A micro-nano photonic structure with large preparation tolerance and customizable sensitivity, a preparation method and application thereof

Abstract

The application provides a micro-nano photonic structure with large preparation tolerance and customizable sensitivity, a preparation method and application thereof, and belongs to the technical field of micro-nano photonic structures.The micro-nano photonic structure comprises, from bottom to top, a substrate layer, a high-reflection layer, a polymer structure and a metal layer in sequence.The high-reflection layer is bonded to the substrate layer through an adhesive layer.The polymer structure is located on the upper surface of the high-reflection layer.The metal layer is deposited on the upper surface of the polymer structure.The spectrum of the micro-nano photonic structure has a significant characteristic peak at a specific wavelength, which is formed by Wood anomaly and Fabry-Perot cavity mode coupling.In a certain parameter tolerance range, the coupling mode operating wavelength and sensing sensitivity hardly change.The micro-nano photonic structure can be applied to an optical sensor and has extremely high preparation tolerance and customizable sensitivity.

Description

Technical Field

[0001] This invention relates to the field of micro-nano photonic structure technology, and more specifically, to a micro-nano photonic structure with large fabrication tolerance and customizable sensitivity, its fabrication method, and its applications. Background Technology

[0002] Currently, research in the field of micro-nano photonic sensors focuses on improving sensor performance indicators, such as quality factor (Q-value) and sensitivity. Methods to improve Q-value and sensitivity mainly include: 1. Coupling different modes through folded photonic crystal bands to obtain a Q-value and sensor sensitivity much higher than that of a single band; 2. Controlling overall radiation loss by adjusting the structural parameters of the microstructure, thereby obtaining a high Q-value; 3. Systems supporting continuous bound states (BIC) in hybrid photonic structures can achieve ultra-high Q-value and sensitivity. However, all current high-performance solutions have significant limitations. For example, BIC systems are extremely sensitive to wave vector direction and structural parameters; wave vector direction deviations in mode coupling schemes can easily lead to band splitting. Furthermore, regarding structural tolerance, high-precision samples are currently fabricated using two main methods: ultraviolet lithography and electron beam lithography. While ultraviolet lithography enables mass production of devices, it suffers from poor precision. Electron beam lithography, although offering higher precision, has excessively high fabrication costs and extremely low efficiency. Therefore, developing novel micro / nano photonic structures that combine high sensing performance, large fabrication tolerance, and low cost is urgently needed. In existing technologies, even small deviations in structural parameters can lead to significant degradation in sensing performance, severely limiting the application of high-performance micro / nano photonic sensors. Therefore, a robust design is urgently required to ensure that micro / nano photonic sensors maintain stable optical performance under parameter fluctuations, balancing performance, cost, and mass production feasibility. Summary of the Invention

[0003] The technical problem to be solved by this invention is: how to improve the fabrication tolerance of high-performance micro-nano photonic sensors so that they can still maintain high sensing performance even when there is a large deviation from the design parameters.

[0004] To address the aforementioned technical problems, this invention provides a micro / nano photonic structure with large fabrication tolerance and customizable sensitivity, wherein the micro / nano photonic structure comprises, from bottom to top:

[0005] Substrate layer;

[0006] A high-reflectivity layer, wherein the high-reflectivity layer is bonded to the substrate layer by an adhesive layer, and its thickness is greater than or equal to 80 nm;

[0007] A polymer structure, wherein the polymer structure is a periodic pore array, and the polymer structure is fabricated on the upper surface of a high-reflectivity layer;

[0008] A metal layer is deposited on the upper surface of the polymer structure, and the high-reflectivity layer is parallel to the metal layer;

[0009] The micro / nano photonic structure, upon receiving an incident light field, can generate a coupling mode between Wood's anomaly and Fabry-Perot cavity resonance. In this coupling mode, the resonant wavelength... The resonant wavelength is equal to the value of the sensing sensitivity S. Satisfying formula (a):

[0010] (a)

[0011] in, The resonant wavelength of the coupling mode is expressed in nanometers. The period of a micro / nano photonic structure is represented by a unit of nanometers. The dielectric constant represents the environment surrounding the micro / nano photonic structure.

