Grating sheet and manufacturing method thereof, manufacturing method of visible light narrowband filter

Abstract

The application discloses a grating sheet, and belongs to an optical element. The grating sheet comprises a substrate, a film system formed by alternately stacking a plurality of high-refractive-film layers and low-refractive-film layers on the substrate to form a Fabry-Perot cavity structure, and the film system structure is (HL)^n(LH)^n-1L0.66H 0.66L, wherein H is a high-refractive-film layer, L is a low-refractive-film layer, the thickness of H and L is 1 / 4 wavelength optical thickness, and 7<=n<=10. The application further relates to a preparation method of the grating sheet and a manufacturing method of a visible light narrow-band filter using the grating sheet for light control.

Description

Technical Field

[0001] This invention relates to the field of optical elements, and in particular to grating sheets and their manufacturing methods, and methods for manufacturing visible light narrowband filters using grating sheets. Background Technology

[0002] Narrowband filters are a subcategory of bandpass filters. Their definition is the same as that of bandpass filters, which allow light signals to pass through in a specific wavelength band while blocking light signals on both sides outside this band. The difference is that the passband of a narrowband filter is narrower. Generally, filters with a passband width (FWHM) of less than 4nm are called narrowband filters.

[0003] Filters are commonly designed using Fabry-Perot cavity stacking. The fabrication of the filter is achieved by monitoring the optical control curve using the corresponding center wavelength. Based on the optical control method, there are two types: white light control and laser control. White light control uses a halogen lamp as the white light source to illuminate the monitoring filter, and then the light signal is fed into a spectrophotometer to obtain the corresponding transmittance signal. Laser control uses a laser as the light source to illuminate the monitoring filter, and then the light signal is fed into a detector to obtain the corresponding head power signal. For visible light wavelength filters, white light control is usually used as the monitoring method. However, white light control has relatively poor monochromaticity, resulting in low transmittance of the fabricated narrowband filter, which fails to meet requirements. Therefore, laser control is used as the monitoring method. Lasers in the visible light band are divided into single-wavelength lasers and tunable lasers. Single-wavelength lasers can only produce filters of a single wavelength, while the wavelength range of tunable lasers is often less than 100nm. If multiple wavelength filters need to be produced, multiple lasers need to be purchased, which makes the production cost extremely expensive and may even require the special customization of lasers with specific wavelengths. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one of the objectives of the present invention is to provide a grating sheet, on the basis of a traditional white light control, thereby improving the monochromaticity of the white light control and thus realizing the fabrication of a narrowband filter with multiple wavelengths of visible light.

[0005] In order to overcome the shortcomings of the prior art, the second objective of this invention is to provide a method for manufacturing a grating sheet, which can improve the monochromaticity of white light control, thereby realizing the manufacturing of a narrowband filter with multiple wavelengths of visible light.

[0006] To overcome the shortcomings of the prior art, a third objective of this invention is to provide a method for manufacturing a visible light narrowband filter, enabling the production of multi-wavelength filters using traditional white light control technology.

[0007] One of the objectives of this invention is achieved through the following technical solution:

[0008] A grating sheet includes a substrate on which a Fabry-Perot cavity structure is formed by alternating stacks of multiple high-refractive-index and low-refractive-index films. The film structure is (HL)^n(LH)^n-1L0.66H 0.66L, where H is a high-refractive-index film and L is a low-refractive-index film. The thicknesses of H and L are 1 / 4 wavelength optical thicknesses, and 7≤n≤10.

[0009] Furthermore, the resolution of the grating sheet is less than or equal to 0.5 nm.

[0010] Furthermore, the Fabry-Paro cavity structure is (HL)^7(LH)^6L 0.66H0.66L.

[0011] Furthermore, the Fabry-Paro cavity structure is (HL)^10(LH)^9L 0.66H0.66L.

[0012] Furthermore, the material of the high refractive index film is one or a mixture of at least two of the following: Ta2O5, Nb2O5, and TiO2.

[0013] Furthermore, the material of the low refractive index film is one or a mixture of at least two of SiO2, Al2O3, and MgF2.

[0014] Furthermore, the substrate is made of silicon dioxide or silicon.

[0015] The second objective of this invention is achieved by the following technical solution:

[0016] A method for manufacturing a grating sheet, used to manufacture any of the above-mentioned grating sheets, includes the following steps:

[0017] Creating the substrate;

[0018] The first monitoring chip is used for optical control, and a film is deposited on the substrate to form a front reflector.

