阅读说明：本技术 一种中性密度片及其制备方法 (Neutral density tablet and preparation method thereof ) 是由 朱元强 陈钢 叶沈航 于 2021-08-13 设计创作，主要内容包括：本发明涉及光学膜层技术领域,尤其涉及一种中性密度片及其制备方法。中性密度片包括依次层叠设置的玻璃基板、金属吸收膜层和介质增透膜层,所述介质增透膜层包括依次层叠设置的第一TiO-(2)介质层、第一MgF-(2)介质层、第二TiO-(2)介质层、第二MgF-(2)介质层、第三TiO-(2)介质层和第三MgF-(2)介质层；所述第一TiO-(2)介质层背离第一MgF-(2)介质层的一侧与金属吸收膜层贴合；通过在设于玻璃基板上的金属吸收膜层的表面上增设介质增透膜层,并采用特定的介质增透膜层以及具体参数配置,以达到减少金属吸收膜层的反射率,同时不会影响金属吸收膜层的吸收效果。(The invention relates to the technical field of optical film layers, in particular to a neutral density sheet and a preparation method thereof. The neutral density sheet comprises a glass substrate, a metal absorption film layer and a medium antireflection film layer which are sequentially stacked, wherein the medium antireflection film layer comprises a first TiO layer which is sequentially stacked 2 Dielectric layer and first MgF 2 Dielectric layer, second TiO 2 Dielectric layer, second MgF 2 Dielectric layer, third TiO 2 A dielectric layer and a third MgF 2 A dielectric layer; the first TiO 2 The dielectric layer deviates from the first MgF 2 One side of the dielectric layer is attached to the metal absorption film layer; the dielectric antireflection film layer is additionally arranged on the surface of the metal absorption film layer arranged on the glass substrate, and the specific dielectric antireflection film layer and the specific parameter configuration are adopted, so that the reflectivity of the metal absorption film layer is reduced, and the absorption effect of the metal absorption film layer is not influenced.)

1. The neutral density sheet comprises a glass substrate, a metal absorption film layer and a medium antireflection film layer which are sequentially stacked, and is characterized in that the medium antireflection film layer comprises a first TiO layer which is sequentially stacked₂Dielectric layer and first MgF₂Dielectric layer, second TiO₂Dielectric layer, second MgF₂Dielectric layer, third TiO₂A dielectric layer and a third MgF₂A dielectric layer; the first TiO₂The dielectric layer deviates from the first MgF₂One side of the dielectric layer is attached to the metal absorption film layer;

the refractive index of the glass substrate measured at a wavelength of 550nm is 1.52; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm, and the first TiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 37.9nm, and the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

2. The neutral density sheet comprises a glass substrate, a metal absorption film layer and a medium antireflection film layer which are sequentially stacked, and is characterized in that the medium antireflection film layer comprises TiO layers which are stacked mutually₂Dielectric layer and MgF₂A dielectric layer; the TiO is₂Dielectric layer deviating from MgF₂One side of the dielectric layer is attached to the metal absorption film layer;

the refractive index of the glass substrate measured at a wavelength of 550nm is 1.52; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17;the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

3. The neutral density tablet of claim 1 or 2, wherein the metal absorbing film layer is made of chromium.

4. The neutral density sheet of claim 1 or 2, wherein the glass substrate is a K9 glass substrate.

5. The preparation method of the neutral density tablet is characterized by comprising the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology;

the forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming a first TiO on one side of the metal absorption film layer far away from the glass substrate₂Dielectric layer and first MgF₂Dielectric layer, second TiO₂Dielectric layer, second MgF₂Dielectric layer, third TiO₂A dielectric layer and a third MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm,the first TiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 37.9nm, and the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

6. The preparation method of the neutral density tablet is characterized by comprising the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology;

the forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming TiO on one side of the metal absorption film layer away from the glass substrate₂Dielectric layer and MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

7. The method for preparing a neutral density tablet according to claim 5 or 6, wherein the metal absorbing film layer is made of chromium.

8. The method of producing a neutral density sheet according to claim 5 or 6, wherein the glass substrate is a K9 glass substrate.

Technical Field

The invention relates to the technical field of optical film layers, in particular to a neutral density sheet and a preparation method thereof.

Background

The commonly used absorption material is a metal material, that is, a metal material with a certain thickness is prepared on a transparent glass carrier to realize the absorption or attenuation of a certain proportion of light intensity. However, the metal material has strong absorption characteristics and strong reflection characteristics; for example, in some optical systems, strong reflections can have negative effects, such as increased signal noise, imaging ghosting, and the like.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the neutral density sheet and the preparation method thereof are provided, so that the reflectivity of the metal absorption film layer is reduced, and the absorption effect of the metal absorption film layer is not influenced.

