Visible light-infrared-laser multi-band spectral selective modulation film

Abstract

The application discloses a visible light-infrared-laser multi-waveband spectrum selective regulation film, and belongs to the technical field of optical film and spectrum regulation. The total layer number of the film is 8, and from bottom to top, the film comprises a substrate, an infrared spectrum regulation film layer, a laser spectrum regulation film layer and a visible light spectrum regulation film layer in sequence; the infrared spectrum regulation film layer comprises metal film A, silicon film A, metal film B and silicon film B in sequence from bottom to top; the laser spectrum regulation film layer comprises silica film and germanium film from bottom to top; and the visible light spectrum regulation film layer comprises one layer of silicon film or zinc sulfide film. The application realizes the selective emission characteristics of the film in the infrared waveband, maintains a low emissivity in part of the infrared waveband, and radiates heat by using other infrared wavebands; meanwhile, the spectrum response of the film in the 10.6 mu m laser waveband is regulated. By changing the material and structural parameters of the visible light spectrum regulation film layer, the visible light reflection spectrum and apparent color of the film can be adjusted. The film can realize the cooperative regulation of the spectrum characteristics of visible light, infrared and laser wavebands, and can be applied to the fields of multi-waveband optical regulation, heat radiation management and optical device surface functionalization.

Description

Technical Field

[0001] This invention relates to the field of optical thin films and spectral modulation technology, and in particular to a visible-infrared-laser multi-band spectral selective modulation thin film. Background Technology

[0002] With the development of optical thin films, infrared thermal management, laser optics, and multifunctional optoelectronic devices, the demand for synergistic control of the same thin film structure across different spectral bands is constantly increasing. However, due to the differences in optical response mechanisms across different bands, simultaneously achieving multiple functions such as visible light spectral control, infrared radiation modulation, and specific laser wavelength suppression within the same thin film system often requires consideration of multiple factors, including material optical constants, film thickness, interface coupling effects, and structural stability, leading to mutual constraints between the performance of each band. Therefore, multi-band optical thin films with the ability to control visible light, infrared light, and specific laser wavelengths have significant application potential in fields such as spectral control, thermal radiation management, and surface functionalization of optical devices.

[0003] Currently, visible light spectral modulation technology is mainly achieved through composite coatings, such as patents 201510420635.1, 202511175638.3, and 202511059931.3. While these technologies can achieve visible light spectral modulation within a certain range, they primarily rely on material composition and pigment ratios, lacking the ability to synergistically modulate the spectral characteristics of the mid- and far-infrared regions and specific laser wavelengths, making it difficult to simultaneously meet the needs of multi-band spectral modulation.

[0004] In the infrared band, the thermal radiation characteristics of an object's surface are closely related to its temperature and surface emissivity. According to the Stefan-Boltzmann law, the thermal radiation exchange between the object and its surroundings can be altered by controlling the surface temperature or adjusting the surface emissivity. Traditional low-emissivity materials typically maintain a low emissivity across a wide infrared band. While this reduces radiation intensity in some bands, it may also inhibit heat dissipation through thermal radiation, leading to an increase in surface temperature. Therefore, achieving differentiated emissivity control across different infrared bands is crucial for balancing spectral performance and radiative heat dissipation capabilities in specific bands. For example, a low emissivity can be maintained in the 3-5 μm and 8-14 μm infrared bands, while the emissivity can be increased in the 5-8 μm band. This allows for enhanced radiative heat transfer capabilities within this band, achieving synergistic regulation between infrared spectral characteristics and thermal management performance.

[0005] Currently, infrared spectral modulation films capable of selective infrared radiation are mainly achieved through resonant cavity film structures and metasurfaces. Resonant cavity film structures utilize Fabry-Perot resonators to achieve selective absorption in the infrared band, as exemplified by patents 201510362845.X, 201510362417.7, 201810663194.1, 202111127984.6, 202211439359.X, and 202311425151.7. Metasurfaces utilize electromagnetic resonance characteristics to achieve selective absorption in the infrared band, as exemplified by patents 201710019819.6, 202110625429.X, and 202411420077.4. The above technologies can achieve a relatively obvious infrared selective spectral response, but their design is usually focused on the infrared band. If visible light color modulation and specific laser wavelength modulation functions are further introduced, spectral coupling can easily occur between different functions, requiring further optimization of the structure.

