and then through a 780 nm long-pass filter 114 to obtain a supercontinuum beam of 780 nm to 1050 nm. Simultaneously, a linear displacement stage 104 adjusts the relative time delay. The two beams are then combined through a 785nm laser narrowband filter 105, focused onto the sample 108 using a 50x objective lens 115, and collected by another 40x objective lens 116. The transmitted light is filtered by a 785nm short-pass filter 117 to remove incident light and is kept horizontally polarized by a polarizer 112. Finally, the signal is coupled to a CCD detector 106 equipped with liquid nitrogen cooling.

[0092] Figure 6 This is a schematic diagram of the inverse Stokes frequency shift of a sample in a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention. Figure 7 yes Figure 6 A magnified view of part A in the middle;

[0093] Figure 8 This is a schematic diagram showing the anti-Stokes frequency shift of a sample and its comparison with the Raman frequency shift in related technologies, based on a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention.

[0094] In other words, Figure 6 This demonstrates the time-resolved broadband coherent anti-Stokes spectrum of multilayer graphene measured according to the method of the present invention. Figure 7 yes Figure 6 A magnified view of part A in the middle, combined with Figure 6 and Figure 7 As shown, with increasing time delay, the spectrum undergoes significant changes due to the gradual removal of electronic noise. A notable phenomenon occurs between 0.9 ps and 1.7 ps, where a characteristic valley-to-peak transition occurs at the phonon energy levels of graphene. Compared to previous methods that only measured single-phonon peak transitions, this method enables the detection of the two-phonon response in multilayer graphene. Based on a comparison of simultaneous detection results for carbon nanotubes and Raman spectroscopy results, as... Figure 8As shown, peak 1 in multilayer graphene corresponds to the G phonon peak of carbon atoms, while peak 2 corresponds to the LOZO' mode phonon of multilayer graphene. In the Raman test results, the LOZO' phonon peak is more than 100 times weaker than the G peak. However, in the time-resolved broadband coherent anti-Stokes Raman (CARS) test results, the LOZO' peak is about 8 times stronger than the G peak. It can be seen that the detection method can achieve the detection of multiple phonon peaks in multilayer graphene and the LOZO' peak produces a significant resonance enhancement effect.

[0095] Since the LOZO' phonon response is extremely weak under spontaneous Raman conditions, it is difficult to extract the dissipation characteristics of the phonon through its full width at half maximum (FWHM). However, after the phonon achieves coherent vibration enhancement through the method proposed in this embodiment of the invention, its dephasing time can be extracted through a time-resolved process, thereby reflecting the dissipation characteristics of the multilayer graphene dual resonant phonon.

[0096] Figure 9 This is a longitudinal optical phonon dephasing process diagram of a sample from a method for detecting the energy carrier dissipation behavior in thermal insulation materials according to an embodiment of the present invention. Figure 9 As shown, during the gradual increase of the delay, the electronic noise decays rapidly within 1 ps, after which the peak intensity of the LOZO' phonon decays exponentially, according to the phonon decay theory formula: Where T2 is the total dephasing time of the phonon, T ph T1 is the pure dephasing time of the phonon, and T2 is the layout decay time of the phonon. According to... Figure 9 The fitting results show that the total dephase time of the LOZO' phonon is about 5.6 ps, which is much higher than the 1 ps of the G mode phonon. This indicates that the dual resonant phonon has a longer lifetime and a slower relaxation rate under coherent excitation conditions.

[0097] Therefore, this invention utilizes broadband coherent anti-Stokes Raman spectroscopy to detect multiphonon coherent vibrations in multilayer graphene and extracts the LOZO' mode phonon decoherence process for the first time, which is of great significance for coherent Raman research on two-dimensional materials and applications of phonon energy dissipation.

[0098] Compared with related technologies—degenerate four-wave mixing technology—this method has the following advantages:

[0099] 1) This method is less expensive, requiring only a laser and a photonic crystal fiber to generate the excitation effect, rather than using a more expensive laser with an optical parametric resonator or a dual-beam laser to achieve the detection requirement.

[0100] 2) This method can simultaneously detect multiple phonons in two-dimensional materials, while degenerate four-wave mixing technology can only detect one mode at a time. This advantage helps to improve the coherent vibration imaging efficiency of two-dimensional materials and shorten the imaging time.

[0101] 3) This method can further provide information on the nonlinear response mechanism inside the material by analyzing the multi-peak intensity ratio information.

[0102] In summary, the technical solution of this invention involves setting up a laser emission module to emit a laser beam; then separating the laser beam using a first filter to form a first laser beam and a second laser beam; next, processing the second laser beam using a supercontinuum beam forming device to form a supercontinuum beam; then, phase-delaying the first laser beam using a phase delay line to form a pump beam; the wavelength range of the supercontinuum beam is wider than that of the pump beam; then, combining the supercontinuum beam and the pump beam using a second filter to form a combined beam; finally, the combined beam illuminates the surface of the sample and is transmitted through the sample to form a transmitted beam; then, a photodetector collects the transmitted beam; finally, a controller controls the delay time of the phase delay line to change once, receiving one transmitted beam, and processing each transmitted beam to obtain the corresponding time-resolved broadband coherent anti-Stokes frequency shift. Based on the different time-resolved broadband coherent anti-Stokes frequency shifts, the longitudinal optical phonon decoherence process of the sample is normalized and extracted. In this way, multimodal coherent phonon detection of the sample can be achieved.

