A metal polarization beam splitter

Abstract

This invention provides a metal polarization beam splitter, which consists of a top metal-dielectric-metal structure supported by a comb-shaped insulating medium and a bottom metal-dielectric-metal structure supported by the comb-shaped insulating medium. The comb-shaped insulating medium is arranged in a regular period or randomly. When incident light with a wavelength much larger than the width of the comb-shaped insulating medium irradiates the device, the light wave will be transmitted if the polarization direction is perpendicular to the comb distribution direction, and reflected if the polarization direction is parallel to the comb distribution direction, thereby achieving a polarization beam splitting effect. This invention uses a combination of comb-shaped medium and metal to form a polarization beam splitter, resulting in a thin structural layer. This not only achieves a high degree of polarization of the beam after splitting, but also overcomes the problems of large size and integration difficulties associated with traditional beam splitters.

Description

Technical Field

[0001] This invention relates to an optical device, specifically a metal polarization beam splitter. Background Technology

[0002] Polarizing beam splitters are fundamental optical devices in the field of optics, primarily used to split an incident light beam into two orthogonally polarized outgoing beams. They have wide applications in optical measuring instruments, optical displays, and optical manipulation. Currently, the main device capable of polarizing beam splitting is the polarizing beam splitter prism, formed by cementing two triangular prisms together. Light of different polarizations is reflected or transmitted at the cemented surface of the prisms, thus achieving the polarizing beam splitting effect. However, polarizing beam splitters are bulky, difficult to integrate, and unsuitable for miniaturized, integrated optical systems. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the volume limitations of traditional polarization beam splitters by using a comb-shaped insulating medium and a metal structure with extremely small thickness to form a polarization beam splitting structure, so that the device can be easily integrated into miniaturized optics.

[0004] The technical solution of this invention is to propose using a comb-shaped insulating medium and the metal-medium-metal structure at the top and bottom of the comb-shaped insulating medium to form an integrated structure, so that light with a polarization state perpendicular to the comb structure can be transmitted, and light with a polarization state parallel to the comb structure can be reflected, so as to achieve a polarization beam splitting result with a high degree of polarization on an extremely thin structure.

[0005] A metal polarizing beam splitter, characterized as follows.

[0006] The insulating medium is arranged in a comb-like pattern, with a multi-layered structure of metal-dielectric-metal combination placed on top of the comb-like insulating medium and a multi-layered structure of metal-dielectric-metal combination placed at the bottom of the comb-like insulating medium.

[0007] The lateral distribution of the comb-shaped insulating medium is either periodic or random.

[0008] The metal-dielectric-metal structure at the top and bottom of the comb-shaped insulating medium can be repeated once or multiple times in the longitudinal direction.

[0009] The width and spacing of the comb-shaped insulating dielectric lines are much smaller than the wavelength of the incident light.

[0010] The height of the comb-shaped insulating medium is greater than the total thickness of the metal-dielectric-metal structure.

[0011] The cross-section of the comb-shaped insulating medium is rectangular or inverted trapezoidal.

[0012] The entire structural layer is supported by a light-transmitting dielectric substrate.

[0013] The comb-shaped insulating medium is a supporting structure with a top metal-dielectric-metal structure.

[0014] The comb-shaped insulating medium always extends in one direction.

[0015] The metal material in the metal-dielectric-metal configuration is a high-conductivity metal.

[0016] The dielectric material in the metal-dielectric-metal configuration and the comb-shaped insulating dielectric can be the same or different dielectric materials.

[0017] The comb-shaped insulating dielectric material is an optical material with low absorption or no absorption of incident light.

[0018] The comb-shaped insulating dielectric structure is prepared by photolithography, etching, or imprinting processes.

[0019] The metal-dielectric-metal structure is prepared by a film deposition process.

[0020] The substrate supporting the entire structural layer is a flat surface or a curved surface of other optical devices.

[0021] When incident light is incident perpendicularly or obliquely onto the surface of the device, the light whose polarization direction is perpendicular to the extension direction of the comb-shaped insulating medium will be transmitted, while the light wave whose polarization direction is parallel to the extension direction of the comb-shaped insulating medium will be reflected, thereby producing a polarization beam splitting effect.

[0022] The advantages of this invention compared to the prior art are:

[0023] (1) Since the present invention uses a thin comb-like structure to achieve polarization beam splitting, the size of the polarization beam splitting device is much smaller than that of the traditional polarization beam splitting prism, making it easy to integrate into a miniaturized system;

[0024] (2) Since the beam splitting structure used in this invention is a comb-shaped insulating dielectric supported top metal-dielectric-metal structure and bottom metal-dielectric-metal structure, the polarization degree of the beam splitting obtained by transmission or reflection is high.

[0025] (3) Since the comb-shaped insulating medium in the beam splitting structure of the present invention is a low-absorption optical material, the device has a low absorption rate and the energy loss of the polarized beam after beam splitting is small. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the comb-shaped structure of the metal polarization beam splitter of the present invention, wherein 11 is a light-transmitting dielectric substrate, 13 is a comb-shaped insulating dielectric, 14 is the top metal structure of the comb-shaped insulating dielectric, 12 is the bottom metal structure of the comb-shaped insulating dielectric, and 15 is the dielectric structure between the two metal layers.