[0006] Currently, laser spectral modulation devices are mainly implemented using composite coatings, such as patents 200710015544.5, 201710161001.8, 201711383816.7, 202310040064.3, and 202310224473.9. These patents achieve low reflectivity or high absorption characteristics in the laser band by combining different materials in proportion and processing them through high-temperature calcination, uniform mixing, and bonding. The above solutions are mainly designed for specific laser wavelengths, and their ability to synergistically modulate broadband infrared selective thermal radiation and visible light reflectance spectrum remains relatively limited.

[0007] To simultaneously obtain spectral responses across multiple wavebands, existing research has employed photonic crystals or multilayer resonant film structures. Photonic crystals are artificial metamaterials whose dielectric constant varies periodically along a single direction, forming photonic band gaps through periodic structures to block the propagation of electromagnetic waves at specific frequencies. Resonant cavity film structures achieve selective absorption of electromagnetic waves through the Fabry-Perot resonant cavity multi-beam interference effect and the tunneling effect of ultrathin metal films. For example, patent 202011125741.4 discloses a [ZnSe / CaF2] structure. N / [ZnSe / Te] M A photonic crystal structure exhibits high reflectivity (98.6% and 95.1% in the 3-5 μm and 8-14 μm wavelength ranges, respectively), with maximum reflectivity of 4.1% and 4.9% near 1.05-1.08 μm and 10.55-10.65 μm, respectively. It also displays different visible light characteristics, including blue, green, and yellow. Patent 202310208937.7 discloses a [SiO2 / Si] structure. NA photonic crystal structure exhibits high average reflectivity (96.2% and 93.0% in the 3-5 μm and 8-14 μm wavelength ranges, respectively), relatively low reflectivity (51.5% in the 5-8 μm range), and a significantly low reflectivity (0.4% at 10.6 μm). By varying the thickness of the top SiO2 film, different visible light apparent colors such as green, blue, and yellow can be obtained. However, this photonic crystal only achieves its excellent performance at specific angles, which is not conducive to practical applications. Furthermore, the required number of film layers and excessive thickness lead to complex fabrication processes and high time costs. Patent 202210542145.9 discloses a [AB]... k [CDC] m A heterogeneous film structure exhibits reflectivity exceeding 80.0% in both the 3-5 μm and 8-14 μm wavelength ranges, forming a distinct low-reflectivity narrow band near 10.6 μm. Furthermore, this structure displays an orange luster in the visible light spectrum, with reflectivities of 15%, 20%, and 5% at 0.93 μm, 1.06 μm, and 1.54 μm, respectively. However, this structure exhibits high average reflectivity in the 5-8 μm range, resulting in poor radiative heat dissipation performance. Additionally, it has a limited number of visible light colors, making it unsuitable for use in multi-color gamut backgrounds.

[0008] In summary, although existing multi-band optical thin films can achieve spectral modulation of visible light, infrared and laser bands separately or partially, the following problems still exist when designing multiple bands in synergy: (1) There is obvious optical coupling between different functional film layers, and improving the spectral performance of one band may affect the response of other bands; (2) It is still difficult to achieve differentiated emissivity modulation between different infrared bands such as 3-5 μm, 5-8 μm and 8-14 μm, and it is difficult to balance infrared spectral performance and radiation heat dissipation performance; (3) It is difficult to achieve synergistic adjustment between the 10.6 μm laser wavelength response, the wide-band infrared spectral characteristics and the visible light reflection spectrum; (4) Some existing multi-band film systems adopt periodic photonic crystal structures or have many film layers, which have problems such as large overall thickness, complex preparation process and high sensitivity to incident angle. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of existing multi-band spectral selective control films, such as difficulty in synergistically adjusting the spectral performance of different bands, insufficient infrared radiation heat dissipation capacity, and complex preparation processes and high costs due to the large number of film layers. The invention provides a visible-infrared-laser multi-band spectral selective control film. By synergistically designing the combination and structural parameters of different material film layers, it achieves synergistic control of visible light reflectance spectrum, infrared selective emission characteristics, and 10.6 μm laser wavelength spectral response with a smaller number of film layers. Simultaneously, it takes into account the low emissivity characteristics and radiation heat dissipation performance of a specific infrared band, thereby simplifying the film preparation process and improving its application potential in multi-band optical control, thermal radiation management, and surface functionalization of optical devices.

