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

Abstract

The application discloses a wide-spectrum detection method based on two-dimensional material non-degenerate three-photon absorption, which comprises the following steps: preparing a photoelectric detector based on a two-dimensional material, configuring a non-degenerate light source required for corresponding non-degenerate three-photon absorption of 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 a signal light to be detected according to the analysis result to obtain detection information. The application widens the infrared light detection spectral range, and utilizes three light beams to perform regulation and control, and is more flexible and changeable.

Description

TECHNICAL FIELD

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

[0002] A photodetector is an optoelectronic device that converts optical signals into electrical signals. From the perspective of detection wavelength, infrared photodetectors can be divided into near-infrared photodetectors (0.75-3 μm), mid-infrared photodetectors (3-15 μm), and far-infrared photodetectors (15-1000 μm). The optical communication band belongs to the range of near-infrared bands, and the sensitivity requirement for the photodetector is relatively high. The near-infrared photodetector meets this requirement and can effectively and accurately capture signals with low intensity. High-performance photodetectors play an important role in optoelectronic displays, environmental monitoring, optical communication, and military applications.

[0003] Currently, traditional infrared photodetectors are mainly based on indium gallium arsenide (InGaAs) and mercury cadmium telluride (HgCdTe) materials, but as the application demand grows, such detectors face some problems. First, the preparation process of traditional photodetectors is relatively complex and expensive. In addition, such photodetectors have high dark current noise at room temperature, and a low-temperature working environment is needed to reduce the dark current. Cooling equipment needs to be added to the detection system, resulting in an increase in the volume and cost of the photodetection system. Therefore, it is an urgent need to develop an infrared photodetector with low cost, simple preparation process, small size, and high performance.

[0004] In existing designs, two-dimensional materials represented by graphene have attracted widespread attention due to their unique structure and optical, electrical, and mechanical properties, and have made a name for themselves in the field of photodetectors, meeting the needs of optical communication, thermal imaging, medical treatment, and military applications. Two-dimensional layered materials have high carrier mobility, strong light-matter interaction, and strong mechanical toughness, and their optoelectronic properties can be changed by adjusting the number of layers to obtain a very wide spectral response range. However, photodetectors based on two-dimensional materials currently also have some difficulties. First, to mass-produce two-dimensional materials, it is difficult to control the uniformity of their thickness. In addition, due to the atomic-level thickness, the light absorption of two-dimensional materials is insufficient. To solve this problem, the number of material layers is usually increased, but this will result in high dark current noise and reduce the sensitivity of detection.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] The main purpose of the present application is to provide a wide spectrum detection method based on two-dimensional material non-degenerate three-photon absorption, aiming at solving the problems of narrow spectrum detection, large equipment volume, high cost and small material band gap selection range caused by infrared wavelength limitation of the traditional photodetector in the prior art.

[0007] The first aspect of the embodiment of the present application provides a wide spectrum detection method based on two-dimensional material non-degenerate three-photon absorption, which comprises the following steps: preparing a photodetector based on two-dimensional material, configuring a non-degenerate light source required for non-degenerate three-photon absorption corresponding to the photodetector; controlling the non-degenerate light source to irradiate the photodetector to obtain photoelectric information; analyzing the photoelectric information to obtain an analysis result; and controlling the photodetector to detect a to-be-detected signal light according to the analysis result to obtain detection information.

[0008] Optionally, in an embodiment of the present application, the non-degenerate light source comprises two pump lights and a preset signal light, and the photoelectric information comprises photocurrent data; the step of controlling the non-degenerate light source to irradiate the photodetector to obtain photoelectric information specifically comprises: using an optical element to irradiate the two pump lights and the preset signal light onto the photodetector to cause a non-degenerate three-photon absorption process of the three lights and the two-dimensional material; and collecting photocurrent data generated by the photodetector.

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

[0010] Optionally, in an embodiment of the present application, the analysis result further comprises a non-degenerate three-photon absorption coefficient; and the step of collecting the photocurrent data generated by the photodetector further comprises: establishing a mathematical model between photo-induced conduction electron density and incident light intensity; and calculating the non-degenerate three-photon absorption coefficient of the two-dimensional material according to the mathematical model and the photocurrent data.

