One-dimensional photonic crystal and dual-parameter detection device based on one-dimensional photonic crystal

Abstract

The application belongs to the technical field of photonic crystal sensing, and relates to a one-dimensional photonic crystal and a dual-parameter detection device based on the one-dimensional photonic crystal. The one-dimensional photonic crystal comprises a first dielectric material layer, a second dielectric material layer and a sodium chloride solution defect layer. The sodium chloride solution defect layer is a containing space formed by the first dielectric material layer and the second dielectric material layer. The first dielectric material layer and the second dielectric material layer are arranged on the two sides of the sodium chloride solution defect layer and extend to the two sides of the sodium chloride solution defect layer. The one-dimensional photonic crystal is matched with a vector network analyzer, and can simultaneously measure the temperature and the concentration of the sodium chloride solution. The influence of the temperature is eliminated through formula inversion, and the content of the sodium chloride in the solution is accurately calibrated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photonic crystal sensing, and particularly relates to a one-dimensional photonic crystal and a dual-parameter detection device based on the one-dimensional photonic crystal. BACKGROUND

[0002] Different concentrations of sodium chloride solution can simulate seawater environment to carry out various experiments, and facilitate the research of green and environmentally friendly products that can alleviate marine problems. The determination of the concentration of sodium chloride in seawater has an important role in the detection and protection of the marine environment. The temperature has a certain influence on the refractive index of the sodium chloride solution, and the solubility of the sodium chloride solution also has a certain relationship with the temperature. Monitoring the sodium chloride solution and the temperature can help to calibrate the specific solution concentration and remove the influence of the temperature on the solution concentration measurement.

[0003] The existing measurement method is a chemical analysis method mainly relying on chemical reaction and material measurement relationship to determine the concentration of the measured liquid, and the process is relatively complex and the workload is relatively large. Physical methods include optical sensing method, microwave sensing method, ultrasonic measurement method, etc. However, such sensing methods are greatly affected by sample characteristics, measurement environment, experimental conditions and other factors. The microwave sensing method is greatly affected by the environmental temperature and the temperature of the measured substance, and the ultrasonic measurement method has a small frequency range and is difficult to distinguish low concentration. The one-dimensional photonic crystal and the dual-parameter detection device based on the one-dimensional photonic crystal can simultaneously measure the temperature and the solution concentration, eliminate the influence of the temperature through formula inversion, and accurately calibrate the sodium chloride content in the solution, which has important significance. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a one-dimensional photonic crystal and a dual-parameter detection device based on the one-dimensional photonic crystal, which can simultaneously measure the temperature and the concentration of the sodium chloride solution, eliminate the influence of the temperature through formula inversion, and accurately calibrate the sodium chloride content in the solution.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] The one-dimensional photonic crystal is a layered structure, comprising a first dielectric material layer, a second dielectric material layer and a sodium chloride solution defect layer; the first dielectric material layer and the second dielectric material layer are arranged on each side of the sodium chloride solution defect layer, and the first dielectric material layer and the second dielectric material layer are alternately arranged and extend to the direction of the two sides of the sodium chloride solution defect layer; the sodium chloride solution defect layer is adjacent to the first dielectric material layer on one side and adjacent to the second dielectric material layer on the other side; the number of layers of the first dielectric material layer and the second dielectric material layer on each side of the sodium chloride solution defect layer is the same, and the total number of layers of the first dielectric material layer and the second dielectric material layer on the two sides of the sodium chloride solution defect layer is the same.

[0007] Further, the sodium chloride solution defect layer is a cavity formed by the first dielectric material layer and the second dielectric material layer, for injecting sodium chloride solution.

[0008] Further, the thickness of the sodium chloride solution defect layer is 365 nm.

[0009] Further, the first dielectric material layer is a potassium dihydrogen phosphate crystal layer.

[0010] Further, the refractive index of the first dielectric material layer is 1.53.

[0011] Further, the second dielectric material layer is a titanium dioxide layer.

[0012] Further, the refractive index of the first dielectric material layer is 2.49, and the central wavelength is 1000 nm.

[0013] The two-parameter detection device based on the one-dimensional photonic crystal comprises a vector network analyzer, a signal transmitting end, a signal receiving end and the one-dimensional photonic crystal; the vector network analyzer is connected with the signal transmitting end and the signal receiving end through wires; and the one-dimensional photonic crystal is arranged between the signal transmitting end and the signal receiving end.

[0014] Further, the relationship between the concentration of sodium chloride solution and the defect peak position is:

[0015] S = 1.771 lambda - 1753

[0016] Wherein, S is the concentration of sodium chloride solution, and lambda is the wavelength of the defect mode peak position.

