Novel light splitting film of light splitting prism and manufacturing method of novel light splitting film

Abstract

The invention discloses a novel beam splitting film of a beam splitting prism and a manufacturing method of the novel beam splitting film. A novel beam splitting film of a beam splitting prism comprises an outer layer film and a middle layer film which are arranged up and down. The middle-layer film comprises metal films and high-refractive-index dielectric film layers which are alternately arranged; the middle layer film is used for being arranged between a substrate and the outer layer film; the film layer, in contact with the substrate, of the middle-layer film is the high-refractive-index dielectric film layer; and the outer layer film is a single-layer low-refractive-index medium antireflection film. The transmittance of the novel beam splitting film to visible light with the wavelength ranging from 415 nm to 615 nm is 80% or above, and the transmittance of the novel beam splitting film to near-infrared light with the wavelength ranging from 940 nm to 1500 nm is smaller than 20%.

Description

Technical Field

[0001] The invention relates to the technical field of optical films, and in particular to a novel prism light-splitting film design and a manufacturing method thereof. Background Art

[0002] With the development of the optical industry, the use of beam splitters is increasing. They can split a beam of light into two beams according to a certain reflection and transmission ratio. They are mostly used in laser optical systems, lighting optical systems, and spectrometer systems. Beam splitters are made of optical glass coatings, with a beam splitter film on the beam splitting surface. They can split the light beam into reflected light and transmitted light according to certain requirements and methods.

[0003] There are currently two technical approaches to achieve spectroscopic films. The first is dielectric films. In order to achieve the purpose of spectroscopic film, the film design and preparation of dielectric films are relatively thick, resulting in large changes in surface shape, complex preparation and difficult to control. However, for high-precision optical systems, the surface shape requirements are extremely high, so the preparation of dielectric spectroscopic films needs to overcome the problem of surface shape changes. The second is metal spectroscopic films. Metal spectroscopic films have good neutrality, simple preparation process, and good chemical stability, but they have large absorption losses and low spectroscopic efficiency.

[0004] At present, a kind of spectral film which can overcome the shortcomings of dielectric film and metal spectral film can be realized, which has simple preparation and excellent spectral effect. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a new type of light-splitting film for a light-splitting prism and a manufacturing method thereof, which has solved at least one of the above-mentioned technical problems.

[0006] The technical solution of the present invention is: a novel light splitting film of a light splitting prism, characterized in that it comprises an outer film and a middle film arranged up and down;

[0007] The middle layer film includes metal films and high refractive index medium film layers arranged alternately;

[0008] The middle layer film is used to be arranged between the substrate and the outer layer film; the film layer in contact with the substrate is the high refractive index medium film layer;

[0009] The outer film is a single-layer low-refractive-index medium anti-reflection film.

[0010] Furthermore, the substrate is fused quartz.

[0011] Furthermore, the substrate is glass or a lens.

[0012] Furthermore, the period number of the high refractive index medium film layer is not less than 3.

[0013] Furthermore, the single-layer low-refractive-index medium anti-reflection film is TiO2.

[0014] Furthermore, the method for selecting the film thickness of the high refractive index dielectric film layer is as follows: the dielectric thickness at which the spectral intensity of the new spectroscopic film reaches a specific intensity at the wavelength of the incident light is obtained by using the transmission matrix method and the pin-type optimization algorithm as the film thickness.

[0015] Furthermore, in the middle layer film, the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer and the outer film are arranged in order from the side adjacent to the substrate to the side away from the substrate; the thickness of the first dielectric film layer is 33.27nm; the thickness of the first metal layer is 11.69nm; the thickness of the second dielectric film layer is 69.94nm; the thickness of the second metal layer is 12.16nm; the thickness of the third dielectric film layer is 69.76nm; the thickness of the third metal layer is 11.64nm; the thickness of the outer film is 33.08nm;

[0016] The first dielectric film layer, the second dielectric film layer and the third dielectric film layer are made of TiO2, the first metal film, the second metal film and the third metal film are made of metal material Ag, and the outer film is made of Ti3O5.

