CN113835214B - Spectral modulation device based on spatial morphology modulation and preparation method thereof - Google Patents

Abstract

The invention provides a spectral modulation device with spatial topography control and a preparation method thereof. The spectral modulation device includes: a support layer whose upper surface is a continuous surface topography with a spatial slope at different spatial positions, and a support layer attached to the upper surface of the support layer. The light modulation layer has a periodic micro-nano structure, and different spatial positions of the spectrum modulation device have different transmission spectra for the spectrum of the incident light. The spectral modulation device provided by the present invention can obtain an optical modulation layer with a filter response by duplicating a fixed-period template, and then obtain different filter responses at different spatial positions through spatial morphology control, which can significantly reduce the current similar Process complexity and cost of fabrication of spectral modulation devices.

Description

A spectral modulation device based on spatial morphology modulation and its preparation method

technical field

The invention relates to the technical field of optical devices. The invention specifically relates to an optical filter, a spectral modulation device, a device preparation method, and a detection system for realizing spectral reconstruction.

Background technique

Spectral analysis has become one of the most popular analytical tools in industry and scientific research. Typically, commercial optical spectrum analyzers with high resolution and wide spectral range are expensive and bulky, relying on complex dispersive optics, moving parts, and long optical paths. With the development of nanotechnology and consumer electronics, further miniaturization of spectrometers has received increasing attention due to their potential for integration into devices such as smartphones. At the same time, with the dramatic increase in computing power and reduction in cost, machine learning techniques have been widely used in many research fields, including imaging, fringe pattern analysis, microscopy, and spectroscopy. Therefore, among the methods studied in ultra-compact microspectroscopy, including micro-dispersive optics, narrow-band filter banks or variable filters, Fourier transform and systems based on computational spectral reconstruction, the last is considered to be the most promising one. kind. Currently, most computational spectrometers rely on key devices for random spectrum-to-space mapping, including disordered structures in photonic chips, multimode waveguides, spectral filters based on colloidal quantum dot hybrids, and specially designed nanowires, all of which require Special design, and complex production process.

Periodically arranged one-dimensional or two-dimensional photonic crystals can be used to construct wavelength-selective devices. Due to the existence of photonic crystal band gaps, it can be selective in terms of the overall effect of multiple reflections and refractions. Certain wavelengths of light are transmitted, while other wavelengths are reflected, thus having a spectral modulation effect. Fabricating high-refractive index dielectric thin films on the surface of designed photonic crystals is expected to confine incident light of a specific wavelength in the waveguide composed of thin dielectric layers through wave vector matching, and obtain a more obvious filtering response. The preparation of metal thin films on the surface of photonic crystals is also expected to excite the surface plasmon effect by incident light of a specific wavelength through wave vector matching, and obtain an obvious filtering effect.

Taking photonic crystal-based light modulation devices as an example, the light modulation devices used in computational spectrometers need to have different spectral modulation responses in the light detection regions corresponding to different positions in space, so the structures of photonic crystals for different modulation units must be different. And its feature size is in the order of sub-wavelength. To obtain precise control of this order, the requirements for device processing technology are very high. At present, the way to realize this type of device is mainly through electron beam lithography or deep ultraviolet lithography, etc., to etch on the semiconductor base material mainly composed of silicon.

Contents of the invention

Aiming at the problems existing in the prior art, the task of the present invention is to provide a spectral modulation device with spatial morphology control and its preparation method. The device realizes different positions in space by copying and turning the template with a fixed period and controlling the spatial morphology. It has different filter responses, which can reduce the process complexity of the current preparation of similar spectral modulation devices. On the other hand, this method can transfer the same periodic photonic crystal structure to the low-refractive index polymer transparent substrate, and can further increase the high-refractive index transparent medium/metal cladding layer to obtain more obvious and space-dependent topographic features. Varying filter response.

In a first aspect, the present invention provides a spectral modulation device based on spatial morphology control.

The spectrum modulation device includes a support layer whose upper surface is a continuous surface topography with a spatial slope at different spatial positions and a light modulation layer attached to the upper surface of the support layer, the spectral modulation device at different positions in space for the incident light Spectra have different filter responses.

The light modulation layer is a periodic micro-nano structure prepared on the surface of a flexible material, and has a certain spectral filtering response.

