An optical fiber imaging element for ultraviolet detection and its preparation method and application

Abstract

The present invention provides an optical fiber imaging element for ultraviolet detection, a preparation method thereof, and an application thereof. The preparation method comprises the following steps: acid-washing a cross section of one end of the optical fiber imaging element to form a microporous structure with a depth of 10 to 50 μm at the cross section, thereby obtaining the acid-washed optical fiber imaging element; the core of the optical fiber imaging element adopts an acid-etchable material, and the cladding adopts an acid-resistant material; CsX and PbX2 are dissolved in an organic solvent to obtain a precursor solution, wherein X is at least one of Cl, Br, and I; heating the precursor solution and introducing gas to carry the gaseous precursor solution to the microporous structure, so that the precursor solution reacts in the microporous structure in a gaseous form to generate CsPbX3 quantum dots, which fill the microporous structure, thereby obtaining a filled optical fiber imaging element; and installing a protective window at the filling surface of the filled optical fiber imaging element to obtain the optical fiber imaging element for ultraviolet detection. The optical fiber imaging element has the advantages of high brightness and high resolution, and can effectively improve the efficiency and resolution of the ultraviolet detector.

Description

Technical Field

[0001] The present invention relates to the field of ultraviolet detection technology, and in particular to an optical fiber imaging element for ultraviolet detection, a preparation method thereof, and applications thereof. Background Art

[0002] In modern photoelectric detection technology, ultraviolet radiation signals are generated by the corona phenomenon in outer space, flames, oil, and high-voltage lines. Therefore, ultraviolet detection has a wide range of application needs in aviation, communications, civil detection and other fields. Therefore, ultraviolet detection is receiving more and more attention and has become another extremely important technology developed after laser detection technology.

[0003] Visible light detection technology based on charge-coupled devices (CCDs) is highly mature, and mass-produced CCDs are already used in most industrial detection and civilian applications. Theoretically, CCDs have a certain response to wavelengths between 0.1 and 1100 nm. However, the detector's polysilicon electrodes strongly absorb light with wavelengths less than 400 nm, limiting their use in ultraviolet (UV) detection.

[0004] Therefore, how to improve the detection efficiency and detection resolution of ultraviolet light by ultraviolet detectors is of great significance to national defense, civilian use and scientific research fields. Summary of the Invention

[0005] The main purpose of the present invention is to provide an optical fiber imaging element for ultraviolet detection and its preparation method and application. The technical problem to be solved is how to improve the detection efficiency and detection resolution of ultraviolet light by the ultraviolet detector, so as to make it more suitable for practical use.

[0006] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions. According to the method for preparing a fiber optic image transmission element for ultraviolet detection proposed by the present invention, the steps include:

[0007] (1) Acid-washing the cross section of one end of the optical fiber imaging element to form a microporous structure at the cross section, wherein the depth of the microporous structure is 10 to 50 μm, thereby obtaining an acid-washed optical fiber imaging element; wherein the core of the optical fiber imaging element is made of an acid-resistant material and the cladding is made of an acid-resistant material;

[0008] (2) dissolving CsX and PbX2 in an organic solvent to obtain a precursor solution; wherein X is at least one of Cl, Br and I;

[0009] (3) heating the aforementioned precursor solution and introducing an inert gas to bring the gaseous precursor solution to the aforementioned microporous structure, so that the aforementioned precursor solution reacts in the aforementioned microporous structure in a gaseous form to generate CsPbX3 quantum dots, which fill the aforementioned microporous structure to obtain a filled optical fiber imaging element; and,

[0010] (4) A protective window is installed on the filling surface of the aforementioned filled optical fiber imaging element to obtain an optical fiber imaging element for ultraviolet detection.

[0011] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0012] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (2), the molar ratio of CsX to PbX2 is 1:0.8-1.2.

[0013] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (2), the aforementioned organic solvent is N,N-dimethylformamide, N,N-dimethylacetamide or N,N-dimethylacrylamide.

[0014] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (3), the temperature of heating the aforementioned precursor solution is 500-700°C.

[0015] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (3), the aforementioned gas introduced is at least one of argon and nitrogen.

[0016] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (4), the material of the aforementioned protective window is quartz, and the thickness is 2 to 3 mm.