[0017] Further, the linear relationship between the refractive index of the first dielectric material layer in the one-dimensional photonic crystal and the temperature is:

[0018] n = a - bT

[0019] Wherein, a = 1.4780, b = 3.5952 * 10-4, T represents temperature, and n represents refractive index.

[0020] Advantages of the present application:

[0021] 1. The present application can simultaneously measure temperature and sodium chloride solution concentration, measure the defect peaks formed in the defect layer at different temperatures and concentrations, and measure the corresponding defect peak frequencies.

[0022] 2. Compared with most single measurement sensors, the measuring device considers the influence of temperature on solution concentration, can effectively improve the measurement sensitivity and accuracy, can perform real-time detection, and is not affected by electromagnetic interference. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0024] Figure 1 is a one-dimensional photonic crystal structure schematic diagram of the embodiment of the present application;

[0025] Figure 2 is a sodium chloride solution concentration and temperature dual-parameter detection device schematic diagram of the embodiment of the present application;

[0026] Figure 3 is a transmittance characteristic diagram of the influence of temperature on defect peak position under the same sodium chloride solution concentration of the embodiment of the present application;

[0027] Figure 4 is a one-dimensional photonic crystal transmittance characteristic diagram corresponding to different sodium chloride solution concentrations of the embodiment of the present application.

[0028] Reference signs:

[0029] 1. One-dimensional photonic crystal; 11. First dielectric material layer; 12. Second dielectric material layer; 13. Sodium chloride solution defect layer; 2. Vector network analyzer; 21. Signal transmitting end; 22. Signal receiving end. DETAILED DESCRIPTION

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, a one-dimensional photonic crystal 1 has a layered structure, including a first dielectric material layer 11, a second dielectric material layer 12, and a sodium chloride solution defect layer 13. Each side of the sodium chloride solution defect layer 13 is provided with a first dielectric material layer 11 and a second dielectric material layer 12. The first dielectric material layer 11 and the second dielectric material layer 12 are alternately arranged and extend towards both sides of the sodium chloride solution defect layer 13. One side of the sodium chloride solution defect layer 13 is adjacent to the first dielectric material layer 11, and the other side is adjacent to the second dielectric material layer 12. The number of first dielectric material layers 11 and second dielectric material layers 12 on each side of the sodium chloride solution defect layer 13 is the same, and the total number of first dielectric material layers 11 and second dielectric material layers 12 on both sides of the sodium chloride solution defect layer 13 is the same.

[0033] In this application, each side of the sodium chloride solution defect layer 13 is provided with 12 alternating layers, which consist of 6 first dielectric material layers 11 and 6 second dielectric material layers 12, with the first dielectric material layers 11 and the second dielectric material layers 12 alternately arranged. Of course, in some disclosures, the number of alternating layers can also be an even number, such as 8, 10, or 14.

[0034] In this application, the sodium chloride solution defect layer 13 is a cavity formed by the first dielectric material layer 11 and the second dielectric material layer 12, which is used to inject sodium chloride solution.

[0035] Specifically, the thickness of the sodium chloride solution defect layer 13 is 365 nm.

[0036] Specifically, the first dielectric material layer 11 is a potassium dihydrogen phosphate crystal layer, and the refractive index of the first dielectric material layer 11 is 1.53.

[0037] Specifically, the second dielectric material layer 12 is a titanium dioxide layer, and the first dielectric material layer 11 has a refractive index of 2.49 and a central wavelength of 1000nm.

[0038] It should be noted that the structure of the one-dimensional photonic crystal 1 used for this detection is (AB). n C(BA) n, A represents the first dielectric material layer 11, B represents the second dielectric material layer 12, C represents the sodium chloride solution defect layer 13, n represents the arrangement period number of the two kinds of medium layers before and after the defect layer C, wherein n = 6, the physical thickness of the first dielectric material layer 11 is determined according to the refractive index of potassium dihydrogen phosphate crystal and an arbitrary central wavelength, the physical thickness of the second dielectric material layer 12 is determined according to the refractive index of titanium dioxide and an arbitrary central wavelength, and the physical thicknesses of the first dielectric material layer 11 and the second dielectric material layer 12 and the refractive indexes thereof all satisfy that the optical path is a quarter of the central wavelength, the central wavelength refers to the wavelength of the incident light of the one-dimensional photonic crystal, that is, the wavelength of the light emitted by the signal emission end. The physical thickness of the defect layer is 365 nm.