[0019] The monitoring chip is replaced with a second monitoring chip for optical control. A coating is deposited on the front reflector to form a rear reflector. The front reflector and the rear reflector together form a Fabry-Perot cavity structure.

[0020] Furthermore, the first surveillance video and the second surveillance video are the same type of surveillance video.

[0021] The third objective of this invention is achieved by the following technical solution:

[0022] A method for manufacturing a visible light narrowband filter includes the following steps:

[0023] Place any of the above-mentioned grating sheets in front of a white light-controlled spectrophotometer;

[0024] Halogen lamps are used as white light sources to emit light and illuminate the monitoring screen. The corresponding light intensity signal is received through a lens and then guided into a spectrophotometer through an optical fiber to obtain the corresponding light intensity signal.

[0025] A visible light narrowband filter is formed by performing light-controlled coating on the filter substrate.

[0026] Compared to existing technologies, the grating sheet of this invention is prepared using a secondary coating method, resulting in high center wavelength accuracy and achieving high transmittance within a specific wavelength range, while maintaining high cutoff in other wavelength cutoff bands. By placing the grating sheet in front of a white light-controlled spectrophotometer, no additional laser is required for white light control; the grating sheet can be prepared on traditional white light-controlled equipment to achieve a visible light narrowband filter with an FWHM < 4nm. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the grating sheet of the present invention;

[0028] Figure 2 for Figure 1 A schematic diagram illustrating the fabrication of a grating sheet;

[0029] Figure 3 To monitor the optical control value of the first coating of the grating sheet using a wavelength of 550nm;

[0030] Figure 4 To monitor the optical control value of the second coating of the grating sheet using a wavelength of 550nm;

[0031] Figure 5 The spectral characteristic curves of the grating sheet fabricated using 550nm wavelength monitoring are shown.

[0032] Figure 6 To monitor the optical control value of the first coating of the grating sheet using an 808nm wavelength;

[0033] Figure 7 To monitor the optical control value of the second coating of the grating sheet using an 808nm wavelength;

[0034] Figure 8 The spectral characteristic curves of the grating sheet fabricated using 808nm wavelength monitoring are shown.

[0035] In the diagram: 10, substrate; 20, Fabry-Perot cavity; 30, spectrophotometer; 40, grating; 50, lens; 60, halogen lamp. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that when a structure is said to be "fixed to" another structure, it can be directly on the other structure or it can be fixed through another intermediate structure. When a structure is said to be "connected to" another structure, it can be directly connected to the other structure or it may be fixed through another intermediate structure. When a structure is said to be "set on" another structure, it can be set directly on the other structure or it may be set through another intermediate structure. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this article are for illustrative purposes only.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] like Figure 1 As shown, the grating sheet 40 of the present invention includes a substrate 10. The substrate 10 has a film system formed by alternating stacks of multiple high-refractive-index and low-refractive-index films, creating a Fabry-Perot cavity structure 20. The film system structure is (HL)^n(LH)^n-1L0.66H0.66L, where H is a high-refractive-index film and L is a low-refractive-index film. The thickness of H and L is 1 / 4 wavelength optical thickness, and 7≤n≤10. The resolution of the grating sheet 40 is less than or equal to 0.5 nm. The high-refractive-index film is made of one or a mixture of at least two of Ta2O5, Nb2O5, and TiO2. The low-refractive-index film is made of one or a mixture of at least two of SiO2, Al2O3, and MgF2. The substrate 10 is made of silicon dioxide or silicon.

[0040] This invention also relates to a method for manufacturing the above-mentioned grating sheet, comprising the following steps:

[0041] Create substrate 10;

[0042] The first monitoring chip is used for optical control, and a film is deposited on the substrate 10 to form a front reflector.

[0043] The monitoring chip was replaced with a second monitoring chip for optical control. A coating was applied to the front reflector to form the rear reflector. The front reflector and the rear reflector together formed the Fabry-Perot cavity 20 structure.

[0044] For the specific structure and fabrication method of the grating sheet 40, please refer to Examples 1 and 2.

[0045] Example 1

[0046] In Example 1, the structure of the grating sheet 40 is (HL)^7(LH)^6L0.66H0.66L, where H is a high-refractive-index film layer and L is a low-refractive-index film layer. Both the high-refractive-index and low-refractive-index film layers have a thickness of 1 / 4 wavelength optical thickness. The grating sheet 40 is fabricated using 550nm wavelength optical monitoring. Details are shown in Table 1, which details the film layer structure and control method of the grating sheet 40.