[0017] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, the steps further include: before step (4), coating a silicon dioxide film layer on the filling surface of the aforementioned filled optical fiber imaging element.

[0018] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (4), the method for installing the aforementioned protective window is: dripping coupling glue on the aforementioned silicon dioxide film layer, placing the aforementioned protective window, and then curing the aforementioned coupling glue.

[0019] The purpose of the present invention and the solution to the technical problem are also achieved by adopting the following technical solutions. According to the present invention, an optical fiber image transmission element for ultraviolet detection is proposed, which includes:

[0020] An optical fiber imaging element, wherein the core of the optical fiber imaging element is made of an acid-etchable material and the cladding is made of an acid-resistant material, and the core of the optical fiber imaging element is recessed at a cross section at one end thereof, forming a microporous structure with a depth of 10 to 50 μm at the cross section;

[0021] CsPbX3 quantum dots, the aforementioned CsPbX3 quantum dots are filled in the aforementioned microporous structure; and

[0022] A protective window is provided on the cross section of the optical fiber imaging element filled with the CsPbX3 quantum dots.

[0023] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions: According to the present invention, an application of the aforementioned optical fiber image transmission element for ultraviolet detection in the field of ultraviolet detection is proposed.

[0024] Through the above technical solution, the optical fiber image transmission element for ultraviolet detection and its preparation method and application of the present invention have at least the following advantages:

[0025] The present invention proposes a method for preparing an optical fiber imaging element for ultraviolet detection. The element utilizes an optical fiber imaging element with a core made of an acid-etchable material and a cladding made of an acid-resistant material. Using an acid etching method, a high-precision, uniformly arranged microporous structure is created across the cross-section of the optical fiber imaging element. The depth of the microporous structure is controlled to be 10 to 50 μm. The microporous structure is then filled with CsPbX3 quantum dots, where X is at least one of Cl, Br, and I. The CsPbX3 quantum dots have high photoluminescence quantum yield, excellent color purity, and a tunable band gap. Controlling the filling thickness to 10 to 50 μm allows them to act as a UV-absorbing, light-sensitive material, achieving high luminescence intensity and long-term stability, improving detection efficiency and lifetime. Furthermore, filling with CsPbX3 quantum dots enables efficient luminescence from a single optical fiber, effectively enhancing detection resolution. Light converted from the quantum dots within the microporous structure upon UV irradiation is transmitted by the corresponding optical fiber, with each optical fiber acting as a separate imaging unit. This significantly improves resolution compared to the diffusely reflected light from stimulated emission of traditional quantum dot materials. In addition, by combining Cl, Br, and I ions, CsPbX3 quantum dots that emit visible light of any wavelength can be prepared, and the combination can be selected according to the actual application scenario.

[0026] CsPbX3 quantum dots are produced directly within the microporous structure using chemical vapor deposition (CVD) from a precursor solution containing CsX and PbX2. This method allows for rapid and dense filling of CsPbX3 quantum dots, resulting in high purity and excellent luminescence, making it suitable for industrial production.

[0027] The optical fiber imaging element for ultraviolet detection prepared by the present invention has the advantages of high brightness and high resolution, effectively improving the detection efficiency and detection resolution of the ultraviolet detector, and is of great significance to the fields of national defense, civil use and scientific research.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the optical fiber imaging element for ultraviolet detection disclosed in Example 1 of the present invention;

[0030] Figure 2 Schematic diagram of the structure of the optical fiber imaging element for ultraviolet detection disclosed in Example 2 of the present invention;

[0031] Figure 3 Schematic diagram of the structure of the optical fiber imaging element for ultraviolet detection disclosed in Example 3 of the present invention;

[0032] Figure 4 This is a fluorescence spectrum of the quantum dot glass film quartz plate and the optical fiber imaging element for ultraviolet detection in Example 1 of the present invention;

[0033] Figure 5 This is a fluorescence spectrum diagram of the quantum dot glass film quartz plate and the optical fiber imaging element for ultraviolet detection in Example 2 of the present invention;

[0034] Figure 6 This is a fluorescence spectrum diagram of the quantum dot glass film quartz plate and the optical fiber imaging element for ultraviolet detection in Example 3 of the present invention;