[0039] Example two

[0040] The preparation method of the one-dimensional photonic crystal comprises the following steps:

[0041] Firstly, the first dielectric material layer 11 and the second dielectric material layer 12 with designed thicknesses are sequentially grown on the optical substrate by coating or magnetron sputtering, and 6 periods are grown in the same way;

[0042] Then, the second dielectric material layer 12 and the first dielectric material layer 11 of 6 periods are alternately grown, so as to complete the preparation of the one-dimensional photonic crystal.

[0043] It should be noted that in this example, potassium dihydrogen phosphate crystal and titanium dioxide are selected as the two kinds of medium materials, sodium chloride solution is selected as the defect layer, and the structure of (AB)nC(BA)n is adopted, 6 period structures are taken on both sides of the defect layer, a vacuum coating machine with a model of WD.54-450 is selected, KDP sheet is selected as the optical substrate, 6 layers are alternately coated on the optical substrate by coating, and the coating is repeated twice to generate separately. In the first time, the 1st, 3rd and 5th layers are potassium dihydrogen phosphate crystal layers, and the 2nd, 4th and 6th layers are titanium dioxide layers. Firstly, a first layer of potassium dihydrogen phosphate crystal layer with a thickness of 163.4 nm is coated on the optical substrate, then a titanium dioxide layer with a thickness of 100.4 nm is coated on the first layer to obtain one period of the photonic crystal, and then 5 periods are grown in the same way. The operation is repeated twice. A total of 12 periods before and after the defect layer are obtained. The photonic crystal materials generated twice are overlapped together, a gap with a thickness of 365 nm is reserved as the defect layer in the middle, the defect layer is sealed by an acrylic plate around, an injection hole is reserved on the acrylic plate, so as to facilitate the addition of the sodium chloride solution to be measured in the later period, and a one-dimensional photonic crystal as shown in Figure 1 is prepared.

[0044] Example three

[0045] As shown in Figure 2As shown, the two-parameter detection device based on one-dimensional photonic crystal comprises a vector network analyzer 2, the vector network analyzer 2 is connected with a signal transmitting end 21 and a signal receiving end 22 through wires, and a one-dimensional photonic crystal 1 is arranged between the signal transmitting end 21 and the signal receiving end 22.

[0046] The vector network analyzer is a kind of electromagnetic wave energy testing equipment. It can measure the amplitude of various parameters of single-port network or two-port network, and can also measure the phase. The vector network analyzer can display test data by Smith circle diagram.

[0047] The signal transmitted by the signal transmitting end 21 is received by the signal receiving end 22 after passing through the one-dimensional photonic crystal layer 1. The vector network analyzer 2 is connected with a computer signal for data analysis. Preferably, the one-dimensional photonic crystal 1 is arranged in the middle of the signal transmitting end 21 and the signal receiving end 22 to ensure the detection effect.

[0048] In use, the one-dimensional photonic crystal 1 is fixed on the vector network analyzer 2, a sodium chloride solution to be measured is injected into the defect layer, a light beam with a wavelength of 1000 nm is emitted from left to right to the one-dimensional photonic crystal 1, the transmitted light wave is received, the transmittance characteristic diagram is fitted by the vector network analyzer 2, and the concentration of the sodium chloride solution is obtained by inversion according to the peak position of the defect peak in the characteristic diagram. The vector network analyzer 2 selects ZC1100, which provides excellent radio frequency performance, rich software functions and unique hardware concepts. The thickness of the defect layer of the one-dimensional photonic crystal is 365 nm, and the central wavelength of the radio frequency signal emitted by the vector analyzer is 1000 nm.

[0049] The embodiment provides a two-parameter detection device based on one-dimensional photonic crystal, the room temperature is not changed, and the concentrations of 4%, 8%, 12%, 16%, 20%, 24%, 28% and 32% sodium chloride solutions are detected. The working wave band of the detection device is a near-infrared wave band, and the relationship between the concentration of the sodium chloride solution and the peak position of the defect peak is:

[0050] S = 1.771 lambda - 1753

[0051] Wherein, S is the concentration of the sodium chloride solution, and lambda is the wavelength of the defect mode wave peak position.

[0052] The embodiment provides a two-parameter detection device based on one-dimensional photonic crystal, in the case that the concentration of the sodium chloride solution is fixed, the temperature is considered as an environmental influence factor from 0 DEG C to 70 DEG C, the refractive index of the first dielectric material layer 11 in the one-dimensional photonic crystal has a linear relationship with the temperature as follows:

[0053] n = a - bT

[0054] Wherein, a = 1.4780, b = 3.5952*10-4, T represents temperature, n represents refractive index.

[0055] As shown in Figure 2 , the one-dimensional photonic crystal 1 is fixed in the middle of the vector network analyzer 2, and the vector network analyzer 2 realizes the analysis of the transmission spectrum through the transmitting antenna 21 and the receiving antenna 22, and transmits the results to the computer for display.