[0103] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0104] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A device for detecting the energy dissipation behavior of energy carriers in thermal insulation materials, characterized in that, include: Laser emission module, used to emit laser beams; A first filter, located on the laser beam transmission path, is used to separate the laser beam to form a first laser beam and a second laser beam. A supercontinuum beam forming device is located in the transmission path of the second laser beam and is used to process the second laser beam to form a supercontinuum beam; A phase delay line, located on the transmission path of the first laser beam, is used to delay the phase of the first laser beam to form a pump beam; the wavelength range of the supercontinuum beam is wider than the wavelength range of the pump beam. The second filter is located on the transmission path of the supercontinuum beam and the pump beam, and is used to combine the supercontinuum beam and the pump beam to form a combined beam; the combined beam illuminates the surface of the sample and is transmitted by the sample to form a transmitted beam. A photodetector is used to collect the transmitted light beam; The controller is electrically connected to the phase delay line and the photodetector, respectively, and is used to control the delay time of the phase delay line to change once, receive the transmitted beam once, process each transmitted beam, obtain the corresponding time-resolved broadband coherent anti-Stokes frequency shift, and normalize and extract the longitudinal optical phonon decoherence process of the sample based on the different time-resolved broadband coherent anti-Stokes frequency shifts.

2. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The controller controls the delay time variation interval of the phase delay line to be greater than or equal to 0.04 ps and less than n*10. 3 ps, where n is a natural number greater than 0 and less than 10.

3. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The laser emission module includes: A laser used to emit an initial laser beam; A first polarization device is located on the transmission path of the initial laser beam and is used to polarize the initial laser beam to form a first polarized beam. A pair of chirped prisms is located on the transmission path of the first polarized beam and is used to broaden the time spectrum of the first polarized beam to form a time-spectrum broadened laser beam.

4. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 3, characterized in that, Also includes: A second polarizing device is located on the transmission path of the transmitted beam and is used to process the transmitted beam to form a second polarized beam, wherein the polarization direction of the second polarizing device is the same as that of the first polarizing device.

5. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The supercontinuum beam forming device includes a nonlinear photonic crystal fiber and a third filter for processing the second laser beam to form a supercontinuum beam.

6. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, Also includes: Focusing objective group and imaging objective group; The focusing objective lens group is located on the transmission path of the combined beam and is used to process the combined beam to form a focused beam and focus it onto the surface of the sample. The imaging objective lens group is located on the transmission path of the transmitted beam and is used to collect the transmitted beam.

7. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, Also includes: At least one fourth filter is located on the transmission path of the transmitted beam to filter the transmitted beam and form a signal beam; the photodetector is used to collect the signal beam.

8. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The sample includes one of the following: multilayer graphene or carbon nanotubes.

9. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The center wavelength of the laser beam is 800nm, the first filter is a 785nm narrowband filter, and the second filter is a 785nm narrowband filter.

10. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 5, characterized in that, The third filter is a 780nm long-pass filter.

11. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 7, characterized in that, The fourth filter is a 785nm short-pass filter.

12. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The wavelength range of the supercontinuum light is 780 nm to 1050 nm; the wavelength of the pump light is 785 nm.

13. The detection device for energy carrier dissipation behavior in thermal insulation materials according to claim 1, characterized in that, The power of the supercontinuum light wavelength and the power of the pump light wavelength are both 1 ± 0.1 mW.

14. A method for detecting the energy dissipation behavior of energy carriers in thermal insulation materials, implemented based on the detection device for the energy dissipation behavior of energy carriers in thermal insulation materials as described in any one of claims 1-13, characterized in that, The method includes: Configuring the phase delay time of the phase delay line for the i-th time to obtain the i-th transmitted light beam of the sample; Processing the i-th transmitted light beam by combining the time-resolved method to obtain the i-th curve corresponding to the i-th transmitted light beam, and the i-th curve is a curve corresponding to the light intensity and the anti-Stokes frequency shift; Obtaining the first i light intensity value and the first i waveform corresponding to the first anti-Stokes frequency shift range in the i-th curve; Comparing the first i-1 light intensity value and the first i-1 waveform corresponding to the first anti-Stokes frequency shift range in the i-1-th curve; If the first i light intensity value is close to the first i-1 light intensity value, the first i waveform is a peak, and the first i-1 waveform is a trough; then traverse the first i light intensity value to the first N light intensity values corresponding to the first anti-Stokes frequency shift range in the i-th to N-th curves, and perform normalization to extract the longitudinal optical phonon decoherence process of the sample; Where 1 < i < N, both i and N are integers, the first anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to the longitudinal optical phonon; the light intensity value corresponding to the first anti-Stokes frequency shift range in the (N + 1)-th curve is close to the light intensity value corresponding to the second anti-Stokes frequency shift range, and the second anti-Stokes frequency shift range is the anti-Stokes frequency shift range corresponding to the G phonon.

15. The method for detecting the dissipation behavior of energy carriers in the thermal insulation material according to claim 14, wherein The phase delay time of the phase delay line configured for the first time to the N-th time increases in sequence, and the phase delay time configured for the first time is 0 ps.

Images