The flexible material refers to a polymer material with a certain Young's modulus, which can be converted from a liquid state to a solid state by means of ultraviolet light irradiation, temperature control, and the like.

The spatial topography regulation is aimed at the light modulation layer on the surface of the flexible material, and spatially regulates its overall topography, thereby changing the spectral filtering response of the spectral modulation device at different spatial positions.

The light modulation layer and the support layer can be made of the same material in one process, or can be obtained from different materials in different processes.

In one example, the spectrum modulation device further includes a covering layer covering the surface of the light modulation layer and complementary to the topography of the upper surface of the support layer, so that the thickness of the spectrum modulation device formed is uniform.

In one example, the flexible material includes, but is not limited to, highly elastic silicone polymers such as polydimethylsiloxane (PDMS), photoresist, and ultraviolet glue.

Spatially different positions in the light modulation layer have different modulation effects on the spectrum of incident light.

In one example, the light modulation layer is an originally regular and uniform periodic micro-nano structure.

In one example, the light modulation layer is a periodic one-dimensional or two-dimensional photonic crystal structure.

In an example, the shape of the periodic unit is the same everywhere in the space of the light modulation layer.

In an example, the shapes of the periodic units are different in space of the light modulation layer.

In one example, the light modulation layer and the support layer are made of the same flexible material through one process.

In one example, the light modulation layer is a thin film made of a flexible material, which is laid on the surface of a support layer made of different materials.

In one example, the spectrum modulation device includes a support layer, a light modulation layer, and a cladding thin layer covering the upper surface of the light modulation layer.

In one example, in the spectrum modulation device, the cladding layer covering the upper surface of the light modulation layer is a thin layer of a light-transmitting medium with a higher refractive index than a flexible material, such as TiO ₂ , Ta ₂ O ₅ and the like.

In one example, in the spectrum modulation device, the cladding layer covering the upper surface of the light modulation layer is a thin metal layer, such as gold, silver, and the like.

In a second aspect, the present invention provides a method for preparing a spectral modulation device controlled by spatial morphology, comprising the following steps:

(1) Nanoimprint the micro-nano array hard template with a specific period using the flexible material 1, copy the micro-nano array structure to the surface of the flexible material 1, and obtain a flexible stamp;

(2) Controlling the spatial morphology of the flexible stamp to obtain a flexible stamp that produces spatial morphology changes;

(3) Using the flexible stamp whose spatial morphology changes as a soft template, use the flexible material 2 to perform nanoimprinting, copy the micro-nano structure that has been regulated by the spatial morphology in step (2) to the surface of the flexible material 2, and obtain light The modulating layer, while keeping its bottom surface flush during curing, forms a support layer whose spatial topography varies complementary to the shape of the flexible stamp.

In one example, the preparation method further includes step (4), preparing a coating thin layer on the surface of the flexible material 2 to obtain a more obvious characteristic spectral filter response.

In one example, the flexible material 1 is made of highly elastic PDMS material for spatial shape regulation.

In one example, the flexible material 2 adopts ultraviolet glue, which is cured by ultraviolet light to form a light modulation layer.

In one example, in step (3), the flexible stamp is subjected to one-dimensional or two-dimensional shape regulation such as stretching and compression, three-dimensional shape regulation such as bending and twisting, and one or more of the above operations The combination of them can realize the tuning of the micro-nano period at different positions in space.

Further, in an example, in step (3), the back of the flexible stamp is randomly thinned in thickness, and then one or more of the shape control operations such as stretching, compression, bending, and twisting are performed The combination of them can realize the tuning of the micro-nano period at different positions in space.

In one example, in step (3), after obtaining the replicated micro-nano structure of spatial morphology regulation on the surface of the flexible material 2, before the flexible material 2 is completely solidified, it can be further subjected to spatial morphology regulation to A light modulation layer with enhanced spatial topography modulation is obtained.

In one example, the cladding thin layer in step (4) is a thin layer of high refractive index light-transmitting medium, such as TiO ₂ , Ta ₂ O ₅ , etc., so as to obtain enhanced characteristic spectral modulation response through the guided mode resonance effect.

In one example, the cladding thin layer in step (4) is a metal thin layer, such as Au, Ag, etc., so as to obtain enhanced characteristic spectral modulation response through the surface plasmon resonance effect.

