Photoelectric detector and system based on ferroelectric perovskite non-degenerate two-photon absorption

Abstract

The invention relates to the technical field of photoelectric detection, in particular to a photoelectric detector and system based on ferroelectric perovskite non-degenerate two-photon absorption. The photoelectric detector comprises a substrate layer; the metal electrode layer is positioned on the substrate layer; the light absorption layer is located on the substrate layer and is composed of a ferroelectric perovskite thin film; the protective layer is formed by a boron nitride film; the metal electrode layers are located on the two sides of the light absorption layer. The photoelectric detector can perform photoelectric detection by using a ferroelectric perovskite non-degenerate two-photon absorption effect, a detection threshold value is reduced by one order of magnitude, and measurable light current can be generated for weak light without high-peak light power; a built-in electric field generated by spontaneous polarization of the ferroelectric perovskite can effectively separate electron-hole pairs, so that the signal-to-noise ratio and the response speed are greatly improved; and the structure is simple, the cost is low, and high-sensitivity and stable detection on weak light can be realized.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detection technology, and more specifically to a photoelectric detector and system based on ferroelectric perovskite non-degenerate two-photon absorption. Background Technology

[0002] A photodetector is a device that converts light signals into electrical signals and is widely used in communication, imaging, and sensing. Its working principle is based on the photoelectric effect; when light shines on the detector surface, it excites electron transitions, generating photogenerated carriers and thus a photoelectric signal. Currently, the mainstream solutions for photodetectors are based on single-photon absorption or degenerate two-photon absorption. The former involves absorbing a single photon with energy greater than the semiconductor bandgap to excite electron transitions. Devices based on this approach have simple structures, low costs, and linear responses; however, they also have significant drawbacks, being limited by the material bandgap, resulting in a narrow detection spectrum and large dark current. The latter involves simultaneously absorbing two photons of the same energy (below the bandgap) to excite electron transitions, such as... Figure 1 As shown, although the photodetector based on this scheme has a wide detection spectrum, its two-photon absorption cross section is extremely small, requiring extremely high peak light intensity to excite it, resulting in large thermal damage and a high detection threshold.

[0003] Therefore, existing technologies need to be improved. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a photodetector and system based on ferroelectric perovskite non-degenerate two-photon absorption, which aims to solve the problems of high detection threshold and insufficient sensitivity of existing detectors.

[0005] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a photodetector based on ferroelectric perovskite non-degenerate two-photon absorption, comprising: basal layer; Metal electrode layer located on the substrate layer; The light-absorbing layer located on the substrate is composed of a ferroelectric perovskite thin film; The protective layer is composed of a six-part boron nitride thin film; The metal electrode layer is located on both sides of the light absorption layer.

[0006] Optionally, the substrate layer is composed of silicon and / or silicon dioxide.

[0007] Optionally, the metal electrode layer consists of a gold layer with a thickness of 40-80 nm and a chromium layer with a thickness of 5-10 nm.

[0008] Optionally, the channel length of the metal electrode layer is 2-6 μm.

[0009] Optionally, the light-absorbing layer is a ferroelectric perovskite thin film with a thickness of 600-800 nm. The ferroelectric perovskite thin film can be made of (BA)2(MA)Pb2Br7.

[0010] In a second aspect, the present invention provides a photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite, including the aforementioned photoelectric detector based on non-degenerate two-photon absorption of ferroelectric perovskite.

[0011] Optionally, the photoelectric detection system further includes a signal light source, a pump light source, a first reflector, a second reflector, an optical delay line module, a fifth reflector, a first beam splitter, and a second beam splitter. The optical delay line module mainly consists of two mirrors, a second mirror and a third mirror, which are used to adjust the optical path of the pump light so that there is an adjustable optical path difference between the overlapping pump light and the signal light. A pump light generated by the pump source is reflected sequentially by reflector one, reflector two, reflector three, and reflector four to reach the exit surface of beam splitter one. It is reflected and overlaps with the signal light generated by the signal source through beam splitter one. It then passes through beam splitter two and is reflected by reflector five to reach the photodetector based on ferroelectric perovskite non-degenerate two-photon absorption.

[0012] Optionally, the optical path difference is zero.

[0013] Optionally, the light generated by the signal light source and the pump light source is a femtosecond pulsed laser.

[0014] Optionally, the photoelectric detection system further includes a probe for measuring power, the probe being located in the direction of the reflected light from the second beam splitter and used to receive the reflected light passing through the second beam splitter as a reference optical power.