[0011] Optionally, in an embodiment of the present application, the step of controlling the photodetector to detect a to-be-detected signal light according to the analysis result to obtain detection information specifically comprises: if the slope meets a preset requirement, obtaining a wavelength of the to-be-detected signal light; adjusting a wavelength group corresponding to the two pump lights according to the wavelength of the to-be-detected signal light to obtain a target wavelength group, and controlling the two pump lights to irradiate the photodetector according to the target wavelength group; and controlling the photodetector to detect the to-be-detected signal light to obtain detection information of the to-be-detected signal light.

[0012] Optionally, in an 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 to-be-detected signal light 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: the first wavelength and the second wavelength are obtained by adjusting the wavelength group corresponding to the two beams of pump light according to the wavelength of the to-be-detected signal light, 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 non-degenerate three-photon absorption.

[0013] Optionally, in an embodiment of the present application, the detection information includes signal intensity, signal frequency and signal phase; the photodetector is controlled to detect the to-be-detected signal light to obtain detection information of the to-be-detected signal light, specifically including: the photodetector is controlled to detect the to-be-detected signal light to obtain an output electrical signal; the output electrical signal is analyzed to obtain signal intensity, signal frequency and signal phase.

[0014] Optionally, in an embodiment of the present application, the fitting processing of the double logarithmic diagram to obtain the slope further includes: the performance of the photodetector is evaluated to obtain an evaluation result; and the photodetector is optimized according to the evaluation result to obtain an optimized photodetector.

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

[0016]

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

[0018] The mathematical model is represented as:

[0019]

[0020] wherein, is the rate of change of the photo-generated conduction electron density with time in the completely non-degenerate three-photon absorption process, is the three-photon absorption coefficient in the partially non-degenerate three-photon absorption process, I1, I2, I3 are the light intensities of the incident light corresponding to the signal light and the two pump lights, h is the Planck constant, v1, v2, v3 are the frequencies of the incident light corresponding to the signal light and the two pump lights.

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

[0022] A device preparation module is configured to prepare a photoelectric detector based on two-dimensional materials, and the non-degenerate light source required for the photoelectric detector to correspond to non-degenerate three-photon absorption is configured to be completed.

[0023] An irradiation experiment module is configured to control the non-degenerate light source to irradiate the photoelectric detector to obtain photoelectric information.

[0024] A data analysis module is configured to analyze the photoelectric information to obtain an analysis result.

[0025] A signal light detection module is configured to control the photoelectric detector to detect a to-be-detected signal light 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, which completes electron transition by using three energy different photons (i.e., a non-degenerate light source) or two energy same and one different photons (i.e., a non-degenerate light source), excites the nonlinear optical properties of two-dimensional materials, uses the high-order nonlinear optical process to overcome the material band gap selection problem caused by the infrared wavelength limitation, widens the infrared light detection spectral range, and uses three beams of light to perform regulation and control, which is more flexible. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

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

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

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

[0031] Figure 4 is a flow chart of a preferred embodiment of a wide spectrum detection method based on non-degenerate three-photon absorption of two-dimensional materials according to the present application;

[0032] Figure 5 is an optical image of a single-layer MoS2 with electrodes;

[0033] Figure 6 is a log-log graph of the photocurrent based on non-degenerate three-photon absorption versus light intensity for 1250 nm, 1500 nm and 2500 nm excitation;

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

[0035] BRIEF DESCRIPTION OF DRAWINGS

[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 scheme and effect of the present application more clear and definite, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. The described embodiments are only possible technical implementations of the present application, and are not all possible implementations. Based on the embodiments in the present application, those skilled in the art can easily combine the embodiments of the present application to obtain other embodiments without creative labor, and these embodiments are also within the protection scope of the present application.

[0038] In related technologies, to further meet practical applications, enhancing material light absorption, improving sensitivity, and reducing noise are development directions for photodetectors based on two-dimensional materials. Addressing the narrow detection spectrum of traditional photodetectors, this application utilizes non-degenerate three-photon absorption, with three incident beams, allowing flexible control of beam wavelengths and broadening the infrared detection spectrum. Addressing the large size and high cost of traditional photodetectors, this application uses two-dimensional materials to fabricate the photodetector, resulting in a simple and low-cost fabrication process that operates stably at room temperature, avoiding the increased system size associated with adding cryogenic equipment. Addressing the material bandgap selection limitations imposed by infrared wavelength restrictions in traditional photodetectors, this application employs a non-degenerate three-photon absorption method, offering greater freedom in beam wavelength selection and overcoming the technical constraints of limited material selection. This application is logically sound and simple to operate. Utilizing the non-degenerate three-photon absorption process of two-dimensional materials, it avoids phase-matching limitations, operates at room temperature, and broadens the detection spectrum, effectively improving photodetector performance.