In one example, the hard template in the step (1) is an originally regular periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is an originally regular and uniform periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is an originally regular and uniform periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is a one-dimensional or two-dimensional photonic crystal template with a regular and uniform change period.

In one example, the hard template in the step (1) is a one-dimensional or two-dimensional photonic crystal template with a fixed period.

In a third aspect, the present invention provides a method for preparing a spectral modulation device controlled by spatial morphology, comprising the following steps:

(1) Nanoimprint the micro-nano array hard template with a specific period using a flexible material, copy the micro-nano array structure to the surface of the flexible material, and obtain a light modulation layer;

(2) laying the light modulation layer on the support layer with three-dimensional spatial morphology control.

In one example, the preparation method further includes step (3), preparing a thin coating layer on the upper surface of the light modulation layer to obtain a more obvious characteristic spectral filter response.

In one example, the flexible material 1 is made of highly elastic PDMS material to form a flexible stamp.

In one example, the flexible material 2 adopts ultraviolet glue, which is cured by ultraviolet light to form a light modulation layer.

In one example, the cladding thin layer in step (3) is a thin layer of high refractive index light-transmitting medium, such as TiO ₂ , Ta ₂ O ₅ , etc., so as to obtain enhanced characteristic spectral modulation response through the guided mode resonance effect.

In one example, the cladding thin layer in step (3) is a thin metal layer, such as Au, Ag, etc., so as to obtain an enhanced characteristic spectral modulation response through the surface plasmon resonance effect.

In one example, the hard template in the step (1) is an originally regular periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is an originally regular and uniform periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is an originally regular and uniform periodic sub-wavelength micro-nano array structure.

In one example, the hard template in the step (1) is a one-dimensional or two-dimensional photonic crystal template with a regular and uniform change period.

In one example, the hard template in the step (1) is a one-dimensional or two-dimensional photonic crystal template with a fixed period.

In one example, the supporting layer is a hollowed-out light-transmitting plastic bracket, the upper surface of which has a continuous surface topography with a spatial slope at different spatial positions.

In one example, the support layer is based on a cured flexible material, and the topographic characteristics of its upper surface are copied from a template with specific continuous surface topographical changes.

According to the above technical solution, it can be seen that the spectrum modulation device and its preparation method provided by the embodiments of the present invention transfer the micro-nano array structure with a specific period from the hard template to the surface of the flexible material to form a flexible stamp by means of nanoimprinting, and then transfer to the Another flexible material surface obtains a light modulation layer. Then, the light modulation layer is placed on the support layer with the upper surface having a changing surface topography, so as to obtain a spectrum modulation device with different filter responses in different spatial positions.

Compared with the existing schemes that rely on fine processing methods such as electron beam exposure and etching to obtain a light modulation layer that changes periodically with the spatial position, the present invention can use a relatively simple process, low cost, and easy-to-obtain uniform periodic template to obtain micro-nano The optical modulation layer composed of an array structure is modulated in space to construct a spectral filter response that varies with spatial positions.

The existing scheme obtains a fine optical modulation layer that changes periodically with the spatial position through the CMOS processing technology, and its substrate must be semiconductor materials such as silicon base, silicon nitride, and III-V groups. Polymers, such as PDMS, ultraviolet glue, photoresist, etc., have high light transmittance in the visible light region, good chemical stability, simple preparation process, and low cost.

The spectrum modulation device proposed by the method of the present invention can also add a thin coating layer on the surface of the light modulation layer to obtain a filtering effect sensitive to spatial topography including the guided mode resonance effect, so as to obtain more obvious and spatially differentiated features Spectral Spatial Modulation Response.

The spectral modulation device proposed by the method of the present invention can also add a covering layer whose surface topography is complementary to the upper surface of the support layer, so as to obtain a spectral modulation device with uniform thickness.

The spectral modulation device prepared by the method of the invention can be integrated with the photoelectric detection array to realize the integrated and low-cost small-scale computing spectrometer.

Description of drawings

The drawings described here are used to provide a further understanding of the application and constitute a part of the application. The embodiments and descriptions of the application are used to explain the application and do not constitute an improper limitation to the application. Hereinafter, embodiments of the present invention will be described in detail in conjunction with the accompanying drawings, wherein:

Fig. 1 is a three-dimensional schematic diagram of a spectral modulation device with spatial morphology control provided by an embodiment of the present invention, corresponding to three parts from bottom to top: support layer 1, light modulation layer 2, and cover layer 4 of the spectral modulation device.

