Wide spectrum detection method based on two-dimensional material non-degenerate three-photon absorption

Abstract

The invention discloses a wide-spectrum detection method based on two-dimensional material non-degenerate three-photon absorption, and the method comprises the steps: preparing a photoelectric detector based on a two-dimensional material, and configuring a non-degenerate light source needed for completing the non-degenerate three-photon absorption corresponding to the photoelectric detector; controlling the non-degenerate light source to irradiate the photoelectric detector to obtain photoelectric information; analyzing the photoelectric information to obtain an analysis result; and controlling the photoelectric detector to detect the signal light to be detected according to the analysis result to obtain detection information. According to the invention, the infrared light detection spectral range is broadened, and three beams of light are used for regulation and control, which is more flexible and changeable.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technology, and in particular to a broadband detection method and system based on non-degenerate three-photon absorption of two-dimensional materials. Background Art

[0002] A photodetector is an optoelectronic device that converts light signals into electrical signals. Based on their detection wavelength, infrared photodetectors can be divided into near-infrared photodetectors (0.75-3μm), mid-infrared photodetectors (3-15μm), and far-infrared photodetectors (15-1000μm). The optical communication band falls within the near-infrared range, requiring high detector sensitivity. Near-infrared photodetectors meet this requirement and can effectively and accurately capture lower-intensity signals. High-performance photodetectors play an important role in optoelectronic displays, environmental monitoring, optical communications, and military applications.

[0003] Currently, traditional infrared photodetectors are mainly based on materials such as indium gallium arsenide (InGaAs) and mercury cadmium telluride (HgCdTe). However, with the growing demand for applications, these detectors face several challenges. First, the manufacturing process of traditional photodetectors is relatively complex and expensive. In addition, these photodetectors have high dark current noise at room temperature and require a low-temperature operating environment to reduce the dark current. This requires the addition of cooling equipment to the detection system, which increases the size and cost of the photodetection system. Therefore, obtaining infrared photodetectors with low cost, simple manufacturing process, small size, and high performance is an urgent need for current development.

[0004] Among existing designs, two-dimensional materials represented by graphene have attracted widespread attention due to their unique structure and optical, electrical, and mechanical properties. They have also made their mark in the field of photodetectors, and can meet the needs of optical communications, thermal imaging, medical treatment, military, and other fields. Two-dimensional layered materials have high carrier mobility, strong light-matter interaction, and strong mechanical toughness. Their photoelectric properties can be modified by regulating the number of layers to obtain an extremely wide spectral response range. However, photodetectors based on two-dimensional materials currently also face some difficulties. First, in order to prepare two-dimensional materials on a large scale industrial scale, controlling the uniformity of their thickness is a difficult problem; in addition, due to the atomically thin thickness, the light absorption of two-dimensional materials is insufficient. In order to solve this problem, the method of increasing the number of material layers is usually adopted, but this will bring about large dark current noise and reduce the sensitivity of detection.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] The main purpose of this application is to provide a wide-spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials, aiming to solve the problems in the prior art of traditional photodetectors such as narrow detection spectrum, large equipment size, high cost, and small material bandgap selection range due to infrared wavelength limitations.

[0007] A first aspect of an embodiment of the present application provides a wide-spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials, the method comprising: preparing a photodetector based on two-dimensional materials, and configuring a non-degenerate light source required for the non-degenerate three-photon absorption of the photodetector; controlling the non-degenerate light source to illuminate the photodetector to obtain photoelectric information; analyzing the photoelectric information to obtain an analysis result; and controlling the photodetector to detect the signal light to be measured based on the analysis result to obtain detection information.

[0008] Optionally, in one embodiment of the present application, the non-degenerate light source includes two beams of pump light and one beam of preset signal light, and the photoelectric information includes photocurrent data; controlling the non-degenerate light source to illuminate the photodetector to obtain photoelectric information specifically includes: using optical elements to irradiate the two beams of the pump light and the one beam of the preset signal light onto the photodetector, so that the three beams of light and the two-dimensional material undergo a non-degenerate three-photon absorption process; and collecting the photocurrent data generated by the photodetector.