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

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

[0041] See Figure 2 Non-degenerate three-photon absorption is a physical process, further divided into fully non-degenerate three-photon absorption and partially non-degenerate three-photon absorption. Fully non-degenerate three-photon absorption is achieved when the energy of the desired infrared light plus two pump lights of different wavelengths exceeds the material's band gap. Partially non-degenerate three-photon absorption is achieved when the energy of the desired infrared light plus two pump lights of the same wavelength exceeds the material's band gap, or when the energy of the two desired infrared lights plus one pump light of a different wavelength exceeds the material's band gap. In practical applications, because the power of the signal light is relatively low, the latter type of partially non-degenerate three-photon absorption is relatively difficult to achieve.

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

[0043] This photoelectric detection system is constructed based on the broadband detection method of non-degenerate three-photon absorption of two-dimensional materials, as described in this application. Specifically, a photodetector is prepared using monolayer MoS2 material as an example. Figure 3 (The "sample" is shown in the image). After the non-degenerate three-photon absorption process occurs, the photodetector performance is obtained using the source surface. It should be noted that... Figure 3The detector in the block is a detection device, and the sample in the block is a photodetector of an embodiment of the application.

[0044] Specifically, a photodetection system including a light source (such as a laser), optical elements (such as a filter, a beam splitter, a mirror, etc.), a sample (a photodetector made of a material to be measured), and a detection device (such as a source table, a power meter, etc.) is built.

[0045] A two-dimensional material-based non-degenerate three-photon absorption wide-spectrum detection method of an embodiment of the application is described below with reference to the accompanying drawings. In view of the problems of the narrow detection spectrum of the conventional photodetector, the large size and high cost of the equipment, and the small material band gap selection range caused by the limitation of the infrared wavelength in the related art, the application provides a two-dimensional material-based non-degenerate three-photon absorption wide-spectrum detection method. In the method, three photons with different energies (i.e., a non-degenerate light source) or two photons with the same energy and one photon with a different energy (i.e., a non-degenerate light source) are used to complete the electron transition, excite the nonlinear optical properties of the photodetector, and overcome the material band gap selection problem caused by the limitation of the infrared wavelength, thereby widening the infrared light detection spectrum range and using three beams of light for regulation and control, which is more flexible. Thus, the technical problems of the narrow detection spectrum of the conventional photodetector, the large size and high cost of the equipment, and the small material band gap selection range caused by the limitation of the infrared wavelength in the related art are solved.

[0046] The technical solutions of the application are described in detail below with specific embodiments. 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 two-dimensional material-based non-degenerate three-photon absorption wide-spectrum detection method described in the preferred embodiments of the application, as shown in Figure 4 The two-dimensional material-based non-degenerate three-photon absorption wide-spectrum detection method includes the following steps:

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

[0049] The non-degenerate light source includes two pump lights and one preset signal light.

[0050] Specifically, a material with a suitable band gap and strong nonlinear optical properties is selected, such as a two-dimensional material (such as a single-layer MoS2) or a perovskite single crystal (such as MAPbBr3), etc. These materials can support the non-degenerate three-photon absorption process. A photodetector is prepared, and an electrode is mounted on it to measure the photocurrent. A two-dimensional material sample, such as a single-layer MoS2, is prepared and mounted on the electrode to form a photodetector. This step ensures that the sample can effectively convert the optical signal into an electrical signal.

[0051] According to the characteristics of the selected material, the appropriate wavelength of the pump light and the signal light are configured. The pump light and the signal light are configured, the wavelength and the power of the pump light should be able to effectively excite the non-degenerate three-photon absorption process, and the signal light is the infrared light to be detected. Specifically, appropriate pump light wavelengths (such as 1250 nm and 1500 nm) and signal light wavelengths (such as 2500 nm) are selected; the total energy of the pump light and the signal light is ensured to be greater than the band gap energy of the material, so as to realize the non-degenerate three-photon absorption.

