A transient absorption spectroscopy measurement system, method and device for polarized light

Abstract

The present invention discloses a transient absorption spectroscopy measurement system, method and device for polarized light, relating to the technical field of ultrafast spectroscopy measurement. In this system, a laser generating device generates a first laser and a second laser. The first laser is converted into left-handed circularly polarized light or right-handed circularly polarized light by a pump light polarization device to serve as the pump light for exciting a sample to be measured. A first Glan prism converts the second laser into linearly polarized probe light in a specified direction to detect the sample to be measured. A first λ / 4 wave plate converts the probe light after detecting the sample to be measured into linearly polarized light with perpendicular polarizations. A Wollaston prism causes the linearly polarized light with perpendicular polarizations to propagate in different directions to a measurement device respectively. The measurement device calculates the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light. This system can simultaneously measure the transient absorption spectra of left-handed circularly polarized light and right-handed circularly polarized light, thereby reducing measurement errors.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrafast spectroscopy measurement, and particularly to a transient absorption spectroscopy measurement system, method and device for polarized light. Background Art

[0002] Transient absorption spectroscopy is a pump-probe technique on an ultrashort time scale, which can obtain the ultrafast photophysical properties and excited state dynamics of an excited sample on a femtosecond time scale. This technique has been widely applied to scientific research in many fields such as physics, chemistry, materials, and biology. For example, it can measure and study processes such as the relaxation of photo-generated carriers inside optoelectronic material systems and biomolecular reactions on an ultrafast time scale.

[0003] In recent years, the combination of traditional optoelectronics and spintronics has attracted wide attention and application of new optoelectronic devices such as spin light-emitting devices and spin Hall devices. For example, in two-dimensional transition metal sulfides, due to the breaking of time-reversal symmetry, the spin-orbit interaction causes spin splitting of the energy bands, and the splitting at the K point and the K' point is opposite. This property is called spin-valley coupling. This inherent property of two-dimensional transition metal sulfides can be used to design spin / valley electronics devices. Among them, the transient absorption spectra of left-handed and right-handed circularly polarized light are important means to study the photo-generated carriers and their spin dynamics processes in the energy valleys (K point and K' point) inside the material, which is convenient for understanding the mechanism of spin / valley electronics devices and designing the device structure. In the prior art, the transient absorption spectrum of polarized light is usually measured by a transient absorption spectroscopy measurement system for polarized light.

[0004] However, in the transient absorption spectroscopy measurement system in the prior art, only data of one spin direction can be obtained in a single test process. If the transient absorption spectra of two spins are measured at different times and in different batches, measurement errors caused by different external conditions will be introduced. Summary of the Invention

[0005] Based on this, it is necessary to provide a transient absorption spectroscopy measurement system, method and device for polarized light aiming at the above technical problems. This system can simultaneously measure the transient absorption spectra of left-handed circularly polarized light and right-handed circularly polarized light, thereby reducing the errors caused by secondary measurement.

[0006] The present invention adopts the following technical solutions:

[0007] The present invention provides a transient absorption spectroscopy measurement system for polarized light, which system includes: a laser generating device, a pump light polarization device, a probe light polarization device and a measurement device; the probe light polarization device includes a first Glan prism, a first λ / 4 wave plate and a Wollaston prism;

[0008] A laser generating device for generating two lasers, namely a first laser and a second laser;

[0009] A pump light polarization device for converting the first laser into a left-handed circularly polarized pump light or a right-handed circularly polarized pump light; the pump light is used to excite a sample to be measured;

[0010] A first Glan prism for converting the second laser into a linearly polarized probe light in a specified direction; the probe light is used to detect the sample to be measured;

[0011] A first λ / 4 wave plate for converting the probe light after detecting the sample to be measured into linearly polarized lights with perpendicular polarizations; the linearly polarized lights with perpendicular polarizations respectively represent a left-handed circularly polarized probe light and a right-handed circularly polarized probe light;

[0012] A Wollaston prism for making the linearly polarized lights with perpendicular polarizations propagate in different directions so that the left-handed circularly polarized probe light and the right-handed circularly polarized probe light can be received by a measuring device simultaneously;

[0013] A measuring device for obtaining the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light according to the simultaneously received left-handed circularly polarized probe light and right-handed circularly polarized probe light.

[0014] Preferably, the pump light polarization device includes a second Glan prism, a λ / 2 wave plate and a second λ / 4 wave plate; one end of the second Glan prism is connected to the laser generating device, and the other end of the second Glan prism is connected to one end of the second λ / 4 wave plate through the λ / 2 wave plate;

[0015] The second Glan prism is used to receive the first laser emitted by the laser generating device and, together with the λ / 2 wave plate, convert the first laser into a linearly polarized pump light with an adjustable polarization angle;

[0016] The second λ / 4 wave plate is used to convert the linearly polarized pump light into a left-handed circularly polarized light or a right-handed circularly polarized light.

[0017] Preferably, the laser generating device includes a laser amplifier, a beam splitter, a full-automatic optical parametric amplifier, a chopper, a delay line device and a supercontinuum light generating device; the laser amplifier is connected to one end of the beam splitter, the other end of the beam splitter is respectively connected to one end of the full-automatic optical parametric amplifier and the supercontinuum light generating device, the other end of the full-automatic optical parametric amplifier is connected to one end of the chopper, the other end of the chopper is connected to one end of the delay line device, the other end of the delay line device is connected to the pump light polarization device, and the other end of the supercontinuum light generating device is connected to one end of the first Glan prism;

[0018] A beam splitter, which is used to receive the laser emitted by a laser amplifier, and after reflecting and transmitting the laser, generate reflected light and transmitted light, output the first laser with a preset wavelength and pulse width through a full-automatic optical parametric amplifier for the reflected light, and generate supercontinuum white light within a preset spectral range through a supercontinuum light generation device for the transmitted light and output it as the second laser;

[0019] A chopper, which is used to adjust the repetition rate of the first laser from 500 Hz to 250 Hz;

[0020] A delay line device, which is used to adjust the optical path of the first laser to regulate the time when the first laser reaches the sample to be measured compared with the second laser.