[0015] Optionally, a microscopic focusing module is further provided between the reflector five and the photodetector to focus the light passing through the reflector five. This excites the photodetector to produce a degenerate / non-degenerate two-photon absorption effect, thereby generating a measurable photoelectric signal.

[0016] Optionally, the photoelectric detection system further includes a vacuum chamber and a source meter disposed outside the photoelectric detector.

[0017] Beneficial effects: The photodetector based on non-degenerate two-photon absorption of ferroelectric perovskite provided by this invention can perform photoelectric detection by utilizing the non-degenerate two-photon absorption effect of ferroelectric perovskite, reducing the detection threshold by an order of magnitude, and generating measurable photocurrent for weak light without the need for high peak optical power; the built-in electric field generated by the spontaneous polarization of ferroelectric perovskite can effectively separate electron-hole pairs, greatly improving the signal-to-noise ratio and response speed; moreover, it has a simple structure, low cost, and can achieve highly sensitive and stable detection of weak light. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the principle of degenerate two-photon absorption.

[0019] Figure 2 This is a schematic diagram illustrating the principle of non-degenerate two-photon absorption.

[0020] Figure 3 This is a schematic diagram of the structure of a ferroelectric perovskite photodetector.

[0021] Figure 4 This is the optical path diagram of the photoelectric detection system in Example 1.

[0022] Figure 5 This is a comparison chart of the thresholds for degenerate and non-degenerate two-photon absorption of the photodetector in Example 1. Figure 6 This is a comparison chart of the degenerate and non-degenerate two-photon absorption coefficients of the photodetector in Example 1. Detailed Implementation

[0023] This invention provides a photodetector and system based on non-degenerate two-photon absorption of ferroelectric perovskites. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0024] Non-degenerate two-photon absorption refers to the process in which two photons of different energies are simultaneously absorbed by a semiconductor, causing an electron to transition from the valence band to the conduction band. Figure 2 As shown, photodetectors based on non-degenerate two-photon absorption can detect long-wavelength optical signals without narrow bandgap materials and have low dark current. Compared to degenerate two-photon absorption, devices based on non-degenerate two-photon absorption can increase the two-photon absorption cross-section by 1-2 orders of magnitude through near-resonant enhancement with the intermediate virtual state energy level, thereby lowering the detection threshold and exhibiting higher sensitivity at lower optical power. However, conventional semiconductor materials (such as Si and GaAs) are difficult to excite non-degenerate two-photon absorption to generate measurable photoelectric signals due to problems such as short intermediate state lifetime, extremely small absorption cross-section, and low carrier separation efficiency.

[0025] In recent years, ferroelectric perovskite materials have attracted widespread attention in the field of optoelectronic devices due to their unique crystal structure and excellent photoelectric properties. Compared with traditional semiconductors, ferroelectric perovskite materials exhibit advantages such as long diffusion length, high carrier mobility, tunable bandgap, and strong light absorption. Furthermore, the built-in electric field generated by their spontaneous polarization can effectively separate electron-hole pairs, providing gain for nonlinear optical processes. These characteristics make ferroelectric perovskite materials an ideal choice for devices such as photodetectors. However, non-degenerate two-photon absorption requires two photons of different wavelengths to be absorbed simultaneously by the same electron, and the sum of their energies exceeds the bandgap of the perovskite. Although the bandgap of ferroelectric perovskite is tunable, its high defect density and spatially inhomogeneous polarization field result in a small two-photon absorption cross-section and low signal-to-noise ratio. Currently, experimentally stable and tunable two-color femtosecond light sources and ultrafast characterization methods are not yet mature enough. Therefore, current research on ferroelectric perovskite two-photon absorption remains limited to degenerate modes. The non-degenerate two-photon absorption characteristics and the photoelectric detection performance based on non-degenerate two-photon absorption have not yet been explored.

[0026] Based on this, this embodiment provides a photodetector based on ferroelectric perovskite non-degenerate two-photon absorption, such as... Figure 3 As shown, it includes: Basal layer 1-1; Metal electrode layer 1-2 located on the substrate layer 1-1; The light-absorbing layer 1-3 located on the substrate layer 1-1 is composed of a ferroelectric perovskite thin film; Protective layers 1-4 are composed of a six-part boron nitride thin film; The metal electrode layer 1-2 is located on both sides of the light absorption layer 1-3.