[0035] Figure 7 This is a fluorescence spectrum of the quantum dot glass film quartz plate and the optical fiber imaging element for ultraviolet detection in Example 4 of the present invention;

[0036] Figure 8 This is a fluorescence spectrum of the quantum dot glass film quartz plate and the optical fiber imaging element for ultraviolet detection in Example 5 of the present invention;

[0037] Figure 9 1 is a fluorescence spectrum diagram of the optical fiber imaging element for ultraviolet detection in Example 1 of the present invention and the P20 phosphor optical fiber imaging element in Comparative Example 2;

[0038] Figure 10 This is an X-ray diffraction test diagram of CsPbBr3 quantum dots in Example 1 of the present invention.

[0039] Description of reference numerals:

[0040] 1. Quartz window; 2. Epoxy resin glue; 3. CsPbBr3 quantum dots; 4. Acid-washed fiber optic panel; 5. Acid-washed fiber optic cone; 6. Acid-washed fiber optic image inverter. DETAILED DESCRIPTION

[0041] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, provides a detailed description of a fiber optic imaging element for ultraviolet detection, its preparation method, and its specific implementation, structure, features, and effectiveness. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0042] The present invention provides these embodiments to make the present invention thorough and complete, and to fully express the scope of the present invention to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0043] The present invention proposes a method for preparing an optical fiber image transmission element for ultraviolet detection, such as Figures 1 to 3 As shown, the steps include:

[0044] (1) Acid-washing the cross section of one end of the optical fiber imaging element to form a microporous structure at the cross section, wherein the depth of the microporous structure is 10 to 50 μm, thereby obtaining an acid-washed optical fiber imaging element; wherein the core of the optical fiber imaging element is made of an acid-resistant material and the cladding is made of an acid-resistant material;

[0045] (2) dissolving CsX and PbX2 in an organic solvent to obtain a precursor solution; wherein X is at least one of Cl, Br and I;

[0046] (3) heating the aforementioned precursor solution and introducing an inert gas to bring the gaseous precursor solution to the aforementioned microporous structure, so that the aforementioned precursor solution reacts in the aforementioned microporous structure in a gaseous form to generate CsPbX3 quantum dots, which fill the aforementioned microporous structure to obtain a filled optical fiber imaging element; and,

[0047] (4) A protective window is installed on the filling surface of the aforementioned filled optical fiber imaging element to obtain an optical fiber imaging element for ultraviolet detection.

[0048] Specifically, in step (1), the optical fiber imaging element can be selected from an optical fiber panel, an optical fiber light cone or an optical fiber image invertor. Based on the acid resistance of the fiber core and the cladding, the acid solution used for pickling can be selected from at least one acid solution of 0.1 to 3.0 mol / L hydrochloric acid, nitric acid, citric acid and sulfuric acid. The pickling method can produce a regularly arranged microporous structure with holes only at the fiber core position. This method can accurately prepare micropores at the fiber core position without destroying the cladding structure and causing optical crosstalk. In addition, the diameter of the micropores is controlled by adjusting the fiber core diameter, and the depth of the micropores is controlled by adjusting the acid concentration and immersion time, thereby achieving a high-precision, highly uniform and regularly arranged micropore structure with adjustable micropore diameter and depth.

[0049] In step (2), CsPbX3 quantum dots have high photoluminescence quantum yield, excellent color purity and adjustable band gap. The filling thickness is controlled to be 10 to 50 μm, so that they act as ultraviolet light-sensitive materials, achieving high luminescence intensity and long-term stability, improving detection efficiency and detection life. At the same time, after filling with CsPbX3 quantum dots, a single optical fiber can achieve efficient luminescence, effectively improving detection resolution; the light converted by the quantum dot material in the microporous structure after ultraviolet irradiation is transmitted by the corresponding optical fiber, and each optical fiber is a separate image transmission unit. Compared with the diffuse reflection light of stimulated emission of traditional quantum dot materials, the resolution is greatly improved. In addition, by combining the three ions of Cl, Br, and I, CsPbX3 quantum dots that emit visible light of any wavelength can be prepared, and the combination can be selected according to the actual application scenario. The concentration and mass of the precursor solution are adjusted according to the depth and diameter of the micropores. For example, 1-5 mol CsX and 1-5 mol PbX2 can be dissolved in 1-5 ml DMF at a molar ratio of 1:1 to prepare a precursor solution.