[0021] Preferably, the system further includes a sample loading device; focusing lenses are respectively arranged between the sample loading device and the pump light polarization device and the supercontinuum light generation device; the sample loading device is a vacuum device for placing the sample to be measured, the sample loading device is a vacuum device with a transparent glass window, and the sample loading device includes a three-dimensionally movable sample stage, the sample to be measured, a liquid helium circulation cooling device and a vacuum gauge; the pump light output by the pump light polarization device and the probe light output by the supercontinuum light generation device are respectively focused onto the sample to be measured through the corresponding focusing lenses and the vacuum glass window;

[0022] A three-dimensionally movable sample stage, which is used to place the sample to be measured;

[0023] A liquid helium circulation cooling device, which is used to adjust the temperature inside the sample loading device to regulate the temperature of the sample to be measured;

[0024] A vacuum gauge, which is used to detect the vacuum degree in the sample loading device.

[0025] Preferably, the measuring device includes a first spectrometer, a second spectrometer and a computer control unit;

[0026] A first spectrometer, which is used to receive the probe light representing left-handed circular polarization emitted by a Wollaston prism and send the spectral information of the left-handed circularly polarized probe light to the computer control unit;

[0027] A second spectrometer, which is used to receive the probe light representing right-handed circular polarization emitted by a Wollaston prism and send the spectral information of the right-handed circularly polarized probe light to the computer control unit;

[0028] A computer control unit, which is used to obtain the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light according to the received spectral information of the left-handed circularly polarized probe light and the right-handed circularly polarized probe light.

[0029] Preferably, the laser amplifier, the full-automatic optical parametric amplifier, the chopper, the delay line device, the first spectrometer, and the second spectrometer are all electrically connected to the computer control unit to control the coordinated operation of each component through the computer control unit.

[0030] The present invention provides a method for measuring the transient absorption spectrum of polarized light, which is applied to the above-mentioned transient absorption spectrum measurement system for polarized light. The method includes:

[0031] Controlling the laser generating device to generate the first laser and the second laser, and adjusting the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser;

[0032] Converting the first laser into a pump light with left-handed circular polarization or right-handed circular polarization through the pump light polarization device, and emitting the pump light with left-handed circular polarization or right-handed circular polarization onto the sample to be measured to excite the sample to be measured;

[0033] Converting the second laser into a probe light through the Glan prism in the probe light polarization device, and detecting the sample to be measured through the probe light. Passing the probe light transmitted through the sample to be measured through the first λ / 4 wave plate and the Wollaston prism in the probe light polarization device to convert the probe light into linearly polarized light with mutually perpendicular polarizations; The probe light passing through the Glan prism in the probe light polarization device is the synthesis of the probe light with left-handed circular polarization and the probe light with right-handed circular polarization; The linearly polarized lights with mutually perpendicular polarizations respectively represent the probe light with left-handed circular polarization and the probe light with right-handed circular polarization;

[0034] Receiving the probe light representing the left-handed circular polarization and the probe light representing the right-handed circular polarization respectively through the measuring device, and obtaining the transient absorption spectrum of the probe light with left-handed circular polarization and the transient absorption spectrum of the probe light with right-handed circular polarization according to the received probe light with left-handed circular polarization and the probe light with right-handed circular polarization.

[0035] Preferably, the process of obtaining the transient absorption spectrum of the probe light with left-handed circular polarization includes:

[0036] Obtaining the change in the transmittance of the received probe light with left-handed circular polarization with and without the pump light, and calculating the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the probe light with left-handed circular polarization with and without the pump light; or,

[0037] Obtaining the change in the reflectance of the received probe light with left-handed circular polarization with and without the pump light, and calculating the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the reflectance of the probe light with left-handed circular polarization with and without the pump light.

[0038] Preferably, the process for obtaining the transient absorption spectrum of the right-circularly polarized probe light includes:

[0039] Obtaining the change in the transmittance of the received right-circularly polarized probe light with and without the pump light, and calculating the transient absorption spectrum of the right-polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the right-circularly polarized probe light with and without the pump light; or,

[0040] Obtaining the change in the reflectance of the received right-circularly polarized probe light with and without the pump light, and calculating the transient absorption spectrum of the right-polarized light of the sample to be measured at the corresponding test delay time according to the change in the reflectance of the right-circularly polarized probe light with and without the pump light.

[0041] The present invention provides a device for measuring the transient absorption spectrum of polarized light, including:

[0042] A laser generation module, configured to control a laser generating device to generate a first laser and a second laser, and adjust the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser;

[0043] An excitation module, configured to convert the first laser into a left-circularly polarized or right-circularly polarized pump light through a pump light polarization device, and emit the left-circularly polarized or right-circularly polarized pump light onto the sample to be measured to excite the sample to be measured;

[0044] A detection module, configured to convert the second laser into a probe light through a Glan prism in the probe light polarization device, and detect the sample to be measured through the probe light. The probe light transmitted through the sample to be measured passes through a first λ / 4 wave plate and a Wollaston prism in the probe light polarization device to convert the probe light into linearly polarized lights with perpendicular polarizations; the probe light passing through the Glan prism in the probe light polarization device is a combination of a left-circularly polarized probe light and a right-circularly polarized probe light; the linearly polarized lights with perpendicular polarizations respectively represent the left-circularly polarized probe light and the right-circularly polarized probe light;

[0045] A measurement module, configured to respectively receive the probe light representing the left-circularly polarized light and the probe light representing the right-circularly polarized light through a measuring device, and obtain the transient absorption spectrum of the left-circularly polarized probe light and the transient absorption spectrum of the right-circularly polarized probe light according to the received left-circularly polarized probe light and right-circularly polarized probe light.

[0046] The present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the above method for measuring the transient absorption spectrum of polarized light is implemented.

[0047] The present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the transient absorption spectrum measurement method of the above-mentioned polarized light is realized.

