Metal grating polarization beam splitter

Abstract

The utility model provides a metal grating polarization beam splitter, which relates to the technical field of optical devices and comprises a transparent base layer, a first metal pattern layer and a second metal pattern layer which are sequentially stacked. The second metal pattern layer is made of a single-metal coating or a first alloy coating with high conductivity, hardness and stress matching capacity, so that the polarization beam splitter is excellent in corrosion resistance, scraping resistance and the like, static accumulation on the surface of the polarization beam splitter is prevented, the polarization beam splitter is compatible with a subsequent etching process, and the polarization beam splitter is suitable for large-scale production. The possible problem of film stripping or structural damage is avoided, and the overall stability of the polarization beam splitter is improved. Besides, by controlling the thickness of the second metal pattern layer, the thickness of the second metal pattern layer is smaller than that of the first metal pattern layer, the cost and the optical performance are effectively balanced, and it is ensured that the polarization beam splitter keeps economical efficiency while guaranteeing functions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical devices, in particular to a metal grating polarization beam splitter. BACKGROUND

[0002] Polarized light is widely used in modern optical technology, especially in optical communication, optical storage, optical sensing and other applications, and plays an important role. As a kind of core optical device, polarization beam splitter has the function of polarized filtering of incident light, part of which is transmitted and part of which is reflected, and the polarization directions of the two are perpendicular to each other. In order to meet the needs of modern optical applications, polarization beam splitter requires a wide range of incident angles and working spectrum, so that large-angle and broadband polarization beam splitter has important practical application value.

[0003] In the traditional metal grating polarization beam splitter, elemental metals such as aluminum and silver are widely used due to their good electrical conductivity and reflectivity. The dispersion characteristics of these metal materials make them an ideal choice for manufacturing polarization beam splitters, especially in industrial applications and mass production. However, the application of aluminum and silver faces certain technical challenges. First of all, these metal materials are prone to oxidation and corrosion, which leads to performance degradation. Secondly, aluminum and silver are relatively soft and have weak mechanical properties, which are easily scratched and damaged during use.

[0004] In order to solve these problems, a layer of oxide protective film such as SiO2 or Al2O3 is usually coated on the surface of the metal. This oxide layer can effectively prevent further oxidation and corrosion of the metal. However, the oxide layer has some shortcomings. First of all, the oxide layer itself does not have electrical conductivity, so static electricity can easily accumulate on the surface, which may cause static damage. In addition, the difference in thermal expansion coefficient between the metal and the oxide is large, which may cause interfacial stress between the film layers and further cause local peeling of the film layers, thereby affecting the optical performance and service life. CONTENT OF THE INVENTION

[0005] The purpose of the present application is to provide a metal grating polarization beam splitter to overcome the shortcomings of the prior art.

[0006] To achieve the above purpose, the technical scheme adopted by the embodiments of the present application is as follows:

[0007] The embodiments of the present application provide a metal grating polarization beam splitter, which comprises a transparent base layer, a first metal pattern layer and a second metal pattern layer which are sequentially stacked, the second metal pattern layer is a single metal coating or a first alloy coating, and the thickness of the second metal pattern layer is less than the thickness of the first metal pattern layer.

[0008] Optionally, the second metal pattern layer is a single metal coating, and the single metal coating is a titanium coating, a chromium coating or a nickel coating.

[0009] Optionally, the second metal pattern layer is a first alloy coating, and the first alloy coating is a chromium-titanium alloy coating, a nickel-chromium alloy coating or a nickel-titanium alloy coating.

[0010] Optionally, at least one third metal pattern layer is further stacked between the transparent base layer and the first metal pattern layer, and the third metal pattern layer is a second alloy coating.

[0011] Optionally, the second alloy coating is an aluminum alloy coating or a silver alloy coating.

[0012] Optionally, the first metal pattern layer is a silver coating or an aluminum coating.

[0013] Optionally, the thickness of the first metal pattern layer is 50-200 nm.

