Anti-reflection film on surface of optical instrument and preparation method of anti-reflection film

Abstract

The invention relates to the technical field of optical films, in particular to an anti-reflection film on the surface of an optical instrument and a preparation method of the anti-reflection film. A plasma generating device is adopted to blow the surface of the glass substrate pre-cleaned in the step S1; adopting an atomic layer deposition technology to deposit an ALD-Ta2O5 seed layer on the surface of the glass substrate subjected to purging in S2; and alternately depositing ALD-SiO2 layers and ALD-Ta2O5 layers on the upper surface of the ALD-Ta2O5 seed layer of S3 by adopting an atomic layer deposition technology to obtain the anti-reflection film with the composite laminated layer. The uniform and compact inorganic coating grows on the surface of the glass substrate material through the atomic layer deposition technology, and the good anti-reflection effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical film, in particular to an anti-reflective and anti-fouling film on the surface of optical instruments and a preparation method thereof. BACKGROUND

[0002] In the imaging, detection, measurement and optical signal transmission processes of optical instruments, light often needs to pass through optical elements such as lenses, prisms, window sheets and protective glasses multiple times. However, ordinary optical glass or transparent substrate materials have strong reflection on incident light, and the reflection loss of a single optical interface is about 4%. In an optical system composed of multiple optical elements, the reflection loss will accumulate, resulting in a significant reduction in light energy utilization, thereby affecting the imaging brightness, contrast and measurement accuracy of the optical instrument, and greatly reducing the overall performance of the optical system.

[0003] To solve the above problems, the prior art usually prepares an anti-reflective and anti-fouling film on the surface of the optical instrument to improve its performance. Common preparation processes include sol-gel method, vacuum electron beam evaporation method and magnetron sputtering method, etc. However, these preparation methods have many defects: first, it is difficult to accurately control the thickness and film layer structure of the film, and it is easy to form an over-thick or uneven coating, resulting in increased internal stress, reduced toughness and insufficient adhesion of the film, and thus cracks and peeling defects occur, causing the anti-reflective and anti-fouling performance to fail; second, the preparation cost is high, which limits its application in high-end optical instruments; third, for optical elements with complex structures such as curved surfaces and irregular shapes, it is difficult to achieve uniform coverage and good shape retention of the film, which restricts the application effect of the anti-reflective and anti-fouling film in complex optical systems.

[0004] To this end, the existing patent CN202411886537.2 discloses an anti-reflective and anti-fouling film on the surface of photovoltaic packaging glass and a preparation method thereof, which uses a TiO2 / SiO2 system to construct a laminated film. However, it has some problems: TiO2 has intrinsic absorption in the visible light band, especially in the short wave band, and has a large dispersion coefficient, which is not conducive to achieving flat and anti-reflective effect in a wide wave band range; at the same time, ALD-TiO2 film is prone to crystallization during deposition or subsequent heat treatment, resulting in increased surface roughness of the film layer, enhanced interface scattering, and significantly decreased stability of optical constants and controllability of thickness, which is difficult to meet the use requirements of high-precision optical instruments.

[0005] Therefore, it is of great significance to develop an anti-reflective and anti-fouling film with universality, excellent optical performance, strong adhesion and applicability to complex optical instrument surfaces, and a preparation method thereof, for improving the imaging quality, measurement accuracy and overall performance of optical instruments. SUMMARY

[0006] The application aims to provide an antireflection and antifouling film for optical instrument surface and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the application provides a preparation method of an antireflection and antifouling film for optical instrument surface, comprising the following steps: S1, pre-cleaning of the glass substrate surface; S2, purging of the glass substrate surface: using a plasma generating device to purge the glass substrate surface pre-cleaned in S1; S3, deposition of a seed layer: using atomic layer deposition technology to deposit an ALD-Ta2O5 seed layer on the glass substrate surface purged in S2; S4, deposition of a composite stack: using atomic layer deposition technology to alternately deposit an ALD-SiO2 layer and an ALD-Ta2O5 layer on the surface of the ALD-Ta2O5 seed layer in S3, so as to obtain an antireflection and antifouling film with a composite stack.