[0048] The above-mentioned at least one technical solution adopted by the present invention can achieve the following beneficial effects:

[0049] In the transient absorption spectrum measurement system of polarized light provided by the present invention, a first laser and a second laser are generated by a laser generating device. The pump light polarization system converts the first laser into left-handed circularly polarized light or right-handed circularly polarized light to excite the sample, and the second laser is converted into a probe light that can be regarded as the synthesis of left-handed and right-handed circularly polarized lights with equal amplitudes by a first Glan prism to detect the sample. After the probe light finishes detection, the left-handed and right-handed circularly polarized probe lights are converted into linearly polarized lights with perpendicular polarizations by a first λ / 4 wave plate, and then a Wollaston prism is used to separate the linearly polarized lights with perpendicular polarizations to propagate in different directions. In this way, the left-handed and right-handed circularly polarized lights can be observed simultaneously, that is, the population of carriers in the K and K' valleys can be obtained simultaneously, and the transient absorption spectra of left-handed circularly polarized light and right-handed circularly polarized light are measured simultaneously, thereby reducing the measurement error. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0051] Figure 1 is a schematic structural diagram of a transient absorption spectrum measurement system of polarized light provided by the present invention;

[0052] Figure 2 is a schematic structural diagram of another transient absorption spectrum measurement system of polarized light provided by the present invention;

[0053] Figure 3 is a schematic structural diagram of another transient absorption spectrum measurement system of polarized light provided by the present invention;

[0054] Figure 4 is a schematic structural diagram of another transient absorption spectrum measurement system of polarized light provided by the present invention;

[0055] Figure 5 is a schematic structural diagram of another transient absorption spectrum measurement system of polarized light provided by the present invention;

[0056] Figure 6 is a schematic structural diagram of another transient absorption spectrum measurement system of polarized light provided by the present invention;

[0057] Figure 7 Schematic flow chart of a method for measuring transient absorption spectrum of polarized light provided by the present invention;

[0058] Figure 8 Schematic flow chart of another method for measuring transient absorption spectrum of polarized light provided by the present invention;

[0059] Figure 9 Schematic diagram of a device for measuring transient absorption spectrum of polarized light provided by the present invention;

[0060] Figure 10 Schematic diagram of a computer device for implementing the method for measuring transient absorption spectrum of polarized light provided by the present invention.

[0061] Description of reference numerals:

[0062] 100, system; 101, laser generating device; 102, pump light polarization device; 103, probe light polarization device; 104, measuring device; 105, first Glan prism; 106, first λ / 4 wave plate; 107, Wollaston prism; 108, sample to be measured; 109, sample loading device;

[0063] 201, second Glan prism; 202, λ / 2 wave plate; 203, second λ / 4 wave plate;

[0064] 301, laser amplifier; 302, beam splitter; 303, full-automatic optical parametric amplifier; 304, chopper; 305, delay line device; 306, supercontinuum light generating device;

[0065] 401, focusing lens;

[0066] 501, first spectrometer; 502, second spectrometer; 503, computer control unit. Detailed implementation manners

[0067] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work shall fall within the protection scope of the present invention.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

[0069] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0070] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0071] In the description of the embodiments of this application, unless otherwise clearly specified and limited, technical terms such as "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0072] The present invention provides a transient absorption spectroscopy measurement system for polarized light, as Figure 1 shown. The system 100 includes: a laser generating device 101, a pump light polarization device 102, a probe light polarization device 103, and a measurement device 104; the probe light polarization device 103 includes a first Glan prism 105, a first λ / 4 wave plate 106, and a Wollaston prism 107.

[0073] The laser generating device 101 is used to generate two lasers, namely a first laser and a second laser.

[0074] The pump light polarization device 102 is used to convert the first laser into a left-handed circularly polarized pump light or a right-handed circularly polarized pump light; the pump light is used to excite the sample to be measured 108.

[0075] The first Glan prism 105 is used to convert the second laser into a probe light linearly polarized in a specified direction; the probe light is used to detect the sample 108 to be measured.

[0076] The first λ / 4 wave plate 106 is used to convert the probe light after detecting the sample to be measured into linearly polarized lights with perpendicular polarizations; the linearly polarized lights with perpendicular polarizations respectively represent the left-handed circularly polarized probe light and the right-handed circularly polarized probe light.

[0077] The Wollaston prism 107 is used to make the linearly polarized lights with perpendicular polarizations propagate in different directions, so that the left-handed circularly polarized probe light and the right-handed circularly polarized probe light can be simultaneously received by the measuring device 104.

[0078] The measuring device 104 is used to obtain the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light according to the simultaneously received left-handed circularly polarized probe light and right-handed circularly polarized probe light.

[0079] It should be noted that the system 100 further includes a sample loading device 109, and the sample loading device 109 is used to load the sample 108 to be measured.

[0080] Wherein, the output end of the laser generating device 101 is respectively connected to the first Glan prism 105 of the probe light polarization device 103 and one end of the pump light polarization device 102, the other ends of the first Glan prism 105 of the probe light polarization device 103 and the pump light polarization device 102 are both connected to one end of the sample loading device 109, the other end of the sample loading device 109 is connected to one end of the first λ / 4 wave plate 106 in the probe light polarization device 103, the other end of the first λ / 4 wave plate 106 is connected to one end of the Wollaston prism 107, and the other end of the Wollaston prism 107 is respectively connected to the measuring device 104.

[0081] The first Glan prism (Glan) 105 can filter out linearly polarized lights in other directions to obtain a probe light linearly polarized in a single direction. Among them, the linearly polarized probe light can be regarded as the synthesis of two left-handed circularly polarized lights and right-handed circularly polarized lights with equal amplitudes; the first λ / 4 wave plate 106 can convert the signal light with circular polarization in the probe light into linearly polarized signal light, that is, the first λ / 4 wave plate 106 can convert the left-handed circularly polarized light and the right-handed circularly polarized light into linearly polarized lights with perpendicular polarizations; the Wollaston prism (Wollaston) 107 can decompose the linearly polarized probe light into left-handed and right-handed circularly polarized probe lights and let them propagate separately in different directions at a certain angle.

[0082] In an exemplary embodiment, such as Figure 2As shown, the pump light polarization device 102 includes a second Glan prism 201, a λ / 2 wave plate 202, and a second λ / 4 wave plate 203. One end of the second Glan prism 201 is connected to the laser generating device 101, and the other end of the second Glan prism 201 is connected to one end of the second λ / 4 wave plate 203 through the λ / 2 wave plate 202.

[0083] The second Glan prism 201 is configured to receive the first laser emitted by the laser generating device 101, and convert the first laser into a linearly polarized pump light with an adjustable polarization angle together with the λ / 2 wave plate 202. The second λ / 4 wave plate 203 is configured to convert the linearly polarized pump light into a left-handed circularly polarized light or a right-handed circularly polarized light.

