CN114414499B - Time-resolved brillouin spectroscopic system - Google Patents
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- 239000000696 magnetic material Substances 0.000 claims description 7
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/2889—Rapid scan spectrometers; Time resolved spectrometry
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
Abstract
A time resolved brillouin spectroscopic system comprising: a quasi-particle excitation means to excite quasi-particles locally in the sample; the laser light source is used for generating laser, and the laser is focused on a target position of the sample and generates Brillouin scattering with the quasi-particles to generate Brillouin scattering light; the Fabry-Perot interferometer is used for outputting Brillouin scattered light with a preset frequency; the detector is used for detecting the Brillouin scattered light with a preset frequency and converting the Brillouin scattered light into an electric signal; the data acquisition device is used for acquiring preset frequency of the Brillouin scattered light to obtain preset frequency information; the time-to-digital converter is used for reading the electric signal and the preset frequency information to obtain the relation between the photon number of the Brillouin scattering light with the preset frequency at the target position and time; and the computer is used for obtaining the relationship between the intensity and time of the quasi-particles with the preset frequency at the target position according to the relationship between the photon number and time of the Brillouin scattering light with the preset frequency at the target position.
Description
Technical Field
The invention relates to the technical field of Brillouin spectrum testing, in particular to a time-resolved Brillouin spectrum system.
Background
The detection and study of the dynamic evolution process of low frequency quasi-particles helps to understand the basic physical properties of these quasi-particles and the corresponding device design (e.g., time response of the device, etc.). Specifically, the low-frequency quasi-particles include acoustic phonons (quasi-particles of acoustic waves), plasmas (quasi-particles of collective excitation of electrons), magnons (quasi-particles of collective excitation of electron spins, i.e., spin waves), and the like. Taking spin waves as an example, the study of spin fluctuation mechanics is one of the core problems of spintronics. Spintronics mainly relates to research on intrinsic spin and related magnetic moment of electrons, and is one of the hot spot research fields of current condensed state physics. Spin waves are a collective propagation process of electron spin precession in magnetically ordered materials, having characteristic frequencies in the GHz range, and therefore, spin waves can be easily excited and detected by using a microwave technique. The magnon is used as a quasi-particle of spin wave, and can be coupled with an optical microcavity to obtain a spin wave optical device, which has important significance in the research of spin quantum devices and cavity quantum electrodynamics.
In recent decades, the brillouin scattering technology has become the leading edge technology of experimental research on linear and nonlinear spin waves. Brillouin scattering is a type of inelastic light scattering resulting from the collective excitation of a system of condensed matter capable of producing a time-varying density modulation, such as magnons (spin waves) or acoustic phonons (acoustic waves). As an optically lossless test method, brillouin scattering does not necessarily require external pumping, and has remarkable sensitivity. The high sensitivity of brillouin scattering allows it to detect thermally activated incoherent spin waves in a system without external excitation, even in a single layer of magnetic material.
At present, the related Brillouin spectrum system can detect the frequency information of spin waves, but cannot observe the precession of the spin waves in a time domain, and cannot study the intensity of the spin waves and the evolution process of the frequency with time.
Disclosure of Invention
Accordingly, it is a primary objective of the present invention to provide a time-resolved brillouin spectroscopic system, which is designed to at least partially solve at least one of the above-mentioned problems.
To achieve the above object, as an embodiment of one aspect of the present invention, there is provided a time-resolved brillouin spectral system including:
the surface of the quasi-particle excitation device is provided with a sample, and the quasi-particle excitation device is suitable for absorbing microwave pulse signals so as to locally excite quasi-particles in the sample;
the laser source is suitable for generating laser, the laser is focused on a target position of the sample and generates Brillouin scattering with the quasi-particles to generate Brillouin scattering light, the Brillouin scattering light has at least one frequency, and the target position is adjustable;
the Fabry-Perot interferometer is suitable for outputting Brillouin scattered light with preset frequency;
the detector is suitable for detecting the Brillouin scattered light with the preset frequency and converting the detected Brillouin scattered light signal with the preset frequency into an electric signal;
the data acquisition device is suitable for acquiring preset frequency of the Brillouin scattered light to obtain preset frequency information;
the time-to-digital converter is suitable for reading the electric signal and the preset frequency information to obtain the relation between the photon number of the Brillouin scattering light with the preset frequency at the target position and time;
the computer is suitable for obtaining the relationship between the intensity and time of the quasi-particles with preset frequency at the target position according to the relationship between the photon number and time of the Brillouin scattering light with the preset frequency at the target position;
and adjusting the preset frequency to obtain the relationship between the intensity and time of the quasi-particles with different frequencies at the target position.