[0008] Preferably, the pre-cleaning in S1 comprises: using deionized water to clean the surface of the glass substrate, then using an organic solvent to soak and clean the glass substrate, and performing drying treatment after cleaning.

[0009] More preferably, the organic solvent comprises one or more of ethanol and acetone.

[0010] Preferably, the purging in S2 comprises: placing the pre-cleaned glass substrate into an ALD chamber, setting the plasma power of the plasma generating device to 1200 W, using a mixed gas of oxygen and argon as the purging gas, purging the surface of the glass substrate, and the purging time is 10 min to 20 min.

[0011] Preferably, the deposition of the ALD-Ta2O5 seed layer in S3 comprises: in the ALD chamber, setting the temperature range to 200-250 DEG C, vacuumizing to 0 Pa to 20 Pa, using argon as the carrier gas to alternately pass in a tantalum precursor and an oxidizing agent, and repeatedly depositing to obtain the ALD-Ta2O5 seed layer.

[0012] Preferably, the tantalum precursor in S3 comprises one of tantalum pentachloride and pentakis(dimethylamino)tantalum, and the oxidizing agent comprises one of water vapor and ozone.

[0013] Preferably, the alternately depositing in S4 comprises: S401, in the ALD chamber, using argon as the carrier, passing in a silicon precursor under the assistance of oxygen plasma, and repeatedly depositing to obtain the ALD-SiO2 layer; S402, on the surface of the ALD-SiO2 layer, a tantalum precursor and an oxidizing agent are alternately introduced in sequence with argon as a carrier gas, and the deposition is repeated for multiple cycles to obtain an ALD-Ta2O5 layer; S403, the ALD-SiO2 layer of S401 and the ALD-Ta2O5 layer of S402 are repeatedly deposited to obtain an ALD-Ta2O5 / SiO2 composite stack.

[0014] Preferably, the number of cycles in S3 and S4 is 100-2500.

[0015] More preferably, the silicon precursor in S4 is bis (diethylamino) silane, and the oxygen plasma is the oxidizing agent.

[0016] An antireflection and antifouling film for the surface of an optical instrument is prepared by the above-mentioned method.

[0017] Preferably, the ALD-Ta2O5 / SiO2 composite stack comprises an ALD-Ta2O5 seed layer and an ALD-Ta2O5 / SiO2 composite stack, the ALD-Ta2O5 / SiO2 composite stack comprises an ALD-Ta2O5 layer and an ALD-SiO2 layer deposited alternately, the number of ALD-SiO2 layers is two, and the ALD-Ta2O5 layer is located between the two ALD-SiO2 layers.

[0018] Preferably, the thickness of the ALD-Ta2O5 seed layer is 11-14 nm; the thickness of the ALD-Ta2O5 layer in the ALD-Ta2O5 / SiO2 composite stack is 96-123 nm; the thickness of the ALD-SiO2 layer located on the lower side of the ALD-Ta2O5 layer is 25-32 nm; and the thickness of the ALD-SiO2 layer located on the upper side of the ALD-Ta2O5 layer is 68-88 nm.

[0019] More preferably, the total thickness of the antireflection and antifouling film is 200-257 nm.

[0020] The mechanism of the application is as follows: Ta2O5 has a wider band gap structure (compared to TiO2), has extremely low intrinsic absorption loss in the entire visible light band, especially in the short wave band, and has a small dispersion coefficient, which can accurately match the engineering design requirements of interference antireflection and achieve flat antireflection effect in a wide wave band range; and SiO2 as a low refractive index material forms a reasonable refractive index level gradient with Ta2O5, which can significantly weaken the interface reflection through the destructive interference of light and improve the overall light transmission efficiency.