[0050] In step (3), CsPbX3 quantum dots are directly reacted and generated at the microporous structure using a precursor solution containing CsX and PbX2 as raw materials by chemical vapor deposition. For example, the precursor solution can be placed at the air inlet of a tube furnace, and the optical fiber imaging element with a microporous array is placed at the exhaust port. The gas flow rate is controlled at 80-120 mL / min, and the heating temperature of the tube furnace is controlled according to the composition of X. After the CsPbX3 quantum dots fill the microporous structure, the CsPbX3 quantum dots that protrude from the panel cross section are scraped off. This method allows for rapid and dense filling of CsPbX3 quantum dots, high preparation efficiency, and high purity and good luminescence effect of the generated CsPbX3 quantum dots, which is conducive to industrial production. The organic solvent can be selected to be an organic solvent that can dissolve CsX and PbX2, is volatile, and does not react with the optical fiber imaging element. No specific restrictions are made here.

[0051] The protective window can protect the filled CsPbX3 quantum dots from being contaminated or falling off. The protective window can be made of transparent materials such as quartz, organic glass, and resin.

[0052] The optical fiber imaging element for ultraviolet detection prepared by the method of the present invention has the advantages of high brightness and high resolution, effectively improving the detection efficiency and detection resolution of the ultraviolet detector, and is of great significance to the fields of national defense, civil use and scientific research.

[0053] In some embodiments, in step (2), the molar ratio of CsX to PbX2 is 1:0.8-1.2.

[0054] Specifically, this ratio is determined by the chemical formula of CsPbX3. If the molar ratio of CsX to PbX2 is greater than 1:0.8 or less than 1:1.2, the resulting CsPbX3 quantum dots contain a high amount of byproducts. More preferably, the molar ratio of CsX to PbX2 is 1:1.

[0055] In some embodiments, in step (2), the aforementioned organic solvent is N,N-dimethylformamide, N,N-dimethylacetamide or N,N-dimethylacrylamide.

[0056] Specifically, N,N-dimethylformamide (DMF) has excellent solubility: DMF is a polar solvent with excellent solubility properties. It can dissolve a variety of inorganic and organic substances, and can dissolve CsX and PbX2 well. DMF also has good chemical stability and is relatively stable at high temperatures. Furthermore, DMF has low viscosity and low surface tension, with a boiling point of only 153°C, making it easy to vaporize. The physical and chemical properties of N,N-dimethylacetamide and N,N-dimethylacrylamide are similar to those of DMF.

[0057] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (3), the temperature of heating the aforementioned precursor solution is 500-700°C.

[0058] Specifically, at temperatures below 500°C, the reaction rate between CsX and PbX2 to form CsPbX3 quantum dots is slow. At temperatures above 700°C, the evaporation rate of the precursor solution is too fast, making it difficult to control and placing high demands on the equipment. Therefore, the temperature of the precursor solution is controlled between 500°C and 700°C.

[0059] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (3), the aforementioned gas introduced is at least one of argon and nitrogen.

[0060] In particular, argon and nitrogen are inert gases commonly used in industrial production.

[0061] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (4), the material of the aforementioned protective window is quartz, and the thickness is 2 to 3 mm.

[0062] Specifically, quartz has good light transmittance, and has good hardness and wear resistance.

[0063] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, the steps further include: before step (4), coating a silicon dioxide film layer on the filling surface of the aforementioned filled optical fiber imaging element.

[0064] Specifically, the coating of the silicon dioxide film can better isolate water and oxygen and protect the CsPbX3 quantum dots. The thickness of the silicon dioxide film can be 2-5 μm.

[0065] In some embodiments, according to the aforementioned method for preparing an optical fiber imaging element for ultraviolet detection, in step (4), the method for installing the aforementioned protective window is: dripping coupling glue on the aforementioned silicon dioxide film layer, placing the aforementioned protective window, and then curing the aforementioned coupling glue.