[0056] As shown in Figure 3 , in the case of fixed concentration of sodium chloride solution, the environmental factors are considered when the temperature is from 0℃ to 70℃, and the Figure 3 transmittance characteristic diagram is obtained, as shown in the figure, the change of temperature affects the refractive index of potassium dihydrogen phosphate crystal, and the refractive index presents a weakening trend as a whole with the increase of temperature, and the defect peak frequency obtained by simulation exists deviation.

[0057] As shown in Figure 4 , the room temperature is kept constant, and the concentrations of 4%, 8%, 12%, 16%, 20%, 24%, 28% and 32% of sodium chloride solution are detected, and the corresponding transmittance characteristic diagram under different concentrations is obtained. From Figure 4 , it can be seen that with the increase of the concentration of the solution, the wavelength of the defect mode wave peak gradually moves to the long wave direction from 992.32nm when the solution concentration is 4%, and the moving amplitude is proportional to the change of the solution concentration. The refractive index sensitivity of sodium chloride solution is 57nm / RIU. At this time, the solution refractive index sensitivity is high, which indicates that the change of sodium chloride solution concentration can be captured by the one-dimensional defect type photonic crystal model. The data of sodium chloride solution under different concentrations and the position of the defect mode are sorted out, and the fitting equation is obtained by fitting the data analysis:

[0058] S = 1.771λ-1753

[0059] Wherein, S is the concentration of sodium chloride solution, and λ is the wavelength of the defect mode wave peak position.

[0060] The defect peak wavelength obtained from the vector network analyzer 2 is brought into the fitting equation, and the concentration of sodium chloride solution can be obtained by inversion.

[0061] The application discloses a two-parameter detection device based on one-dimensional photonic crystal, which is composed of a limited period one-dimensional photonic crystal 1 formed by two different dielectric materials arranged alternately according to a certain period and a sodium chloride solution as a defect layer, and has a structure of (AB)nC(BA)n, wherein A represents potassium dihydrogen phosphate crystal (KDP), B represents titanium dioxide (TiO2), C represents the sodium chloride solution, and n represents the number of the arrangement period of the two media before and after the defect layer C.

[0062] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A one-dimensional photonic crystal, wherein the one-dimensional photonic crystal has a layered structure, characterized in that, It includes a first dielectric material layer (11), a second dielectric material layer (12), and a sodium chloride solution defect layer (13); each side of the sodium chloride solution defect layer (13) is provided with the first dielectric material layer (11) and the second dielectric material layer (12), the first dielectric material layer (11) and the second dielectric material layer (12) are alternately arranged in sequence and extend towards both sides of the sodium chloride solution defect layer (13), one side of the sodium chloride solution defect layer (13) is adjacent to the first dielectric material layer (11), and the other side is adjacent to the second dielectric material layer (12). The number of the first dielectric material layer (11) and the second dielectric material layer (12) on each side of the sodium chloride solution defect layer (13) is the same, and the total number of the first dielectric material layer (11) and the second dielectric material layer (12) on both sides of the sodium chloride solution defect layer (13) is the same. The sodium chloride solution defect layer (13) is a cavity formed by the first dielectric material layer (11) and the second dielectric material layer (12) for injecting sodium chloride solution; The first dielectric material layer (11) is a potassium dihydrogen phosphate crystal layer; The relationship between sodium chloride solution concentration and defect peak position is as follows: S = 1.771λ - 1753 Where S is the concentration of sodium chloride solution, and λ is the wavelength of the defect mode peak position; The refractive index of the first dielectric material layer is linearly related to temperature as follows: ,in , T represents temperature, and n represents refractive index.

2. The one-dimensional photonic crystal according to claim 1, characterized in that, The thickness of the sodium chloride solution defect layer (13) is 365 nm.

3. The one-dimensional photonic crystal according to claim 1, characterized in that, The second dielectric material layer (12) is a titanium dioxide layer.

4. The one-dimensional photonic crystal according to claim 1, characterized in that, The second dielectric material layer (12) has a refractive index of 2.49 and a central wavelength of 1000 nm.

5. A dual-parameter detection device based on a one-dimensional photonic crystal, comprising a vector network analyzer (2), a signal transmitter (21), a signal receiver (22), and a one-dimensional photonic crystal as described in any one of claims 1-4, characterized in that, The vector network analyzer (2) is connected to the signal transmitter (21) and the signal receiver (22) via wires, and the one-dimensional photonic crystal is disposed between the signal transmitter (21) and the signal receiver (22).

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