According to an embodiment of the present invention, the above-mentioned time-resolved brillouin spectrum system further includes:
a microwave source adapted to generate a continuous microwave signal.
According to an embodiment of the present invention, the above-mentioned time-resolved brillouin spectrum system further includes:
the pulse generator is suitable for generating pulse signals and inputting the pulse signals into the microwave source so as to convert continuous microwave signals into microwave pulse signals.
According to an embodiment of the invention, the pulse generator is further arranged to emit a first timing signal for causing the time-to-digital converter to start counting photons of the brillouin light.
According to an embodiment of the invention, the pulse generator emits the first timing signal simultaneously with the pulse signal.
According to the embodiment of the invention, in the case that the detector cannot detect the brillouin light with the preset frequency, the second timing signal is sent out, and the second timing signal is used for stopping the time-to-digital converter from counting photons of the brillouin light.
According to the embodiment of the invention, the time-to-digital converter obtains the preset frequency according to the preset frequency information; and counting photons of the Brillouin scattered light according to the electric signal, so as to obtain the relationship between the number of photons of the Brillouin scattered light with the preset frequency at the target position and time.
According to an embodiment of the invention, the quasi-particles are acoustic phonons, plasmons or magnons.
According to the embodiment of the invention, under the condition that the quasi-particles are magnons, the sample is a magnetic material, and the quasi-particle excitation device is a resonant cavity; in the case where the quasi-particles are plasmas, the sample is a metallic material or a semiconductor material.
According to the time-resolved brillouin spectrum system provided by the embodiment of the invention, laser generated by the laser light source is focused on a target position of a sample and is subjected to brillouin scattering with the quasi-particles to obtain brillouin scattered light, the brillouin scattered light passes through the fabry-perot interferometer and then outputs brillouin scattered light with preset frequency, frequency information of the brillouin scattered light with the preset frequency and information of photon number change along with time are respectively acquired by the data acquisition device and the time-to-time converter, finally, the time-resolved brillouin spectrum is obtained through the relation between the intensity and time of the quasi-particles with the preset frequency on the target position after calculation by the computer, and the relation between the intensity and time of the quasi-particles with different frequencies on the target position is obtained through adjusting the preset frequency. By changing the target position, the relationship among the intensity, frequency, time and space of the quasi-particles can be obtained, and the construction of a four-dimensional image of the quasi-particle intensity as a function of the frequency, time and space of the quasi-particles can be realized.
Drawings
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
fig. 1 schematically shows a block diagram of a time resolved brillouin spectroscopic system provided according to an embodiment of the present invention;
fig. 2 schematically shows a schematic diagram of the operation of the time-to-digital converter shown in fig. 1.
Reference numerals:
10-microwave source 20-pulse generator
30-detector 31-quasi-particle excitation device 32-fabry-perot interferometer
40 data acquisition device 50-time-to-digital converter 60-computer
70-laser light source
Detailed Description
The present invention will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.
It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.
Aiming at the existing Brillouin spectrum system, the invention provides a time-resolved Brillouin spectrum system, which adopts the Brillouin spectrum technology and combines an time-to-digital converter to observe the precession of quasi-particles in the time domain and study the evolution of the intensity and frequency of the quasi-particles along with the time; the pulse generator and the detector are respectively connected with the time-to-digital converter, so that the time for starting counting and stopping counting of the time-to-digital converter can be respectively controlled, and the occupation of the internal memory of the time-to-digital converter by blank detection data is avoided. The invention can provide a time-resolved Brillouin spectrum system which is easy to build, low in cost and capable of being remotely controlled, can detect the precession of quasi-particles, and can research spin-related properties such as spin lattice interaction, glass-Einstein condensation, spin dynamics driven by spin transfer torque and the like.