[0084] Among them, the first laser emitted by the laser generating device 101 first enters the second Glan prism 201. The second Glan prism 201 and the λ / 2 wave plate 202 change the linearly polarized first laser output by the laser generating device 101 into a linearly polarized pump light with an adjustable polarization angle, and its polarization direction forms a 45-degree clockwise or 45-degree counterclockwise angle with the fast axis of the second λ / 4 wave plate 203, and can respectively form a left-handed circularly polarized light or a right-handed circularly polarized light, and finally serve as the pump light for exciting the sample.

[0085] In an exemplary embodiment, as Figure 3 shown, the laser generating device 101 includes a laser amplifier 301, a beam splitter 302, a full-automatic optical parametric amplifier 303, a chopper 304, a delay line device 305, and a supercontinuum light generating device 306. The laser amplifier 301 is connected to one end of the beam splitter 302, and the other end of the beam splitter 302 is respectively connected to one end of the full-automatic optical parametric amplifier 303 and the supercontinuum light generating device 306. The other end of the full-automatic optical parametric amplifier 303 is connected to one end of the chopper 304, the other end of the chopper 304 is connected to one end of the delay line device 305, the other end of the delay line device 305 is connected to the pump light polarization device 102, and the other end of the supercontinuum light generating device 306 is connected to one end of the first Glan prism 105.

[0086] The beam splitter 302 is configured to receive the laser emitted by the laser amplifier 301, and generate reflected light and transmitted light after reflection and transmission of the laser, output the first laser with a preset wavelength and pulse width through the full-automatic optical parametric amplifier 303 for the reflected light, and generate a supercontinuum white light within a preset spectral range as the second laser through the supercontinuum light generating device 306 for the transmitted light. The chopper 304 is configured to adjust the repetition frequency of the first laser from 500 Hz to 250 Hz. The delay line device 305 is configured to adjust the optical path of the first laser to adjust the time when the pump light arrives at the sample to be measured 108 compared with the probe light.

[0087] The other end of the delay line device 305 is connected to the pump light polarization device 102 , and is substantially connected to the second Glan prism 201 in the pump light polarization device 102 .

[0088] The laser amplifier 301 can be a femtosecond laser amplifier, which can generate ultrafast lasers and be divided into a beam of light with higher power and a beam of light with lower power after passing through the beam splitter 302; for example, the femtosecond laser amplifier outputs a laser with a pulse width of 35fs, a repetition rate of 500Hz, and a central wavelength of 800nm. The femtosecond laser is divided into two beams of light (transmitted light and reflected light) after passing through the transmission and reflection (2:8) beam splitter 302.

[0089] The reflected light has a relatively strong energy, and the pump light of the required wavelength and pulse width is outputted through the fully automatic optical parametric amplifier 303, and then the repetition rate of the pump light can be changed from 500 Hz to 250 Hz through the chopper 304; the pump light reaches the delay line device 305 after passing through the chopper 304, and the position of the delay line is controlled by the measuring device 104, so as to adjust the test delay time of the first laser, so as to adjust the time when the pump light reaches the sample to be tested 108 compared with the detection light. Then, the first laser reaches the second Glan prism 201 of the pump light polarization system through the delay line device 305.

[0090] The energy of the transmitted light part is relatively weak, and it passes through the supercontinuum light generating device 306, for example, and is focused by a lens onto a 5 mm thick sapphire crystal (or calcium fluoride crystal, or a cuvette filled with heavy water), to generate supercontinuum white light with a spectral range of 400-800 nm as the second laser (detection light).

[0091] Among them, the femtosecond laser amplifier mainly includes diode pumping, neodymium-doped yttrium vanadate continuous laser, titanium sapphire-doped mode-locked seed laser, neodymium-doped lithium yttrium fluoride laser and titanium sapphire-doped regenerative amplifier, which generates femtosecond pulse laser with a repetition rate of 500Hz and a central wavelength of 800nm.

[0092] The delay line device 305 includes a collimation system and an electric precision mechanical translation stage. By adjusting the position of the electric precision mechanical translation stage (ie, the optical path of the pump light), the time it takes for the pump light to reach the sample 109 compared to the detection light is controlled.

[0093] The supercontinuum light generating device 306 includes a focusing-collimation system and a supercontinuum light generating medium. The supercontinuum light generating medium is a nonlinear optical medium, such as heavy water, sapphire or calcium fluoride. A suitable medium can be selected according to experimental requirements.

[0094] In one embodiment, Figure 4As shown, a focusing lens 401 is respectively arranged between the sample loading device 109, the pump light polarization device 102 and the supercontinuum light generating device 306; the sample loading device 109 is a vacuum device with a transparent glass window, and the sample loading device 109 includes a three-dimensionally movable sample stage, a sample to be measured 108, a liquid helium circulation cooling device and a vacuum gauge; the pump light output by the pump light polarization device 102 and the probe light output by the supercontinuum light generating device 306 are respectively focused on the sample to be measured 108 through the corresponding focusing lens 401 and the vacuum glass window.

[0095] The three-dimensionally movable sample stage is used to place the sample to be measured 108; the liquid helium circulation cooling device is used to adjust the temperature inside the sample loading device 109 to adjust the temperature of the sample to be measured 108; the vacuum gauge is used to detect the vacuum degree in the sample loading device 109.

[0096] The liquid helium circulation cooling device can provide an extreme environment with precise temperature control in the full temperature range of 5K to 300K for the sample to be measured 108; the vacuum degree in the sample loading device 109 can reach 10-7 mbar.

[0097] The probe light and the pump light are converged on the sample to be measured 108 through the vacuum glass window of the sample loading device, and then the probe light enters the first λ / 4 wave plate 106 of the probe light polarization system through the vacuum glass window.

[0098] According to theoretical calculations, the measurement of the transient absorption spectrum of the polarized light of optoelectronic materials needs to be carried out in a low-temperature environment. Therefore, in this embodiment, by setting the liquid helium circulation cooling device, the temperature of the sample to be measured 108 in the sample loading device 109 is kept in the required low-temperature environment during the measurement process, so that the measurement system can control the environmental temperature of the sample to be measured 108, and the transient absorption spectra of two spin directions can be measured at one time, reducing the measurement error and shortening the test time.