[0066] Specifically, the coupling glue can be epoxy resin glue 2. For example, use a syringe to drop 0.2-0.5 ml of epoxy resin glue 2 at the center of the silicon dioxide film layer, and control the protective window to slowly lower vertically until it fully contacts the silicon dioxide film layer. At this point, the epoxy resin glue 2 has a thickness of 5-10 μm. Then, cure it at 60°C for 3-6 hours to achieve complete curing.

[0067] The present invention provides an optical fiber image transmission element for ultraviolet detection, which comprises:

[0068] An optical fiber imaging element, wherein the core of the optical fiber imaging element is made of an acid-etchable material and the cladding is made of an acid-resistant material, and the core of the optical fiber imaging element is recessed at a cross section at one end thereof, forming a microporous structure with a depth of 10 to 50 μm at the cross section;

[0069] CsPbX3 quantum dots, the aforementioned CsPbX3 quantum dots are filled in the aforementioned microporous structure; and

[0070] A protective window is provided on the cross section of the optical fiber imaging element filled with the CsPbX3 quantum dots.

[0071] The present invention proposes an application of the aforementioned optical fiber imaging element for ultraviolet detection in the field of ultraviolet detection. For example, the optical fiber imaging element for ultraviolet detection proposed by the present invention can be installed on an ultraviolet detector for use.

[0072] The present invention will be further described below with reference to specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0073] Unless otherwise specified, the materials and reagents mentioned below are commercially available products familiar to those skilled in the art. Unless otherwise specified, the methods described are all well-known methods in the art. Unless otherwise defined, technical or scientific terms used shall have the same meanings as those commonly understood by those skilled in the art.

[0074] In the following embodiments, the core of the optical fiber imaging element is made of an acid-etchable material. The core composition, calculated by mole percentage of oxides, includes: SiO2: 30.3-36.4%; B2O3: 18.9-20.2%; La2O3: 5.9-6.1%; the total content of BaO and CaO is 33.7-39.4%; Al2O3: 1.6-2.3%; TiO2: 2.0-2.9%; and the cladding of the optical fiber imaging element is 1.6-2.3%. Acid-resistant materials are used, and the cladding components, calculated by molar percentage of oxides, include: SiO2: 70.5~74.5%; PbO: 12.0~12.5%; Bi2O3: 0~2.0%; the total content of Na2O, K2O, Rb2O and Cs2O is: 5.8~7.7%; the total content of BaO and MgO is: 4.6~6.7%; Al2O3: 1.1~3.0%; TiO2: 0~2.0%.

[0075] Example 1:

[0076] This embodiment provides a fiber optic image transmission element for ultraviolet detection and a preparation method thereof. The schematic diagram of the structure is shown in FIG. Figure 1 .

[0077] (1) The optical fiber imaging element in this embodiment uses an optical fiber panel with a core diameter of 10 μm and a thickness of 10 mm. The cross section of the optical fiber panel is immersed in a 1 L nitric acid solution with a concentration of 0.5 mol / L for 2 hours to form a regularly arranged microporous structure with a diameter of 10 μm and a depth of 10 μm in the cross section of the optical fiber panel, thereby obtaining an acid-washed optical fiber panel 4.

[0078] (2) Dissolve 2 mol of CsBr and 2 mol of PbBr2 in 2 mol of DMF to prepare a precursor solution.

[0079] (3) The precursor solution was placed at the air inlet of a tube furnace, and the pickled optical fiber panel 4 was placed at the exhaust port. The circulating gas was nitrogen, and the gas flow rate was controlled at 100 mL / min. The temperature of the tube furnace was 600°C. After the precursor solution was completely evaporated, the microporous structure was observed to be completely filled. The CsPbBr3 quantum dots 3 that protruded from the panel cross section were scraped off to obtain a filled optical fiber panel.

[0080] (4) A 4 μm thick silicon dioxide film is deposited to isolate water and oxygen. 0.3 ml of epoxy resin glue 2 is dripped into the center of the silicon dioxide film using a syringe. The 2 mm thick quartz window 1 is controlled to slowly descend vertically until it is in full contact with the silicon dioxide film. At this time, the thickness of the epoxy resin glue 2 is 10 μm. The window is then cured at 60°C for 5 hours to achieve complete curing, thereby obtaining an optical fiber imaging element for ultraviolet detection.