[0027] Figure 2This is a three-dimensional diagram of the metal polarization beam splitter of the present invention, wherein 21 is a light-transmitting dielectric substrate, 23 is a comb-shaped insulating dielectric, 24 is the top metal structure of the comb-shaped insulating dielectric, 22 is the bottom metal structure of the comb-shaped insulating dielectric, and 25 is the dielectric structure between the two metal layers.

[0028] Figure 3 The diagram shows a cross-sectional view of the metal polarizing beam splitter of the present invention. Its top and bottom structures are composed of multiple layers of metal-dielectric-metal, wherein 31 is a light-transmitting dielectric substrate, 33 is a comb-shaped insulating dielectric, 34 is the top metal structure of the comb-shaped insulating dielectric, 32 is the bottom metal structure of the comb-shaped insulating dielectric, and 35 is the dielectric structure between the two metal layers.

[0029] Figure 4 The diagram shows a cross-sectional view of the metal polarizing beam splitter of the present invention. Its comb-shaped insulating medium is inverted trapezoidal, wherein 41 is a light-transmitting dielectric substrate, 43 is the comb-shaped insulating medium, 44 is the top metal structure of the comb-shaped insulating medium, 42 is the bottom metal structure of the comb-shaped insulating medium, and 45 is the dielectric structure between the two metal layers.

[0030] Figure 5 The transmittance spectrum of the metal polarization beam splitter of this invention when the incident light polarization is perpendicular to the comb structure.

[0031] Figure 6 The reflectance spectrum of the metal polarization beam splitter of this invention when the incident light polarization is parallel to the comb structure. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, those skilled in the art can implement all the contents of the claims of the present invention through the following embodiments.

[0033] Example 1.

[0034] A metal polarization beam splitter is implemented as follows.

[0035] As attached Figure 1 The insulating medium shown is distributed in a comb shape. A three-layer structure consisting of a metal-dielectric-metal combination is placed on top of the comb-shaped insulating medium, and a three-layer structure consisting of a metal-dielectric-metal combination is placed at the bottom of the comb-shaped insulating medium.

[0036] The lateral distribution of the comb-shaped insulating medium is periodically arranged with a period of 60 nm.

[0037] The width of the comb-shaped insulating dielectric lines is 30 nm, and the spacing between the lines is 30 nm, which is much smaller than the wavelength of the incident light.

[0038] The height of the comb-shaped insulating dielectric is 100 nm, and the thickness of each of the top and bottom metal-dielectric-metal layers is 30 nm.

[0039] The cross-section of the comb-shaped insulating medium is rectangular.

[0040] The entire structural layer is supported by a transparent silicon dioxide substrate.

[0041] The comb-shaped insulating medium always extends in one direction.

[0042] In the metal-dielectric-metal series, the metallic material is aluminum, which has high electrical conductivity.

[0043] The dielectric material in the metal-dielectric-metal configuration is the same as that in the comb-shaped insulating dielectric; both are silica glass materials with low absorption.

[0044] The comb-shaped insulating dielectric structure is prepared by photolithography and etching processes.

[0045] Metal-dielectric-metal structures are fabricated using an electron beam deposition process.

[0046] The substrate supporting the entire structural layer is planar.

[0047] After the incident visible light wave passes through this device, the transmittance and reflectance of the two orthogonally polarized states are as follows: Figure 5 and Figure 6 As shown, where Figure 5 This indicates the transmittance of light waves with a polarization direction perpendicular to the direction in which the comb structure extends. This result shows that the transmittance is high under this polarization state. Figure 6 This indicates the reflectivity of light waves whose polarization direction is parallel to the extension direction of the comb-like structure. The result shows high reflectivity under this polarization state. Combined with... Figure 5 and Figure 6 The results show that two orthogonally polarized light waves achieve polarization separation on the surface of this device through transmission and reflection.

[0048] Example 2.

[0049] A metal polarization beam splitter is implemented as follows.

[0050] As attached Figure 3 The insulating medium shown is distributed in a comb shape. A five-layer structure composed of metal-dielectric-metal combination is placed on top of the comb-shaped insulating medium, and a five-layer structure composed of metal-dielectric-metal combination is placed at the bottom of the comb-shaped insulating medium.

[0051] The lateral distribution of the comb-shaped insulating medium is randomly arranged.

[0052] The average width of the comb-shaped insulating dielectric lines is 40 nm, and the average spacing between the lines is 40 nm, which is much smaller than the wavelength of the incident light.

[0053] The height of the comb-shaped insulating dielectric is 120 nm, and the thickness of each of the top and bottom metal-dielectric-metal layers is 20 nm.

[0054] The cross-section of the comb-shaped insulating medium is rectangular.

[0055] The entire structural layer is supported by a light-transmitting optical plastic substrate.

[0056] The comb-shaped insulating medium always extends in one direction.

[0057] In the metal-dielectric-metal composition, the metallic material is silver, which has high electrical conductivity.