[0099] It should be noted that in Figure 4 , in this application, not only a focusing lens 401 is respectively arranged between the sample loading device 109, the pump light polarization device 102 and the supercontinuum light generating device 306, but also a focusing lens 401 is arranged between the sample loading device and the first λ / 4 wave plate 106, and two focusing lenses 401 are respectively arranged between the Wollaston prism 107 and the measuring device 104.

[0100] There are also 5 focusing lenses 401 in the system 100, please refer to Figure 4, a focusing lens 401 is provided between the first Glan prism 105 and the sample loading device 109 to focus the detection light emitted by the first Glan prism 105 onto the sample 108 to be measured of the sample loading device 109; a focusing lens 401 is provided between the pump light polarization device 102 and the sample loading device 109 to focus the pump light emitted by the pump light polarization device 102 onto the sample 108 to be measured of the sample loading device 109; a focusing lens 401 is provided between the sample loading device 109 and the first λ / 4 wave plate 106, and two focusing lenses 401 are provided between the Wollaston prism 107 and the measuring device 104 to focus the left-handed circularly polarized detection light and the right-handed circularly polarized detection light emitted by the Wollaston prism 107 onto the measuring device 104 through two optical paths respectively.

[0101] In an exemplary embodiment, as Figure 5 shown, the measuring device 104 includes a first spectrometer 501, a second spectrometer 502 and a computer control unit 503; one ends of the first spectrometer 501 and the second spectrometer 502 are respectively connected to the Wollaston prism 107 through focusing lenses 401, and the other ends of the first spectrometer 501 and the second spectrometer 502 are respectively connected to the computer control unit 503.

[0102] The first spectrometer 501 is configured to receive the left-handed circularly polarized detection light emitted by the Wollaston prism 107 and send the spectral information of the left-handed circularly polarized detection light to the computer control unit 503; the second spectrometer 502 is configured to receive the right-handed circularly polarized detection light emitted by the Wollaston prism 107 and send the spectral information of the right-handed circularly polarized detection light to the computer control unit 503; the computer control unit 503 is configured to obtain the transient absorption spectrum of the left-handed circularly polarized detection light and the transient absorption spectrum of the right-handed circularly polarized detection light according to the received spectral information of the left-handed circularly polarized detection light and the right-handed circularly polarized detection light.

[0103] The Wollaston prism 107 emits the decomposed left-handed and right-handed circularly polarized detection lights in different directions, and then they are respectively received by the first spectrometer 501 and the second spectrometer 502; that is, the first spectrometer 501 receives the left-handed circularly polarized detection light emitted by the Wollaston prism 107, analyzes the spectral information of the left-handed circularly polarized detection light according to the received left-handed circularly polarized detection light, and then sends the spectral information of the left-handed circularly polarized detection light to the computer control unit 503; the second spectrometer 502 receives the right-handed circularly polarized detection light emitted by the Wollaston prism 107, analyzes the spectral information of the right-handed circularly polarized detection light according to the received right-handed circularly polarized detection light, and then sends the spectral information of the right-handed circularly polarized detection light to the computer control unit 503. Among them, the spectral information may include transmittance, reflectance, absorbance, etc.

[0104] In an exemplary embodiment, as Figure 6 shown, a laser amplifier 301, a fully automatic optical parametric amplifier 303, a chopper 304, a delay line device 305, a first spectrometer 501, and a second spectrometer 502 are all electrically connected to a computer control unit 503 to control the coordinated operation of each component through the computer control unit 503.

[0105] The computer control unit 503 can control the output power of the laser amplifier 301, the gain of the fully automatic optical parametric amplifier 303, the switching state of the chopper 304, the position of the delay line in the delay line device 305, and the working states of the first spectrometer 501 and the second spectrometer 502, etc. For example, the computer control unit 503 can adjust the position of the delay line according to a preset interval control instruction, so that there is a delay time for the probe light to reach the sample to be measured 108 relative to the pump light, and then read and process the spectral shape and intensity of the probe light before and after the pump light excites the sample to be measured 108, and finally calculate the transient absorption spectra of left-handed and right-handed circularly polarized light of the sample to be measured 108 at the corresponding delay time according to the spectral data.

[0106] Based on the above system, the present invention further provides a method for testing the transient absorption spectrum of polarized light, which is applied to the transient absorption spectrum measurement system of polarized light in any of the above embodiments, as Figure 7 shown, and specifically includes the following steps:

[0107] S701, control the laser generating device to generate a first laser and a second laser, and adjust the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser.

[0108] It should be noted that ensuring that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser is essentially to ensure that there is a test delay time for the probe light to reach the sample to be measured relative to the pump light.

[0109] When measuring the transient absorption spectrum of polarized light, first, turn on the laser generating device to generate pump light and probe light, and adjust the optical path of the pump light so that there is a delay when the probe light and the pump light reach the sample to be measured. In this way, the spectral information of the probe light before and after the pump light excites the sample to be measured can be collected.

[0110] S702, convert the first laser into left-handed circularly polarized or right-handed circularly polarized pump light through the pump light polarization device, and emit the left-handed circularly polarized or right-handed circularly polarized pump light onto the sample to be measured to excite the sample to be measured.

[0111] It should be noted that when using left-handed circularly polarized pump light or right-handed circularly polarized pump light as the condition for exciting the sample to be measured, the pump light polarization system can be set to convert the pump light into left-handed circularly polarized pump light or right-handed circularly polarized pump light according to the experimental requirements. In this way, the material properties under different excitation conditions can be measured, that is, the transient absorption spectra of left-handed circularly polarized light and right-handed circularly polarized light under different polarized light excitations.

[0112] S703, the second laser is converted into the probe light by the Glan prism in the probe light polarization device, and the sample to be measured is detected by the probe light. The probe light passing through the sample to be measured passes through the first λ / 4 wave plate and Wollaston prism in the probe light polarization device to convert the probe light into linearly polarized light with perpendicular polarizations; the probe light passing through the Glan prism in the probe light polarization device is a combination of left-handed circularly polarized probe light and right-handed circularly polarized probe light; the linearly polarized lights with perpendicular polarizations respectively represent left-handed circularly polarized probe light and right-handed circularly polarized probe light.

[0113] S704, the measurement device respectively receives the probe light representing left-handed circularly polarized light and right-handed circularly polarized light, and based on the received left-handed circularly polarized probe light and right-handed circularly polarized probe light, obtains the transient absorption spectra of the left-handed circularly polarized probe light and the right-handed circularly polarized probe light.