[0012] When light waves at any angle are incident on the micro / nano photonic structure provided by this invention, the reflection spectrum of the micro / nano photonic structure can generate a reflection valley at a specific wavelength. This reflection valley is generated by the coupling between the Wood's anomaly mode and the Fabry-Perot cavity. When the reflection spectrum is generated, its electric field is mainly concentrated in the slit of the polymer structure and the metal layer. The electric field in the polymer structure is formed by the Fabry-Perot cavity, and the electric field in the metal layer is mainly formed by the Wood's anomaly mode. These two modes are coupled to each other, forming the reflection valley at the specific wavelength. The Wood's anomaly mode is the dominant coupling mode.

[0013] As a preferred option The range is 380nm~15µm.

[0014] Preferably, the polymer structure is a micro / nano structure of arbitrary shape.

[0015] Preferably, the polymer structure is made of any one of photoresist, electronic adhesive, chalcogenide glass, imprinting adhesive, hot melt adhesive, and UV-curable adhesive.

[0016] Preferably, the material of the high-reflectivity layer is selected from any one or more of gold, silver, aluminum, germanium, and multilayer dielectric films.

[0017] Preferably, the resonant wavelength of the micro / nano photonic structure The range is 380 nm to 15 µm.

[0018] Preferably, the metal layer is made of one or more of gold, silver, aluminum, copper, cadmium, and nickel.

[0019] Preferably, the thickness of the metal layer is 10 nm to 3 µm.

[0020] When the structural parameters of the polymer structure and / or the height of the metal layer fluctuate within a certain range, the reflection valley at the aforementioned specific wavelength will hardly produce dispersion, and the refractive index and sensitivity of the micro-nano photonic structure will not change. This makes the micro-nano photonic structure provided by the present invention have a high fabrication tolerance, and can be processed using processes with lower fabrication precision such as ultraviolet lithography and electroplating. This significantly improves the fabrication efficiency of high-performance micro-nano photonic structures while reducing fabrication costs.

[0021] Meanwhile, through dipole decomposition, the ratio of the scattering intensities of the two or more dominant dipoles in the micro-nano photonic structure is a constant within a certain preparation tolerance range. The coupling mode is dominated by the Wood's anomaly mode, and the resonance wavelength of the coupling mode shows a strong correlation with the structural period of the polymer structure. Thus, it can be seen that the bulk refractive index sensitivity of the micro-nano photonic structure can be customized by changing the structural period of the polymer structure.

[0022] A second aspect of this invention provides a method for fabricating the micro / nano photonic structure described in the first aspect, which possesses large fabrication tolerance and customizable sensitivity, comprising the following steps:

[0023] S1: An adhesion layer and a high-reflectivity layer are sequentially deposited on a clean substrate material using electron beam evaporation, magnetron sputtering, or electroplating techniques.

[0024] S2: Spin-coating polymer onto the surface of the high-reflectivity layer;

[0025] S3: Photolithography, nanoimprinting, or 3D printing are used to obtain polymer structures;

[0026] S4: Deposit a metal layer on the polymer structure using electron beam evaporation, magnetron sputtering or electroplating techniques to obtain a micro-nano photonic structure with large fabrication tolerance and customizable sensitivity.