[0081] (5) The same precursor solution as in step (2) is placed at the air inlet of the tube furnace, and a quartz substrate with a thickness of 12 mm is placed at the exhaust port. The circulating gas is nitrogen, the gas flow rate is controlled at 100 mL / min, the temperature of the tube furnace is 600 ° C, and a layer of 10 μm thick CsPbBr3 quantum dots 3 is deposited on the surface of the quartz substrate to obtain a quantum dot glass film quartz plate.

[0082] The prepared CsPbBr3 quantum dots 3 were subjected to X-ray diffraction test, and the results were as follows: Figure 10 As shown in Figure 3, it can be seen that the peaks correspond one to one with the PDF standard comparison card, proving that high-purity CsPbBr3 quantum dots 3 have been successfully synthesized.

[0083] The fluorescence spectra of the quantum dot glass film quartz plate and the ultraviolet detection optical fiber imaging element in this embodiment were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 4 As shown, A is the luminous intensity curve of the quantum dot glass film quartz plate, and B is the luminous intensity curve of the optical fiber imaging element for ultraviolet detection. The peak position of the quantum dot glass film quartz plate is at 530nm and the peak shape is sharp, and the relative luminous intensity is 100%. The peak position of the optical fiber imaging element for ultraviolet detection is at 530nm and the peak shape is sharp, indicating that the luminous purity of the sample is high; the relative luminous intensity is 80%, and the luminous intensity is only lost by 20%, indicating that the luminous intensity of the sample is high. Using ultraviolet light as the light source to test the resolution of the optical fiber panel in this embodiment is 50.8lp / mm, and the resolution of the optical fiber imaging element for ultraviolet detection is 50.8lp / mm, indicating that there is no loss of resolution when filling quantum dots in the microporous structure.

[0084] Example 2:

[0085] This embodiment provides a fiber optic image transmission element for ultraviolet detection, and its structural diagram is shown in FIG. Figure 2 .

[0086] This embodiment differs from Example 1 in that the optical fiber imaging element utilizes an optical fiber taper with a core diameter of 10 μm and a thickness of 10 mm. Furthermore, the pickled optical fiber panel 4 in Example 1 is replaced by a pickled optical fiber taper 5 in this embodiment; the filled optical fiber panel in Example 1 is replaced by a filled optical fiber taper in this embodiment.

[0087] The fluorescence spectra of the quantum dot glass film quartz plate and the ultraviolet detection optical fiber imaging element in this embodiment were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 5 As shown, A is the luminous intensity curve of the quantum dot glass film quartz plate, and B is the luminous intensity curve of the optical fiber imaging element for ultraviolet detection. The peak position of the quantum dot glass film quartz plate is at 530nm and the peak shape is sharp, and the relative luminous intensity is 100%. The peak position of the optical fiber imaging element for ultraviolet detection is at 530nm and the peak shape is sharp, indicating that the luminous purity of the sample is high; the relative luminous intensity is 75%, and the luminous intensity is only lost by 25%, indicating that the luminous intensity of the sample is high. Using ultraviolet light as the light source to test the resolution of the optical fiber light cone in this embodiment is 50.8lp / mm, and the resolution of the optical fiber imaging element for ultraviolet detection is 50.8lp / mm, indicating that there is no loss of resolution when filling quantum dots in the microporous structure.

[0088] Example 3:

[0089] This embodiment provides a fiber optic image transmission element for ultraviolet detection, and its structural diagram is shown in FIG. Figure 3 .

[0090] This embodiment differs from Embodiment 1 in that the optical fiber image transmission element utilizes an optical fiber image inverter with a core diameter of 10 μm and a thickness of 10 mm. Furthermore, the pickled optical fiber panel 4 in Embodiment 1 is replaced by the pickled optical fiber image inverter 6 in this embodiment; the filled optical fiber panel in Embodiment 1 is replaced by the filled optical fiber image inverter in this embodiment.