Fig. 2 is a schematic diagram of the micro-nano array hard template structure for obtaining the light modulation layer. (a) is a schematic diagram of a one-dimensional structure, and (b) is a schematic diagram of a two-dimensional structure.

Fig. 3 is a schematic cross-sectional view of the spectrum modulation device. (a) shows that the material of the support layer is different from that of the light modulation layer, (b) shows that there is a thin coating layer above the light modulation layer, and (c) shows that the material of the support layer is the same as that of the light modulation layer.

FIG. 4 is a schematic cross-sectional view of the light modulation layer. (a) shows a uniform periodic distribution, (b) shows a gradually changing periodic distribution, and (c) shows a random periodic distribution.

Fig. 5 is a schematic diagram of a spectrometer system provided by an embodiment of the present invention. From top to bottom are: polarization control device 5 , spectrum modulation device 6 , light detection array 7 .

Fig. 6 is a spectral response arrangement of a spectral modulation device controlled by spatial morphology provided by an embodiment of the present invention. Shown in (a) is the schematic diagram of the spectral response arrangement of the spectral modulation device obtained by the gradual change period in the embodiment, and (b) is the schematic diagram of the spectral response arrangement of the spectral modulation device obtained by the surface random deformation in the embodiment, and its spectrum The response distribution is related to the surface deformation characteristics.

FIG. 7 is a schematic plan view of a photodetector array and a planned detector unit provided by an embodiment of the present invention. The small grid in the figure represents the unit pixel of the detector, and the large grid represents the detector unit composed of unit pixels and corresponding to the response of the spectral modulation device. Wherein, the photodetector unit can be adaptively divided according to the response distribution of different spectral modulation devices.

in

1. Support layer; 2. Optical modulation layer; 3. Coating film; 4. Covering layer; 5. Polarization control device; 6. Spectrum modulation device; 7. Optical detection array

Detailed ways

In order to make the purpose, technical solution and advantages of the present application more clear, the following will be described in detail in conjunction with the embodiments and accompanying drawings. The described embodiments are only some of the embodiments of the present application, not all of them.

The technical solutions provided by various embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

Specific embodiments of the present application provide a spectral modulation device with spatial morphology control and a preparation method thereof, and introduce a spectrometer system based on the spectral modulation device.

Example 1:

Traditional spectrometers are bulky due to the need for spatial dispersion components and corresponding spatial collimation and other optical components, and are relatively expensive due to the precision requirements of the required optical components. With the increasing demand for small-volume and low-cost micro-spectrometers, many spectrometer miniaturization schemes have appeared on the market, including dispersion type, narrow-band filter type, Fourier transform type, and computational reconstruction type micro-spectrometers. With the rapid development of computer technology, computational reconstruction miniature spectrometers have received more attention. However, the schemes of computationally reconstructing micro-spectrometers proposed so far have relatively high requirements on the preparation process of spatial modulation devices, which leads to complex preparation and high cost. The core spectral modulation device used for spectral reconstruction used in this example has significant advantages in terms of cost and process complexity due to its simple preparation process and low cost, and can be used to replace related spectral modulation devices that require complex processing and careful design .

Fig. 1 is a schematic exploded view of the spectrum modulation device in this embodiment, and Fig. 3(a) is a schematic cross-sectional view of the spectrum modulation device in this embodiment. FIG. 2 is a hard template with a specific periodic micro-nano array structure used to obtain an optical modulation layer. In this embodiment, a one-dimensional grating as shown in FIG. 2( a ) is used. Figure 3 shows the light modulation layer obtained in this embodiment, which can be a uniform periodic micro-nano array structure (a) obtained through a uniform one-dimensional grating hard template, or a one-dimensional grating hard template with periodic changes. A micro-nano array structure (b) with a uniformly varying period or a micro-nano array structure (c) with a randomly varying period. The structure in Figure 3(b)(c) can also be obtained by stretching or compressing the flexible stamp along the grid line direction through the hard template with uniform one-dimensional grating in the process of nanoimprinting and overmolding. FIG. 4 is a schematic cross-sectional view of the spectrum modulation device obtained in this example, including a support layer 1 , a light modulation layer 2 , and optionally prepared thin coating layers 3 and covering layers 4 . Wherein the light modulation layer 2 is based on a flexible material substrate.