[0009] Optionally, in one embodiment of the present application, the analysis result is a slope; the analysis of the photoelectric information to obtain the analysis result specifically includes: processing the photocurrent data to obtain a double logarithmic graph of photocurrent and photoelectricity; fitting the double logarithmic graph to obtain the slope.

[0010] Optionally, in one embodiment of the present application, the analysis results also include a non-degenerate three-photon absorption coefficient; the acquisition of the photocurrent data generated by the photodetector further includes: establishing a mathematical model between the photogenerated conduction electron density and the incident light intensity; and calculating the non-degenerate three-photon absorption coefficient of the two-dimensional material based on the mathematical model and the photocurrent data.

[0011] Optionally, in one embodiment of the present application, according to the analysis result, controlling the photodetector to detect the signal light to be measured to obtain detection information, specifically including: if the slope meets the preset requirements, obtaining the wavelength of the signal light to be measured; according to the wavelength of the signal light to be measured, adjusting the wavelength group corresponding to the two beams of the pump light to obtain a target wavelength group, and controlling the two beams of the pump light to irradiate the photodetector according to the target wavelength group; controlling the photodetector to detect the signal light to be measured to obtain detection information of the signal light to be measured.

[0012] Optionally, in one embodiment of the present application, the target wavelength group includes a first wavelength and a second wavelength corresponding to the two beams of pump light, respectively; the wavelength group corresponding to the two beams of pump light is adjusted according to the wavelength of the signal light to be measured to obtain a target wavelength group, and the two beams of pump light are controlled to irradiate the photodetector according to the target wavelength group, specifically: according to the wavelength of the signal light to be measured, the wavelength group corresponding to the two beams of pump light is adjusted to obtain a first wavelength and a second wavelength, so that the two beams of pump light irradiate the photodetector according to the first wavelength and the second wavelength, so that the two beams of pump light, the preset signal light and the two-dimensional generate non-degenerate three-photon absorption.

[0013] Optionally, in one embodiment of the present application, the detection information includes signal strength, signal frequency and signal phase; controlling the photodetector to detect the signal light to be measured to obtain the detection information of the signal light to be measured specifically includes: controlling the photodetector to detect the signal light to be measured to obtain an output electrical signal; analyzing the output electrical signal to obtain signal strength, signal frequency and signal phase.

[0014] Optionally, in one embodiment of the present application, the double logarithmic graph is fitted to obtain a slope, and then the method further includes: performing a performance evaluation on the photodetector to obtain an evaluation result; and optimizing the photodetector based on the evaluation result to obtain an optimized photodetector.

[0015] Optionally, in one embodiment of the present application, the mathematical model is expressed as:

[0016]

[0017] in, is the rate of change of the photogenerated conduction electron density with time during the partial non-degenerate three-photon absorption process, α3(ν1; ν2; ν2) is the three-photon absorption coefficient during the partial non-degenerate three-photon absorption process, I1 and I2 are the intensities of the signal light and the pump light corresponding to the incident light, h is the Planck constant, and v1 and v2 are the frequencies of the signal light and the pump light corresponding to the incident light; or

[0018] The mathematical model is expressed as:

[0019]

[0020] in, is the rate of change of the photogenerated conduction electron density with time in the completely nondegenerate three-photon absorption process, α3(v1; v2; v3) is the three-photon absorption coefficient in the partially nondegenerate three-photon absorption process, I1, I2, I3 are the intensities of the signal light and the two pump beams corresponding to the incident light, h is the Planck constant, and v1, v2, v3 are the frequencies of the signal light and the two pump beams corresponding to the incident light.

[0021] A second aspect of the embodiments of the present application further provides a broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials, wherein the broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials comprises:

[0022] A device preparation module is used to prepare a photodetector based on two-dimensional materials and configure the non-degenerate light source required for the photodetector to correspond to non-degenerate three-photon absorption;

[0023] an irradiation experiment module, used for controlling the non-degenerate light source to irradiate the photodetector to obtain photoelectric information;

[0024] A data analysis module, configured to analyze the photoelectric information and obtain analysis results;

[0025] The signal light detection module is used to control the photoelectric detector to detect the signal light to be measured according to the analysis result to obtain detection information.