[0021] Therefore, the application has the following beneficial effects by using the above-mentioned antireflection and antifouling film for the surface of an optical instrument and the preparation method thereof. (1) The ALD-Ta2O5 seed layer and ALD-Ta2O5 layer of the present invention can maintain a stable amorphous structure, avoiding problems such as increased surface roughness and enhanced interface scattering caused by easy crystallization of TiO2; at the same time, Ta2O5 and SiO2 have good nucleation matching, and a flat and dense interface can be formed during the atomic layer deposition process, effectively reducing interface reflection loss and ensuring the stability of optical constants and thickness control accuracy.

[0022] (2) The Ta2O5 / SiO2 composite stack of the present invention has stronger chemical inertness and no photocatalytic effect of TiO2, which can avoid the performance degradation of the film due to chemical changes during long-term use; and the amorphous structure gives the film better mechanical compatibility, reduces internal stress concentration, and combined with the strong substrate adhesion brought by plasma pretreatment, further improves the service stability of the film in complex environments. Compared with the traditional TiO2 / SiO2 system, the Ta2O5 / SiO2 system performs better in key dimensions such as absorption loss, dispersion control, crystallization risk and interface quality, and can take into account high transmittance, broadband antireflection, long-term stability and process controllability, making it more suitable for the use requirements of high-precision optical instruments.

[0023] (3) The present invention uses atomic layer deposition (ALD) technology, which can achieve precise control at the atomic level and has good surface conformability. It can form a uniform film layer on a substrate with a complex 3D surface. It can prepare ALD-Ta2O5 / SiO2 stacked thin film with extremely high uniformity on glass substrate, achieve ideal anti-reflection and anti-reflection effect, effectively reduce light loss and improve photoelectric conversion efficiency. The prepared ALD-Ta2O5 / SiO2 stacked thin film has high oxygen sensitivity and shows high response to O2, indicating that the film has excellent performance in terms of gas sensitivity and structural characteristics and has excellent quality. Compared with thermal evaporation and magnetron sputtering technology, the present invention combines plasma activation pretreatment with ALD deposition process to form a stronger bonding force between the film and the glass substrate, which significantly improves the durability and stability of the film.

[0024] (4) The anti-reflective and anti-reflective film prepared by the present invention has excellent density and uniformity. The thickness at the nanometer level can achieve good anti-reflective and anti-reflective effects, effectively avoiding defects such as increased internal stress, cracks, and peeling caused by excessive coating deposition thickness.

[0025] (5) The antireflective and anti-reflective film prepared by the technology of the present invention has good environmental stability, can adapt to complex environments such as outdoor environments, and ensure the performance stability of optical instruments during long-term use.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the antireflective and anti-reflective film prepared in Example 1 of the present invention; Figure 2 This is a graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Example 1 of this invention; Figure 3 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Example 1 of this invention; Figure 4 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Example 2 of this invention; Figure 5 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Example 3 of this invention; Figure 6 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Comparative Example 1 of this invention; Figure 7 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Comparative Example 2 of this invention; Figure 8 This is a simulated graph showing the relationship between reflectivity and wavelength of the antireflective and anti-reflective thin film prepared in Comparative Example 3 of this invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0029] Example 1 This invention provides an anti-reflection and anti-reflection film for the surface of optical instruments, the preparation method of which includes the following steps: S1. Pre-cleaning of the glass substrate surface: Use deionized water to clean the glass surface to remove impurities, then use ethanol organic solvent to soak and clean the glass surface, and dry it after cleaning to remove surface chemical contaminants.

[0030] S2. Purging of the glass substrate surface: The pre-cleaned glass substrate from S1 is placed in the ALD chamber. An inductively coupled plasma (ICP) generator inside the chamber further removes impurities from the substrate surface. The plasma power is set to 1200W, and a mixture of oxygen and argon is used as the purging gas. The purging time is 15 minutes. Plasma treatment further removes surface contaminant particles from the glass substrate and improves coating adhesion.

[0031] S3. Seed layer deposition: An ALD-Ta2O5 seed layer is deposited on the glass substrate surface after S2 purging. In the ALD chamber, the temperature is set to 225℃ and the vacuum is evacuated to 0Pa. Argon gas is used as the carrier gas and tantalum pentachloride and water vapor are alternately introduced in sequence. The deposition is repeated 255 times to obtain an ALD-Ta2O5 seed layer with a thickness of 14nm.