[0114] For the specific limitations of the transient absorption spectrum measurement method of polarized light in this embodiment, reference can be made to the limitations of the transient absorption spectrum measurement system of polarized light in the above text, which will not be elaborated here.

[0115] In an exemplary embodiment, based on the step file, the optical path of the pump light can be adjusted by moving the position of the optical element on the delay line device. In this way, the test delay time is increased based on the reference position; the reference position is the position of the delay line when the pump light and the probe light reach the sample to be measured simultaneously.

[0116] Among them, the step file can be a data file used to define the change of step parameters during the test process. The step file can include the optical path adjusted each time; it can gradually increase the optical path based on the reference position according to a preset step, thereby increasing the test delay time.

[0117] Among them, since the delay line device changes the test delay time, the arrival times of the probe light and the pump light at the sample to be measured are inconsistent. In addition, due to the chopper, when the probe light detects the sample to be measured, the sample to be measured has two states: excited and unexcited. Therefore, the probe light received by the spectrometer also has two situations: excited by the pump light and not excited by the pump light. The transient absorption spectrum of polarized light of the sample to be measured at the corresponding test delay time can be determined according to the spectral information of the probe light with and without the pump light.

[0118] Among them, taking spectral information such as transmittance and reflectance as examples, the process of obtaining the transient absorption spectrum of the probe light with left-handed circular polarization includes: obtaining the change in the transmittance of the received probe light with left-handed circular polarization with and without the pump light, and calculating the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the probe light with left-handed circular polarization with and without the pump light; or obtaining the change in the reflectance of the received probe light with left-handed circular polarization with and without the pump light, and calculating the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the reflectance of the probe light with left-handed circular polarization with and without the pump light.

[0119] The first spectrometer analyzes the probe light with left-handed circular polarization received with the pump light to determine the transmittance or reflectance of the probe light with left-handed circular polarization with the pump light, and the first spectrometer analyzes the probe light with left-handed circular polarization received without the pump light to determine the transmittance or reflectance of the probe light with left-handed circular polarization without the pump light.

[0120] Calculate the change in the transmittance of the probe light with left-handed circular polarization with and without the pump light according to the transmittance of the probe light with left-handed circular polarization with the pump light and the transmittance of the probe light with left-handed circular polarization without the pump light, as shown in formula (1).

[0121]

[0122] Among them, T pump+probe is the transmittance with the pump light, T probe is the transmittance without the pump light, is the change in transmittance.

[0123] Calculate the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the probe light with left-handed circular polarization with and without the pump light, as shown in formula (2).

[0124]

[0125] Among them, ΔOD is the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time.

[0126] Calculate the change in the reflectance of the probe light with left-handed circular polarization with and without the pump light according to the reflectance of the probe light with left-handed circular polarization with the pump light and the reflectance of the probe light with left-handed circular polarization without the pump light, as shown in formula (3).

[0127]

[0128] Among them, R pump+probe is the reflectivity in the presence of pump light, R probe is the reflectivity without pump light, is the change of reflectivity.

[0129] According to the change of reflectivity of left-handed circularly polarized detection light in the presence or absence of pump light, the transient absorption spectrum of left-handed polarized light of the sample to be tested at the corresponding test delay time is calculated, as shown in formula (4).

[0130]

[0131] In an exemplary embodiment, the process of acquiring the transient absorption spectrum of right-handed circularly polarized detection light includes: acquiring the change in transmittance of the received right-handed circularly polarized detection light in the presence or absence of pump light, and calculating the transient absorption spectrum of the right-handed polarized light of the sample to be tested at the corresponding test delay time based on the change in transmittance of the right-handed circularly polarized detection light in the presence or absence of pump light; or, acquiring the change in reflectivity of the received right-handed circularly polarized detection light in the presence or absence of pump light, and calculating the transient absorption spectrum of the right-handed polarized light of the sample to be tested at the corresponding test delay time based on the change in reflectivity of the right-handed circularly polarized detection light in the presence or absence of pump light.

[0132] The specific principle of calculating the transient absorption spectrum of right-handed polarized light in this embodiment is the same as the specific principle of calculating the transient absorption spectrum of left-handed polarized light in the above embodiment, and the embodiments of this application will not be repeated here.

[0133] In an exemplary embodiment, the present application also provides a method for measuring transient absorption spectra of polarized light, wherein the laser generating device includes a femtosecond laser amplifier, a beam splitter, a fully automatic optical parameter device, a delay line device and a supercontinuum light generating device, such as Figure 8 As shown, the method comprises the following steps:

[0134] S801, turn on the femtosecond laser amplifier, and use a beam splitter to split the laser emitted by the femtosecond laser amplifier into two beams: a beam of light with higher energy (reflected light) enters the pump optical path, and a beam of light with lower energy (transmitted light) enters the detection optical path.

[0135] S802, adjusting the parameters of the fully automatic optical parametric device and the parameters of the chopper, passing the light with stronger energy through the fully automatic optical parametric device and the chopper, and outputting the pump light with the required wavelength, pulse width and repetition rate.

[0136] S803, adjusting the supercontinuum light generating device to output detection light through the supercontinuum light generating device with weaker energy.

[0137] Among them, the adjusted supercontinuum light generation device includes selecting a suitable nonlinear medium (such as heavy water, sapphire or calcium fluoride crystal), and outputting supercontinuum white light with appropriate intensity and stable spectral shape as the probe light by passing the light with weak energy through the supercontinuum light generation device.

[0138] S804, adjust the polarization directions of the pump light and the probe light.

[0139] The polarization direction of the probe light can be adjusted by the first Glan prism in the probe light polarization system; and the polarization direction of the pump light can be adjusted by the second Glan prism, λ / 2 wave plate and second λ / 4 wave plate in the pump light polarization system.

[0140] S805, fix the sample to be measured on the sample holder of the sample loading device, evacuate the sample loading device, and set the test temperature.

[0141] Among them, the sample holder is a three-dimensional movable sample holder.

[0142] S806, adjust the delay line to make the reference position of the delay line when the pump light and the probe light reach the sample simultaneously, and increase the test delay time based on the reference position according to the selected step file.

[0143] Among them, increasing the test delay time based on the reference position is to ensure that the entire process of sample excitation and carrier relaxation can be detected.