[0026] Beneficial effects: The present application provides a wide-spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials. This method completes electron transitions through three photons of different energies (i.e., a non-degenerate light source) or two photons of the same energy and one different energy (i.e., a non-degenerate light source), thereby stimulating the nonlinear optical properties of two-dimensional materials. By utilizing this high-order nonlinear optical process, the material band gap selection problem caused by infrared wavelength limitations is overcome, the infrared light detection spectrum range is broadened, and three beams of light are used for regulation, which is more flexible and changeable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 is a schematic diagram of the degenerate three-photon absorption process;

[0029] Figure 2 This is a schematic diagram of the non-degenerate three-photon absorption process;

[0030] Figure 3It is a diagram of the photoelectric detection system;

[0031] Figure 4 This is a flow chart of a preferred embodiment of the present invention's method for broadband detection based on non-degenerate three-photon absorption of two-dimensional materials;

[0032] Figure 5 This is an optical image of a single-layer MoS2 carrying an electrode;

[0033] Figure 6 The following is a log-log plot of the photocurrent and light intensity dependence based on non-degenerate three-photon absorption under 1250nm, 1500nm, and 2500nm excitation.

[0034] Figure 7 This is a structural diagram of a preferred embodiment of the present application's wide-spectrum detection system based on non-degenerate three-photon absorption of two-dimensional materials.

[0035] Description of reference numerals:

[0036] 100. Device preparation module; 200. Irradiation experiment module; 300. Data analysis module; 400. Signal light detection module. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and effects of this application clearer and more specific, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. The described embodiments are only possible technical implementations of this application and are not all possible implementations. Based on the embodiments in this application, those skilled in the art can fully combine the embodiments of this application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of this application.

[0038] In the related art, in order to further meet the needs of practical applications, enhancing material light absorption, improving sensitivity, and reducing noise are the development directions of photodetectors based on two-dimensional materials. In response to the problem that traditional photodetectors have a narrow detection spectrum, this application is based on non-degenerate three-photon absorption. With three beams of light incident, the wavelength of the light beam can be flexibly controlled to broaden the infrared detection spectrum range; in response to the problem that traditional photodetector equipment is large in size and high in cost, this application uses two-dimensional materials as the basis to prepare photodetectors. The preparation process is simple and the cost is low. It can also work normally and stably at room temperature, avoiding the problem of increased detector system volume caused by the addition of low-temperature equipment; in response to the material band gap selection problem caused by the infrared wavelength limitation of traditional photodetectors, this application adopts the method of non-degenerate three-photon absorption, which has a higher degree of freedom in the selection of light beam wavelength and can overcome the technical difficulties of material selection and its limitation. This application has reasonable logic and simple operation. It utilizes the non-degenerate three-photon absorption process of two-dimensional materials, has the advantages of avoiding the limitation of phase matching, can operate at room temperature, and broaden the detection spectrum range, effectively improving the performance of photodetectors.

[0039] First, the principles of degenerate three-photon absorption and non-degenerate three-photon absorption in this application are introduced:

[0040] See also Figure 1 The physical process of degenerate three-photon absorption: when the energy of three identical infrared photons is greater than the band gap of the material, degenerate three-photon absorption can be achieved.

[0041] See also Figure 2 Nondegenerate three-photon absorption is a physical process that can be categorized into fully nondegenerate three-photon absorption and partially nondegenerate three-photon absorption. Fully nondegenerate three-photon absorption occurs when the energy of the infrared light being detected plus two other pump lights of different wavelengths exceeds the material bandgap. Partial nondegenerate three-photon absorption occurs when the energy of the infrared light being detected plus two other pump lights of the same wavelength exceeds the material bandgap, or when the energy of two infrared lights being detected plus one pump light of a different wavelength exceeds the material bandgap. In practical applications, the latter type of partially nondegenerate three-photon absorption is relatively difficult to achieve due to the relatively low power of the signal light.

[0042] Secondly, see Figure 3 , the system architecture of the photoelectric detection system of this application is introduced.