In order to solve the above technical problems, a first technical solution adopted by the present invention is:

a neutral density sheet comprises a glass substrate, a metal absorption film layer and a medium antireflection film layer which are sequentially stacked, wherein the medium antireflection film layer comprises a first TiO layer which is sequentially stacked₂Dielectric layer and first MgF₂Dielectric layer, second TiO₂Dielectric layer, second MgF₂Dielectric layer, third TiO₂A dielectric layer and a third MgF₂A dielectric layer; the first TiO₂The dielectric layer deviates from the first MgF₂One side of the dielectric layer is attached to the metal absorption film layer;

the refractive index of the glass substrate measured at a wavelength of 550nm is 1.52; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm, and the first TiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 37.9nm, and the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

The second technical scheme adopted by the invention is as follows:

the neutral density sheet comprises a glass substrate, a metal absorption film layer and a medium anti-reflection film layer which are sequentially stacked, wherein the medium is increasedThe permeable membrane layer comprises TiO which are mutually laminated₂Dielectric layer and MgF₂A dielectric layer; the TiO is₂Dielectric layer deviating from MgF₂One side of the dielectric layer is attached to the metal absorption film layer;

the refractive index of the glass substrate measured at a wavelength of 550nm is 1.52; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

The third technical scheme adopted by the invention is as follows:

a preparation method of a neutral density tablet comprises the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology;

the forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming a first TiO on one side of the metal absorption film layer far away from the glass substrate₂Dielectric layer and first MgF₂Dielectric layer, second TiO₂Dielectric layer, second MgF₂Dielectric layer, third TiO₂A dielectric layer and a third MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm, and the first T isiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 37.9nm, and the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

The fourth technical scheme adopted by the invention is as follows:

a preparation method of a neutral density tablet comprises the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology;

the forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming TiO on one side of the metal absorption film layer away from the glass substrate₂Dielectric layer and MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

The invention has the beneficial effects that:

according to the neutral density sheet and the preparation method thereof, the dielectric antireflection film layer is additionally arranged on the surface of the metal absorption film layer arranged on the glass substrate, and the specific dielectric antireflection film layer and the specific parameter configuration are adopted, so that the reflectivity of the metal absorption film layer is reduced, and the absorption effect of the metal absorption film layer is not influenced.

Drawings

FIG. 1 is a schematic structural diagram of a neutral density sheet according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the reflectivity of a conventional metal absorption film according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the transmittance of a conventional metal absorption film layer according to a first embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the reflectivity of a metal absorption film according to a first embodiment of the invention;

FIG. 5 is a schematic diagram of the transmittance of a metal absorption film layer according to a first embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a neutral density patch according to a second embodiment of the present invention;

FIG. 7 is a diagram illustrating the reflectivity of a conventional metal absorption film according to a second embodiment of the present invention;

FIG. 8 is a schematic diagram of the transmittance of a conventional metal absorption film layer according to a second embodiment of the present invention;

FIG. 9 is a schematic view of the reflectivity of the metal absorption film layer according to the second embodiment of the invention;

FIG. 10 is a graph illustrating the transmittance of a metal absorber film according to a second embodiment of the present invention;

description of reference numerals:

1. a glass substrate; 2. a metal absorbing film layer; 3. a dielectric anti-reflection film layer; 31. first TiO 2₂A dielectric layer; 32. first MgF₂A dielectric layer; 33. second TiO₂A dielectric layer; 34. second MgF₂A dielectric layer; 35. third TiO₂A dielectric layer; 36. third MgF₂A dielectric layer;

4. a glass substrate; 5. a metal absorbing film layer; 6. a dielectric anti-reflection film layer; 61. TiO 2₂A dielectric layer; 62. MgF₂A dielectric layer.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

EXAMPLE one (neutral density sheet having a transmittance of 50%)

Referring to fig. 1 to 5, the neutral density sheet provided by the present invention comprises a plurality of layers sequentially stackedThe glass substrate 1, the metal absorption film layer 2 and the medium antireflection film layer 3 are arranged, wherein the medium antireflection film layer 3 comprises a first TiO layer which is sequentially stacked₂Dielectric layer 31, first MgF₂Dielectric layer 32, second TiO₂Dielectric layer 33, second MgF₂Dielectric layer 34, third TiO₂Dielectric layer 35 and third MgF₂A dielectric layer 36; the first TiO₂Dielectric layer 31 faces away from the first MgF₂One side of the dielectric layer 32 is attached to the metal absorbing film layer 2; in this embodiment, the metal absorption film layer 2 is made of chromium. The glass substrate 1 is a commonly used K9 glass substrate.

Wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm, and the first TiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 37.9nm, and the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

From the above description, the beneficial effects of the present invention are:

the dielectric antireflection film layer is additionally arranged on the surface of the metal absorption film layer arranged on the glass substrate, and the specific dielectric antireflection film layer and the specific parameter configuration are adopted, so that the reflectivity of the metal absorption film layer is reduced, and the absorption effect of the metal absorption film layer is not influenced. Through the parameter configuration, the reflectivity of the metal absorption film layer measured at the wavelength of 380nm-780nm can be reduced from 18.1% to 1%.

Specifically, as shown in FIGS. 2-3, for the neutral density sheet having only the metal absorption film layer with ND 50%, the reflectance of Cr is as high as Rave 18.1% @ 380-. Through the design of the scheme, as shown in fig. 4-5, the measured reflectivity Rave is 1.0% @ 380-. The reflectivity of the metal absorbing film layer measured at the wavelength of 380nm-780nm is reduced from 18.1 percent to 1 percent.

The invention also provides a preparation method of the neutral density tablet, which comprises the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology; wherein, the physical vapor deposition technology specifically adopts magnetron sputtering or electronic evaporation technology.

The forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming a first TiO on one side of the metal absorption film layer far away from the glass substrate₂Dielectric layer and first MgF₂Dielectric layer, second TiO₂Dielectric layer, second MgF₂Dielectric layer, third TiO₂A dielectric layer and a third MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the first TiO₂Dielectric layer, second TiO₂A dielectric layer and a third TiO₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the first MgF₂Dielectric layer, second MgF₂A dielectric layer and a third MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 7.1nm, and the first TiO₂The thickness of the dielectric layer is 38.1nm, and the first MgF₂The thickness of the dielectric layer is 197.8nm, and the second TiO₂The thickness of the dielectric layer is 24.1nm, and the second MgF is₂The thickness of the dielectric layer is 379nm, the third TiO₂The thickness of the dielectric layer is 25.1nm, and the third MgF₂The thickness of the dielectric layer was 109 nm.

By the above preparation method, the neutral density sheet can be obtained and the claimed technical effects can be achieved.

Example two (neutral density sheet having a transmittance of 40%)

Referring to fig. 6 to 10, the neutral density sheet provided by the invention comprises a glass substrate 4, a metal absorption film layer 5 and a dielectric antireflection film layer 6 which are sequentially stacked, wherein the dielectric antireflection film layer 6 comprises TiO which are stacked mutually₂Dielectric layer 61 and MgF₂A dielectric layer 62; the TiO is₂Dielectric layer 61 faces away from MgF₂One side of the dielectric layer 62 is attached to the metal absorbing film layer 5; in this embodiment, the metal absorption film layer is made of chromium. The glass substrate is a commonly used K9 glass substrate.

The refractive index of the glass substrate measured at a wavelength of 550nm is 1.52; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

From the above description, the beneficial effects of the present invention are:

the dielectric antireflection film layer is additionally arranged on the surface of the metal absorption film layer arranged on the glass substrate, and the specific dielectric antireflection film layer and the specific parameter configuration are adopted, so that the reflectivity of the metal absorption film layer is reduced, and the absorption effect of the metal absorption film layer is not influenced. Through the parameter configuration, the reflectivity of the metal absorption film layer measured at the wavelength of 380nm-780nm can be reduced from 23.5% to 1.8%.

Specifically, as shown in FIGS. 7-8, for the neutral density sheet with only the metal absorption film ND 40%, the Cr film thickness is increased to 6.5nm, the reflectance is correspondingly increased to Rave 23.5% @ 380-. Through the design of the scheme, as shown in fig. 9-10, the measured reflectivity Rave is 1.8% @ 380-. The reflectivity of the metal absorbing film layer measured at the wavelength of 380nm-780nm is reduced from 23.5 percent to 1.8 percent.

The invention also provides a preparation method of the neutral density tablet, which comprises the following steps:

s1, preparing a glass substrate;

s2, sequentially forming a metal absorbing film layer and a medium antireflection film layer on the upper surface of the glass substrate by adopting a physical vapor deposition technology; wherein, the physical vapor deposition technology specifically adopts magnetron sputtering or electronic evaporation technology.

The forming of the dielectric antireflection film layer specifically comprises the following steps:

sequentially forming TiO on one side of the metal absorption film layer away from the glass substrate₂Dielectric layer and MgF₂A dielectric layer;

wherein the glass substrate has a refractive index of 1.52 measured at a wavelength of 550 nm; the refractive index of the metal absorption film layer measured under the wavelength of 550nm is 3.17; the TiO is₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 2.3; the MgF₂The refractive indexes of the dielectric layers measured under the wavelength of 550nm are all 1.38;

the thickness of the metal absorption film layer is 10.2nm, and the TiO is₂The thickness of the dielectric layer is 34.2nm, and the MgF is₂The thickness of the dielectric layer was 78.8 nm.

By the above preparation method, the neutral density sheet can be obtained and the claimed technical effects can be achieved.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.