[0027] It should be noted that in this embodiment, the metal electrode layer serves as the source and drain of the photodetector, the ferroelectric perovskite thin film serves as the optical functional layer, and the ferroelectric perovskite thin film encapsulates the hexagonal boron nitride thin film to isolate it from water and oxygen. The detector using this embodiment can achieve non-degenerate two-photon absorption. When light shines on the photodetector, a single-photon absorption effect occurs when the energy of a single photon is greater than the band gap of the ferroelectric perovskite in the photodetector. Since two-photon absorption is divided into degenerate two-photon absorption and non-degenerate two-photon absorption, a degenerate two-photon absorption effect occurs when the ferroelectric perovskite thin film of the photodetector simultaneously absorbs two photons with the same energy (a single photon energy below the band gap, and two identical photons with energies greater than the band gap); a non-degenerate two-photon absorption effect occurs when the ferroelectric perovskite in the photodetector simultaneously absorbs two photons with different energies (each photon energy below the band gap, and the sum of the energies of the two different photons greater than the band gap). In practical applications, the photon with higher energy may also undergo degenerate two-photon absorption. Therefore, when performing non-degenerate two-photon absorption, the intensity of the photon with higher energy needs to be controlled below the intensity threshold for degenerate two-photon absorption.

[0028] In one embodiment, the substrate layer is composed of silicon and / or silicon dioxide.

[0029] In one embodiment, the metal electrode layer consists of a gold layer with a thickness of 40-80nm (preferably 50nm, but also 40nm, 60nm, 70nm, 80nm, etc.) and a chromium layer with a thickness of 5-10nm (preferably 10nm, but also 5nm, 6nm, 7nm, 8nm, 9nm).

[0030] In some embodiments, the channel length of the metal electrode layer is 2-6 μm.

[0031] It should be noted that the electrode layer channel length is 2-6μm, which can be 2μm, 3μm, 4μm, 5μm, or 6μm. This range is the parameter with better device performance obtained through different control groups. Within this range, the ferroelectric perovskite device has a larger photocurrent and a lower detection threshold.

[0032] In some embodiments, the light-absorbing layer is a ferroelectric perovskite thin film with a thickness of 600-800 nm. The ferroelectric perovskite thin film can be made of (BA)₂(MA)Pb₂Br₇.

[0033] It should be noted that the method for fabricating the photodetector of the present invention includes the following steps: A metal electrode layer is fabricated on a substrate layer, a light-absorbing layer is fabricated on the metal electrode layer, and finally a protective layer is fabricated on the light-absorbing layer. Specifically, this includes: Photoresist (PMMA 950K) is dropped onto the substrate surface and then spin-coated using a spin coater. Heating is then applied to obtain a solid photoresist covering the substrate. Next, electrode patterns are etched onto the photoresist using high-resolution electron beam lithography, and metal electrodes are deposited using electron beam evaporation to serve as the source and drain electrodes of the photodetector. Subsequently, under nitrogen protection, bulk ferroelectric perovskite material, such as (BA)2(MA)Pb2Br7, is stripped using polydimethylsiloxane to obtain a ferroelectric perovskite film, which is then transferred to the metal electrodes. The transferred ferroelectric perovskite film is then encapsulated with a hexagonal boron nitride film to isolate it from water and oxygen. Finally, the source and drain electrodes of the detector are connected to the chip carrier using conductive silver paste and an ultrasonic aluminum wire bonding machine to obtain the photodetector. This invention uses the ferroelectric perovskite material (BA)2(MA)Pb2Br7 as an example, but is not limited to (BA)2(MA)Pb2Br7 and also includes other ferroelectric perovskite materials.

[0034] This embodiment also provides a photoelectric detection system based on ferroelectric perovskite non-degenerate two-photon absorption, including the aforementioned photoelectric detector 1 based on ferroelectric perovskite non-degenerate two-photon absorption.

[0035] In one specific implementation, such as Figure 4 As shown, the photoelectric detection system also includes a signal light source 10-1, a pump light source 10-2, an optical delay line module, a third reflector 4, a fourth reflector 5, a fifth reflector 6, a first beam splitter 7, and a second beam splitter 8. The optical delay line module mainly consists of a second mirror 3 and a third mirror 4, which are used to adjust the optical path of the pump light so that there is an adjustable optical path difference between the overlapping pump light and the signal light. It should be noted that the optical delay line module also includes an electric translation platform.