[0144] Before determining the reference position of the delay line, it is necessary to carefully adjust the coincidence degree of the pump light and the probe light, adjust the delay line to find the position with the maximum transient absorption signal, and set the appropriate intensity of the pump light.

[0145] S807, start the measurement, and the computer control unit calculates the transient absorption spectra of the left-handed and right-handed polarized lights of the sample to be measured at the corresponding test delay times.

[0146] Compared with the prior art, the present invention has the following beneficial effects:

[0147] (1) The present invention provides a transient absorption spectrum measurement system for polarized light of spin-valley polarization of transition metal dichalcogenides (TMDs). In one measurement, it can simultaneously detect left-handed and right-handed circularly polarized lights, that is, simultaneously obtain the population conditions of carriers in the K and K' valleys, simplifies the experimental process, improves the experimental efficiency, and reduces the measurement error.

[0148] (2) Optical properties different from those at room temperature may be observed in conventional two-dimensional TMDs materials in a low-temperature environment. The present invention provides a test system that combines transient absorption detection technology and a low-temperature control system, bringing a new dimension (temperature) to the study of the characteristics of two-dimensional TMDs materials.

[0149] (3) The present invention realizes the adjustability of the polarization angle of the pump light by installing a Glan prism, a λ / 2 wave plate, and a λ / 4 wave plate, which can meet the excitation of the sample to be measured by pump light with different polarization angles, thus bringing more comprehensive experimental analysis.

[0150] The above is the method for measuring the transient absorption spectrum of polarized light provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding device for measuring the transient absorption spectrum of polarized light, as Figure 9 shown.

[0151] Figure 9 Schematic diagram of a device for measuring the transient absorption spectrum of polarized light provided by the present invention. The device 900 for measuring the transient absorption spectrum of polarized light includes:

[0152] A laser generation module 901, configured to control a laser generating device to generate a first laser and a second laser, and adjust the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser;

[0153] An excitation module 902, configured to convert the first laser into a left-handed circularly polarized or right-handed circularly polarized pump light through a pump light polarization device, and emit the left-handed circularly polarized or right-handed circularly polarized pump light onto the sample to be measured to excite the sample to be measured;

[0154] A detection module 903, configured to convert the second laser into detection light through a Glan prism in the detection light polarization device, and detect the sample to be measured through the detection light. The detection light passing through the sample to be measured passes through a first λ / 4 wave plate and a Wollaston prism in the detection light polarization device to convert the detection light into linearly polarized light with perpendicular polarizations; the detection light passing through the Glan prism in the detection light polarization device is a combination of left-handed circularly polarized detection light and right-handed circularly polarized detection light; the linearly polarized light with perpendicular polarizations respectively represents left-handed circularly polarized detection light and right-handed circularly polarized detection light;

[0155] A measurement module 904, configured to respectively receive the left-handed circularly polarized detection light and the right-handed circularly polarized detection light through a measurement device, and obtain the transient absorption spectrum of the left-handed circularly polarized detection light and the transient absorption spectrum of the right-handed circularly polarized detection light according to the received left-handed circularly polarized detection light and right-handed circularly polarized detection light.

[0156] For the specific limitations of the transient absorption spectrum measurement device for polarized light, reference may be made to the limitations of the transient absorption spectrum measurement method for polarized light in the foregoing text, which will not be elaborated here. Each module in the above-mentioned transient absorption spectrum measurement device for polarized light can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory of the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0157] The present invention also provides a computer-readable storage medium, which stores a computer program that can be used to execute the above-mentioned Figure 7 transient absorption spectrum measurement method for polarized light provided.

[0158] The present invention also provides Figure 10 the structural schematic diagram of the computer device shown in, as Figure 10 shown, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the above-mentioned Figure 7 transient absorption spectrum measurement method for polarized light provided.

[0159] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to the memory, storage, database, or other media used in the various embodiments provided by the present invention can include at least one of non-volatile and volatile memories. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. The volatile memory can include random access memory (RAM) or an external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0160] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in the present invention.

Claims

1. A transient absorption spectroscopy measurement system for polarized light, characterized in that, The system includes: a laser generation device, a pump light polarization device, a probe light polarization device, and a measurement device; the probe light polarization device includes a first Glan prism, a first λ / 4 wave plate, and a Wollaston prism; the pump light polarization device includes a second Glan prism, a λ / 2 wave plate, and a second λ / 4 wave plate; one end of the second Glan prism is connected to the laser generation device, and the other end of the second Glan prism is connected to one end of the second λ / 4 wave plate through the λ / 2 wave plate; A laser generation device for generating two lasers, namely a first laser and a second laser respectively; The second Glan prism for receiving the first laser emitted by the laser generation device and converting the first laser into linearly polarized pump light with an adjustable polarization angle together with the λ / 2 wave plate; The second λ / 4 wave plate for converting the linearly polarized pump light into left-handed circularly polarized pump light or right-handed circularly polarized pump light; the left-handed circularly polarized pump light or the right-handed circularly polarized pump light is used to excite the sample to be measured; The first Glan prism for converting the second laser into probe light linearly polarized in a specified direction; the probe light is used to detect the sample to be measured; The first λ / 4 wave plate for converting the probe light after detecting the sample to be measured into linearly polarized light with perpendicular polarizations; the linearly polarized light with perpendicular polarizations respectively represents left-handed circularly polarized probe light and right-handed circularly polarized probe light; The Wollaston prism for making the linearly polarized light with perpendicular polarizations propagate in different directions so that the left-handed circularly polarized probe light and the right-handed circularly polarized probe light can be received by the measurement device simultaneously; The measurement device for obtaining the transient absorption spectrum of the left-handed circularly polarized light and the transient absorption spectrum of the right-handed circularly polarized light according to the simultaneously received left-handed circularly polarized probe light and right-handed circularly polarized probe light; The laser generation device includes a laser amplifier, a beam splitter, a full-automatic optical parametric amplifier, a chopper, a delay line device, and a supercontinuum light generation device; the laser amplifier is connected to one end of the beam splitter, the other end of the beam splitter is respectively connected to one end of the full-automatic optical parametric amplifier and the supercontinuum light generation device, the other end of the full-automatic optical parametric amplifier is connected to one end of the chopper, the other end of the chopper is connected to one end of the delay line device, the other end of the delay line device is connected to the pump light polarization device, and the other end of the supercontinuum light generation device is connected to one end of the first Glan prism; The beam splitter for receiving the laser emitted by the laser amplifier and generating reflected light and transmitted light after reflection and transmission of the laser, outputting the first laser with a preset wavelength and pulse width through the full-automatic optical parametric amplifier for the reflected light, and generating supercontinuum white light within a preset spectral range as the second laser through the supercontinuum light generation device for the transmitted light; The chopper for adjusting the repetition frequency of the first laser from 500 Hz to 250 Hz; The delay line device for adjusting the optical path of the first laser to regulate the time when the first laser reaches the sample to be measured compared with the second laser.