[0010] The technical solution adopted in this invention is: a visible light-infrared-laser multi-band spectral selective control film, wherein the multilayer film structure is composed of a substrate, an infrared spectral control film layer, a laser spectral control film layer and a visible light spectral control film layer from bottom to top; the infrared spectral control film layer consists of a metal film A, a silicon film A, a metal film B and a silicon film B with different thicknesses from bottom to top; the laser spectral control film layer consists of a silicon dioxide film and a germanium film from bottom to top; and the visible light spectral control film layer consists of only one layer of material.

[0011] As a preferred basic structure, the above-mentioned visible-infrared-laser multi-band spectrally selectively modulated thin film includes substrate materials such as single-crystal silicon, sapphire, stainless steel, polyvinyl alcohol, and polyimide.

[0012] As a preferred basic structure, the above-mentioned visible light-infrared-laser multi-band spectral selective modulation thin film includes metal film A and metal film B materials including tungsten, gold, silver, copper, aluminum, chromium, molybdenum and alloy materials.

[0013] As a preferred basic structure, the above-mentioned visible light-infrared-laser multi-band spectral selective modulation film includes silicon and zinc sulfide as the visible light spectral modulation film material.

[0014] As a preferred basic structure, the above-described visible-infrared-laser multi-band spectrally selective control film is characterized in that the thickness of the metal film A in the infrared spectral control film layer is 150±50 nm, the thickness of the silicon film A in the infrared spectral control film layer is 750±100 nm, the thickness of the metal film B in the infrared spectral control film layer is 15±10 nm, the thickness of the silicon film B in the infrared spectral control film layer is 400±50 nm, the thickness of the silicon dioxide film in the laser spectral control film layer is 1750±100 nm, the thickness of the germanium film in the laser spectral control film layer is 800±100 nm, and the thickness of the silicon film in the visible light spectral control film layer is 30±20 nm.

[0015] The innovativeness and good effects of this invention are:

[0016] 1. This invention proposes a visible-infrared-laser multi-band spectrally selective control thin film. The infrared spectral control film layer is designed as a metal film A, a silicon film A, a metal film B, and a silicon film B arranged sequentially from bottom to top. A double Fabry-Perot resonator is formed through optical coupling between the metal and silicon films. Combined with the emissivity enhancement characteristics of the ultrathin metal film, selective control of emissivity in different infrared bands is achieved. The thin film can achieve high emissivity in the non-atmospheric window band (5-8 μm) to enhance the radiative heat transfer capability in this band, while maintaining low emissivity in the atmospheric window bands (3-5 μm and 8-14 μm). This balances infrared spectral selective control and radiative heat dissipation performance, improving the insufficient radiative heat dissipation capability of traditional wide-band low-emissivity materials.

[0017] 2. This invention proposes a visible-infrared-laser multi-band spectrally selective control film, which further incorporates a laser spectrally selective control layer composed of a silicon dioxide film and a germanium film on top of an infrared spectrally selective control layer. Utilizing multi-beam interference theory and the high infrared absorption characteristics of the ultrathin metal layer in the infrared spectrally selective control layer, the laser spectrally selective control layer is designed. By precisely controlling the optical constants and optical thickness of the materials, the film achieves extremely low reflectivity at a typical laser wavelength of 10.6 μm, thereby significantly reducing the laser echo signal and effectively realizing the laser spectral control function. This multi-layer composite design allows the film to maintain its infrared selective radiation infrared spectral control performance while expanding its spectral control capability to the 10.6 μm laser band, achieving multi-band spectrally selective control effects.