[0014] Optionally, the thickness of the second metal pattern layer is 1-20 nm.

[0015] Optionally, the thickness of the third metal pattern layer is 1-20 nm.

[0016] Optionally, an anti-reflection film is arranged on at least one side surface of the transparent base layer.

[0017] The beneficial effects of the present application include:

[0018] The present application provides a metal grating polarization beam splitter, which comprises a transparent base layer, a first metal pattern layer and a second metal pattern layer stacked in sequence. The second metal pattern layer is made of a single metal coating or a first alloy coating with strong conductivity, hardness and stress matching capability, so that the polarization beam splitter performs well in terms of corrosion resistance, scratch resistance and the like, and also prevents static accumulation on the surface of the polarization beam splitter. In addition, the polarization beam splitter is compatible with the subsequent etching process, avoids possible film peeling or structural damage problems, and improves the overall stability of the polarization beam splitter. Furthermore, by controlling the thickness of the second metal pattern layer, the thickness of the second metal pattern layer is less than the thickness of the first metal pattern layer, effectively balancing the cost and optical performance, and ensuring that the polarization beam splitter is functional while maintaining economy. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0020] Figure 1 A structural schematic diagram of a metal grating polarizing beam splitter provided by an embodiment of the present application;

[0021] Figure 2 A structural schematic diagram of a metal grating polarizing beam splitter provided by an embodiment of the present application;

[0022] Figure 3 A flow chart of a method for preparing a metal grating polarizing beam splitter provided by an embodiment of the present application;

[0023] Figure 4 A structural schematic diagram of a structure provided by an embodiment of the present application, in which an anti-reflection film is arranged on both sides of a transparent base layer;

[0024] Figure 5 A structural schematic diagram of a structure provided by an embodiment of the present application, in which a grating pattern is formed in organic glue 6.

[0025] Icon: 1-transparent base layer; 2-first metal pattern layer; 3-second metal pattern layer; 4-third metal pattern layer; 5-anti-reflection film; 6-organic glue. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. It should be noted that each feature in the embodiments of the present application can be combined with each other, and the combined embodiments are still within the protection scope of the present application, without conflict.

[0028] It should be noted that: similar labels and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0029] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In one aspect of the present application, a metal grating polarization beam splitter is provided, which aims to achieve high-efficiency light splitting effect and excellent mechanical performance by optimizing the layer structure and material design. As shown in Figure 1 and Figure 2 The polarization beam splitter includes a transparent base layer 1, a first metal pattern layer 2 and a second metal pattern layer 3 arranged in sequence. The transparent base layer 1 serves as the input layer of the light beam and has good light transmission performance to ensure that the light beam can smoothly enter the optical element and be transmitted downward. The first metal pattern layer 2 is above the transparent base layer 1 and performs preliminary modulation on the light beam through specific pattern design, thereby playing a core function of the beam splitter. The second metal pattern layer 3 is located on top of the first metal pattern layer 2, and its main function is to effectively prevent the first metal pattern layer 2 from being corroded or scratched during use, thereby improving the long-term stability and reliability of the polarization beam splitter.

[0033] Specifically, the second metal pattern layer 3 can adopt a single metal coating or a first alloy coating, and this design choice is based on its excellent electrical conductivity, hardness, and good stress matching with the first metal pattern layer 2. The material of the second metal pattern layer 3 needs to have strong corrosion resistance and high hardness to effectively prevent damage to the first metal pattern layer 2 by the external environment, especially under mechanical friction or other external forces, which can prolong the service life of the optical element. Moreover, through the electrical conductivity of the second metal pattern layer 3, it can prevent static accumulation on the surface of the polarization beam splitter. In addition, through reasonable material ratio and interlayer stress optimization, the stress difference between the second metal pattern layer 3 and the first metal pattern layer 2 can be effectively controlled, and it is compatible with the subsequent etching process, avoiding possible film peeling or structural damage problems, and improving the overall stability of the polarization beam splitter.