[0091] The fluorescence spectra of the quantum dot glass film quartz plate and the ultraviolet detection optical fiber imaging element in this embodiment were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 6 As shown, A is the luminous intensity curve of the quantum dot glass film quartz plate, and B is the luminous intensity curve of the optical fiber imaging element for ultraviolet detection. The peak position of the quantum dot glass film quartz plate is at 530nm and the peak shape is sharp, and the relative luminous intensity is 100%. The peak position of the optical fiber imaging element for ultraviolet detection is at 530nm and the peak shape is sharp, indicating that the luminous purity of the sample is high; the relative luminous intensity is 62%, and the luminous intensity is only lost by 38%, indicating that the luminous intensity of the sample is high. Using ultraviolet light as the light source to test the resolution of the optical fiber image inverter in this embodiment is 50.8lp / mm, and the resolution of the optical fiber imaging element for ultraviolet detection is 50.8lp / mm, indicating that there is no loss of resolution when filling quantum dots in the microporous structure.

[0092] Example 4:

[0093] This embodiment provides a fiber optic imaging element for ultraviolet detection and a method for preparing the same.

[0094] The difference between this embodiment and embodiment 1 is that in step (2), 2 mol of CsCl and 2 mol of PbCl2 are dissolved in 2 mol of DMF to prepare a precursor solution; and in step (3), the temperature of the tube furnace is 700°C.

[0095] The fluorescence spectra of the quantum dot glass film quartz plate and the ultraviolet detection optical fiber imaging element in this embodiment were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 7 As shown, A is the luminous intensity curve of the quantum dot glass film quartz plate, and B is the luminous intensity curve of the optical fiber imaging element for ultraviolet detection. The peak position of the quantum dot glass film quartz plate is at 450nm and the peak shape is sharp, and the relative luminous intensity is 100%. The peak position of the optical fiber imaging element for ultraviolet detection is at 450nm and the peak shape is sharp, indicating that the luminous purity of the sample is high; the relative luminous intensity is 80.2%, and the luminous intensity is only lost by 19.8%, indicating that the luminous intensity of the sample is high. Using ultraviolet light as the light source to test the resolution of the optical fiber image inverter in this embodiment is 50.8lp / mm, and the resolution of the optical fiber imaging element for ultraviolet detection is 50.8lp / mm, indicating that there is no loss of resolution when filling the quantum dot glass powder in the microporous structure.

[0096] Example 5:

[0097] This embodiment provides a fiber optic imaging element for ultraviolet detection and a method for preparing the same.

[0098] The difference between this embodiment and embodiment 1 is that in step (2), 2 mol of CsI and 2 mol of PbI2 are dissolved in 2 mol of DMF to prepare a precursor solution; and in step (3), the temperature of the tube furnace is 500°C.

[0099] The fluorescence spectra of the quantum dot glass film quartz plate and the ultraviolet detection optical fiber imaging element in this embodiment were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 8As shown, A is the luminous intensity curve of the quantum dot glass film quartz plate, and B is the luminous intensity curve of the optical fiber imaging element for ultraviolet detection. The peak position of the quantum dot glass film quartz plate is at 630nm and the peak shape is sharp, and the relative luminous intensity is 100%. The peak position of the optical fiber imaging element for ultraviolet detection is at 630nm and the peak shape is sharp, indicating that the luminous purity of the sample is high; the relative luminous intensity is 79.7%, and the luminous intensity is only lost by 20.3%, indicating that the luminous intensity of the sample is high. Using ultraviolet light as the light source to test the resolution of the optical fiber image inverter in this embodiment is 50.8lp / mm, and the resolution of the optical fiber imaging element for ultraviolet detection is 50.8lp / mm, indicating that there is no loss of resolution when filling the quantum dot glass powder in the microporous structure.

[0100] Comparative Example 1:

[0101] The optical fiber panel in Example 1 was used as a substrate, and a 10 μm thick perovskite quantum dot glass film was prepared on its surface to obtain a quantum dot glass film optical fiber imaging element. The specific method was as follows: the perovskite quantum dot glass powder in Example 1 was dispersed in anhydrous ethanol to prepare a quantum dot dispersion liquid. 0.2 ml of the quantum dot dispersion liquid was dripped onto the surface of the optical fiber panel. The spin coating method was controlled at a speed of 800 rpm for 60 seconds. After spin coating, the substrate was heated in an oven at 60°C for 30 minutes to form a 10 μm thick quantum dot glass film on the substrate surface.