[0047]

[0048]

[0049] Table 1

[0050] Ta₂O₅ and SiO₂ were used as the materials for processing the high and low refractive index films. Ta₂O₅ has a refractive index of 2.22861 near 550 nm, while SiO₂ has a refractive index of 1.47464 near 550 nm. The grating sheet 40 has a structure of (HL)₇(LH)₆L₀.₆₆H₀.₆L, consisting of 29 layers. Since two adjacent layers are low refractive index films L, they can be deposited in a single pass; in practice, 28 deposits were performed. The thickness of the film in the 14th deposit was twice that of the others.

[0051] Specifically, in the fabrication of the grating sheet 40, the first monitoring sheet (monitoring sheet 1) is used to first fabricate the first 8 layers of film to form the front reflector. At this time, the light control value is as follows: Figure 3 As shown, the horizontal axis represents the physical thickness of the film, and the vertical axis represents the transmittance of the film. Then, the first monitoring sheet (monitoring sheet 1) is replaced with the second monitoring sheet (monitoring sheet 2) to prepare the subsequent 20 layers. At this point, the light control values ​​are as follows: Figure 4 As shown, the horizontal axis represents the physical thickness of the membrane layer, and the vertical axis represents the transmittance of the membrane layer. The first and second monitoring sheets are the same type of monitoring sheet. Because the transmittance of the first monitoring sheet will decrease during use, it needs to be replaced with a new monitoring sheet. The specific control method is shown in Table 1.

[0052] The spectral characteristic curve of the grating sheet 40 fabricated using optical monitoring with a wavelength of 550 nm is shown in the figure. Figure 5 As shown, the resolution (FWHM) is 0.285nm.

[0053] Example 2

[0054] In Example 2, the structure of the grating sheet 40 is (HL)^10(LH)^9L0.66H0.66L, where H is a high-refractive-index film layer and L is a low-refractive-index film layer. Both the high-refractive-index and low-refractive-index film layers have a thickness of 1 / 4 wavelength optical thickness. The grating sheet 40 is fabricated using 808nm wavelength optical monitoring. Details are shown in Table 2, which presents the film layer structure and control method of the grating sheet 40.

[0055] Floor number Material QW thickness Thickness (nm) surveillance video Control method 1 <![CDATA[Ta2O5]]> 1.000 93.06 1 Direct light control 2 <![CDATA[SiO2]]> 1.000 138.19 1 Direct light control 3 <![CDATA[Ta2O5]]> 1.000 93.06 1 Direct light control 4 <![CDATA[SiO2]]> 1.000 138.19 1 Direct light control 5 <![CDATA[Ta2O5]]> 1.000 93.06 1 Direct light control 6 <![CDATA[SiO2]]> 1.000 138.19 1 Direct light control 7 <![CDATA[Ta2O5]]> 1.000 93.06 1 Direct light control 8 <![CDATA[SiO2]]> 1.000 138.19 1 Direct light control 9 <![CDATA[Ta2O5]]> 1.000 93.06 1 Direct light control 10 <![CDATA[SiO2]]> 1.000 138.19 1 Direct light control 11 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 12 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 13 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 14 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 15 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 16 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 17 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 18 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 19 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 20 <![CDATA[SiO2]]> 1.000 276.37 2 Direct light control 21 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 22 <![CDATA[SiO2]]> 2.000 138.19 2 Direct light control 23 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 24 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 25 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 26 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 27 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 28 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 29 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 30 <![CDATA[SiO2]]> 1.000 138.19 2 Time / Crystal Control 31 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 32 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 33 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 34 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 35 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 36 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 37 <![CDATA[Ta2O5]]> 1.000 93.06 2 Direct light control 38 <![CDATA[SiO2]]> 1.000 138.19 2 Direct light control 39 <![CDATA[Ta2O5]]> 0.660 61.42 2 Time / Crystal Control 40 <![CDATA[SiO2]]> 0.660 91.2 2 Time / Crystal Control

[0056] Ta₂O₅ and SiO₂ were used as the materials for processing the high and low refractive index films. Ta₂O₅ has a refractive index of 2.17065 near 808 nm, while SiO₂ has a refractive index of 1.4618 near 808 nm. The grating sheet 40 has a structure of (HL)⁻¹⁰(LH)⁻⁹L⁰.⁶⁶H⁰.⁶⁶L, consisting of 41 layers. Since two adjacent layers are low refractive index films (L), they can be deposited in a single pass; in practice, 40 deposits were performed. The thickness of the film in the 22nd deposit was twice that of the others.