[0027] A third aspect of the present invention provides an application of the micro / nano photonic structure described in the first aspect, which has large fabrication tolerance and customizable sensitivity, the application including the use of the micro / nano photonic structure in the fabrication of biomolecular sensors, gas sensors or particle sensors.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The micro-nano photonic structure provided by this invention achieves strong robustness to fluctuations in key structural parameters through the synergistic coupling of Wood's anomaly mode and Fabry-Perot cavity. When the structural parameters of the polymer structure and the thickness of the metal layer are within a certain range, the characteristic valleys of this micro-nano photonic structure hardly exhibit dispersion, and the sensitivity and quality factor remain stable. This significantly reduces the manufacturing precision requirements of high-performance micro-nano photonic structures and solves the problem of overall structural performance degradation caused by small parameter deviations in the prior art. Thanks to the high fabrication tolerance mentioned above, the micro-nano photonic structure provided by this invention can use low-precision fabrication processes to replace electron beam exposure processes, providing a technical foundation for the large-scale mass production of high-performance sensors. Attached Figure Description

[0030] Figure 1 A schematic diagram of the micro-nano photonic structure provided for a specific embodiment of the present invention;

[0031] Figure 2 This is a flowchart illustrating the fabrication process of the micro / nano photonic structure provided by the present invention.

[0032] Figure 3 The reflection spectrum of the micro-nano photonic structure in Embodiment 1 of the present invention;

[0033] Figure 4 This is a mode electric field diagram of the micro / nano photonic structure in Embodiment 1 of the present invention under normal incidence of a plane wave of light;

[0034] Figure 5 The graph shows the test results of the sensing parameters of the micro-nano photonic structure in Embodiment 1 of the present invention within different parameter ranges;

[0035] Figure 6 This is a process diagram illustrating the method for achieving different volume refractive index sensitivities using micro / nano photonic structures in Embodiment 2 of the present invention.

[0036] Figure 7 The following are reflection spectra of the micro / nano photonic structure in Embodiment 2 of the present invention under different periodic conditions as a function of the environmental refractive index.

[0037] Figure 8 The graph shows the calculated results of the bulk refractive index sensitivity of the four micro / nano photonic structures with grating ridge periods in Embodiment 2 of the present invention.

[0038] Figure 9 The optical path for verifying the micro-nano photonic structure in Embodiment 3 of the present invention is shown in the SEM and reflection spectrum of its structure.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Substrate layer, 2. High reflectivity layer, 3. Polymer structure, 4. Metal layer. Detailed Implementation

[0041] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter range described in the present invention. Reasonable variations derived therefrom are still within the protection scope of the present invention.

[0042] It should be noted that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0043] Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some instances, terms having a conventional meaning are defined herein for clarification or ease of reference, and such definitions should not be construed as indicating a significant difference from conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and employed by conventional methods. Unless otherwise stated, the use of commercially available reagents and instruments shall be performed according to the manufacturer's instructions and parameters.

[0044] As described in the background art, currently, high-performance micro-nano photonic structures can only be fabricated using processes such as electron beam exposure due to their low fabrication tolerance. This results in high fabrication costs and low fabrication efficiency for high-performance micro-nano photonic structures. Based on this, the specific embodiments of the present invention provide a micro-nano photonic structure with a wide range of fabrication tolerances, its fabrication method, and its application.

[0045] The micro / nano photonic structures provided in the specific embodiments of this invention possess the characteristics of wide fabrication tolerance and customizable sensitivity. See [link to specific embodiments]. Figure 1 The micro-nano photonic structure provided in the specific embodiments of the present invention includes, from bottom to top, the following:

[0046] Substrate 1;

[0047] A high-reflectivity layer 2 is bonded to the substrate layer 1 via an adhesive layer, and its thickness is greater than or equal to 80 nm.

[0048] Polymer structure 3, which is a periodic pore array, is fabricated on the upper surface of high reflectivity layer 2;

[0049] Metal layer 4 is deposited on the upper surface of the polymer structure 3, and the high-reflectivity layer 2 is parallel to the metal layer 4;

[0050] The micro / nano photonic structure, upon receiving an incident light field, can generate a coupling mode between Wood's anomaly and Fabry-Perot cavity resonance. In this coupling mode, the resonant wavelength... The resonant wavelength is equal to the value of the sensing sensitivity S. Satisfying formula (a):

[0051] (a)

[0052] in, The resonant wavelength of the coupling mode is expressed in nanometers. The period of a micro / nano photonic structure is represented by a unit of nanometers. The dielectric constant represents the environment surrounding the micro / nano photonic structure.