[0032] S4. Deposition of composite layers: Alternating deposition of ALD-SiO2 and ALD-Ta2O5 layers on the surface of the ALD-Ta2O5 seed layer in S3 yields a 257 nm thick antireflection and antireflection film with a composite layer, such as... Figure 1 As shown; specifically as follows: S401. In the ALD chamber, with constant temperature and vacuum, argon gas is used as a carrier and bis(diethylamino)silane is introduced under the assistance of oxygen plasma. After 221 cycles, an ALD-SiO2 layer with a thickness of 32 nm is deposited. S402. On the surface of the ALD-SiO2 layer, tantalum pentachloride and water vapor are alternately introduced in sequence using argon as the carrier gas, and the deposition is carried out in 2236 cycles to obtain an ALD-Ta2O5 layer with a thickness of 123nm. S403. On the surface of the ALD-Ta2O5 layer, bis(diethylamino)silane is introduced under the assistance of oxygen plasma using argon as a carrier and deposited for 607 cycles to obtain an ALD-SiO2 layer with a thickness of 88 nm.

[0033] Example 2 This invention provides an anti-reflection and anti-reflection film for the surface of optical instruments, the preparation method of which includes the following steps: S1. Pre-cleaning of the glass substrate surface: Use deionized water to clean the glass surface to remove impurities, then use acetone organic solvent to soak and clean the glass surface, and dry it after cleaning to remove surface chemical contaminants.

[0034] S2. Purging of the glass substrate surface: The pre-cleaned glass substrate from S1 is placed in the ALD chamber. An inductively coupled plasma (ICP) generator inside the chamber further removes impurities from the substrate surface. The plasma power is set to 1200W, and a mixture of oxygen and argon is used as the purging gas. The purging time is 10 minutes. Plasma treatment further removes surface contaminant particles from the glass substrate and improves coating adhesion.

[0035] S3. Seed layer deposition: An ALD-Ta2O5 seed layer is deposited on the glass substrate surface after S2 purging. In the ALD chamber, the temperature is set to 200℃ and the vacuum is evacuated to 10Pa. Argon gas is used as the carrier gas and tantalum pentachloride and water vapor are alternately introduced in sequence. After 200 cycles, an ALD-Ta2O5 seed layer with a thickness of 11nm is obtained.

[0036] S4. Deposition of composite stack: Alternating deposition of ALD-SiO2 and ALD-Ta2O5 layers on the surface of the ALD-Ta2O5 seed layer in S3 yields a 200nm thick antireflection and antireflection film with a composite stack; details are as follows: S401. In the ALD chamber, with constant temperature and vacuum, argon gas is used as a carrier and bis(diethylamino)silane is introduced under the assistance of oxygen plasma. After 172 cycles, an ALD-SiO2 layer with a thickness of 25 nm is deposited. S402. On the surface of the ALD-SiO2 layer, tantalum pentachloride and water vapor are alternately introduced in sequence using argon as the carrier gas and the cycle is repeated 1745 times to obtain an ALD-Ta2O5 layer with a thickness of 96nm. S403. On the surface of the ALD-Ta2O5 layer, bis(diethylamino)silane is introduced under the assistance of oxygen plasma using argon as a carrier and deposited for 469 cycles to obtain an ALD-SiO2 layer with a thickness of 68 nm.

[0037] Example 3 This invention provides an anti-reflection and anti-reflection film for the surface of optical instruments, the preparation method of which includes the following steps: S1. Pre-cleaning of the glass substrate surface: Use deionized water to clean the glass surface to remove impurities, then use ethanol organic solvent to soak and clean the glass surface, and dry it after cleaning to remove surface chemical contaminants.