The flexible material includes, but is not limited to, highly elastic silicone polymers such as polydimethylsiloxane (PDMS) and various thermosensitive and photosensitive polymers, such as photoresist, ultraviolet glue, and the like. In this embodiment, the light modulation layer is based on a one-dimensional grating structure controlled by spatial morphology obtained on the surface of ultraviolet glue, and a layer of _TiO2 film is also deposited on the surface of the light modulation layer. The function of this coating film is to realize the guided mode Resonance, as shown in Figure 4(c). The material of the grating can be ultraviolet glue with a refractive index of 1.2-1.8. When the light is incident on the grating, as the refractive index of the grating material increases, the filter response wavelength shifts to a longer wavelength. The larger the grating period, the longer the filter response wavelength. Therefore, according to the different refractive index materials of the photonic crystal and the different periods of the grating, different spectral responses can be realized at various positions in the photonic crystal, and this effect can be represented by FIG. 6 .

In this embodiment, in order to fabricate a micro-nano array structure with surface topography changes on the surface of a flexible substrate, firstly, a one-dimensional grating hard template based on silicon material is used, and the method of nanoimprinting is adopted, and the one-dimensional grating is molded with PDMS The structure is transferred from the hard template surface to the PDMS surface, obtaining a flexible stamp. In this process, an appropriate volume ratio of PDMS prepolymer and curing agent is configured according to the thickness and elasticity of the required PDMS film. Based on this PDMS flexible stamp, the surface structure of the PDMS flexible stamp is copied to the surface of polymer materials such as ultraviolet glue through nanoimprinting technology again, and the light modulation layer thin layer is obtained by ultraviolet light curing, heating curing and other methods. In order to enhance the spectral response effect, a certain thickness of high refractive index dielectric material film, such as _TiO2 film, can be deposited on the surface of the light modulation layer by magnetron sputtering or ion beam evaporation. 0.05-1 times. Then fix the light modulation layer film on the surface of the support layer with spatial topography changes, and prepare a cover layer with surface topography changes complementary to the support layer, which is inverted on the upper surface of the light modulation layer, and the formed spectrum modulation device is shown in Figure 4 (a) (b) shown. Wherein, the support layer can be another transparent flexible material obtained by means of mold turning, nanoimprinting, etc., or it can be a light-transmitting hollow curved surface bracket obtained by 3D printing or other means.

In order to obtain photonic crystals with different spectral filter responses at different positions, in the above-mentioned flexible stamp preparation process, stretching, compression, bending or twisting the flexible stamp can be used to produce two-dimensional or three-dimensional deformation to realize spatial Morphology control, and in the next step, by curing a certain thickness of UV glue, simultaneously obtain a light modulation layer and a support layer based on the same material.

The specific preparation process is as follows: first, using a silicon-based one-dimensional grating hard template, using the method of nanoimprinting, using PDMS to overturn the mold, transferring the one-dimensional grating structure from the surface of the hard template to the surface of PDMS to obtain a flexible stamp. In this process, an appropriate volume ratio of PDMS prepolymer and curing agent is configured according to the thickness and elasticity of the required PDMS film, and when curing the PDMS flexible stamp, the thickness change is obtained by, for example, tilting the mold containing PDMS , but the surface grating structure is complementary to the PDMS flexible stamp of the silicon template. In order to obtain a periodically changing light modulation layer, the PDMS flexible stamp can be stretched or compressed in the direction perpendicular to the grid lines. Due to the different thicknesses at different positions, the deformation caused by stretching or compression is different under the same force, which can produce Varying grating period. In order to obtain a support layer for spatial morphology control, the PDMS flexible stamp is bent or twisted to produce two-dimensional or three-dimensional deformation, and then based on the spatial morphology of the PDMS flexible stamp, again through nanoimprint technology, While replicating the surface micro-nano structure of the PDMS flexible stamp to the surface of polymer materials such as UV glue, the resulting two-dimensional or three-dimensional deformation is also copied to the surface of the support layer made of polymer materials such as UV glue, and then using ultraviolet The formed light modulation layer and support layer are obtained by photocuring, heat curing and other methods. In order to enhance the spectral response effect, it is also possible to deposit a certain thickness of high refractive index dielectric material film on the surface of the light modulation layer by means of magnetron sputtering or ion beam evaporation.