[0052] It is worth noting that the present application is based on the non-degenerate 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 different photon to complete the electronic transition, excite the nonlinear optical properties of the sample, use this high-order nonlinear optical process to break through the phase matching restriction, and the application range is wider; overcome the problem of material band gap selection caused by the limitation of infrared wavelength, and widen the infrared light detection spectral range; three beams of light are used for regulation and control, which is more flexible. The device of the present application only needs two-dimensional material and electrode to complete the wide-spectrum 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, which meets the demand of small size of photoelectric detector system.

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

[0054] In one possible implementation, the photoelectric information includes photocurrent data. Two beams of the pump light and one beam of the preset signal light are irradiated onto the photoelectric detector by using an optical element, so that the three beams of light undergo a non-degenerate three-photon absorption process; and photocurrent data generated by the photoelectric detector is collected.

[0055] Specifically, three beams of light are focused on the two-dimensional material sample by using an optical element, and it is ensured that they can accurately irradiate the effective detection area of the sample; the light source is turned on, so that the three beams of light irradiate the sample at the same time, and it is ensured that the energy and the phase relationship of the three beams of light meet the condition of non-degenerate three-photon absorption, so that the non-degenerate three-photon absorption process occurs; a detection device such as a source table is used to record the change of photocurrent with light intensity (i.e., photocurrent data), and a log-log graph (double logarithmic graph) of photocurrent and light intensity is usually obtained.

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

[0057] In one 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 a slope.

[0058] Specifically, the measured photocurrent data is processed, a log-log plot of photocurrent vs. light intensity is drawn, and by fitting the plot, the slope can be obtained, verifying the generation of non-degenerate three-photon absorption induced photocurrent, and analyzing the log-log plot of photocurrent vs. light intensity (i.e. double logarithmic plot), if the slope after fitting is 1 (preset requirement is within 1-1.1), it proves that the non-degenerate three-photon absorption process occurs.

[0059] Further, the collected light intensity and photocurrent data are logarithmically transformed, i.e. the logarithm (usually natural logarithm or common logarithm) of each light intensity value is taken, and the corresponding photocurrent value is also logarithmically transformed; the transformed data points are plotted using data processing software (such as Excel, MATLAB, Python, etc.) to obtain a log-log plot of photocurrent vs. light intensity; a fitting model is selected, and if the data points show a linear trend in the log-log plot, it may mean that there is a power-law relationship between the photocurrent and the light intensity, at which time a linear regression model can be used to fit these data points. Perform fitting, and use the selected data processing software to perform linear regression fitting on the data points in the log-log plot; after fitting is complete, the software will output the slope of the fitted straight line, which in the log-log plot is actually the estimated value of the power exponent of the power-law relationship between the photocurrent and the light intensity in the original data.

[0060] It should be understood that non-degenerate three-photon absorption refers to a process in which a molecule or atom simultaneously absorbs three different energy photons to transition from a ground state to an excited state, which usually occurs under high-intensity laser radiation and requires that the coherence and power of the laser reach a certain level. The relationship between the slope and three-photon absorption: if the slope (i.e. power exponent) obtained by fitting is greater than 1 and close to 3 (taking into account experimental errors and simplification of the theoretical model), it may indicate that the generation of photocurrent is related to the non-degenerate three-photon absorption process.

[0061] Referring to Figure 5 and Figure 6 , Figure 5 is the optical image of a single-layer MoS2 electrode, which is used by the present application to make a photodetector to detect 2500nm signal light with 1250nm and 1500nm light as pump light, to obtain a log-log plot of photocurrent vs. light intensity, and the slope after fitting is 1, proving the generation of non-degenerate three-photon absorption induced photocurrent, and the occurrence of 2500nm band detection based on single-layer MoS2 non-degenerate three-photon absorption. The present application successfully detects weak 2500nm photons, proving the potential of using non-degenerate three-photon absorption effect to realize wide-spectrum detection of near-infrared and even mid-infrared.

[0062] In a possible implementation, the performance of the photodetector is evaluated to obtain an evaluation result; and the photodetector is optimized according to the evaluation result to obtain an optimized photodetector.