[0043] The photoelectric detection system is constructed based on the broadband detection method of non-degenerate three-photon absorption of two-dimensional materials in this application. Taking a single-layer MoS2 material as an example, a photoelectric detector ( Figure 3 After the non-degenerate three-photon absorption process occurs, the photodetector performance is obtained using the source meter. It should be noted that Figure 3The detector in the figure is a detection device, and the sample in the box is a photoelectric detector according to an embodiment of the present application.

[0044] Specifically, a photoelectric detection system is constructed, which includes a light source (such as a laser), optical elements (such as filters, beam splitters, reflectors, etc.), samples (photodetectors made of the material to be tested) and detection devices (such as source meters, power meters, etc.).

[0045] The following describes the wide-spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials according to an embodiment of the present application with reference to the accompanying drawings. In response to the problems in the above-mentioned related technologies that traditional photodetectors have a narrow detection spectrum, large equipment volume, high cost, and a small range of material band gap selection due to infrared wavelength limitations, the present application provides a wide-spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials. In this method, three photons with different energies (i.e., non-degenerate light sources) or two photons with the same energy and one different photon (i.e., non-degenerate light sources) are used to complete electron transitions and stimulate the nonlinear optical properties of the photodetector. By utilizing this high-order nonlinear optical process, the material band gap selection problem caused by infrared wavelength limitations is overcome, the infrared light detection spectrum range is broadened, and three beams of light are used for regulation, which is more flexible and changeable. Thus, the technical problems in the related technologies that traditional photodetectors have a narrow detection spectrum, large equipment volume, high cost, and a small range of material band gap selection due to infrared wavelength limitations are solved.

[0046] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0047] The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials described in the preferred embodiment of the present application is as follows: Figure 4 As shown, the broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials includes the following steps:

[0048] In step S101, a photodetector based on a two-dimensional material is prepared, and a non-degenerate light source required for the photodetector to correspond to non-degenerate three-photon absorption is configured.

[0049] The non-degenerate light source includes two beams of pump light and a beam of preset signal light.

[0050] Specifically, materials with suitable band gaps and strong nonlinear optical properties are selected, such as two-dimensional materials (such as single-layer MoS2) or perovskite single crystals (such as MAPbBr3). These materials can support non-degenerate three-photon absorption processes. Photodetectors are prepared and electrodes are mounted on them to measure photocurrent. A sample of two-dimensional material, such as single-layer MoS2, is prepared and mounted on electrodes to form a photodetector. This step ensures that the sample can effectively convert optical signals into electrical signals.

[0051] Based on the characteristics of the selected material, configure pump and signal light of appropriate wavelengths. The pump light wavelength and power should effectively stimulate nondegenerate three-photon absorption, while the signal light should be the infrared light to be detected. Specifically, select appropriate pump light wavelengths (such as 1250nm and 1500nm) and signal light wavelengths (such as 2500nm). Ensure that the total energy of the pump and signal light exceeds the band gap energy of the material to achieve nondegenerate three-photon absorption.

[0052] It is worth noting that this application is based on the nondegenerate three-photon absorption process in nonlinear optics. The core is to use three photons with different energies or two photons with the same energy and one photon with different energy to complete electron transitions and stimulate the nonlinear optical properties of the sample. By using this high-order nonlinear optical process, the phase matching limitation is broken through and the application range is wider. It overcomes the material bandgap selection problem caused by the infrared wavelength limitation and broadens the infrared light detection spectrum range. The use of three beams of light for regulation is more flexible and changeable. The device of this application only requires two-dimensional materials and electrodes to complete broadband photoelectric detection. The preparation process is easy to understand, the processing cost is low, the process is simple, and it can be operated at room temperature, meeting the demand for small size of photoelectric detector systems.

[0053] In step S102, the non-degenerate light source is controlled to illuminate the photodetector to obtain photoelectric information.

[0054] In one possible implementation, the photoelectric information includes photocurrent data. An optical element is used to irradiate the two pump light beams and the one preset signal light beam onto the photodetector, causing the three beams to undergo a non-degenerate three-photon absorption process; and the photocurrent data generated by the photodetector is collected.