[0018] 3. This invention proposes a visible-infrared-laser multi-band spectrally selective control film, which further integrates a visible-infrared spectrally selective control film layer on top of the infrared and laser spectrally selective control film layers. The core of this design is to utilize the principle of thin-film structural color without affecting the infrared-laser spectrally selective control characteristics. Specifically, by precisely controlling the optical thickness of the control layer, the interference effect generated by visible light in the thin film is used to regulate its reflection or absorption of specific visible light bands, thereby presenting the desired color. Thus, according to the visible-infrared spectrally selective control requirements of different application scenarios, the color rendering state of its surface is adjusted by the optical thickness of the visible-infrared stealth film layer, achieving a highly efficient visible-infrared spectrally selective control effect. This design enables the visible-infrared-laser multi-band spectrally selective control film to significantly enhance its visual adaptability in complex environments while maintaining the infrared spectral selective control and laser spectral selective control characteristics of infrared selective radiation, achieving a visible-infrared-laser multi-band spectrally selective control effect.

[0019] In summary, this invention achieves synergistic control of visible light reflectance spectrum, infrared selective emission characteristics, and 10.6 μm laser wavelength spectral response within the same multilayer thin film structure through the coordinated design of infrared spectral control layers, laser spectral control layers, and visible light spectral control layers. The total number of film layers is only 8, with a total thickness of approximately 3 μm. Compared to multi-period photonic crystal or complex micro / nano structures for multi-band spectral control, this invention features fewer film layers, smaller overall thickness, relatively simple structure, and easier fabrication process, which helps reduce fabrication complexity and processing costs, and has the potential to further expand the fabrication area. Furthermore, this invention utilizes a double Fabry-Perot resonator structure containing an ultrathin metal film to achieve selective emission in the infrared band. Based on this, it further synergistically introduces laser spectral control layers and visible light spectral control layers, achieving synergistic control of multi-band spectral characteristics while minimizing the mutual influence of spectral performance across different bands. This can be applied to multi-band optical control, thermal radiation management, and surface functionalization of optical devices. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic cross-sectional view of a thin film with multi-band spectral selectivity control via visible light, infrared, and laser.

[0022] Figure 2This is a schematic cross-sectional view of an infrared spectral modulation film for a multi-band spectral selective modulation film of visible light, infrared, and laser.

[0023] Figure 3 This is a schematic cross-sectional view of a laser spectral modulation film for a multi-band spectral selective modulation film of visible light, infrared, and laser.

[0024] Figure 4 This is a cross-sectional schematic diagram of Example 1 of the visible light-infrared-laser multi-band spectral selectivity control thin film of the present invention.

[0025] Figure 5 This is a reflectance spectrum of a visible-infrared-laser multi-band spectrally selectively modulated thin film according to Example 1 of the present invention in the 3-14 μm band.

[0026] Figure 6 This is a visible light band reflectance spectrum of a visible light-infrared-laser multi-band spectral selective control thin film according to Example 1 of the present invention, when the surface Si layer thickness is 20 nm.

[0027] Figure 7 This invention relates to the effect of a 20 nm thick Si layer on the reflectance spectrum in the 3-14 μm band when the surface of a visible-infrared-laser multi-band spectral selectivity control thin film is used in Example 1.

[0028] Figure 8 This is a reflectance spectrum of a visible-infrared-laser multi-band spectrally selectively modulated thin film according to Example 2 of the present invention in the 3-14 μm band.

[0029] Figure 9 This invention relates to the effect of a visible light band reflectance spectrum on the surface Si layer thickness of a 30 nm thin film with visible light-infrared-laser multi-band spectral selectivity modulation in Example 2.

[0030] Figure 10 This is the reflectance spectrum of a visible-infrared-laser multi-band spectral selective control thin film of the present invention in the 3-14 μm band.

[0031] Figure 11 This invention relates to the effect of a visible light band reflectance spectrum on the surface Si layer thickness of a 40 nm thin film with visible light-infrared-laser multi-band spectral selectivity modulation in Example 3.