According to one aspect of the present general inventive concept there is provided a time resolved brillouin spectroscopic system comprising: the surface of the quasi-particle excitation device is provided with a sample, and the quasi-particle excitation device is suitable for absorbing microwave pulse signals so as to locally excite quasi-particles in the sample; the laser source is suitable for generating laser, the laser is focused on a target position of the sample and generates Brillouin scattering with the quasi-particles to generate Brillouin scattering light, the Brillouin scattering light has at least one frequency, and the target position is adjustable; the Fabry-Perot interferometer is suitable for outputting Brillouin scattered light with preset frequency; the detector is suitable for detecting the Brillouin scattered light with the preset frequency and converting the detected Brillouin scattered light signal with the preset frequency into an electric signal; the data acquisition device is suitable for acquiring preset frequency of the Brillouin scattered light to obtain preset frequency information; the time-to-digital converter is suitable for reading the electric signal and the preset frequency information to obtain the relation between the photon number of the Brillouin scattering light with the preset frequency at the target position and time; the computer is suitable for obtaining the relationship between the intensity and time of the quasi-particles with preset frequency at the target position according to the relationship between the photon number and time of the Brillouin scattering light with the preset frequency at the target position; and adjusting the preset frequency to obtain the relationship between the intensity and time of the quasi-particles with different frequencies at the target position.
Fig. 1 schematically shows a block diagram of a time resolved brillouin spectral system provided according to an embodiment of the present invention.
As shown in fig. 1, the time-resolved brillouin spectroscopic system includes a quasi-particle excitation device 31, a laser light source 70, a fabry-perot interferometer 32, a detector 30, a data acquisition device 40, a time-to-digital converter 50, and a computer 60.
According to an embodiment of the present invention, a sample is placed on the surface of the quasi-particle excitation device 31, and the quasi-particle excitation device 31 is adapted to absorb microwave pulse signals to locally excite quasi-particles in the sample.
According to an embodiment of the invention, the laser source 70 is adapted to generate laser light which is focused on a target location of the sample to form a laser spot, the target location of the sample being adjustable. The laser light having a certain energy (frequency) generated by the laser light source 70 is focused on a target position of the sample and brillouin scattering occurs with the quasi-particles on the target position, and brillouin scattered light is generated, which has at least one frequency.
According to the embodiment of the present invention, the frequency of the microwave pulse signal received by the quasi-particle excitation device 31 is equal to the resonance frequency of the quasi-particle excitation device 31, so that the quasi-particle excitation device 31 can absorb the microwave pulse signal to the maximum extent to excite the quasi-particles locally in the sample. The wave propagation corresponding to the quasi-particles reaches the laser spot position, and the quasi-particles and photons of the incident laser generate Brillouin scattering, so that Brillouin scattering light is generated. Based on the combined action of the microwave pulse signal and the quasi-particle excitation means 31, the quasi-particles locally excited in the sample have at least one frequency, so that the brillouin scattered light generated accordingly has at least one frequency.
According to an embodiment of the present invention, the fabry-perot interferometer 32 is adapted to output brillouin scattered light having a predetermined frequency. Specifically, the fabry-perot interferometer 32 has a plurality of frequency channels therein, each of which has a certain preset frequency, that is, each channel can only pass the brillouin scattered light having the preset frequency, thereby realizing frequency selection of the output brillouin scattered light and outputting only the brillouin scattered light having the preset frequency.
According to an embodiment of the present invention, the detector 30 is adapted to detect brillouin light having a preset frequency and convert the detected brillouin optical signal having the preset frequency into an electrical signal.
According to an embodiment of the present invention, the data acquisition device 40 is adapted to acquire a preset frequency of the brillouin scattered light, so as to obtain preset frequency information. Specifically, the data acquisition device 40 is synchronized with the scanning platform inside the fabry-perot interferometer 32, and after the brillouin scattered light with the preset frequency passes through the preset frequency channel corresponding to the fabry-perot interferometer 32, the data acquisition device 40 can acquire the corresponding preset frequency.
According to an embodiment of the present invention, the time-to-digital converter 50 is adapted to read the electrical signal and the preset frequency information to obtain the relationship between the number of photons of the brillouin scattered light having the preset frequency at the target position and time.
According to an embodiment of the present invention, the computer 60 is adapted to obtain the relationship between the intensity and time of the quasi-particles having the preset frequency at the target position from the relationship between the number of photons of the brillouin scattered light having the preset frequency at the target position and time. The computer 60 communicates with the pulse generator 20, the data acquisition device 40 and the time-to-digital converter 50, and obtains a time evolution image of the quasi-particle intensity and frequency according to the relationship between the photon numbers and time of the brillouin scattered light with different preset frequencies recorded by the time-to-digital converter 50. The frequency channel of the fp interferometer 32 is adjusted, that is, the preset frequency is adjusted, so as to obtain the relationship between the photon number and time of the brillouin scattered light with different frequencies at the target position, and further obtain the relationship between the intensity and time of the quasi-particles with different frequencies at the target position.