Since the grating structure obtains different transmission spectra under different incident angles, in this example, as the incident angle gradually increases, the characteristic response of the obtained transmission spectrum gradually shifts to shorter wavelengths. The distorted surface deformed photonic crystal realizes different spectral responses at different positions through different incident angles at each position. The twisting operation can be two-dimensional random twisting on the surface grating film of ultraviolet adhesive with less hardness to generate random two-dimensional deformation, and the photonic crystal prepared by using the twisted ultraviolet adhesive film has random filter spectral response at different positions; By making the flexible stamp thin, the PDMS surface grating film can be used as a light modulation layer and fixed on the surface of the support layer. Before implementing the above spatial morphology regulation, operations such as random thinning and hole digging can be performed on the back of the flexible stamp to further enhance the randomness of the morphology regulation.

The spectrometer system constructed based on the spectral modulation device controlled by spatial morphology in this example is shown in Figure 5, which mainly includes a polarization control device, a spectral modulation device and a photodetection array. In the case of parallel light incidence, for the spectral modulation device controlled by two-dimensional shape, different spectral responses will be produced due to the different periods of the spectral modulation device. Specifically, in this example, it is the grating structure with a larger period. The longer the wavelength of the spectral characteristic response; or the period is uniform, the corresponding spectrum of the one-dimensional grating structure with different spatial slope is different. In this way, the photonic crystal can be divided into N units according to different positions, where the maximum number of unit divisions is limited by the number of pixels in the detector, and each unit corresponds to a response characteristic R _n , as shown in Figure 6(a), The division of the corresponding detector array unit is shown in Fig. 7(a). For the spectral modulation device controlled by three-dimensional space shape, the corresponding response characteristics of each unit are shown in Figure 6(b), and the division of the corresponding detector array units is shown in Figure 7(b).

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (9)

1. A preparation method of a spectrum modulation device with a space morphology regulation function comprises the following steps:

(1) Nanoimprinting is carried out on the micro-nano array hard template with a specific period by using a first flexible material, and the micro-nano array structure is copied to the surface of the first flexible material to obtain a flexible seal;

(2) Performing space morphology regulation and control on the flexible seal to obtain a flexible seal generating space morphology change;

(3) And taking the flexible seal generating the space shape change as a soft template, carrying out nanoimprint by using a second flexible material, copying the micro-nano structure subjected to space shape regulation to the surface of the second flexible material to obtain a light modulation layer, simultaneously applying enough second flexible material and keeping the bottom surface of the second flexible material flush in the curing process to form a support layer with the space shape change complementary with the shape of the flexible seal.

2. The method of claim 1, further comprising the step of (4) preparing a thin layer of coated high refractive index light transmissive medium or metal on the surface of the second flexible material to obtain a more pronounced characteristic spectral response.

3. The method of claim 1 or 2, wherein the spatial morphology modulation in step (2) comprises

One-dimensional and two-dimensional morphology regulation and control, including stretching and compression;

three-dimensional morphology regulation, including bending and twisting;

one or a combination of a plurality of morphology regulation modes;

or firstly, thinning the thickness of the back surface of the flexible seal at specific different positions, and then implementing one or a combination of several of the regulation modes.

4. The method of claim 1 or 2, wherein the micro-nano array hard template has a regular and uniform periodic micro-nano structure or a one-dimensional or two-dimensional photonic crystal structure with periodic and/or shape changes.

5. A spatial profile control based spectral modulation device obtainable by the method according to claim 1, characterized by comprising: the upper surface is a supporting layer with continuous surface morphology and spatial slopes at different spatial positions, and a light modulation layer attached to the upper surface of the supporting layer, wherein the light modulation layer has a periodic micro-nano structure, and the spectrum of incident light at different spatial positions of the spectrum modulation device has different transmission spectrums.

6. The device of claim 5, wherein the light modulation layer further comprises a cladding layer on the surface.

7. The device of claim 6, wherein the coating layer is a high refractive index light-transmitting medium layer made of TiO ₂ Or Ta ₂ O ₅ 。

8. The device of claim 6, wherein the coating layer is a metal layer made of Au or Ag.

9. The device of claim 6, further comprising a cover layer overlying the cover layer surface complementary to the topography of the upper surface of the support layer such that the resulting device has a uniform thickness.

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