[0038] S2. Purging of the glass substrate surface: The pre-cleaned glass substrate from S1 is placed in the ALD chamber. An inductively coupled plasma (ICP) generator inside the chamber further removes impurities from the substrate surface. The plasma power is set to 1200W, and a mixture of oxygen and argon is used as the purging gas. The purging time is 20 minutes. Plasma treatment further removes surface contaminant particles from the glass substrate and improves coating adhesion.

[0039] S3, Seed layer deposition: An ALD-Ta2O5 seed layer is deposited on the glass substrate surface after S2 purging. In the ALD chamber, the temperature is set to 250℃ and the vacuum is evacuated to 20Pa. Argon gas is used as the carrier gas and tantalum pentachloride and water vapor are alternately introduced in sequence. The deposition is repeated 218 times to obtain an ALD-Ta2O5 seed layer with a thickness of 12nm.

[0040] S4. Deposition of composite stack: Alternating deposition of ALD-SiO2 and ALD-Ta2O5 layers on the surface of the ALD-Ta2O5 seed layer in S3 yields a 225nm thick antireflection and antireflection film with a composite stack; details are as follows: S401. In the ALD chamber, with constant temperature and vacuum, argon gas is used as a carrier and bis(diethylamino)silane is introduced under the assistance of oxygen plasma. After 193 cycles, an ALD-SiO2 layer with a thickness of 28 nm is obtained. S402. On the surface of the ALD-SiO2 layer, tantalum pentachloride and water vapor are alternately introduced in sequence using argon as the carrier gas, and the deposition is carried out in 1964 cycles to obtain an ALD-Ta2O5 layer with a thickness of 108nm. S403. On the surface of the ALD-Ta2O5 layer, bis(diethylamino)silane was introduced under oxygen plasma assistance using argon as a carrier and deposited for 531 cycles to obtain an ALD-SiO2 layer with a thickness of 77 nm.

[0041] Comparative Example 1 The difference from Example 1 is that an ALD-Ta2O5 seed layer with a thickness of 15 nm (273 cycles) is deposited in S3; an ALD-SiO2 layer with a thickness of 34 nm (234 cycles) is deposited in S401; an ALD-Ta2O5 layer with a thickness of 132 nm (2400 cycles) is deposited in S402; and an ALD-SiO2 layer with a thickness of 94 nm (648 cycles) is deposited in S403. The total thickness of the resulting antireflective and anti-reflective film is 275 nm.

[0042] Comparative Example 2 The difference from Example 1 is that an ALD-Ta2O5 seed layer with a thickness of 16 nm (291 cycles) is deposited in S3; an ALD-SiO2 layer with a thickness of 37 nm (255 cycles) is deposited in S401; an ALD-Ta2O5 layer with a thickness of 144 nm (2618 cycles) is deposited in S402; and an ALD-SiO2 layer with a thickness of 103 nm (710 cycles) is deposited in S403. The total thickness of the antireflective and anti-reflective film obtained is 300 nm.

[0043] Comparative Example 3 The total thickness of the antireflective and anti-reflective film is 274 nm, which includes a glass substrate and successively thick ALD-TiO2 seed layer of 16 nm (216 cycles), ALD-SiO2 layer of 40 nm (276 cycles), ALD-TiO2 layer of 54 nm (730 cycles), ALD-SiO2 layer of 17 nm (117 cycles), ALD-TiO2 layer of 44 nm (595 cycles), and ALD-SiO2 layer of 103 nm (710 cycles).

[0044] Test The glass substrate sample coated with the antireflection and anti-reflection film prepared in Example 2 was placed on a microspectrophotometer for reflectance testing. Four points (test point 1, test point 2, test point 3, and test point 4) were selected for measurement. The test results are shown below. Figure 2 .

[0045] like Figure 2 As shown, within the wavelength range of 400-700 nm, the reflectivity of the glass substrate coated with the antireflective and anti-reflective film prepared in Example 2 is all below 0.5%. That is, when the glass substrate is coated on only one side, after deducting the slight absorption and scattering effects, the transmittance can reach 99%, which indicates that the prepared antireflective and anti-reflective film has a very good antireflective and anti-reflective effect. In addition, the curves fitted from the four points on the glass substrate are very close, with no obvious offset or fluctuation, indicating that the atomic layer deposition (ALD) technology has excellent control over the uniformity of the film layer. The film grows uniformly on the surface of the glass substrate, which can avoid the imaging distortion or measurement accuracy reduction of optical instruments caused by local reflection differences.