According to an embodiment of the present invention, computer 60 interacts with pulse generator 20, data acquisition device 40, and time-to-digital converter 50 to be able to handle a large number of photon counting events. The time-to-digital converter 50 can obtain the relationship between the photon number and time of brillouin scattered light having different preset frequencies. For each preset frequency, the time-to-digital converter 50 derives the relationship between the number of photons of brillouin scattered light that interact with the excited quasi-particles over a number of pulse periods during the detection time of that preset frequency. Since the pulse width and the pulse period of each microwave pulse signal are the same, the time-to-digital converter 50 can correspondingly superimpose the relationship between the number of photons of the brillouin scattered light, which interacts with the excited quasi-particles, and the time in a plurality of microwave pulse periods at a preset frequency, to obtain the relationship between the number of photons of the brillouin scattered light and the time. The computer 60 may set the detection time of the brillouin light of different preset frequencies, and may obtain the preset frequency/intensity of the corresponding quasi-particle according to the preset frequency/photon number of the brillouin light. Therefore, the computer 60 can obtain the relationship between the intensity, the frequency and the time of the quasi-particles at the target position according to the relationship between the photon number and the time of the brillouin scattering light with different preset frequencies at the target position. By changing the target position, the relationship among the intensity, frequency, time and space of the quasi-particles can be obtained, and the construction of the four-dimensional image of the quasi-particle intensity as a function of the frequency, time and space of the quasi-particles can be realized.
According to an embodiment of the invention, the time resolved brillouin spectral system further comprises a microwave source 10, the microwave source 10 being arranged to generate a microwave signal, which is a continuous microwave signal.
According to an embodiment of the present invention, the time-resolved brillouin spectral system further comprises a pulse generator 20 adapted to generate a pulse signal, and to input the pulse signal to the microwave source 10, such that a continuous microwave signal is converted into a microwave pulse signal. The pulse generator 20 is capable of generating a pulse signal having a pulse period T and a pulse width Δt.
The pulse generator 20 is also arranged to emit a first timing signal for causing the time-to-digital converter 50 to start counting photons of brillouin light, according to an embodiment of the present invention.
According to an embodiment of the present invention, the pulse generator 20 emits the first timing signal simultaneously with the pulse signal.
According to an embodiment of the present invention, in the case where the detector 30 cannot detect the brillouin light having the preset frequency, a second timing signal for stopping the time-to-digital converter 50 from counting photons of the brillouin light is emitted. By controlling the time for which the time-to-digital converter 50 stops counting with the detector 30, it is possible to avoid the blank detection data occupying the memory of the time-to-digital converter 50.
According to an embodiment of the present invention, the time-to-digital converter 50 obtains the preset frequency of the brillouin scattered light according to the preset frequency information provided by the data acquisition device 40; the photons of the brillouin light are counted based on the electrical signal supplied from the detector 30, and the relationship between the number of photons of the brillouin light and time is obtained.
According to an embodiment of the invention, the quasi-particles are acoustic phonons, plasmons or magnons.
According to the embodiment of the invention, under the condition that the quasi-particles are magnons, the sample is a magnetic material, and the quasi-particle excitation device is a resonant cavity; in the case where the quasi-particles are plasmas, the sample is a metallic material or a semiconductor material.
In the case that the quasi-particles are magnons, the time-resolved brillouin spectroscopic system may further include a magnetic field generating device (not shown) that applies a magnetic field to the magnetic material on the surface of the resonator 31, thereby enabling the time-resolved brillouin spectroscopic system to study spin-lattice interactions, glass-einstein condensation, spin dynamics driven by spin transfer torque, and other spin-related properties, according to an embodiment of the present invention.
Fig. 2 schematically shows a schematic diagram of the operation of the time-to-digital converter shown in fig. 1.
As shown in fig. 2, each rectangular box in fig. 2 is a memory cell, each memory cell stores one photon of brillouin scattered light, the width of each memory cell is the highest time resolution of the time-to-digital converter 50, one circle in fig. 2 represents recording one photon, T is the pulse period, and Δt is the pulse width.
During the time that the corresponding frequency channel of the fabry-perot interferometer 32 is on, a plurality of photons of brillouin scattered light having the same frequency as the frequency channel pass through. Fig. 2 records the number of all photons passing through the fabry-perot interferometer 32 versus time during which a certain frequency channel is on.