2. The system according to claim 1, wherein The system further includes a sample loading device; focusing lenses are respectively arranged between the sample loading device and the pump light polarization device and the supercontinuum light generating device; the sample loading device is a vacuum device with a transparent glass window, and the sample loading device includes a three-dimensional movable sample stage, a sample to be measured, a liquid helium circulation cooling device and a vacuum gauge; the pump light output by the pump light polarization device and the probe light output by the supercontinuum light generating device are respectively focused onto the sample to be measured through the corresponding focusing lenses and the vacuum glass window; A three-dimensional movable sample stage for placing the sample to be measured; A liquid helium circulation cooling device for adjusting the temperature inside the sample loading device to adjust the temperature of the sample to be measured; A vacuum gauge for detecting the vacuum degree in the sample loading device.

3. The system according to claim 1, wherein The measuring device includes a first spectrometer, a second spectrometer and a computer control unit; The first spectrometer is used to receive the probe light representing left-handed circular polarization emitted by the Wollaston prism and send the spectral information of the left-handed circular polarization probe light to the computer control unit; The second spectrometer is used to receive the probe light representing right-handed circular polarization emitted by the Wollaston prism and send the spectral information of the right-handed circular polarization probe light to the computer control unit; The computer control unit is used to obtain the transient absorption spectrum of the left-handed circular polarization probe light and the transient absorption spectrum of the right-handed circular polarization probe light according to the received spectral information of the left-handed circular polarization probe light and the right-handed circular polarization probe light.

4. The system according to claim 3, wherein The laser amplifier, the full-automatic optical parametric amplifier, the chopper, the delay line device, the first spectrometer and the second spectrometer are all electrically connected to the computer control unit to control the coordinated operation of each component through the computer control unit.

5. A method for measuring the transient absorption spectrum of polarized light, characterized in that, The method is applied to the system according to any one of claims 1-4, and the method includes: Controlling the laser generating device to generate a first laser and a second laser, and adjusting the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser; Converting the first laser into a pump light with left-handed circular polarization or right-handed circular polarization through the pump light polarization device, and emitting the pump light with left-handed circular polarization or right-handed circular polarization onto the sample to be measured to excite the sample to be measured; Converting the second laser into a probe light through the Glan prism in the probe light polarization device, and detecting the sample to be measured with the probe light. The probe light transmitted through the sample to be measured passes through the first λ / 4 wave plate and the Wollaston prism in the probe light polarization device to convert the probe light into linearly polarized light with mutually perpendicular polarizations; the probe light passing through the Glan prism in the probe light polarization device is a synthesis of the left-handed circular polarization probe light and the right-handed circular polarization probe light; the linearly polarized light with mutually perpendicular polarizations respectively represents the left-handed circular polarization probe light and the right-handed circular polarization probe light; Receiving the probe light representing left-handed circular polarization and the probe light representing right-handed circular polarization respectively through the measuring device, and obtaining the transient absorption spectrum of the left-handed circular polarization probe light and the transient absorption spectrum of the right-handed circular polarization probe light according to the received left-handed circular polarization probe light and right-handed circular polarization probe light.

6. The method according to claim 5, characterized in that The process of obtaining the transient absorption spectrum of the left-handed circular polarization probe light includes: Obtain the change in the transmittance of the received left-handed circularly polarized probe light with and without the pump light, and calculate the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the left-handed circularly polarized probe light with and without the pump light; or, Obtain the change in the reflectance of the received left-handed circularly polarized probe light with and without the pump light, and calculate the transient absorption spectrum of the left-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the reflectance of the left-handed circularly polarized probe light with and without the pump light.

7. The method according to claim 5, wherein The process of obtaining the transient absorption spectrum of the right-handed circularly polarized probe light includes: Obtain the change in the transmittance of the received right-handed circularly polarized probe light with and without the pump light, and calculate the transient absorption spectrum of the right-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the transmittance of the right-handed circularly polarized probe light with and without the pump light; or, Obtain the change in the reflectance of the received right-handed circularly polarized probe light with and without the pump light, and calculate the transient absorption spectrum of the right-handed polarized light of the sample to be measured at the corresponding test delay time according to the change in the reflectance of the right-handed circularly polarized probe light with and without the pump light.

8. A transient absorption spectroscopy measurement device for polarized light, characterized in that, The device is applied to the system according to any one of claims 1-4, and the device includes: A laser generation module for controlling a laser generating device to generate a first laser and a second laser, and adjusting the optical path of the first laser to ensure that there is a test delay time for the second laser to reach the sample to be measured relative to the first laser; An excitation module for converting the first laser into a left-handed circularly polarized or right-handed circularly polarized pump light through a pump light polarization device, and emitting the left-handed circularly polarized or right-handed circularly polarized pump light onto the sample to be measured to excite the sample to be measured; A detection module for converting the second laser into a probe light through a Glan prism in the probe light polarization device, and detecting the sample to be measured through the probe light. The probe light transmitted through the sample to be measured passes through a first λ / 4 wave plate and a Wollaston prism in the probe light polarization device to convert the probe light into linearly polarized light with perpendicular polarizations; the probe light passing through the Glan prism in the probe light polarization device is a combination of a left-handed circularly polarized probe light and a right-handed circularly polarized probe light; the linearly polarized lights with perpendicular polarizations respectively represent the left-handed circularly polarized probe light and the right-handed circularly polarized probe light; A measurement module for respectively receiving the probe light representing the left-handed circularly polarized probe light and the right-handed circularly polarized probe light through a measuring device, and obtaining the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light according to the received left-handed circularly polarized probe light and right-handed circularly polarized probe light.

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