[0036] A pump light generated by pump source 10-2 is reflected sequentially by reflector 12, reflector 23, reflector 34, and reflector 45 to reach the exit surface of beam splitter 7. It is reflected and overlaps with the signal light generated by signal source 10-1 through beam splitter 7. It passes through beam splitter 28 and is reflected by reflector 56 to reach the photodetector 1 based on ferroelectric perovskite non-degenerate two-photon absorption.

[0037] To analyze the two-photon absorption performance of the sample, we need to calculate the two-photon absorption coefficient. The two-photon absorption coefficient of the sample can be determined by the following formula:

[0038]

[0039] The photocurrents generated during single-photon absorption and degenerate and non-degenerate two-photon absorption are respectively denoted as... , and , At the incident light frequency of light intensity is The degenerate two-photon absorption coefficient under signal pulse excitation; At incident light frequencies of and The light intensities are respectively and The non-degenerate two-photon absorption coefficient under the co-excitation of signal pulse and gate pulse. The single-photon absorption coefficient is... , These represent the signal pulse widths for single-photon absorption and two-photon absorption, respectively. , , , , The incident light frequencies are respectively , , The laser spot radius is given by , and 2a and 2b represent the length and width of the effective detection area of ​​photodetector 1, respectively. By measuring the photocurrent and combining it with the above formula, a quantitative analysis of the two-photon absorption characteristics of ferroelectric perovskite materials can be achieved.

[0040] It should be noted that the optical delay line module with fs-level precision can compensate for the optical path difference. This system can achieve precise synchronization of two pulses in both time and space dimensions, ensuring effective excitation of non-degenerate two-photon absorption.

[0041] This embodiment can receive two beams of the same / different wavelengths on a photodetector, and then obtain signals such as dark current and photocurrent of the photodetector under the action of bias voltage; by changing the power of the incident light, the power dependence of the photodetector can be obtained, and the key technical indicators of the photodetector can be obtained by calculation.

[0042] In one implementation, the optical path difference is zero.

[0043] This embodiment compensates for optical path difference using a delay line device with fs-level precision. This system can achieve precise synchronization of two pulses in both time and space dimensions, ensuring effective excitation of non-degenerate two-photon absorption.

[0044] It should be noted that the optical path difference can be adjusted by using the motorized translation stage of the moving delay line module, during which the change in the transmittance of the signal light can be detected. As the translation stage moves, the optical path difference between the two beams changes, and the transmittance of the signal light also changes accordingly. When the optical path difference between the two beams is zero, the change in the transmittance of the signal light will reach its maximum value, at which point the position where the optical path difference is zero can be determined.

[0045] It should be noted that the angles of reflector one, reflector two, reflector three, reflector four, and reflector five are adjusted according to experimental needs.

[0046] In one embodiment, the light generated by the signal light source 10-1 and the pump light source 10-2 is a femtosecond pulse laser.

[0047] In one embodiment, the photoelectric detection system further includes a probe 9 for measuring power. The probe 9 is located in the direction of the reflected light from the beam splitter 8 and is used to receive the reflected light after passing through the beam splitter 8 as a reference optical power.

[0048] The system in this embodiment has two beams: one is a signal beam and the other is a pump beam. After being reflected by a mirror, they are combined into one beam at a beam splitter and then split into two beams at another beam splitter. One beam is received by a power probe and used as a reference power, while the other beam is focused onto the surface of the device to excite the photodetector to produce a degenerate / non-degenerate two-photon absorption effect, generating a measurable photoelectric signal.

[0049] In some embodiments, a microscopic focusing module 11 is further provided between the reflector 5 6 and the photodetector 1 to focus the light passing through the reflector 5 6. This excites the photodetector to generate a degenerate / non-degenerate two-photon absorption effect, producing a measurable photoelectric signal.

[0050] In some embodiments, the photoelectric detection system further includes a vacuum chamber 12 and a source meter 13 disposed outside the photoelectric detector 1.

[0051] It should be noted that the vacuum chamber 12 is used to install the photodetector, isolate it from external water and oxygen, and ensure the sensitivity and accuracy of the photodetector; the source meter 13 is used to provide a bias voltage to the photodetector and measure the photocurrent data.

[0052] The present invention will be further described below through specific embodiments.

[0053] Example 1 1. Photodetectors based on non-degenerate two-photon absorption of ferroelectric perovskites, such as... Figure 3 As shown, it includes the base layer 1-1; Metal electrode layers 1-2; Light-absorbing layers 1-3 are composed of ferroelectric perovskite thin films; Protective layers 1-4 are composed of six boron nitride films.