[0046] The antireflection and anti-reflection films prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to reflectance simulation tests using existing optical thin film design software. The simulation results are shown in […]. Figures 3-8 .

[0047] like Figures 3-8 As shown, in the wavelength range of 400~700nm, the reflectivity of Example 1 is within 0.5%, exhibiting the characteristics of low reflection, wide band and flatness. This is because the film layer thickness ratio makes the reflected light of each layer meet the destructive interference condition, and the low absorption and low dispersion characteristics of the Ta2O5 / SiO2 system further suppress the reflectivity fluctuation within the band.

[0048] The reflectivity of Example 2 is between 0.25% and 7%, and the reflectivity of Example 3 is between 0.25% and 2.7%. The reflectivity is particularly good in the short wavelength band of 400-600nm (reflectivity ≤0.5%). The reflectivity in the long wavelength band increases slightly but still meets practical requirements.

[0049] Comparative Example 1 exhibits a reflectivity between 0.25% and 2.6% in a portion of the visible light wavelength range (400-600nm). Compared to Example 1, its overall wavelength reflectivity uniformity is relatively higher. The core reason for this is the increase in the total film thickness and the deviation of the thickness ratio between the Ta2O5 functional layer (132nm) and the SiO2 layer (34nm on the lower side and 94nm on the upper side) from the optimal value. This leads to an imbalance in optical thickness, disrupts the destructive interference condition, and causes the reflection valley / peak to shift towards longer or shorter wavelengths due to thickness variations, resulting in increased reflectivity in the target wavelength band. The reflectivity of Comparative Example 2 ranged from 0.75% to 12.1%, and its reflectivity across the entire wavelength band was significantly higher than that of the Example. This was due to the further increase in film thickness (ALD-Ta2O5 seed layer 16nm, ALD-Ta2O5 functional layer 144nm, and upper ALD-SiO2 layer 103nm). The thickness ratio of high-refractive-index Ta2O5 to low-refractive-index SiO2 changed, the interface reflection was enhanced, and the phase superposition relationship of reflected light from each layer changed, affecting the overall reflectivity level. This fully demonstrates that the film thickness must be strictly controlled within the range of 11-14nm (ALD-Ta2O5 seed layer) and 25-123nm (ALD-Ta2O5 layer) specified in this invention in order to ensure optical performance.

[0050] Comparative Example 3 only achieved low reflectance below 0.5% in the 450-700nm wavelength range, with significantly higher reflectance in the 400-450nm short-wavelength range, failing to achieve uniform antireflection across the entire visible light spectrum. This is directly related to the intrinsic absorption characteristics and high dispersion coefficient of TiO2 in the short-wavelength range. Compared to Example 1 (Ta2O5 / SiO2 system), the antireflection band of the TiO2 / SiO2 system in Comparative Example 3 is narrow, and its surface roughness and reflectance drift are easily increased due to TiO2 crystallization during long-term use. In contrast, the Ta2O5 / SiO2 system used in this invention can extend the low-reflection band to the entire visible light range of 400-700nm, and its optical performance is more stable, fully verifying the significant advantages of the Ta2O5 / SiO2 system in wide-band antireflection and performance stability.