[0055] Specifically, optical elements are used to focus three beams of light onto a two-dimensional material sample, ensuring that they can accurately illuminate the effective detection area of ​​the sample; the light source is turned on so that the three beams of light are simultaneously illuminated on the sample, ensuring that their energy and phase relationship meet the conditions for non-degenerate three-photon absorption, and a non-degenerate three-photon absorption process occurs. A source meter and other detection devices are used to record the change of photocurrent with light intensity (i.e., photocurrent data). What is usually obtained is a log-log graph (double logarithmic graph) of photocurrent and light intensity.

[0056] In step S103, the photoelectric information is analyzed to obtain an analysis result.

[0057] In a possible implementation, the analysis result is a slope. The photocurrent data is processed to obtain a double logarithmic graph of photocurrent and photoelectricity; and the double logarithmic graph is fitted to obtain the slope.

[0058] Specifically, the measured photocurrent data is processed and a log-log graph of photocurrent and light intensity is plotted. By fitting the graph, the slope can be obtained to verify the generation of non-degenerate three-photon absorption-induced photocurrent. The log-log graph of photocurrent and light intensity (i.e., a double logarithmic graph) is analyzed. If the slope after fitting is 1 (the preset requirement is within 1-1.1), it proves that a non-degenerate three-photon absorption process has occurred.

[0059] Furthermore, the collected light intensity and photocurrent data are logarithmically transformed. That is, the logarithm of each light intensity value (usually the natural logarithm or the common logarithm) is taken, and the corresponding photocurrent value is also logarithmically transformed. Data processing software (such as Excel, MATLAB, Python, etc.) is used to plot the transformed data points to obtain a log-log graph of photocurrent and light intensity. A fitting model is selected. In the log-log graph, if the data points show a straight line trend, it may mean that there is a power-law relationship between photocurrent and light intensity. In this case, a linear regression model can be used to fit these data points. Execute the fitting, using the selected data processing software, and perform a linear regression fit on the data points in the log-log graph. After the fitting is complete, the software will output the slope of the fitted line. In the log-log graph, this slope is actually an estimate of the power exponent of the power-law relationship between photocurrent and light intensity in the original data.

[0060] It is important to understand that non-degenerate three-photon absorption refers to the process in which a molecule or atom simultaneously absorbs three photons of different energies, transitioning from the ground state to the excited state. This process typically occurs under high-intensity laser radiation and requires the laser's coherence and power to reach a certain level. The relationship between the slope and three-photon absorption: If the slope (i.e., the power exponent) obtained from the fitting is greater than 1 and close to 3 (taking into account experimental errors and simplifications in the theoretical model), this may indicate that the generation of photocurrent is related to the non-degenerate three-photon absorption process.

[0061] See also Figure 5 and Figure 6 , Figure 5 This is an optical image of a single-layer MoS2 electrode. This application uses it to make a photodetector, using 1250nm and 1500nm light as pump light to detect 2500nm signal light. The resulting log-log plot of photocurrent and light intensity is 1 after fitting, proving the generation of non-degenerate three-photon absorption-induced photocurrent. Detection of the 2500nm band based on non-degenerate three-photon absorption of monolayer MoS2 occurs. This application successfully detects weak photons at 2500nm, demonstrating the potential of using non-degenerate three-photon absorption to achieve wide-spectrum detection in the near-infrared and even mid-infrared.

[0062] In a possible implementation, a performance evaluation is performed on the photodetector to obtain an evaluation result; and based on the evaluation result, the photodetector is optimized to obtain an optimized photodetector.

[0063] Specifically, the performance of the photodetector can be evaluated based on the magnitude and stability of the photocurrent. Furthermore, the three-photon absorption coefficient of the two-dimensional material can be calculated to further characterize the material's nonlinear optical properties.

[0064] In one possible implementation, the analysis results also include a non-degenerate three-photon absorption coefficient. A mathematical model is established between the density of photogenerated conduction electrons and the incident light intensity; and the non-degenerate three-photon absorption coefficient of the two-dimensional material is calculated based on the mathematical model and the photocurrent data.