[0053] In the above embodiments, the high-reflectivity layer serves as a reflective layer to reflect most of the light; the metal layer serves to work together with the polymer to generate the Wood's anomalous mode.

[0054] In the above embodiments, The range is 380nm~15µm.

[0055] In the above embodiments, polymer structure 3 is a micro / nano structure of arbitrary shape.

[0056] More specifically, in the above embodiments, the sensitivity of the micro-nano photonic structure is affected by the structural parameters of the polymer structure 3, and its sensing sensitivity can be customized by controlling the structural period of the polymer structure 3.

[0057] In the above embodiments, the material of polymer structure 3 is selected from any one of photoresist, electronic adhesive, chalcogenide glass, imprinting adhesive, hot melt adhesive, and UV curing adhesive.

[0058] More specifically, in the above embodiments, the preparation process of polymer structure 3 is preferably any one of spin coating lithography, nanoimprinting, and 3D printing.

[0059] In the above embodiments, the material of the high reflectivity layer 2 is selected from any one or more of gold, silver, aluminum, germanium, and multilayer dielectric films.

[0060] To ensure that the high-reflectivity layer 2 has sufficient reflectivity, the thickness of the high-reflectivity layer 2 in the micro-nano photonic structure in the above embodiment should be greater than or equal to 80 nm.

[0061] In the above embodiments, the resonant wavelength of the micro / nano photonic structure The range is 380 nm to 15 µm.

[0062] As mentioned above, It can be adjusted through the structural periodicity of the polymer structure.

[0063] In the above embodiments, the material of the metal layer is selected from any one or more of gold, silver, aluminum, copper, cadmium, and nickel.

[0064] More specifically, in the above embodiments, the thickness of the metal layer is preferably 10 nm to 3 μm.

[0065] More specifically, in the above embodiments, the substrate layer 1 is preferably a rigid substrate, and the material of the substrate layer 1 is preferably any one of silicon, silicon oxide, and ceramic.

[0066] More specifically, to ensure sufficient adhesion between the substrate layer 1 and the high-reflectivity layer 2, the material of the adhesion layer is preferably any one of titanium, chromium, and nickel.

[0067] The micro-nano photonic structure provided in the specific embodiments of the present invention, after being subjected to an incident light field, generates a Wood's anomaly and a Fabry-Perot cavity resonance coupling mode, which is dominated by the Wood's anomaly (WA) mode and resonates with the Fabry-Perot cavity (FP). This coupling mode is manifested in the reflection spectrum as the generation of a reflection valley at a specific wavelength. Under this coupling mode, the electric field is mainly concentrated in the slit of the polymer structure 3 and the metal layer 4. The electric field in the polymer structure 3 is formed by the Fabry-Perot resonator, and the electric field in the metal layer 4 is mainly formed by the Wood's anomaly mode. These two modes are coupled to each other, forming the aforementioned reflection valley at the specific wavelength.

[0068] Experimental verification shows that when the structural parameters of polymer structure 3 and / or the height of metal layer 4 fluctuate within a certain range, the aforementioned reflection valley hardly undergoes dispersion, and the refractive index and sensitivity of the micro-nano photonic structure do not change. In other words, when the structural parameters of polymer structure 3 and / or the height of metal layer 4 fluctuate within a certain range, the refractive index and sensitivity of the micro-nano photonic structure provided by the specific embodiment of the present invention can remain stable. This means that the micro-nano photonic structure prepared by processes with lower precision than electron beam evaporation, such as ultraviolet lithography, magnetron sputtering, and electroplating, has the same sensitivity as the micro-nano photonic structure prepared by electron beam evaporation. This indicates that the micro-nano photonic structure provided by the specific embodiment of the present invention has a wide range of preparation tolerances, and high-performance micro-nano photonic structures can be prepared using technologies with lower cost and lower preparation precision.