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

[0064] In a possible implementation, the analysis result further includes a non-degenerate three-photon absorption coefficient. A mathematical model is established between the photoconductive electron density and the incident light intensity; and the non-degenerate three-photon absorption coefficient of the two-dimensional material is calculated according to the mathematical model and the photocurrent data.

[0065] Specifically, the three-photon absorption coefficient is calculated, and the non-degenerate three-photon absorption coefficient of the material is calculated by using the established mathematical model and experimental data. 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 has the ability to characterize the nonlinear optical properties of the two-dimensional material. While obtaining the photocurrent, the three-photon absorption coefficient of the two-dimensional material can be calculated.

[0067] The mathematical model of the three-photon absorption coefficient depends on the photoconductive electron density N generated by the degenerate and non-degenerate three-photon absorption processes, and is expressed as: (degenerate three-photon absorption process)

[0068] (partial non-degenerate three-photon absorption process) (complete non-degenerate three-photon absorption process)

[0069] Preferably, the complete non-degenerate three-photon absorption process or the partial non-degenerate three-photon absorption process is used.

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

[0071] According to the current and electron number relationship formula J = ngv d , n is the concentration of carriers (here, electrons), q is the charge amount of an electron, v d is the drift speed of the carrier (electron), the photoelectric current J D3PA / J ND3PA generated by the degenerate / non-degenerate three-photon absorption process can be calculated, and compared with the photoelectric current J single generated by the single-photon absorption process, so as to obtain the three-photon absorption coefficient:

[0072]

[0073] wherein, J is the photoelectric current, which is the current formed by the directional movement of the photo-generated electrons under the action of the electric field; J D3PA , J ND3PA1 , J ND3PA2 , J single respectively represent the photoelectric current generated by the degenerate three-photon absorption, partial non-degenerate three-photon absorption, complete non-degenerate three-photon absorption and single-photon absorption processes. L is the sample thickness, which is the distance of the interaction between light and matter; α1 is a linear absorption coefficient, which represents the ability of the material to single-photon absorption; I'1, I'2, I'3 and I' single are the peak light intensities of the incident light, which are the maximum values of the light intensity over time; t1 and t3 are the pulse widths of the single-photon absorption and three-photon absorption processes respectively, that is, the time duration of the light pulse over time;

[0074]

[0075] wherein, F1, F2, F3 are geometric factors related to the spot shape and size, used to correct the difference in photocurrent caused by different spot sizes, which are calculated by integration, considering the two-dimensional distribution of the spot; ω1, ω2, ω3, ω4 are the radii of the laser spots with incident light frequencies v1, v2, v3, v4 respectively, representing the size of the spot in the cross section; a, b represent the half of the length and the half of the width of the effective detection area respectively, 2a, 2b represent the length and the width of the effective detection area respectively, i.e. the size of the area that the detector can respond to the optical signal; x, y represent the coordinates of the spot in the two-dimensional plane. single single wherein, ω1, ω2, ω3, ω4 are the radii of the laser spots with incident light frequencies v1, v2, v3, v4 respectively, representing the size of the spot in the cross section; a, b represent the half of the length and the half of the width of the effective detection area respectively, 2a, 2b represent the length and the width of the effective detection area respectively, i.e. the size of the area that the detector can respond to the optical signal; x, y represent the coordinates of the spot in the two-dimensional plane.

[0076] In step S104, according to the analysis result, the photodetector is controlled to detect the to-be-detected signal light to obtain detection information.

[0077] In a possible implementation, if the slope meets the preset requirement, the wavelength of the to-be-detected signal light is obtained; the wavelength group corresponding to the two pump lights is adjusted according to the wavelength of the to-be-detected signal light to obtain a target wavelength group; the two pump lights are controlled to irradiate the photodetector according to the target wavelength group, and the photodetector is controlled to detect the to-be-detected signal light to obtain detection information of the to-be-detected signal light.

[0078] Specifically, when detecting the to-be-detected signal light, first, the wavelength of the signal light is obtained, and the wavelengths of the two pump lights are adjusted according to experimental requirements or physical mechanisms (such as nonlinear optical effects, optical amplification, etc.) to ensure that the pump light, the signal light, and the two-dimensional material can generate the expected non-degenerate three-photon absorption. In the photodetection system, it is ensured that the photodetector has been correctly set and calibrated so as to accurately convert the received optical signal into an electrical signal. Finally, the electrical signal output by the photodetector is processed and analyzed to obtain the detection information of the to-be-detected signal light, which can include parameters such as the intensity, frequency, and phase of the signal.