As shown in FIG. 2, taking spin waves as an example, the time to start counting by the time-to-digital converter 50 is t 0 The time-to-digital converter 50 may be recorded at t i The number of photons of the brillouin scattered light of the time-of-arrival digital converter 50 at the time (i=1, 2,3 …), wherein the photons of the brillouin scattered light of the time-of-arrival digital converter 50 are stored in the corresponding memory cell. The photon numbers in the corresponding time of the pulse periods are accumulated, and the relationship between the photon numbers of the brillouin scattering light with the preset frequency and the time can be obtained.
For example, in the first pulse period in which the time-to-digital converter 50 starts recording, the number of photons recorded in the first resolution time is 10, the number of photons recorded in the second resolution time is 20, and the number of photons recorded in the third resolution time is 15; in the second pulse period, the number of photons recorded in the first resolution time is 11, the number of photons recorded in the second resolution time is 12, the number of photons recorded in the third resolution time is 13, the number of photons of the two pulse periods is accumulated, the corresponding number of photons recorded in the first resolution time is 21, the number of photons recorded in the second resolution time is 32, and the number of photons recorded in the third resolution time is 28. According to the method, the photon numbers in the recorded pulse periods are accumulated to obtain the time evolution of the photon numbers of the brillouin scattering light with different preset frequencies at the current laser spot position. By moving the position of the laser spot, the time evolution of the intensity of the spin wave with different preset frequencies at different positions can be obtained, and a four-dimensional image with the spin wave intensity as a frequency, time and space function can be constructed.
According to the embodiment of the present invention, the resolution of the time-to-digital converter 50 can reach ps order, but due to the uncertain relationship, the resolution of the time-to-digital converter 50 is limited by the mirror pitch of the fabry-perot interferometer 32, so the overall resolution of the time-resolved brillouin spectral system provided by the present invention is ns order. The time-resolved Brillouin spectrum system provided by the invention can realize the observation of the precession of spin waves in the time domain, and research the intensity and the frequency evolution of the spin waves along with time.
According to a specific embodiment of the present invention, the time-resolved brillouin spectrum system provided by the present invention is used to measure the time-evolution curve of the intensity of the spin wave generated by external excitation in Yttrium Iron Garnet (YIG).
The YIG is connected to the microwave source 10 via a resonant cavity 31, such as an antenna or coplanar waveguide (not shown), and the microwave source 10 generates a continuous microwave signal having a frequency equal to the resonant frequency of the resonant cavity 31 to ensure that the microwave signal is maximally absorbed by the resonant cavity 31, thereby locally exciting spin waves in the YIG.
The pulse generator 20 generates a pulse signal having a pulse width of 30ns and a pulse period of 128ns, and inputs the pulse signal into the microwave source 10 to convert the continuous microwave signal into a microwave pulse signal. At the same time, the pulse generator 20 emits a first timing signal (i.e., the time at which the externally excited spin wave is generated), at which time the time-to-digital converter 50 starts counting.
When locally excited spin waves in YIG propagate to the laser spot position and brillouin scattering occurs with the incident photons, the brillouin scattered light passes through the fabry-perot interferometer 32, and is detected by the detector 30. The detector 30 outputs an electrical signal, and the time-to-digital converter 50 counts the photons of the brillouin light and correspondingly records the time t when the detector 30 detects the photons of the brillouin light based on the electrical signal i The relationship between the photon number of the brillouin scattered light and time is obtained. When the detector 30 cannot detect the brillouin scattered light, a second timing signal is output for stopping the counting of the time-to-digital converter 50. At the same time, due to the data acquisition device 40 and the sweep inside the fabry-perot interferometer 32The time-to-digital converter 50 is also able to obtain the frequency information of the brillouin scattered light in synchronization with the scanning stage. The obtained relationship between the number of photons of the brillouin scattered light and time and the frequency information of the brillouin scattered light are input to the computer 60, and the relationship between the intensity of the spin wave and the frequency and time can be constructed. By moving the laser spot, it is also possible to construct a four-dimensional image of spin wave intensity as a function of frequency, time and space.