[0058] The dielectric material in the metal-dielectric-metal configuration is the same as that in the comb-shaped insulating dielectric; both are silica glass materials with low absorption.

[0059] The comb-shaped insulating dielectric structure is prepared by an imprinting process.

[0060] Metal-dielectric-metal structures are fabricated using an electron beam deposition process.

[0061] The substrate supporting the entire structural layer is a curved optical surface.

[0062] When incident visible light waves pass through this device, the light waves with polarization directions perpendicular to the extension direction of the comb structure have high transmittance, while the light waves with polarization directions parallel to the extension direction of the comb structure have high reflectance. This indicates that the two orthogonally polarized light waves achieve polarization separation on the surface of this device through transmission and reflection.

[0063] Example 3.

[0064] A metal polarization beam splitter is implemented as follows.

[0065] As attached Figure 4 The insulating medium shown is distributed in a comb shape. A three-layer structure consisting of a metal-dielectric-metal combination is placed on top of the comb-shaped insulating medium, and a three-layer structure consisting of a metal-dielectric-metal combination is placed at the bottom of the comb-shaped insulating medium.

[0066] The lateral distribution of the comb-shaped insulating medium is periodically arranged with a period of 100 nm.

[0067] The width of the comb-shaped insulating dielectric lines is 50 nm, and the spacing between the lines is 50 nm, which is much smaller than the wavelength of the incident light.

[0068] The height of the comb-shaped insulating dielectric is 130 nm, and the thicknesses of the top and bottom metal-dielectric-metal layers are 40 nm, 20 nm, and 40 nm, respectively.

[0069] The cross-section of the comb-shaped insulating medium is an inverted trapezoid.

[0070] The entire structural layer is supported by a light-transmitting optical plastic substrate.

[0071] The comb-shaped insulating medium always extends in one direction.

[0072] In the metal-dielectric-metal category, the metallic material is gold, which has high electrical conductivity.

[0073] The dielectric material in the metal-dielectric-metal configuration is the same as that in the comb-shaped insulating dielectric; both are silicon dioxide materials with low absorption.

[0074] The comb-shaped insulating dielectric structure was fabricated using photolithography.

[0075] Metal-dielectric-metal structures are fabricated using an electron beam deposition process.

[0076] When incident visible light waves pass through this device, the light waves with polarization directions perpendicular to the extension direction of the comb structure have high transmittance, while the light waves with polarization directions parallel to the extension direction of the comb structure have high reflectance. This indicates that the two orthogonally polarized light waves achieve polarization separation on the surface of this device through transmission and reflection.

[0077] The parts of this invention not described in detail are well-known in the field.

Claims

1. A metal polarizing beam splitter, characterized in that: the insulating medium is distributed in a comb shape, a multi-layer structure composed of metal-dielectric-metal combination is placed on the top of the comb-shaped insulating medium, and a multi-layer structure composed of metal-dielectric-metal combination is placed at the bottom of the comb-shaped insulating medium; the lateral distribution of the comb-shaped insulating medium is periodic or random; the metal-dielectric-metal structure at the top and bottom of the comb-shaped insulating medium can be repeated once or multiple times in the longitudinal direction; the width and spacing of the lines of the comb-shaped insulating medium are much smaller than the wavelength of the incident light; the height of the comb-shaped insulating medium is greater than the total thickness of the metal-dielectric-metal structure; the cross-section of the comb-shaped insulating medium is rectangular or inverted trapezoidal.

2. The metal polarization beam splitter according to claim 1, wherein the entire structural layer is supported by a light-transmitting dielectric substrate.

3. The metal polarization beam splitter according to claim 1, wherein the comb-shaped insulating medium is a supporting structure of a top metal-dielectric-metal structure.

4. In a metal polarizing beam splitter according to claim 1, the extension direction of the comb-shaped insulating medium always faces one direction.

5. The metal polarization beam splitter according to claim 1, wherein the metal material in the metal-dielectric-metal configuration is a high-conductivity metal.

6. In the metal polarization beam splitter according to claim 1, the dielectric material in the metal-dielectric-metal configuration and the comb-shaped insulating dielectric can be the same or different dielectric materials.

7. The metal polarizing beam splitter according to claim 1, wherein the comb-shaped insulating dielectric material is an optical material with low absorption rate or no absorption of incident light.

8. The metal polarization beam splitter according to claim 1, wherein the comb-shaped insulating dielectric structure is prepared by photolithography, etching or imprinting processes.

9. A metal polarization beam splitter according to claim 1, wherein the metal-dielectric-metal structure is prepared by a film deposition process.

10. A metal polarizing beam splitter according to claim 1 or 2, wherein the substrate supporting the entire structural layer is a plane or a curved surface of other optical devices.

11. A metal polarizing beam splitter according to claim 1, wherein when incident light is incident perpendicularly or obliquely onto the surface of the metal polarizing beam splitter, light with a polarization direction perpendicular to the extension direction of the comb-shaped insulating medium will be transmitted, and light waves with a polarization direction parallel to the extension direction of the comb-shaped insulating medium will be reflected, thereby producing a polarizing beam splitting effect.

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