[0079] It should be noted that the intensities of the pump light and the signal light in the non-degenerate three-photon absorption need to be controlled, because when the laser intensity is high enough, if the photon energy is greater than one-third of the material band gap, it is possible to directly generate degenerate three-photon absorption. In order to avoid this situation, the intensities of the pump light and the signal light need to be controlled to be below the degenerate three-photon absorption excitation threshold. Three-photon absorption is a fifth-order nonlinear optical process, which has a requirement for the excitation light intensity compared with low-order linear and nonlinear optical processes. In order to be able to excite the non-degenerate three-photon absorption process of the material while meeting the above requirements, the range of the intensity of each incident light needs to be controlled.

[0080] ​It can be understood that the non-degenerate three-photon absorption photodetector design scheme based on heterojunction or plasmonic material has the core technical features of using non-degenerate three-photon absorption technology to complete photodetection, and other materials do not have the characteristics of simple manufacturing process, low cost, and more practicality of single-layer two-dimensional materials. The extremely wide spectrum photodetector based on non-degenerate three-photon absorption can greatly widen the detection spectrum range by selecting the pump light and signal light with a large energy difference.

[0081] Second, the wide spectrum detection system based on two-dimensional material non-degenerate three-photon absorption according to the embodiment of the application is described with reference to the accompanying drawings.

[0082] Figure 7 The wide spectrum detection system based on two-dimensional material non-degenerate three-photon absorption according to the embodiment of the application is a block diagram.

[0083] As shown in Figure 7 The wide spectrum detection system based on two-dimensional material non-degenerate three-photon absorption 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 configured to configure a non-degenerate light source corresponding to a photodetector, wherein the photodetector is prepared based on two-dimensional material.

[0085] The irradiation experiment module 200 is configured to control the non-degenerate light source to irradiate the photodetector to obtain photoelectric information.

[0086] The data analysis module 300 is configured to analyze the photoelectric information to obtain an analysis result.

[0087] The signal light detection module 400 is configured to control the photodetector to detect a to-be-detected signal light according to the analysis result to obtain detection information.

[0088] In the description of the present specification, the description of 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 the present specification, the illustrative description of the above terms does 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, the skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0089] Furthermore, the terms "first", "second", etc. are used herein only to describe different instances, and do not imply or suggest relative importance or a number of the indicated technical features. Thus, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited.

[0090] Any process or method descriptions or blocks in flow charts described herein and elsewhere can be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing the specified logical function or process. It should also be understood that the functions could be implemented by one or more modules, segments or portions of code without changing the meaning or scope of the preferred embodiments of the present application.

[0091] It should be understood that the application of the present application is not limited to the above examples, and those of ordinary skill in the art can make improvements or changes according to the above description, and all such improvements and changes shall fall within the scope of the claims of the present application.