[0069] Meanwhile, through dipole decomposition, the energy ratio of the scattering intensity of the two or more dominant dipoles in the micro-nano structure is a constant within a certain preparation tolerance range. Here, the energy ratio of the ring dipole to the electric quadrupole moment is mainly 3. It is determined that the resonance wavelength of the coupling mode dominated by the Wood's anomaly mode is strongly correlated with the structural period, that is, the sensitivity of the micro-nano photonic structure can be customized by the structural period.

[0070] See Figure 2 , Figure 2 The method for fabricating micro / nano photonic structures with large fabrication tolerance and customizable sensitivity, as provided in the specific embodiments of the present invention, specifically includes the following steps:

[0071] S1: An adhesion layer and a high-reflectivity layer 2 are sequentially deposited on a clean silicon wafer by electron beam evaporation, magnetron sputtering or electroplating.

[0072] S2: Spin-coating polymer onto the surface of high-reflectivity layer 2;

[0073] S3: Photolithography, nanoimprinting, or 3D printing are performed on the polymer to obtain polymer structure 3;

[0074] S4: Deposit a metal layer 4 on the polymer structure 3 using electron beam evaporation, magnetron sputtering or electroplating techniques to obtain a micro-nano photonic structure with large fabrication tolerance and customizable sensitivity.

[0075] The micro-nano photonic structures with large fabrication tolerance and customizable sensitivity provided by the above embodiments can be used to manufacture biomolecular sensors, gas sensors or particle sensors.

[0076] The technical solution of the present invention will be further illustrated below by taking a polymer structure as the grating structure as an example and through specific embodiments.

[0077] Example 1

[0078] See Figure 3 When the silicon substrate of the micro-nano photonic structure is 0.5 mm thick, the adhesion layer is a titanium adhesion layer with a thickness of 3 nm, the high reflectivity layer 2 is made of gold with a height of 200 nm, the polymer structure 3 is made of polymethyl methacrylate and has a grating structure with a grating ridge width of 400 nm and a grating ridge height of 400 nm, and the metal layer 4 is made of gold with a height of 60 nm, under the normal incidence of a plane wave of light, the reflection spectrum of the aforementioned micro-nano photonic structure can generate a reflection valley at 770 nm. This reflection valley is the characteristic valley of the micro-nano photonic structure.

[0079] Figure 4 This is the mode electric field diagram of the micro / nano photonic structure in this embodiment under normal plane wave incidence of light, from... Figure 4As can be seen, the characteristic valley at 770 nm in the reflection spectrum of the micro / nano photonic structure in this embodiment originates from the coupling between the Wood's anomaly mode and the Fabry-Perot cavity, through... Figure 4 It can be seen that the electric field of this micro-nano photonic structure is mainly concentrated on the inner surface of the slit of the polymer structure 3 and the metal layer 4. The electric field in the slit of the polymer structure 3 is formed by the Fabry-Perot cavity, and the electric field of the metal layer 4 is formed by the Wood's anomaly mode. The coupling of these two modes forms the aforementioned characteristic valley at 770 nm.

[0080] For a single Wood anomaly pattern, it satisfies formula (b):

[0081] (b)

[0082] In formula (b), n represents the order of the Wood anomaly (taken as n=1), and p represents the period of the microstructure. Indicates the environmental refractive index of the microstructure. This indicates the spectral location of the Wood anomaly. For this formula, the first-order Wood anomaly in the spectrum is only related to the period of its microstructure and the ambient refractive index. Since the volume refractive index is defined as the mode dispersion caused by a unit change in the ambient refractive index, formula (b) is transformed into formula (c):

[0083] (c)

[0084] In formula (c), This indicates the volume refractive index sensitivity of the structure. That is, for a first-order Wood's anomaly, its volume refractive index is always equal to its microstructure period. However, for Wood's anomalies as plasma modes, they have extremely high radiation losses, making it difficult to obtain a high quality factor. To solve this technical problem, this invention couples a Fabry-Perot cavity with the Wood's anomaly mode to reduce its radiation losses, thereby improving the fabrication tolerance.