[0102] The resolution of the quantum dot glass film fiber-optic imaging element tested using ultraviolet light as a light source was 45.3 lp / mm. This is lower than the resolution of the ultraviolet detection fiber-optic imaging element in Example 1, demonstrating that the perovskite quantum dot glass powder filled into the microporous structure of the fiber faceplate effectively improves resolution.

[0103] Comparative Example 2:

[0104] The difference between Comparative Example 2 and Example 1 is that the perovskite quantum dot glass powder is replaced with P20 phosphor to obtain a P20 phosphor optical fiber imaging element.

[0105] The fluorescence spectra of the optical fiber imaging element for ultraviolet detection in Example 1 and the above-mentioned P20 phosphor optical fiber imaging element were tested using a fluorescence spectrometer. The test results are shown in Figure 2. Figure 9 As shown in Figure 1, B is the luminous intensity curve of the fiber optic imaging element for UV detection in Example 1, and C is the luminous intensity curve of the P20 phosphor fiber optic imaging element. Taking the luminous intensity of the fiber optic imaging element for UV detection in Example 1 as 100%, the luminous intensity of the P20 phosphor fiber optic imaging element is only 47%, indicating low luminous intensity. Furthermore, its wide half-width (FWHM) indicates poor luminous purity. The fiber optic imaging element provided by the present invention exhibits high luminous intensity and purity, effectively improving detection efficiency.

[0106] The technical features in the claims and / or the specification of the present invention may be combined, and the manner of combination is not limited to the combination obtained by reference in the claims. The technical solutions obtained by combining the technical features in the claims and / or the specification are also within the scope of protection of the present invention.

[0107] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiment based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an optical fiber imaging element for ultraviolet detection, characterized in that: The steps include: (1) Acid-washing the cross section of one end of the optical fiber imaging element to form a microporous structure at the cross section, wherein the depth of the microporous structure is 10 to 50 μm, thereby obtaining an acid-washed optical fiber imaging element; wherein the core of the optical fiber imaging element is made of an acid-resistant material and the cladding is made of an acid-resistant material; (2) dissolving CsX and PbX2 in an organic solvent to obtain a precursor solution; wherein X is at least one of Cl, Br and I; (3) heating the precursor solution and introducing an inert gas to bring the gaseous precursor solution to the microporous structure, causing the precursor solution to react in the microporous structure in a gaseous form to generate CsPbX3 quantum dots, filling the microporous structure to obtain a filled optical fiber imaging element; and (4) A protective window is installed on the filling surface of the filled optical fiber imaging element to obtain an optical fiber imaging element for ultraviolet detection.

2. The preparation method according to claim 1, characterized in that In step (2), The molar ratio of CsX to PbX2 is 1:0.8-1.

2.

3. The preparation method according to claim 1, characterized in that In step (2), The organic solvent is N,N-dimethylformamide, NN-dimethylacetamide or N,N-dimethylacrylamide.

4. The preparation method according to claim 1, characterized in that In step (3), The precursor solution is heated to a temperature of 500-700°C.

5. The preparation method according to claim 1, characterized in that In step (3), The gas introduced is at least one of argon and nitrogen.

6. The preparation method according to claim 1, characterized in that In step (4), The protection window is made of quartz and has a thickness of 2 to 3 mm.

7. The preparation method according to claim 1, characterized in that The steps also include: before step (4), coating a silicon dioxide film layer on the filling surface of the filled optical fiber imaging element.

8. The preparation method according to claim 7, characterized in that In step (4), the method for installing the protective window is: dripping coupling glue on the silicon dioxide film layer, placing the protective window, and then curing the coupling glue.

9. An optical fiber imaging element for ultraviolet detection, characterized in that: It includes: An optical fiber imaging element, wherein the core of the optical fiber imaging element is made of an acid-etchable material, the cladding is made of an acid-resistant material, and the core is recessed at a cross section of one end of the optical fiber imaging element, forming a microporous structure with a depth of 10 to 50 μm at the cross section; CsPbX3 quantum dots, wherein the CsPbX3 quantum dots are filled in the microporous structure; wherein X is at least one of Cl, Br and I; and A protective window is provided on the cross section of the optical fiber imaging element filled with the CsPbX3 quantum dots.

10. Use of the optical fiber imaging element for ultraviolet detection according to claim 9 in the field of ultraviolet detection.

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