[0051] Therefore, the present invention employs the above-mentioned anti-reflection and anti-reflection film on the surface of an optical instrument and its preparation method. The resulting anti-reflection and anti-reflection film has a very good anti-reflection and anti-reflection effect, effectively reducing light loss and improving photoelectric conversion efficiency.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for making an antireflective, transparent thin film on an optical instrument surface, characterized by: The method comprises the following steps: S1, pre-cleaning of the surface of the glass substrate; S2, purging of the surface of the glass substrate: using a plasma generating device to purge the surface of the glass substrate after S1 pre-cleaning; S3, depositing a seed layer: using atomic layer deposition technology to deposit an ALD-Ta2O5 seed layer on the surface of the glass substrate after S2 purging; S4, depositing a composite stack: using atomic layer deposition technology to alternately deposit an ALD-SiO2 layer and an ALD-Ta2O5 layer on the surface of the ALD-Ta2O5 seed layer of S3 to obtain an anti-reflective and anti-fouling thin film with a composite stack.

2. A method of making an anti-reflective, transparent thin film on the surface of an optical instrument according to claim 1, characterized in that: The pre-cleaning in S1 is to clean the surface of the glass substrate with deionized water, then immerse the glass substrate in an organic solvent for cleaning, and then perform drying treatment after cleaning.

3. The method of making an anti-reflective, transparent thin film on the surface of an optical instrument according to claim 1, wherein: The purging in S2 is to place the pre-cleaned glass substrate into an ALD chamber, set the plasma power of the plasma generating device to 1200W, use a mixed gas of oxygen and argon as the purging gas, and purge the surface of the glass substrate for 10-20min.

4. The method of making an anti-reflective, transparent thin film on the surface of an optical instrument according to claim 1, wherein: The deposition of the ALD-Ta2O5 seed layer in S3 is to set the temperature range to 200-250℃ in the ALD chamber, vacuumize to 0-20Pa, and alternately introduce a tantalum precursor and an oxidizing agent into the chamber with argon as the carrier gas to deposit the ALD-Ta2O5 seed layer through multiple cycles.

5. A method of making an anti-reflective, transparent thin film on the surface of an optical instrument according to claim 4, characterized in that: The tantalum precursor in S3 includes one of pentachlorotantalum and pentakis(dimethylamino)tantalum, and the oxidizing agent includes one of water vapor and ozone.

6. The method of making an anti-reflective, transparent thin film on the surface of an optical instrument according to claim 4, wherein: The alternating deposition in S4 includes: S401, in the ALD chamber, introduce a silicon precursor into the chamber with argon as the carrier gas under the assistance of oxygen plasma to deposit the ALD-SiO2 layer through multiple cycles; S402, on the surface of the ALD-SiO2 layer, alternately introduce a tantalum precursor and an oxidizing agent into the chamber with argon as the carrier gas to deposit the ALD-Ta2O5 layer through multiple cycles; S403, repeat the deposition of the ALD-SiO2 layer of S401 and the ALD-Ta2O5 layer of S402 to obtain the ALD-Ta2O5 / SiO2 composite stack.

7. A method of making an anti-reflective, transparent thin film on the surface of an optical instrument as defined in claim 6, wherein: The number of cycles for the multiple cycles of deposition in S3 and S4 is 100-2500.

8. An antireflective, transparent thin film for optical instrument surfaces, characterized in that: The anti-reflective and anti-fouling thin film is prepared by the method of any one of claims 1-7.

9. An anti-reflective, high transmission coating for an optical instrument surface as defined in claim 8, wherein: The anti-reflective and anti-fouling thin film comprises an ALD-Ta2O5 seed layer and an ALD-Ta2O5 / SiO2 composite stack, the ALD-Ta2O5 / SiO2 composite stack comprises alternately deposited ALD-Ta2O5 layers and ALD-SiO2 layers, the number of ALD-SiO2 layers is two, and the ALD-Ta2O5 layers are located between the two ALD-SiO2 layers.

10. An anti-reflective, high transmission coating for an optical instrument surface as defined in claim 9, wherein: The thickness of the ALD-Ta2O5 seed layer is 11-14nm; the thickness of the ALD-Ta2O5 layers in the ALD-Ta2O5 / SiO2 composite stack is 96-123nm; the thickness of the ALD-SiO2 layer located on the lower side of the ALD-Ta2O5 layers is 25-32nm; and the thickness of the ALD-SiO2 layer located on the upper side of the ALD-Ta2O5 layers is 68-88nm.

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