The invention provides a time resolution Brillouin spectrum system, which utilizes a microwave pumping technology to locally excite spin waves in a magnetic material; the precession of the spin wave is observed on the time domain through the time-to-digital converter, so that the strength and the frequency evolution of the spin wave along with time and space can be studied; the pulse generator and the detector are respectively connected with the time-to-digital converter, so that the time for starting counting and stopping counting of the time-to-digital converter can be respectively controlled, and the occupation of the internal memory of the time-to-digital converter by blank detection data is avoided.
In addition, the time-resolved brillouin spectrum system provided by the invention can be simply and conveniently realized and operated, the cost required for constructing the time-resolved brillouin spectrum system is very low, and all devices can be integrated in the same software for remote control. Besides the frequency information of spin waves can be given in the frequency domain, the time-resolved Brillouin spectrum system can observe the unsteady spin wave precession process in the time domain, can be applied to the research of spin-related properties of magnetic materials, such as magnon-magnon interaction, glass-Einstein condensation, spin dynamics driven by spin transfer torque and the like, and is suitable for popularization and use in laboratories. The time-resolved Brillouin spectrum system provided by the invention has wide applicability, and can be suitable for researching other quasi-particles (such as acoustic phonons, plasmas and the like).
The time-resolved brillouin spectrum system provided by the embodiment of the invention can combine an independent brillouin spectrum technology with a microwave pumping technology and a time sequence technology, and can realize detection and research of a dynamic evolution process of low-frequency quasi-particles.
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the invention thereto, but to limit the invention thereto, and any modifications, equivalents, improvements and equivalents thereof may be made without departing from the spirit and principles of the invention.
Claims (7)
1. A time resolved brillouin spectroscopic system comprising:
the surface of the quasi-particle excitation device is provided with a sample, and the quasi-particle excitation device is suitable for absorbing microwave pulse signals so as to locally excite quasi-particles in the sample;
the laser source is suitable for generating laser, the laser is focused on a target position of the sample and generates Brillouin scattering with the quasi-particles to generate Brillouin scattering light, the Brillouin scattering light has at least one frequency, and the target position is adjustable;
the Fabry-Perot interferometer is suitable for outputting Brillouin scattered light with preset frequency;
the detector is suitable for detecting the Brillouin scattered light with a preset frequency and converting the detected Brillouin scattered light signal with the preset frequency into an electric signal;
the data acquisition device is suitable for acquiring the preset frequency of the Brillouin scattered light to obtain the preset frequency information;
the time-to-digital converter is suitable for reading the electric signal and the preset frequency information to obtain the relation between the photon number of the Brillouin scattering light with the preset frequency at the target position and time;
the computer is suitable for obtaining the relation between the intensity of the quasi-particles with preset frequency and the time of the target position according to the relation between the photon number of the Brillouin scattering light with the preset frequency and the time of the Brillouin scattering light with the preset frequency;
the preset frequency is regulated, and the relationship between the intensity and time of the quasi-particles with different frequencies at the target position is obtained;
wherein, the time-resolved brillouin spectral system further comprises:
a microwave source adapted to generate a continuous microwave signal;
a pulse generator adapted to generate a pulse signal and to input said pulse signal into said microwave source, such that said continuous microwave signal is converted into said microwave pulse signal.
2. The time-resolved brillouin spectral system as claimed in claim 1, wherein,
the pulse generator is further configured to issue a first timing signal for causing the time-to-digital converter to start counting photons of the brillouin scattered light.
3. The time-resolved brillouin spectral system as claimed in claim 2, wherein,
the pulse generator emits the pulse signal and emits the first timing signal at the same time.
4. The time-resolved brillouin spectral system as claimed in claim 1, wherein,
and when the detector cannot detect the Brillouin scattered light with the preset frequency, sending out a second timing signal, wherein the second timing signal is used for stopping the time-to-digital converter from counting photons of the Brillouin scattered light.
5. The time-resolved brillouin spectral system as claimed in claim 1, wherein,
the time-to-digital converter obtains the preset frequency according to the preset frequency information; and counting photons of the brillouin scattered light according to the electric signal, so as to obtain a relationship between the number of photons of the brillouin scattered light with the preset frequency at the target position and time.
6. The time-resolved brillouin spectral system as claimed in claim 1, wherein,
the quasi-particles are acoustic phonons, plasmas or magnons.
7. The time resolved brillouin spectral system as claimed in claim 6, wherein,
in the case that the quasi-particles are magnons, the sample is a magnetic material, and the quasi-particle excitation device is a resonant cavity;
in the case where the quasi-particles are plasmas, the sample is a metallic material or a semiconductor material.
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