[0085] For the micro / nano photonic structure provided in this embodiment, the Wood's anomaly mode and the Fabry-Perot cavity coupling mode can be expressed by formula (a):

[0086] (a)

[0087] In formula (a), The resonant wavelength of the coupling mode is expressed in nanometers. The period of a micro / nano photonic structure is represented by a unit of nanometers. The dielectric constant represents the environment surrounding the micro / nano photonic structure.

[0088] As can be seen from formula (a), the coupling strength between the Wood anomaly mode and the Fabry-Perot cavity can be controlled by changing the grating ridge width (w) of the polymer structure, the height (h) of the polymethyl methacrylate grating, and the thickness (t) of the metal layer.

[0089] When the parameters of the grating structure and the metal layer 4 structure in this embodiment are adjusted, the resonant wavelength and sensitivity of the micro / nano photonic structure change as follows: Figure 5 As shown, where Figure 5 In this context, 'a' represents the effect of the width variation of the micro / nano photonic structure grating on its spectrum. Figure 5 In this context, b represents the relationship between the mode wavelength position used in the micro / nano photonic structure and the sensor sensitivity and grating width. Figure 5 In this context, 'c' represents the relationship between the mode intensity, wavelength-period ratio, and grating width used in the micro / nano photonic structure. Figure 5 In this embodiment, d represents the effect of the height variation of the micro / nano photonic structure grating on its spectrum. Figure 5 In this context, 'e' represents the relationship between the mode wavelength position used in the micro / nano photonic structure and the sensor sensitivity and grating height. Figure 5 In this context, f represents the relationship between the mode intensity, wavelength-period ratio, and grating height used in the micro / nano photonic structure. Figure 5 In this embodiment, g represents the effect of the thickness variation of the metal layer 4 of the micro / nano photonic structure on its spectrum. Figure 5 In this context, h represents the relationship between the mode wavelength position used in the micro / nano photonic structure, the sensor sensitivity, and the thickness of the metal layer 4. Figure 5 In this context, i represents the relationship between the mode intensity and wavelength-period ratio used in the micro / nano photonic structure and the thickness of the metal layer 4.

[0090] Depend on Figure 5 As can be seen, when w is 330~420nm, h is 360~400nm, and t is 10~70nm, the Wood's anomaly mode and the Fabry-Perot cavity hardly produce dispersion, and their volume refractive index and sensitivity hardly change. This indicates that the sensing performance of the micro-nano photonic structure hardly changes. This makes the micro-nano photonic structure provided in this embodiment have extremely high fabrication tolerance. Even if low-precision processes such as ultraviolet lithography are used for fabrication and the product has large structural errors, the performance of the micro-nano photonic structure can still be guaranteed.

[0091] Example 2

[0092] Based on the micro / nano photonic structure provided in Example 1, see [link to example]. Figure 6 , Figure 6 a and Figure 6 As shown in result b, the WA-FP mode corresponding to the polymer structure increases with the increase of the 3-period. Simultaneously, the bulk refractive index sensitivity of the micro / nano photonic structure and the position of the mode in the reflection spectrum also gradually increase. Figure 6 a and Figure 6As can be seen from b in Example 1, the sensitivity S of the micro / nano photonic structure provided is numerically equal to the period of the polymer structure 3, i.e., α=1. However, see... Figure 6 c and Figure 6 In the figure d, the bulk refractive index of the micro / nano photonic structure does not increase indefinitely with the increase of the period of polymer structure 3. Within a certain period range, the bulk refractive index of the micro / nano photonic structure may even decrease with the increase of the period of polymer structure 3. In this process, although the bulk refractive index of the micro / nano photonic structure is still related to the period of polymer structure 3, see [reference needed]. Figure 6 The characteristic 'd' in the text is almost invisible in the reflection spectrum, making it impossible to utilize micro / nano photonic structures. Based on this, and in conjunction with the relevant results in Example 1, see [link to example]. Figure 6 e and Figure 6 By increasing parameters such as the height or width of the array structure in polymer structure 3, the intensity of the WA-FP mode can be effectively enhanced, specifically manifested in the re-visibility of the mode intensity in the reflectance spectrum.