[0054] In the fabrication process, Si / SiO2 is used as the substrate layer, and PMMA 950K photoresist is spin-coated onto the substrate. Then, metal electrode layers, such as chromium and gold, are deposited on the silicon wafer by high-resolution electron beam lithography and electron beam evaporation to serve as the source and drain electrodes of the photodetector. Subsequently, under nitrogen protection, a ferroelectric perovskite film, such as (BA)2(MA)Pb2Br7, is stripped using polydimethylsiloxane and transferred to the metal electrodes. The transferred ferroelectric perovskite film is then encapsulated with a hexagonal boron nitride film to isolate it from water and oxygen. Finally, the source and drain electrodes of the device are connected to the chip carrier using conductive silver paste and an ultrasonic aluminum wire bonding machine to obtain the photodetector.

[0055] Photoelectric detection systems, such as Figure 4 As shown, it includes: A photodetector based on ferroelectric perovskite non-degenerate two-photon absorption: 1. Signal source 10-1, pump source 10-2, reflector 1, reflector 2, reflector 3, reflector 4, reflector 5, reflector 5, beam splitter 1, beam splitter 2, beam splitter 8. The second reflector 3 and the third reflector 4 form an optical delay line module, which is used to adjust the optical path of the pump light 10-2 so that there is an adjustable optical path difference between the overlapping pump light and the signal light. A pump light generated by pump source 10-2 is reflected sequentially by reflector 12, reflector 23, reflector 34, and reflector 45 to reach the exit surface of beam splitter 7. It is reflected and overlaps with the signal light generated by signal source 10-1 through beam splitter 7. It passes through beam splitter 28 and is reflected by reflector 56 to reach the photodetector 1 based on ferroelectric perovskite non-degenerate two-photon absorption.

[0056] The optical path difference is zero.

[0057] The reflectors 1-2, 2-3, 3-4, 4-5, and 5-6 are all 45-degree reflectors.

[0058] The light generated by the signal light source 10-1 and the pump light source 10-2 is a femtosecond pulse laser.

[0059] The photoelectric detection system further includes a probe 9 for measuring power, a vacuum chamber 12 located outside the photodetector 1, and a source meter 13. The probe 9 is located in the direction of the reflected light from the beam splitter 8 and is used to receive the reflected light from the beam splitter 8 as a reference optical power. A microscopic focusing module 11 is also provided between the reflector 6 and the photodetector 1 to focus the light passing through the reflector 6. This excites the photodetector to generate a degenerate / non-degenerate two-photon absorption effect, producing a measurable photoelectric signal.

[0060] The reflectors in this embodiment are all Ag reflectors with a silver-plated surface and a protective SiO2 film. They have a diameter of 25.4 mm and a thickness of 5 mm, with an average reflectivity of ≈98.462% in the 450-2000 nm wavelength band. The beam splitters are all plate-shaped beam splitters BSW-10R with a reflection:transmission ratio of 50:50 (wavelength range 400-700 nm), a loss of <3%, a thickness of 1 mm, and dimensions of 25 mm × 36 mm. The reflection:transmission ratio in the 700-800 nm wavelength range is 47:50-42:55 (loss of 2-4%), and they feature low absorption, low dispersion, and a high damage threshold.

[0061] Reflectors 2 (3) and 3 (4) are actually hollow mirrors, employing a hollow pyramidal design with three outer surfaces coated with reflective films. The interior is hollow, without solid glass, thus avoiding material absorption or chromatic aberration. They can reflect parallel light incident from any direction back to its original direction and maintain the optical path transmission direction unchanged when the motorized translation stage moves. Adjusting the optical path difference is achieved by mounting reflectors 2 (3) and 3 (4) on the motorized translation stage and moving the stage to change the optical path. The translation stage has a minimum accuracy of 1 μm and can achieve a time delay variation of 6.67 fs. Reflector 1 (2) reflects the pump light into the delay line, and reflector 4 (5) reflects the pump light onto beam splitter 7, coupling it with the signal light into a single beam. Reflectors 1 (2) and 4 (5) need to withstand high incident optical power and low loss, have fixed positions, and ensure that the optical path of the pump light is similar to that of the signal light and can be compensated for by the delay line.