[0017] Alternatively, the middle layer film comprises, from the side adjacent to the substrate to the side away from the substrate, the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer, the fourth dielectric layer, the fourth metal layer and the outer film in order; the thickness of the first dielectric film layer is 37.71nm; the thickness of the first metal layer is 10.08nm; the thickness of the second dielectric film layer is 81.34nm; the thickness of the second metal layer is 11.15nm; the thickness of the third dielectric film layer is 64.64nm; the thickness of the third metal layer is 2.38nm; the thickness of the fourth dielectric film layer is 25.58nm; the thickness of the fourth metal layer is 8nm; the thickness of the outer film is 35.49nm;

[0018] The first dielectric film layer, the second dielectric film layer, the third dielectric film layer and the fourth dielectric film layer are made of Ta2O5, the first metal film, the second metal film, the third metal film and the fourth metal film are made of metal material Ag, and the outer film is made of Ta2O5.

[0019] Furthermore, the high refractive index dielectric film layer is made of a mixture of one or more materials selected from TiO2, Ta2O5 and NB2O5.

[0020] Furthermore, the metal film is Ag.

[0021] Furthermore, the outer layer film is TiO2, Ti3O5 or Ta2O5.

[0022] Furthermore, the transmittance of the novel beam splitting film to visible light within the wavelength range of 415-615 nm is above 80%, and the transmittance to near-infrared light within the wavelength range of 940-1500 nm is less than 20%.

[0023] The manufacturing method of the novel light splitting film of the light splitting prism is characterized by comprising the following manufacturing steps:

[0024] S1: The substrate is cleaned by multi-slot ultrasonic cleaning, and after heat drying, is placed in a dedicated umbrella stand of a coating machine, and is placed in an umbrella stand of the coating machine;

[0025] S2: Use a mechanical pump and a diffusion pump to quickly evacuate the vacuum chamber of the coating machine so that the vacuum degree of the vacuum chamber in the coating machine reaches 10-4Pa;

[0026] S3: Use APC to control the auxiliary gas flow;

[0027] S4: Using a high-voltage electron gun and a Hall ion source-assisted method, the evaporation rate of the raw materials of the high-refractive-index dielectric film layer is controlled at 0.25nm / s-0.35nm / s, so that a more stable refractive index and a uniform refractive index on the surface can be obtained.

[0028] S5: Control the current of the electron gun to control the evaporation rate of the metal film to 0.05nm / s-0.15nm / s, so that the metal film has good stability and density;

[0029] S6: Control the current of the electron gun so that the evaporation rate of the single-layer high-refractive-index dielectric anti-reflection film of the outer film is controlled at 0.25nm / s-0.35nm / s to ensure the firmness and film quality of the anti-reflection film;

[0030] S7: controlling the substrate temperature below 60° C. to prevent oxidation of the metal layer at high temperature;

[0031] S8: using an ion source to ionize Ar gas, under the action of a large electric field, bombarding the substrate, so that the coating material quickly reaches the substrate for coating, thereby improving the density of the film layer;

[0032] S9: Control the coating umbrella stand for the coating machine on which the substrate is placed to rotate at a constant speed during coating, so that the coating material of the substrate is evenly distributed;

[0033] S10: After the coating is completed, the substrate must remain still in the coating chamber for 1 hour to allow the substrate to cool down to room temperature and release stress.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. Reduced preparation complexity: Compared with conventional dielectric beam splitters, in order to achieve the beam splitting effect, the overall film structure is thicker, resulting in complex preparation. This film adopts a metal-dielectric structure, which makes the film structure simple and easy to prepare.

[0036] 2. Improve the feasibility of preparation: The metal-medium structure is used during coating to make the film thickness smaller, which has little effect on the surface shape after preparation, effectively improving the feasibility of preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a film layer layout of a novel light-splitting film according to a specific embodiment 1 of the present invention;

[0038] Figure 2 Design a spectrogram for specific embodiment 1 of the present invention;

[0039] Figure 3 A schematic diagram of a film layer layout of a novel light-splitting film according to a specific embodiment 2 of the present invention;

[0040] Figure 4 Design a spectrogram for specific embodiment 2 of the present invention; DETAILED DESCRIPTION

[0041] A new type of spectroscopic film for a spectroscopic prism, comprising an outer film and a middle film arranged up and down; the middle film comprises a metal film M and a high refractive index medium film layer H arranged alternately; the middle film is used to be arranged between a substrate and the outer film; the film layer in contact between the middle film and the substrate is the high refractive index medium film layer; the outer film is a single-layer low refractive index medium anti-reflection film.