[0032] Part numbers in the diagram are labeled as follows: 1. Substrate; 2. Infrared c-film; 21. Metal film A; 22. Silicon film A; 23. Metal film B; 24. Silicon film B; 3. Laser spectral modulation film; 31. Silicon dioxide film; 32. Germanium film; 4. Visible light spectral modulation film. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments: The visible light-infrared-laser multi-band spectral selective control film is characterized in that the multilayer film structure is composed of a substrate 1, an infrared spectral control film layer 2, a laser spectral control film layer 3, and a visible light spectral control film layer 4 from bottom to top; the infrared spectral control film layer 2 is composed of a metal film 21, a silicon film 22, a metal film 23, and a silicon film 24 from bottom to top; the laser spectral control film layer 3 is composed of a silicon dioxide film 31 and a germanium film 32 of different thicknesses from bottom to top; and the visible light spectral control film layer 4 is a single layer of material.

[0034] Figure 1 This is a schematic cross-sectional view of the visible-infrared-laser multi-band spectral selectivity control film according to the present invention. It includes four parts: a substrate, an infrared spectral control film, a laser spectral control film, and a visible light spectral control film.

[0035] Figure 2 This is a schematic cross-sectional view of an infrared spectral modulation film for a multi-band spectral selective modulation film of visible light, infrared, and laser.

[0036] Figure 3 This is a schematic cross-sectional view of a laser spectral modulation film for a multi-band spectral selective modulation film of visible light, infrared, and laser.

[0037] Example 1: A Visible-Infrared-Laser Multi-Band Spectral Selectivity Controlled Thin Film

[0038] Figure 4 This is a cross-sectional schematic diagram of a visible-infrared-laser multi-band spectrally selectively modulated thin film according to Embodiment 1 of the present invention. The multilayer thin film can be prepared by physical vapor deposition methods such as electron beam evaporation, thermal evaporation, or magnetron sputtering, and the designed multilayer film structure is formed by sequentially depositing different material layers.

[0039] Figure 5 This is the reflectance spectrum of the multi-band spectrally selectively modulated thin film described in Embodiment 1 of the present invention in the 3-14 μm band. Figure 5It is known that the average reflectance of the thin film in the 3-5 μm and 8-14 μm bands are 0.856 and 0.745, respectively, while the average reflectance in the 5-8 μm band is 0.458, indicating that the thin film can form a significant selective spectral response in different infrared bands. Under the condition that the thin film transmittance is negligible, according to Kirchhoff's law, higher infrared reflectance corresponds to lower emissivity, and lower reflectance in the 5-8 μm band corresponds to relatively higher emissivity. Therefore, the thin film can maintain low thermal radiation emission characteristics in the 3-5 μm and 8-14 μm bands, while enhancing radiative heat transfer capability in the 5-8 μm band, thus balancing infrared spectral selectivity and radiative heat dissipation performance. Furthermore, the thin film has a reflectance of 3.486% at the typical operating wavelength of CO2 laser (10.6 μm), forming a significant low-reflectance spectral response, indicating that the thin film can achieve synergistic control of the spectral response at the 10.6 μm laser wavelength while maintaining broad-band infrared selective spectral characteristics.

[0040] Figure 6 This is the visible light reflectance spectrum of the multi-band spectrally selectively modulated thin film described in Embodiment 1 of the present invention when the thickness of the surface silicon (Si) film is 20 nm. Figure 6 It is evident that by applying a 20 nm thick surface Si film, the reflectance spectral distribution of the film in the visible light range can be adjusted, resulting in a yellow apparent color. These results demonstrate that by adjusting the visible light spectrum of the surface film, controlling the material type and thickness of the film, the spectral response and apparent color of the film in the visible light band can be altered, thereby achieving the control of the visible light optical properties of the film.