[0034] In addition, the thickness of the second metal pattern layer 3 should be less than the thickness of the first metal pattern layer 2. This design can avoid unnecessary material waste while ensuring that the second metal pattern layer 3 has sufficient protection, thus balancing cost-effectiveness and performance optimization. By controlling the thickness of the second metal pattern layer 3, the cost and optical performance can be effectively balanced to ensure that the polarization beam splitter maintains functionality while remaining economical. This not only reduces production costs, but also improves the manufacturing efficiency of the polarization beam splitter, making it more suitable for industrial applications.

[0035] Optionally, the main role of the transparent base layer 1 material is to provide support for the upper grating or metal coating and allow light to pass through, and it should have good light transmittance and mechanical strength. Generally, optical glass (such as optical-grade float glass, quartz glass), polymer materials (such as polycarbonate, polyethylene, polymethyl methacrylate), fluorides (such as calcium fluoride), ceramic transparent materials (such as aluminum ceramic), etc. can be used. When selecting the appropriate transparent base layer 1 material, the specific application requirements of the metal grating polarization beam splitter (such as wavelength range, power intensity, environmental conditions, etc.) should be considered comprehensively.

[0036] Optionally, the first metal pattern layer 2 is a silver coating or an aluminum coating, and the choice of these two materials is based on their unique advantages in optical applications. Both aluminum and silver have excellent electrical conductivity and high reflectivity, making them ideal materials for realizing the function of metal gratings.

[0037] Specifically, due to the high reflectivity of silver and aluminum coatings, they can effectively reflect the incident light beams and perform polarization filtering by the specific structure of the metal grating. The formation of the metal grating structure mainly depends on the pattern design of the first metal pattern layer 2, which can reflect or transmit the incident light at a specific angle and separate the light beam into two mutually perpendicular polarized lights according to the polarization direction of the light. This design can ensure the high efficiency of the beam splitter in multiple wavelength ranges, which is suitable for optical communication, optical storage, and optical sensing fields.

[0038] In addition, the coating of silver or aluminum not only plays a role in reflection, but also enhances the electrical conductivity of the metal grating layer, which is helpful for the transmission and regulation of electromagnetic waves and optimizes the propagation path of the light beam in the polarization beam splitter. The high electrical conductivity of aluminum and silver enables them to effectively reduce energy loss caused by resistance, thereby improving the overall optical efficiency of the beam splitter. At the same time, the high reflectivity can ensure that the incident light beam is reflected to the designated direction with little loss, enhancing the effect of polarization splitting.

[0039] Optionally, the second metal pattern layer 3 serves as a protective and enhancing layer, and the material selection directly affects the performance and stability of the polarization beam splitter. The second metal pattern layer 3 can adopt a single metal coating, specifically titanium coating, chromium coating, nickel coating, or tungsten coating. These materials have excellent electrical conductivity and hardness, which can provide additional protection and effectively improve the overall stability of the polarization beam splitter.

[0040] Specifically, the titanium coating is widely used in environments requiring high durability and wear resistance due to its excellent corrosion resistance and hardness, which can effectively prevent the first metal pattern layer 2 (such as aluminum coating or silver coating) from being corroded or scratched by the external environment. The chromium coating is known for its high hardness and strong wear resistance, making it particularly suitable for use in environments that need to withstand large mechanical pressure and friction. The nickel coating plays an important role in the protection of optical elements due to its good electrical conductivity, corrosion resistance, and relatively high surface hardness. The tungsten coating performs well in high-temperature environments, effectively enhancing the thermal stability of the grating layer and ensuring the long-term stability of the polarization beam splitter in high-temperature or harsh environments.