[0065] Specifically, the three-photon absorption coefficient is calculated by using the established mathematical model and experimental data to calculate the non-degenerate three-photon absorption coefficient of the material. This can be achieved by comparing the photocurrent generated by the single-photon absorption process with the photocurrent generated by the non-degenerate three-photon absorption process.

[0066] It is worth noting that the device of the present application has the ability to characterize the nonlinear optical properties of two-dimensional materials, and can calculate the three-photon absorption coefficient of the two-dimensional material while obtaining the photocurrent.

[0067] Mathematical model of the three-photon absorption coefficient The density of photogenerated conduction electrons N generated by the degenerate and non-degenerate three-photon absorption process depends on the incident light intensity and is expressed as: (Degenerate three-photon absorption process)

[0068] (Partial non-degenerate three-photon absorption process) (Completely non-degenerate three-photon absorption process)

[0069] Preferably, the present application adopts a completely non-degenerate three-photon absorption process, or a partially non-degenerate three-photon absorption process.

[0070] Where N is the photogenerated conduction electron density, which represents the number of free electrons generated in the material due to the photon absorption process; where α3(v1; v2; v3) represents the time rate of change of the photogenerated conduction electron density in the processes of degenerate three-photon absorption, partially non-degenerate three-photon absorption, and completely non-degenerate three-photon absorption, respectively; λ3(v1; v1; v1) is the degenerate three-photon absorption coefficient under the excitation of a signal pulse with an incident light frequency of v1 and a light intensity of I1; α3(v1; v2; v2) is the partial non-degenerate three-photon absorption coefficient under the co-excitation of a signal pulse and a pump pulse with incident light frequencies of v1, v2, v2, and light intensities of I1, I2, and I2, respectively; α3(v1; v2; v3) is the complete non-degenerate three-photon absorption coefficient under the co-excitation of a signal pulse and two different pump pulses with incident light frequencies of v1, v2, v3, and light intensities of I1, I2, and I3, respectively. I1, I2, and I3 are the intensities of the incident light, corresponding to different light pulses respectively; h is Planck's constant, a basic constant in quantum mechanics; v1, v2, and ν3 are the frequencies of the incident light, corresponding to different light pulses respectively.

[0071] According to the relationship between current and electron number, J=ngv d , n is the concentration of carriers (here electrons), q is the charge of the electrons, v d is the drift velocity of the carrier (electron), and the photocurrent J generated by the degenerate / non-degenerate three-photon absorption process can be calculated. D3PA / J ND3PA , and then combined with the photocurrent J generated by the single photon absorption process single By comparison, the three-photon absorption coefficient can be obtained:

[0072]

[0073] Wherein, J is the photocurrent, which is the current formed by the directional movement of photogenerated electrons under the action of the electric field; J D3PA 、J ND3PA1 、J ND3PA2 、J single They represent the photocurrents generated by degenerate three-photon absorption, partially non-degenerate three-photon absorption, completely non-degenerate three-photon absorption, and single-photon absorption, respectively. L is the sample thickness, which is the distance between light and matter; α1 is the linear absorption coefficient, which represents the material's ability to absorb single photons; I'1, I'2, I'3, I' single is the peak intensity of the incident light, which is the maximum value of the light intensity in time; t1 and t3 are the pulse widths of the single-photon absorption and three-photon absorption processes, that is, the duration of the light pulse in time;

[0074]

[0075] Among them, F1, F2, and F3 are geometric factors related to the shape and size of the light spot, which are used to correct the photocurrent differences caused by different light spot sizes. These factors are calculated by integration, taking into account the two-dimensional distribution of the light spot; ω1, ω2, ω3, ω single The incident light frequencies are v1, v2, v3, and v single The laser spot radius represents the size of the spot in the cross section; a and b represent half the length and half the width of the effective detection area, respectively; 2a and 2b represent the length and width of the effective detection area, respectively, that is, the size of the area in which the detector can respond to light signals; x and y represent the coordinates of the spot on the two-dimensional plane.

[0076] In step S104, according to the analysis result, the photoelectric detector is controlled to detect the signal light to be measured to obtain detection information.