[0041] Figure 7 This is the 3-14 μm reflectance spectrum of the multi-band spectral selectivity modulated thin film described in Example 1 of the present invention when the surface Si film thickness is 20 nm. It is used to analyze the influence of the surface visible light spectral selectivity modulated film on the infrared and 10.6 μm laser band spectral performance. Figure 7 It can be seen that after applying a 20 nm thick Si film, the overall reflectance spectrum of the film in the 3-5 μm, 5-8 μm, and 8-14 μm bands shows little change, while the low reflectance spectral characteristics near 10.6 μm are maintained. This indicates that the surface Si film can effectively adjust the reflectance spectrum and apparent color in the visible light band, while having little impact on the infrared selectivity spectral characteristics and 10.6 μm laser wavelength response of the underlying film system, thus facilitating the synergistic control of spectral performance in the visible, infrared, and laser bands.

[0042] Example 2: A Visible-Infrared-Laser Multi-Band Spectral Selectivity Controlled Thin Film

[0043] Figure 8This is the reflectance spectrum of a visible-infrared-laser multi-band spectrally selectively modulated thin film in the 3-14 μm band, as described in Embodiment 2 of the present invention. Figure 8 It is known that the average reflectance of the thin film in the 3-5 μm and 8-14 μm bands are 0.858 and 0.744, respectively, and the average reflectance in the 5-8 μm band is 0.458, indicating that the thin film can form a significant selective spectral response in different infrared bands. Under the condition that the thin film transmittance is negligible, according to Kirchhoff's law, higher reflectance corresponds to lower emissivity, and the relatively low reflectance in the 5-8 μm band corresponds to higher emissivity. Therefore, the thin film can maintain low thermal radiation emission characteristics in the 3-5 μm and 8-14 μm bands, while exhibiting strong radiative heat transfer capability in the 5-8 μm band, thus achieving a balance between infrared selective spectral control and radiative heat dissipation performance. Furthermore, the thin film has a reflectance of 7.255% at the typical operating wavelength of CO2 laser (10.6 μm), exhibiting a significant low-reflectance spectral response, indicating that the thin film can achieve synergistic control of the spectral response at the 10.6 μm laser wavelength while maintaining broad-band infrared selective spectral characteristics.

[0044] Figure 9 This is the visible light reflectance spectrum of the multi-band spectrally selectively modulated thin film described in Embodiment 2 of the present invention when the thickness of the surface silicon (Si) film is 30 nm. Figure 9 It is known that when the thickness of the Si film on the surface is 30 nm, the reflection spectrum distribution in the visible light band is adjusted through thin-film interference, causing the film to exhibit a purple apparent color. This indicates that by changing the visible light spectrum of the surface to control the thickness of the film, the reflection spectrum and apparent color of the film in the visible light range can be further adjusted, thereby obtaining different visible light optical responses.

[0045] Since the surface Si film layer is only 30 nm thick, which is relatively small compared to the operating wavelength in the mid- and far-infrared bands, this ultrathin surface film layer has little impact on the spectral response of the main multilayer film structure in the infrared and 10.6 μm laser bands. After introducing a 30 nm thick Si film layer, the overall reflectance spectral characteristics of the film in the 3-5 μm, 5-8 μm, and 8-14 μm bands are basically maintained, while the low reflectance spectral response near 10.6 μm is also preserved. The above results indicate that by reasonably adjusting the thickness of the surface Si film layer, it is possible to change the visible light reflectance spectrum and apparent color while minimizing its impact on the infrared selective spectral characteristics and the 10.6 μm laser wavelength response, thereby facilitating the synergistic control of spectral performance in the visible light, infrared, and laser bands.

[0046] Example 3: A Visible-Infrared-Laser Multi-Band Spectral Selectivity Controlled Thin Film

[0047] Figure 10 This is the reflectance spectrum of a visible-infrared-laser multi-band spectrally selectively modulated thin film in the 3–14 μm band, as described in Embodiment 3 of the present invention. Figure 10 It is known that the average reflectance of the thin film in the 3-5 μm and 8-14 μm bands are 0.860 and 0.742, respectively, and the average reflectance in the 5-8 μm band is 0.458, indicating that the thin film has a significant selective spectral response in different infrared bands. Under the condition that the thin film transmittance is negligible, according to Kirchhoff's law, higher reflectance corresponds to lower emissivity, and the relatively low reflectance in the 5-8 μm band corresponds to higher emissivity. Therefore, the thin film can maintain low thermal radiation emission characteristics in the 3-5 μm and 8-14 μm bands, while exhibiting strong radiative heat transfer capability in the 5-8 μm band, thus balancing infrared selective spectral modulation and radiative heat dissipation performance. Furthermore, the thin film has a reflectance of 8.323% at the typical operating wavelength of CO2 laser (10.6 μm), exhibiting a significant low-reflectance spectral response, indicating that the thin film can achieve synergistic modulation of the spectral response at the 10.6 μm laser wavelength while maintaining broad-band infrared selective spectral characteristics.