[0041] Secondly, the coating material of the second metal pattern layer 3 has good stress matching with the aluminum or silver grating structure of the bottom layer, which is crucial for improving the stability of the product and avoiding film layer peeling during the manufacturing process. The aluminum coating or silver coating as the first metal pattern layer 2 has strong electrical conductivity and high reflectivity, which can efficiently reflect light and perform polarization splitting tasks. The hardness and stress matching characteristics of the second metal pattern layer 3 can ensure that there is no stress problem caused by inconsistent thermal expansion between the two metal pattern layers, thereby avoiding the problem of film layer cracking or peeling due to mismatched stress. This feature can enhance the mechanical properties of the polarization beam splitter and ensure its long-term stable operation.

[0042] In addition, the titanium, chromium, nickel or tungsten coating material adopted by the second metal pattern layer 3 is highly compatible with the subsequent etching process, enabling fine pattern etching during the manufacturing process. This compatibility makes the production process more simple, lower in cost, and improves production efficiency. During the subsequent etching process, these materials can maintain stable structure and performance, ensuring the accuracy and consistency of the grating pattern, further enhancing the optical effect of the polarization beam splitter.

[0043] Optionally, the second metal pattern layer 3 is a first alloy coating, and the first alloy coating is a chromium-titanium alloy coating, a nickel-chromium alloy coating, a nickel-titanium alloy coating, or a nickel-chromium-titanium alloy coating.

[0044] Specifically, the selection of the first alloy coating is crucial because they combine the advantages of both single metals and can enhance the overall performance of the metal through the complementarity of elements. For example, the chromium-titanium alloy coating has higher thermal stability while ensuring corrosion resistance, especially suitable for use in high-temperature or large environmental change occasions. The nickel-chromium alloy coating performs well in corrosion resistance, especially in industrial environments, and can resist the erosion of many chemicals while maintaining good mechanical strength. The nickel-titanium alloy coating has extremely high wear resistance and oxidation resistance, and can maintain the integrity of the structure in high-stress environments, especially suitable for optical systems that require high hardness and high durability. The nickel-chromium-titanium alloy coating can combine the advantages of these materials and has extremely strong comprehensive performance, providing durable protection in complex working environments and ensuring the efficiency and stability of the polarization beam splitter.

[0045] The use of the first alloy coating can significantly improve the overall stability of the metal grating polarization beam splitter. The strength, hardness, and wear resistance of the alloy material effectively prevent external factors from damaging the grating layer and maintain the polarization beam splitting ability of the grating. Moreover, the first alloy coating has good stress matching with the aluminum coating or silver coating of the bottom layer, and the second metal pattern layer 3 can withstand larger temperature changes and external stress, thereby reducing structural problems caused by the mismatch of the thermal expansion coefficients of the materials. This design can enhance the reliability of the polarization beam splitter and ensure that it can still work stably and efficiently in a variable working environment.

[0046] In addition, titanium, chromium, nickel, and other materials as constituent elements of the alloy all have good processing performance and relatively low production cost, and the process flow of the alloy coating is highly compatible with the subsequent etching technology, enabling high-precision pattern etching and material deposition during the manufacturing process. This enables the metal grating polarization beam splitter to maintain high process consistency and good yield during the production process, thereby reducing production costs and improving production efficiency.

[0047] Optionally, as Figure 1 andFigure 2 As shown, at least one third metal pattern layer 4 is further stacked between the transparent base layer 1 and the first metal pattern layer 2, and the third metal pattern layer 4 is a second alloy coating layer, further protecting the first metal pattern layer 2 from oxidation and corrosion.

[0048] Specifically, the third metal pattern layer 4 usually adopts an alloy material with excellent corrosion resistance and excellent adhesion as the second alloy coating layer. These materials not only need to have good oxidation resistance and corrosion resistance, but also need to maintain stability under harsh conditions such as high humidity or high temperature. By adding one or more second alloy coating layers between the first metal pattern layer 2 and the transparent base layer 1, a multiple protection barrier can be formed, so that the optical performance of the metal grating polarizing beam splitter can be maintained for a longer period of time.

[0049] Optionally, the second alloy coating layer is an aluminum alloy coating layer or a silver alloy coating layer.