[0057] Specifically, in the fabrication of the grating sheet 40, the first 10 layers of film are fabricated using the first monitoring sheet (monitoring sheet 1) to form the front reflector. At this time, the light control value is as follows: Figure 6 As shown, the horizontal axis represents the physical thickness of the film, and the vertical axis represents the transmittance of the film. Then, the first monitoring sheet (monitoring sheet 1) is replaced with the second monitoring sheet (monitoring sheet 2) to prepare the subsequent 30 layers. At this point, the light control values ​​are as follows: Figure 7 As shown in Table 2, the horizontal axis represents the physical thickness of the membrane layer, and the vertical axis represents the transmittance of the membrane layer. The first and second monitoring sheets are the same type of monitoring sheet. Because the transmittance of the first monitoring sheet will decrease during use, it needs to be replaced with a new monitoring sheet. The specific control method is shown in Table 2.

[0058] The spectral characteristic curve of the grating sheet 40 fabricated using optical monitoring with a wavelength of 808 nm is shown in the figure. Figure 8 As shown, the resolution (FWHM) is 0.125nm.

[0059] Please continue reading. Figure 2 The present invention also relates to a method for manufacturing a visible light narrowband filter, comprising the following steps:

[0060] Place any of the above-mentioned gratings 40 in front of the white light-controlled spectrophotometer 30;

[0061] A halogen lamp 60 is used as a white light source to emit light and illuminate the monitoring screen. The corresponding light intensity signal is received through the lens 50 and then introduced into the spectrophotometer 30 through the fiber optic cable to obtain the corresponding light intensity signal.

[0062] A visible light narrowband filter is formed by performing light-controlled coating on the filter substrate.

[0063] Compared to existing technologies, the grating sheet of this invention is prepared using a secondary coating method, resulting in high center wavelength accuracy for the grating sheet 40. This achieves high transmittance within a specific wavelength range and high cutoff in other wavelength cutoff bands. When the grating sheet 40 is placed in front of a white light-controlled spectrophotometer 30, no additional laser is required for white light control; the preparation of a visible light narrowband filter with an FWHM < 4nm can be performed on traditional white light control equipment.

[0064] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A grating sheet, comprising a substrate, characterized in that: The substrate has a film system formed by alternating stacks of multiple high-refractive-index and low-refractive-index films, forming a Fabry-Perot cavity structure. The film system structure is (HL)^n (LH)^n-1 L0.66H0.66L, where H is a high-refractive-index film and L is a low-refractive-index film. The thickness of H and L is 1 / 4 wavelength optical thickness, and 7≤n≤10. The Fabry-Paro cavity structure is (HL)^7 (LH)^6 L 0.66H0.66L or (HL)^10 (LH)^9 L0.66H0.66L.

2. The grating sheet according to claim 1, characterized in that: The resolution of the grating sheet is less than or equal to 0.5 nm.

3. The grating sheet according to claim 1, characterized in that: The high refractive index film is made of one or a mixture of at least two of the following materials: Ta2O5, Nb2O5, and TiO2.

4. The grating sheet according to claim 1, characterized in that: The material of the low refractive index film is one or a mixture of at least two of the following: SiO2, Al2O3, and MgF2.

5. The grating sheet according to claim 1, characterized in that: The substrate is made of silicon dioxide or silicon.

6. A method for manufacturing a grating sheet, used to manufacture a grating sheet as described in any one of claims 1-5, characterized in that, Includes the following steps: Creating the substrate; The first monitoring chip is used for optical control, and a film is deposited on the substrate to form a front reflector. The monitoring chip is replaced with a second monitoring chip for optical control. A coating is deposited on the front reflector to form a rear reflector. The front reflector and the rear reflector together form a Fabry-Perot cavity structure.

7. The method for fabricating a grating sheet according to claim 6, characterized in that: The first surveillance video and the second surveillance video are the same type of surveillance video.

8. A method for manufacturing a visible light narrowband filter, characterized in that, Includes the following steps: Place the grating sheet as described in any one of claims 1-5 in front of a white light-controlled spectrophotometer; Halogen lamps are used as white light sources to emit light and illuminate the monitoring screen. The corresponding light intensity signal is received through a lens and then guided into a spectrophotometer through an optical fiber to obtain the corresponding light intensity signal. A visible light narrowband filter is formed by performing light-controlled coating on the filter substrate.

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