[0077] In one possible implementation, if the slope meets preset requirements, the wavelength of the signal light to be measured is obtained; based on the wavelength of the signal light to be measured, the wavelength group corresponding to the two beams of pump light is adjusted to obtain a target wavelength group; the two beams of pump light are controlled to illuminate the photodetector according to the target wavelength group, and the photodetector is controlled to detect the signal light to be measured, thereby obtaining detection information of the signal light to be measured.

[0078] Specifically, when detecting the signal light to be measured, the wavelength of the signal light is first obtained. Based on the experimental requirements or physical mechanisms (such as nonlinear optical effects, optical amplification, etc.), the wavelengths of the two pump beams are adjusted to ensure that the pump light, signal light, and two-dimensional material can produce the expected non-degenerate three-photon absorption. In the photoelectric detection system, ensure that the photodetector is correctly set up and calibrated so that it can accurately convert the received optical signal into an electrical signal. Finally, by processing and analyzing the electrical signal output by the photodetector, the detection information of the signal light to be measured is obtained. This information may include parameters such as the signal intensity, frequency, and phase.

[0079] It should be noted that the intensities of both the pump and signal beams in non-degenerate three-photon absorption must be controlled. This is because when the laser intensity is high enough, if the photon energy exceeds one-third of the material's bandgap, degenerate three-photon absorption may occur directly. To avoid this, the intensities of the pump and signal beams must be controlled below the degenerate three-photon absorption excitation threshold. Three-photon absorption is a fifth-order nonlinear optical process, which has higher excitation intensity requirements than lower-order linear and nonlinear optical processes. To achieve these requirements while stimulating non-degenerate three-photon absorption in the material, the range of the incident beam intensities must be controlled.

[0080] It's understandable that the core technical feature of non-degenerate three-photon absorption photodetector designs based on materials like heterojunctions or plasmas is the use of non-degenerate three-photon absorption technology for photodetection. This technology, combined with the simplified fabrication process, low cost, and increased practicality of single-layer two-dimensional materials, is not readily available in other materials. Ultra-broadband photodetectors based on non-degenerate three-photon absorption utilize a significant energy difference between the pump and signal wavelengths, significantly broadening the detection spectral range.

[0081] Next, a broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

[0082] Figure 7 It is a block diagram of a broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials according to an embodiment of the present application.

[0083] like Figure 7 As shown, the broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials includes: a device preparation module 100, an irradiation experiment module 200, a data analysis module 300 and a signal light detection module 400.

[0084] Specifically, the device preparation module 100 is used to configure a non-degenerate light source corresponding to a photodetector, wherein the photodetector is prepared based on a two-dimensional material;

[0085] an irradiation experiment module 200, configured to control the non-degenerate light source to irradiate the photodetector to obtain photoelectric information;

[0086] The data analysis module 300 is used to analyze the photoelectric information and obtain analysis results;

[0087] The signal light detection module 400 is used to control the photoelectric detector to detect the signal light to be measured according to the analysis result to obtain detection information.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0089] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0090] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0091] It should be understood that the application of this application is not limited to the above examples. For ordinary technicians in this field, they can make improvements or changes based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to this application.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials, characterized in that: The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials comprises: Prepare a photodetector based on two-dimensional materials, and configure a non-degenerate light source required for the photodetector to correspond to non-degenerate three-photon absorption; Controlling the non-degenerate light source to illuminate the photoelectric detector to obtain photoelectric information; Analyzing the photoelectric information to obtain analysis results; According to the analysis result, the photoelectric detector is controlled to detect the signal light to be detected to obtain detection information.

2. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 1, characterized in that: The non-degenerate light source includes two pump light beams and a preset signal light beam, and the photoelectric information includes photocurrent data; The controlling the non-degenerate light source to illuminate the photoelectric detector to obtain photoelectric information specifically includes: Using an optical element to irradiate the two beams of pump light and the one beam of preset signal light onto the photodetector, so that the three beams of light undergo a non-degenerate three-photon absorption process with the two-dimensional material; The photocurrent data generated by the photodetector is collected.

3. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 2, characterized in that: The analysis result is the slope; The analyzing the photoelectric information to obtain the analysis result specifically includes: Processing the photocurrent data to obtain a double logarithmic graph of photocurrent and photoelectricity; The double logarithmic graph is fitted to obtain a slope.

4. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 2, characterized in that: The analysis results also include non-degenerate three-photon absorption coefficient; The step of collecting the photocurrent data generated by the photodetector further includes: Establish a mathematical model between the density of photogenerated conduction electrons and the intensity of incident light; The non-degenerate three-photon absorption coefficient of the two-dimensional material is calculated according to the mathematical model and the photocurrent data.

5. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 3, characterized in that: According to the analysis result, controlling the photoelectric detector to detect the signal light to be measured to obtain detection information specifically includes: If the slope meets the preset requirement, obtaining the wavelength of the signal light to be measured; According to the wavelength of the signal light to be measured, the wavelength group corresponding to the two beams of the pump light is adjusted to obtain a target wavelength group, and the two beams of the pump light are controlled to irradiate the photodetector according to the target wavelength group; The photoelectric detector is controlled to detect the signal light to be measured, so as to obtain detection information of the signal light to be measured.

6. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 5, characterized in that: The target wavelength group includes a first wavelength and a second wavelength corresponding to the two beams of pump light respectively; The step of adjusting the wavelength group corresponding to the two pump lights according to the wavelength of the signal light to be measured to obtain a target wavelength group, and controlling the two pump lights to irradiate the photodetector according to the target wavelength group, is specifically as follows: According to the wavelength of the signal light to be measured, the wavelength group corresponding to the two beams of pump light is adjusted to obtain a first wavelength and a second wavelength, so that the two beams of pump light irradiate the photodetector according to the first wavelength and the second wavelength, so that the two beams of pump light, the preset signal light and the two-dimensional produce non-degenerate three-photon absorption.

7. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 5, characterized in that: The detection information includes signal strength, signal frequency and signal phase; The controlling the photoelectric detector to detect the signal light to be measured to obtain the detection information of the signal light to be measured specifically includes: Controlling the photoelectric detector to detect the signal light to be detected to obtain an output electrical signal; The output electrical signal is analyzed to obtain signal strength, signal frequency and signal phase.

8. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 3, characterized in that: The double logarithmic graph is fitted to obtain a slope, and then the following steps are further included: Performing a performance evaluation on the photodetector to obtain an evaluation result; The photoelectric detector is optimized according to the evaluation result to obtain an optimized photoelectric detector.

9. The broadband detection method based on non-degenerate three-photon absorption of two-dimensional materials according to claim 4, characterized in that: The mathematical model is expressed as: in, is the rate of change of the photogenerated conduction electron density with time during the partial non-degenerate three-photon absorption process, α3(v1; v2; v2) is the three-photon absorption coefficient during the partial non-degenerate three-photon absorption process, I1 and I2 are the intensity of the signal light and the pump light corresponding to the incident light, h is the Planck constant, ν1 and ν2 are the frequencies of the signal light and the pump light corresponding to the incident light; or The mathematical model is expressed as: in, is the rate of change of the photogenerated conduction electron density with time in the process of completely non-degenerate three-photon absorption, α3(v1; v2; v3) is the three-photon absorption coefficient in the process of partially non-degenerate three-photon absorption, I1, I2, I3 are the intensities of the signal light and the two pump lights corresponding to the incident light, h is the Planck constant, v1, ν2, ν3 are the frequencies of the signal light and the two pump lights corresponding to the incident light.

10. A broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials, characterized in that: The broadband detection system based on non-degenerate three-photon absorption of two-dimensional materials comprises: A device preparation module, used to prepare a photodetector based on two-dimensional materials, and to configure a non-degenerate light source required for the photodetector to correspond to non-degenerate three-photon absorption; An irradiation experiment module, used for controlling the non-degenerate light source to irradiate the photoelectric detector to obtain photoelectric information; A data analysis module, used to analyze the photoelectric information to obtain analysis results; The signal light detection module is used to control the photoelectric detector to detect the signal light to be detected according to the analysis result to obtain detection information.

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