[0050] Specifically, the aluminum alloy coating layer can be composed of aluminum and titanium, chromium, nickel, or other metal elements or their alloys, while the silver alloy coating layer can be formed by silver and titanium, chromium, nickel, or other metal elements or alloys. The selection of these alloy coating materials is based on their excellent mechanical properties and outstanding oxidation resistance, which can effectively improve the stability and corrosion resistance of the metal grating polarizing beam splitter in different working environments.

[0051] On the one hand, aluminum itself has high reflectivity and good electrical conductivity, and the addition of titanium, chromium, nickel, and other metal elements can not only improve the hardness and wear resistance of the aluminum alloy, but also effectively enhance its oxidation resistance and corrosion resistance. Especially in environments exposed to air for a long time, these alloy coatings can form a strong protective film on the metal surface, preventing the metal pattern layer from being oxidized or chemically corroded. In addition, the aluminum alloy coating material is well matched with the stress of the metal grating structure, which can ensure that the device is not prone to deformation or performance degradation during use.

[0052] On the other hand, silver itself has excellent electrical conductivity and high reflectivity, but it is easily oxidized. Therefore, by combining silver with titanium, chromium, nickel, and other alloy materials, its oxidation resistance and stability can be significantly improved. The application of silver alloy coating in the polarizing beam splitter not only enhances the optical performance of the device, but also maintains long-term stability in harsh environments such as high temperature and high humidity. These silver alloy coatings can provide additional protection for the metal grating, prevent surface damage, and ensure that the polarizing beam splitter does not have performance degradation problems during long-term use.

[0053] Optionally, the thickness of the first metal pattern layer 2 is 50 nm to 200 nm.

[0054] Specifically, the main role of the first metal pattern layer 2 is to serve as a grating layer, realizing the polarization selection function. The design of the metal grating relies on the thickness of the metal pattern layer and the grating structure to adjust the efficiency and extinction suppression ratio. During the patterning process, if the first metal pattern layer 2 is too thick, it may cause an increase in light absorption, which in turn affects the polarization effect of the light beam; while if it is too thin, it may not be able to effectively reflect all the necessary light signals, resulting in an undesirable beam splitting effect. Therefore, precise control of the thickness of the first metal pattern layer 2 not only helps to achieve the desired optical properties, but also enhances the bonding force between the first metal pattern layer 2 and the adjacent pattern layers, ensuring the stability and durability of the metal grating in long-term use. When the thickness of this layer is set in the range of 50nm to 200nm, it can not only guarantee sufficient reflection ability, but also will not excessively increase the optical loss of the material or cause other adverse effects. For example, at a relatively thin thickness of 50nm, the first metal pattern layer 2 can achieve higher light transmittance and reflection efficiency, while at a relatively thick thickness close to 200nm, the stability and corrosion resistance of the first metal pattern layer 2 can be enhanced, which can adapt to more severe application environments.

[0055] Optionally, the thickness of the second metal pattern layer 3 is 1nm to 20nm.

[0056] Specifically, the relatively thin second metal pattern layer 3 not only helps to maintain the optical performance of the first metal pattern layer 2, but also reduces the optical absorption caused by an excessively thick coating layer. In the metal grating, the polarization beam splitting effect of light is closely related to the fineness of the pattern layer, so an excessively thick second metal pattern layer 3 may cause unnecessary optical loss. On the other hand, a moderate coating thickness can reduce material consumption and production costs while ensuring protection functions. Within the range of 1nm to 20nm, the second metal pattern layer 3 can not only provide sufficient protection barrier, but also will not significantly affect the overall optical performance, ensuring that the polarization beam splitter can work efficiently.

[0057] Optionally, the thickness of the third metal pattern layer 4 is 1nm to 20nm.

[0058] Specifically, the third metal pattern layer 4 with a thickness of 1nm to 20nm can provide sufficient protection performance while not excessively affecting the optical properties of the polarization beam splitter. An excessively thick pattern layer will cause light absorption, which in turn reduces the beam splitting efficiency. By controlling the thickness of the third metal pattern layer 4 within this reasonable range, not only can it play a protective role, but also can minimize optical loss and the impact on light beam transmission. In addition, the relatively thin third metal pattern layer 4 can effectively reduce material consumption and production costs, ensuring high efficiency protection while having higher economic efficiency.