[0092] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A wide-spectrum detection method based on two-dimensional material non-degenerate three-photon absorption, characterized in that, The wide-spectrum detection method based on the non-degenerate three-photon absorption of the two-dimensional material comprises: An optoelectronic detector based on a two-dimensional material is prepared, and a non-degenerate light source required by the non-degenerate three-photon absorption corresponding to the optoelectronic detector is configured; The non-degenerate light source is controlled to irradiate the optoelectronic detector to obtain photoelectric information; The photoelectric information is analyzed to obtain an analysis result; According to the analysis result, the optoelectronic detector is controlled to detect a to-be-detected signal light to obtain detection information; The non-degenerate light source comprises two pump lights and a preset signal light, and the photoelectric information comprises photocurrent data; the energies of the two pump lights and the preset signal light are different, or the energies of the two pump lights are the same, and the energy of the pump light is different from that of the preset signal light; The control of the non-degenerate light source to irradiate the optoelectronic detector to obtain photoelectric information specifically comprises: The two pump lights and the preset signal light are irradiated onto the optoelectronic detector by using an optical element, so that the three lights and the two-dimensional material undergo a non-degenerate three-photon absorption process; The photocurrent data generated by the optoelectronic detector is collected; The analysis result is a slope; The analysis of the photoelectric information to obtain an analysis result specifically comprises: The photocurrent data is processed to obtain a double-logarithmic graph of photocurrent and photoelectricity; The double-logarithmic graph is fitted to obtain a slope; The control of the optoelectronic detector to detect a to-be-detected signal light to obtain detection information according to the analysis result specifically comprises: If the slope meets a preset requirement, the wavelength of the to-be-detected signal light is obtained; According to the wavelength of the to-be-detected signal light, a wavelength group corresponding to the two pump lights is adjusted to obtain a target wavelength group, and the two pump lights are controlled to irradiate the optoelectronic detector according to the target wavelength group; The optoelectronic detector is controlled to detect the to-be-detected signal light to obtain detection information of the to-be-detected signal light; The target wavelength group comprises a first wavelength and a second wavelength corresponding to the two pump lights, respectively; According to the wavelength of the to-be-detected signal light, a wavelength group corresponding to the two pump lights is adjusted to obtain a target wavelength group, and the two pump lights are controlled to irradiate the optoelectronic detector according to the target wavelength group, specifically: According to the wavelength of the to-be-detected signal light, a first wavelength and a second wavelength corresponding to the two pump lights are adjusted, so that the two pump lights irradiate the optoelectronic detector according to the first wavelength and the second wavelength, so that the two pump lights, the preset signal light and the two-dimensional material generate a non-degenerate three-photon absorption; The detection information comprises signal intensity, signal frequency and signal phase; The control of the optoelectronic detector to detect the to-be-detected signal light to obtain detection information of the to-be-detected signal light specifically comprises: The optoelectronic detector is controlled to detect the to-be-detected signal light to obtain an output electrical signal; The output electrical signal is analyzed to obtain signal intensity, signal frequency and signal phase.

2. The method of claim 1, wherein the two-dimensional material based non-degenerate three-photon absorption wide spectrum detection method is characterized in that, The analysis result further comprises a non-degenerate three-photon absorption coefficient; The collecting the photocurrent data generated by the photodetector further includes: establishing a mathematical model between photo-induced conduction electron density and incident light intensity; calculating the non-degenerate three-photon absorption coefficient of the two-dimensional material according to the mathematical model and the photocurrent data.

3. The method of claim 1, wherein the two-dimensional material based non-degenerate three-photon absorption wide spectrum detection method is characterized by, The fitting processing on the double logarithmic graph to obtain a slope further includes: performing performance evaluation on the photodetector to obtain an evaluation result; optimizing the photodetector according to the evaluation result to obtain an optimized photodetector.

4. The method of claim 2, wherein the two-dimensional material non-degenerate three-photon absorption based wide spectrum detection method is characterized by, The mathematical model is expressed as: ； wherein, is the rate of change of the photo-generated conduction electron density with time in the partially non-degenerate three-photon absorption process, is the three-photon absorption coefficient in the partially non-degenerate three-photon absorption process, , is the light intensity of the incident light corresponding to the signal light and the pump light, is the Planck constant, , is the frequency of the incident light corresponding to the signal light and the pump light; or The mathematical model is expressed as: ； wherein, is the rate of change of the photo-generated conduction electron density with time in a fully non-degenerate three-photon absorption process, is the three-photon absorption coefficient in a partially non-degenerate three-photon absorption process, , is the light intensity of the incident light corresponding to the signal light and the two pump lights, is the Planck constant, , , is the frequency of the incident light corresponding to the signal light and the two pump lights.

5. A wide-spectrum detection system based on two-dimensional material non-degenerate three-photon absorption, characterized in that, The wide-spectrum detection system based on the non-degenerate three-photon absorption of the two-dimensional material is used to implement the wide-spectrum detection method based on the non-degenerate three-photon absorption of the two-dimensional material, and the wide-spectrum detection system based on the non-degenerate three-photon absorption of the two-dimensional material includes: a device preparation module configured to prepare a photodetector based on a two-dimensional material, and to configure a non-degenerate light source required for the photodetector to correspond to non-degenerate three-photon absorption; an irradiation experiment module configured to control the non-degenerate light source to irradiate the photodetector to obtain photoelectric information; a data analysis module configured to analyze the photoelectric information to obtain an analysis result; a signal light detection module configured to control the photodetector to detect a to-be-detected signal light according to the analysis result to obtain detection information.

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