[0048] Figure 11 This is the visible light reflectance spectrum of the multi-band spectrally selectively modulated thin film described in Embodiment 3 of the present invention when the thickness of the surface silicon (Si) film is 40 nm. Figure 11 It is known that when the thickness of the Si film on the surface is 40 nm, the reflectance spectrum distribution in the visible light band can be adjusted through thin-film interference, causing the film to exhibit a blue apparent color. These results demonstrate that by changing the visible light spectrum of the surface to control the thickness of the film, the reflectance spectrum and apparent color of the film in the visible light range can be adjusted, thereby obtaining different visible light optical responses.

[0049] Since the surface Si film layer is only 40 nm thick, which is relatively small compared to the operating wavelength in the mid- and far-infrared bands, this ultrathin surface film layer has little impact on the spectral response of the main multilayer film structure in the infrared and 10.6 μm laser bands. After introducing a 40 nm thick Si film layer, the film can still maintain the corresponding selective spectral characteristics in the 3-5 μm, 5-8 μm, and 8-14 μm bands, while the low reflectance spectral response near 10.6 μm can also be maintained. This indicates that by reasonably adjusting the thickness of the surface Si film layer, it is possible to change the visible light reflectance spectrum and apparent color while minimizing its impact on the infrared selective spectral characteristics and the 10.6 μm laser wavelength response, thereby facilitating the synergistic control of spectral performance in the visible light, infrared, and laser bands.

[0050] The above description, in conjunction with specific embodiments, provides a detailed explanation of the present invention, but it should not be construed as limiting the specific embodiments to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A visible-infrared-laser multi-band spectral selectivity modulated thin film, characterized in that, The multilayer film structure consists of a substrate (1), an infrared spectral modulation film layer (2), a laser spectral modulation film layer (3), and a visible light spectral modulation film layer (4) from bottom to top. The infrared spectral modulation film layer (2) consists of a metal film A (21), a silicon film A (22), a metal film B (23), and a silicon film B (24) from bottom to top. The laser spectral modulation film layer (3) consists of a silicon dioxide film (31) and a germanium film (32) from bottom to top. The visible light modulation film layer (4) consists of only one layer of material.

2. The visible-infrared-laser multi-band spectral selectivity control thin film according to claim 1, characterized in that, The substrate (1) material includes monocrystalline silicon, sapphire, stainless steel, polyvinyl alcohol and polyimide.

3. The visible-infrared-laser multi-band spectral selectivity control thin film according to claim 1, characterized in that, The materials of the metal film A (21) and metal film B (23) include tungsten, gold, silver, copper, aluminum, chromium, molybdenum and alloy materials.

4. The visible-infrared-laser multi-band spectral selectivity control thin film according to claim 1, characterized in that, The visible light spectrum modulation film (4) material includes silicon and zinc sulfide.

5. The visible-infrared-laser multi-band spectral selectivity control thin film according to claim 1, characterized in that, The thickness of the metal film A (21) in the infrared spectral control film (2) is 150±50 nm, the thickness of the silicon film A (22) in the infrared spectral control film (2) is 750±100 nm, the thickness of the metal film B (23) in the infrared spectral control film (2) is 15±10 nm, the thickness of the silicon film B (24) in the infrared spectral control film (2) is 400±50 nm, the thickness of the silicon dioxide film (31) in the laser spectral control film (3) is 1750±100 nm, the thickness of the germanium film (32) in the laser spectral control film (3) is 800±100 nm, and the thickness of the visible light spectral control film (4) is 30±20 nm.

Images