[0059] Optionally, as Figure 1 and Figure 2As shown, the anti-reflection film 5 is arranged on at least one side surface of the transparent base layer 1. Preferably, the anti-reflection film 5 is arranged on both side surfaces of the transparent base layer 1 to reduce the reflection of light on the interface between the transparent base layer 1 and the external medium, thereby improving the transmittance and overall optical efficiency of the beam splitter.

[0060] Specifically, by reasonably selecting the material and thickness of the anti-reflection film 5, the reflected light can interfere with the incident light in phase, achieving the effect of cancellation, thereby reducing the reflection loss of light. There is usually a large difference in refractive index at the interface between the transparent base layer 1 and the anti-reflection film 5, which easily leads to reflection of the incident light. By adding the anti-reflection film 5 on the surface of the transparent base layer 1, the interference effect of the reflected light can be utilized to effectively reduce this reflection phenomenon, thereby reducing the optical loss caused thereby and optimizing the overall efficiency of the polarization beam splitter.

[0061] The anti-reflection film 5 can be composed of a single material or a multi-layer structure, and common materials include silicon dioxide, magnesium fluoride, etc., which have good light transmittance and low refractive index, and can be effectively matched with the high refractive index material of the transparent base layer 1. The thickness of the anti-reflection film 5 is usually several hundred nanometers, and the thickness is related to the wavelength of the incident light. By precise design and adjustment, effective reflection suppression of light of a specific wavelength can be achieved. The deposition process of the anti-reflection film 5 includes thin film technologies such as evaporation and sputtering, which can accurately control the thickness and uniformity of the film layer, ensuring stable and efficient performance of the anti-reflection film 5.

[0062] In another aspect of the embodiments of the present application, a method for preparing any of the above metal grating polarization beam splitters is provided, such as Figure 3 As shown, the method specifically includes the following steps:

[0063] S10: preparing an anti-reflection film 5 on at least one side surface of the transparent base layer 1;

[0064] S20: preparing one or more third metal pattern layers 4 on the transparent base layer 1;

[0065] S30: preparing a first metal pattern layer 2 on the third metal pattern layer 4;

[0066] S40: preparing a second metal pattern layer 3 on the first metal pattern layer 2;

[0067] S50: coating an organic glue 6 on the surface of the second metal pattern layer 3, and forming a grating pattern in the organic glue 6;

[0068] S60: forming a grating pattern on the second metal pattern layer 3, the first metal pattern layer 2 and the third metal pattern layer 4.

[0069] Specifically, first, prepare a transparent base layer 1 and pre-clean it to remove any contaminants and impurities that may be present on the surface, ensuring the adhesion and uniformity of subsequent coatings. For example... Figure 4 As shown, an antireflection film 5 is deposited on at least one side of the transparent substrate 1. The function of the antireflection film 5 is to reduce light loss by reducing the reflection of light at the interface between the surface of the transparent substrate 1 and the external medium, thereby improving transmittance and optimizing the optical performance of the polarization beam splitter.

[0070] Next, as Figure 1 As shown, one or more third metal pattern layers 4 are prepared on a transparent substrate 1 using methods such as evaporation, sputtering, atomic layer deposition (ALD), or chemical vapor deposition (CVD). The main function of the third metal pattern layer 4 is to provide an adhesion base for the subsequent first metal pattern layer 2, and in practical applications, it also serves to protect the first metal pattern layer 2. The material of the third metal pattern layer 4 is usually a second alloy coating with good conductivity and compatibility with the material of the subsequent first metal pattern layer 2, ensuring the stability and performance optimization of the first metal pattern layer 2.