[0093] See Figure 7 , Figure 7 The results show the volume refractive index sensing performance of gratings with different periods. Figure 7 In the figure, 'a' represents the reflection spectrum of a micro / nano photonic structure with a grating ridge period of 650 nm under different refractive indices. Figure 7 In the figure, b represents the reflection spectrum of a micro / nano photonic structure with a grating ridge period of 970 nm under different refractive indices. Figure 7 In this context, c represents the reflection spectrum of a micro / nano photonic structure with a grating ridge period of 1310 nm under different refractive indices. Figure 7 In the above micro / nano photonic structures, d represents the reflection spectrum of the micro / nano photonic structure with a grating ridge period of 1550 nm under different refractive indices. In all the above micro / nano photonic structures, the thickness of the metal layer 4 is 60 nm, and the polymer structures 3 are all grating structures. The structural parameters are defined as (p, h, w), where p is the period of the polymer structure 3; h is the grating height; and w is the grating ridge width. Figure 7 The grating structure parameters of the micro / nano photonic structure corresponding to 'a' in the figure are (650, 330, 300). Figure 7 The structural parameters of the grating corresponding to b in the micro-nano photonic structure are (970, 500, 650); Figure 7 The structural parameters of the grating corresponding to c in the micro-nano photonic structure are (1310, 840, 670); Figure 7 The structural parameters of the grating in the micro / nano photonic structure corresponding to d are (1550, 1100, 670). Figure 7 It can be seen that when the ambient refractive index is 1, the position of the WA-FP mode in the spectrum is perfectly matched with the period of polymer structure 3, which is in complete agreement with formula (a).

[0094] See Figure 8 , Figure 8 The graph shows the calculated bulk refractive index sensitivity of the aforementioned micro / nano photonic structures with four different grating ridge periods: (650, 330, 300), (970, 500, 650), (1310, 840, 670), and (1550, 1100, 670). Figure 8 As can be seen, the bulk refractive index sensitivities of the four micro / nano photonic structures are 650 nm / RIU, 970 nm / RIU, 1310 nm / RIU, and 1550 nm / RIU, respectively. This indicates that in the micro / nano photonic structure provided by this invention, the spectral mode position of its WA-FP mode in air is numerically identical to its bulk refractive index sensing sensitivity, that is, the resonant wavelength and the sensing sensitivity S are equal.

[0095] Example 3

[0096] To verify the aforementioned conclusions, this embodiment prepared a series of samples with a grating ridge period of 770 nm for experiments. The relevant equipment and results are described in [link to relevant documentation]. Figure 9 ,in, Figure 9 In the diagram, 'a' represents the optical path diagram used in the verification experiment. The specific principle is as follows: the halogen light source is reflected onto the sample surface by a mirror, and then the light is reflected onto the detector and CCD by the sample to test its reflectivity.

[0097] In this embodiment, three micro / nano photonic structures with different grating ridge widths of 380nm, 400nm, and 420nm were fabricated. Related electron microscope images are shown below. Figure 9 As shown in b in the figure.

[0098] Under the conditions of grating ridge period p=770nm, grating height h=400nm, and metal layer 4 thickness t=60nm, using Figure 9 The test platform shown in Figure a tested three micro / nano photonic structures with different grating ridge widths, and the relevant reflection spectra are as follows. Figure 9 As shown in c in the figure.

[0099] In the scenario where the grating ridge period p = 770 nm, the grating height h = 400 nm, and the metal layer 4 thickness t = 60 nm or 70 nm, using Figure 9 The test platform shown in Figure a tests a micro / nano photonic structure with a grating ridge width w of 380 nm, and the relevant reflection spectrum is as follows. Figure 9 As shown in d.