[0062] Figure 5 This is a comparison chart of the threshold values ​​for degenerate and non-degenerate two-photon absorption of the photodetector in Example 1. Figure 5 As shown, when the light intensity is less than 0.5 GW / cm 2 At that time, the non-degenerate two-photon effect could already be detected, while the degenerate two-photon absorption effect requires a light intensity greater than 2 GW / cm². 2 The fact that it can only be detected after a certain period indicates that the excitation threshold of non-degenerate two-photon absorption is an order of magnitude lower than that of degenerate two-photon absorption. Furthermore, with increasing light intensity, the photocurrent excited by non-degenerate two-photon absorption can reach the same order of magnitude as that excited by degenerate two-photon absorption. This demonstrates that photoelectric detection using the non-degenerate two-photon absorption effect of ferroelectric perovskites can lower the detection threshold by an order of magnitude compared to degenerate two-photon absorption, thus obtaining a measurable photoelectric signal.

[0063] Figure 6 This is a comparison chart of the degenerate and non-degenerate two-photon absorption coefficients of the photodetector in Example 1. Figure 6 As shown, the two-photon absorption coefficient based on the non-degenerate two-photon absorption effect is significantly increased, which is 2-6 times higher than that of the degenerate two-photon absorption coefficient.

[0064] In summary, the photodetector based on non-degenerate two-photon absorption of ferroelectric perovskite provided by this invention can perform photoelectric detection by utilizing the non-degenerate two-photon absorption effect of ferroelectric perovskite, reducing the detection threshold by an order of magnitude, and generating measurable photocurrent for weak light without the need for high peak optical power; the built-in electric field generated by the spontaneous polarization of ferroelectric perovskite can effectively separate electron-hole pairs, greatly improving the signal-to-noise ratio and response speed; moreover, it has a simple structure, low cost, and can achieve highly sensitive and stable detection of weak light.

[0065] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A photodetector based on non-degenerate two-photon absorption of ferroelectric perovskite, characterized in that, include: Basal layer (1-1); Metal electrode layer (1-2) located on the substrate layer (1-1); The light-absorbing layer (1-3) located on the substrate layer (1-1) is composed of a ferroelectric perovskite thin film; The protective layers (1-4) are composed of a boron nitride thin film of six parts; The metal electrode layer (1-2) is located on both sides of the light absorption layer (1-3).

2. The photodetector based on ferroelectric perovskite non-degenerate two-photon absorption according to claim 1, characterized in that, The metal electrode layer consists of a gold layer with a thickness of 40-80 nm and a chromium layer with a thickness of 5-10 nm.

3. The photodetector based on ferroelectric perovskite non-degenerate two-photon absorption according to claim 1, characterized in that, The channel length of the metal electrode layer is 2-6 μm.

4. The photodetector based on ferroelectric perovskite non-degenerate two-photon absorption according to claim 1, characterized in that, The thickness of the light-absorbing layer is 600-800 nm.

5. A photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite, characterized in that, The photodetector (1) based on ferroelectric perovskite non-degenerate two-photon absorption, as described in any one of claims 1-4.

6. The photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite according to claim 5, characterized in that, The photoelectric detection system also includes a signal light source (10-1), a pump light source (10-2), a reflector one (2), an optical delay line module, a reflector four (5), a reflector five (6), a beam splitter one (7), and a beam splitter two (8). The optical delay line module is mainly composed of mirror two (3) and mirror three (4), which are used to adjust the optical path of the pump light so that there is an adjustable optical path difference between the overlapping pump light and the signal light; A pump light generated by the pump source (10-2) is reflected sequentially by reflector one (2), reflector two (3), reflector three (4), and reflector four (5) to the exit surface of beam splitter one (7), and is reflected by the signal light generated by the signal source (10-1) through beam splitter one (7), and is reflected by the signal light generated by the signal source (10-1) through beam splitter one (7) to beam splitter two (8), and is reflected by reflector five (6) to the photodetector (1) based on ferroelectric perovskite non-degenerate two-photon absorption.

7. The photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite according to claim 6, characterized in that, The optical path difference is zero.

8. The photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite according to claim 6, characterized in that, The light generated by the signal light source (10-1) and the pump light source (10-2) is a femtosecond pulse laser.

9. The photoelectric detection system based on non-degenerate two-photon absorption of ferroelectric perovskite according to claim 6, characterized in that, The photoelectric detection system also includes a probe (9) for measuring power, a vacuum chamber (12) and a source meter (13) located outside the photoelectric detector (1). The probe (9) is located in the direction of the reflected light of the second beam splitter (8) and is used to receive the reflected light passing through the second beam splitter (8). A microscopic focusing module (11) is also provided between the fifth reflector (6) and the photoelectric detector (1) for focusing the light passing through the fifth reflector (6).

Images