[0071] like Figure 1 As shown, after the third metal pattern layer 4 is prepared, the same evaporation, sputtering, atomic layer deposition, or chemical vapor deposition process is used to prepare the first metal pattern layer 2 on its surface. The first metal pattern layer 2 is typically composed of a metal coating such as silver or aluminum, which has high conductivity and high reflectivity, providing the core grating structure for the metal grating polarization beam splitter. The design and fabrication process of the first metal pattern layer 2 are crucial, ensuring its thickness and the accuracy of the grating structure to achieve efficient polarization beam splitting.

[0072] Subsequently, as Figure 1 As shown, a second metal pattern layer 3 is prepared on the basis of the first metal pattern layer 2 by means of evaporation, sputtering, atomic layer deposition, or chemical vapor deposition. The second metal pattern layer 3 is typically used to provide additional protection and enhance the corrosion resistance of the metal grating, while ensuring the stability and anti-aging properties of the grating structure. The material selection, thickness design, and coating process of the second metal pattern layer 3 have a direct impact on the quality of the final grating structure.

[0073] like Figure 5 As shown, after the fabrication of the second metal pattern layer 3 is completed, an organic adhesive pattern is formed on the surface of the second metal pattern layer 3 by coating with organic adhesive 6. This step uses micro-nano fabrication techniques such as photolithography, nanoimprint lithography, or electron beam lithography to precisely form the desired pattern structure on the surface of the second metal pattern layer 3. The quality of this step directly affects the accuracy of the grating pattern, and it is essential to ensure that the performance of the metal grating meets the expected requirements.

[0074] Finally, as Figure 2As shown, precise grating patterns are formed in the second metal pattern layer 3, the first metal pattern layer 2 and the third metal pattern layer 4 by wet or dry etching techniques. The etching process is a key step in the method, by strictly controlling the etching depth and speed, a high-precision grating structure can be formed on the metal pattern layer. The etched metal grating structure not only can effectively perform polarization beam splitting, but also can ensure long-term stability and durability, suitable for various high-precision optical applications.

[0075] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A metal grating polarization beam splitter, characterized in that, It includes a transparent base layer (1), a first metal pattern layer (2) and a second metal pattern layer (3) stacked in sequence. The second metal pattern layer (3) is a single metal coating or a first alloy coating. The thickness of the second metal pattern layer (3) is less than the thickness of the first metal pattern layer (2).

2. The metal grating polarization beam splitter according to claim 1, characterized in that, The second metal pattern layer (3) is the single metal coating, which is a titanium coating, a chromium coating, or a nickel coating.

3. The metal grating polarization beam splitter according to claim 1, characterized in that, The second metal pattern layer (3) is the first alloy coating, which is a chromium-titanium alloy coating, a nickel-chromium alloy coating, or a nickel-titanium alloy coating.

4. The metal grating polarization beam splitter according to any one of claims 1 to 3, characterized in that, At least one third metal pattern layer (4) is also stacked between the transparent base layer (1) and the first metal pattern layer (2), and the third metal pattern layer (4) is a second alloy coating.

5. The metal grating polarization beam splitter according to claim 4, characterized in that, The second alloy coating is an aluminum alloy coating or a silver alloy coating.

6. The metal grating polarization beam splitter according to any one of claims 1 to 3, characterized in that, The first metal pattern layer (2) is a silver coating or an aluminum coating.

7. The metal grating polarization beam splitter according to any one of claims 1 to 3, characterized in that, The thickness of the first metal pattern layer (2) is 50 nm to 200 nm.

8. The metal grating polarization beam splitter according to any one of claims 1 to 3, characterized in that, The thickness of the second metal pattern layer (3) is 1 nm to 20 nm.

9. The metal grating polarization beam splitter according to claim 4, characterized in that, The thickness of the third metal pattern layer (4) is 1 nm to 20 nm.

10. The metal grating polarization beam splitter according to any one of claims 1 to 3, characterized in that, An antireflective film (5) is provided on at least one side surface of the transparent base layer (1).

Images