[0100] Depend on Figure 9 c and Figure 9As can be seen from d, the reflection spectrum of micro-nano photonic structures has a certain fabrication tolerance for their structure. Taking width as an example, even if the width of the micro-nano photonic structures differs by 40 nm, the position of their modes in the spectrum still does not shift significantly.

[0101] Under the conditions of grating ridge period p=770nm, grating height h=400nm, metal layer 4 thickness t=60nm, and grating ridge width w=380nm, the bulk refractive index sensitivity of the micro / nano photonic structure was tested by adding glycerol solutions of different concentrations to the surface of the micro / nano photonic structure. The test results are as follows: Figure 9 e and Figure 9 As shown in f, by Figure 9 e and Figure 9 As can be seen from f, when the grating ridge period is 770 nm, the bulk refractive index sensitivity of the above micro-nano photonic structures is around 770 nm / RIU, and their absolute errors are all less than 40 nm / RIU. This proves the relevant conclusions in Example 2.

[0102] As can be seen from the above embodiments, the micro-nano photonic structure provided by the present invention has the characteristics of high fabrication tolerance and the ability to customize sensitivity according to the polymer structure period, and has broad application potential.

[0103] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A micro / nano photonic structure with large fabrication tolerance and customizable sensitivity, characterized in that, The micro-nano photonic structure comprises, from bottom to top: Substrate (1); A high-reflectivity layer (2) is bonded to the substrate layer (1) by an adhesive layer, and its thickness is greater than or equal to 80 nanometers. Polymer structure (3), wherein the polymer structure (3) is a periodic grating structure, and the polymer structure (3) is prepared on the upper surface of the high reflectivity layer (2); A metal layer (4) is deposited on the upper surface of the polymer structure (3), and the high reflectivity layer (2) is parallel to the metal layer (4); The micro / nano photonic structure, when subjected to an incident light field at any angle, can generate a coupling mode between Wood's anomaly and Fabry-Perot cavity resonance. Under this coupling mode, the structure periodically... The resonant wavelength is equal to the value of the sensing sensitivity S. Satisfying formula (a): （a） in, The resonant wavelength of the coupling mode is expressed in nanometers. The structural period of a micro / nano photonic structure is represented by a unit of nanometers. The dielectric constant of the environment surrounding the micro / nano photonic structure, and the periodicity of the structure. The range is 380nm~15µm; The resonant wavelength of the micro / nano photonic structure The range is 380nm~15µm.

2. The micro / nano photonic structure as described in claim 1, characterized in that, The polymer structure (3) is made of any one of photoresist, electronic adhesive, chalcogenide glass, imprint adhesive, hot melt adhesive, or UV curing adhesive.

3. The micro / nano photonic structure as described in claim 1, characterized in that, The material of the high reflectivity layer (2) is selected from any one or more of gold, silver, aluminum, germanium, and multilayer dielectric films.

4. The micro / nano photonic structure as described in claim 1, characterized in that, The material of the metal layer (4) is selected from any one or more of gold, silver, aluminum, copper, cadmium, and nickel.

5. The micro / nano photonic structure as described in claim 1, characterized in that, The thickness of the metal layer (4) is 10 nm to 3 µm.

6. A method for fabricating a micro / nano photonic structure with large fabrication tolerance and customizable sensitivity as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: An adhesion layer and a high-reflectivity layer are sequentially deposited on a clean substrate material using electron beam evaporation, magnetron sputtering, or electroplating techniques. S2: Spin-coating polymer onto the surface of the high-reflectivity layer; S3: Photolithography, nanoimprinting, or 3D printing are used to obtain polymer structures; S4: Deposit a metal layer on the polymer structure using electron beam evaporation, magnetron sputtering or electroplating techniques to obtain a micro-nano photonic structure with large fabrication tolerance and customizable sensitivity.

7. An application of the micro / nano photonic structure with large fabrication tolerance and customizable sensitivity as described in any one of claims 1 to 5, characterized in that, The applications include using the micro / nano photonic structure in the fabrication of biomolecular sensors, gas sensors, or particle sensors.

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