[0042] The substrate is fused quartz.

[0043] The substrate is glass or a lens.

[0044] The period number of the high refractive index medium film layer H is not less than 3.

[0045] The single-layer low-refractive-index medium anti-reflection film AR is TiO2.

[0046] The high refractive index dielectric film layer H is made of a mixture of one or more materials selected from TiO2, Ta2O5 and NB2O5.

[0047] The metal film M is Ag. The outer film is TiO2, Ti3O5 or Ta2O5.

[0048] The method for selecting the film thickness of the high refractive index medium film layer H is as follows: the medium thickness at which the spectral intensity of the new spectroscopic film reaches a specific intensity at the wavelength of the incident light is obtained by using the transmission matrix method and the pin-type optimization algorithm as the film thickness. Specific embodiment 1:

[0050] like Figure 1 It can be seen that the first to sixth layers of the light splitting film are formed by alternately stacking high refractive index dielectric film layers H and metal films M. The high refractive index dielectric film layer H can be made of TiO2, the metal film M can be made of metal material Ag, and the outermost layer can be made of Ti3O5. As an oxide, it is relatively strong and protects the material.

[0051] Specifically, in the middle layer film, from the side adjacent to the substrate to the side farthest from the substrate, there are the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer and the outer film; the thickness of the first dielectric film layer is 33.27nm; the thickness of the first metal layer is 11.69nm; the thickness of the second dielectric film layer is 69.94nm; the thickness of the second metal layer is 12.16nm; the thickness of the third dielectric film layer is 69.76nm; the thickness of the third metal layer is 11.64nm; the thickness of the outer film is 33.08nm. Figure 1 The vertical axis is the film thickness in nm. The horizontal axis is the film distribution. The leftmost side of the horizontal axis is the side in contact with the substrate. The horizontal axis is set from the adjacent substrate side to the outside from left to right.

[0052] Design spectrum as Figure 2 As shown, the horizontal axis is wavelength in nm, and the vertical axis is the percentage of transmittance. For visible light in the wavelength range of 415-615nm, the transmittance of the present invention is above 80%, and for near-infrared light in the wavelength range of 940-1500nm, its transmittance is less than 20%.

[0053] Specific embodiment 2, as Figure 3 The first to eighth layers of the spectroscopic film are formed by alternating high-refractive-index dielectric film layers H and metal films M. The high-refractive-index dielectric film layer H can be made of Ta2O5, and the metal film M can be made of metal material Ag. The outermost layer (single-layer low-refractive-index dielectric anti-reflection film AR) is made of Ta2O5, which, as an oxide, is relatively strong and can protect the material.

[0054] Specifically, in the middle layer film, from the side adjacent to the substrate to the side away from the substrate, there are the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer, the fourth dielectric layer, the fourth metal layer and the outer film in order; the thickness of the first dielectric film layer is 37.71nm; the thickness of the first metal layer is 10.08nm; the thickness of the second dielectric film layer is 81.34nm; the thickness of the second metal layer is 11.15nm; the thickness of the third dielectric film layer is 64.64nm; the thickness of the third metal layer is 2.38nm; the thickness of the fourth dielectric film layer is 25.58nm; the thickness of the fourth metal layer is 8nm; the thickness of the outer film is 35.49nm. Figure 3 The vertical axis is the film thickness in nm. The horizontal axis is the film distribution. The leftmost side of the horizontal axis is the side in contact with the substrate. The horizontal axis is set from the side adjacent to the substrate outward from left to right.

[0055] Design spectrum as Figure 4 As shown, the horizontal axis is wavelength in nm, and the vertical axis is the percentage of transmittance. For visible light in the wavelength range of 415-615nm, the transmittance of the present invention is above 80%, and for near-infrared light in the wavelength range of 940-1500nm, its transmittance is less than 20%.

[0056] The manufacturing method of the novel light splitting film of the light splitting prism is characterized by comprising the following manufacturing steps:

[0057] S1: The substrate is cleaned by multi-slot ultrasonic cleaning, and after heat drying, is placed in a dedicated umbrella stand of a coating machine, and is placed in an umbrella stand of the coating machine;

[0058] S2: Use a mechanical pump and a diffusion pump to quickly evacuate the vacuum chamber of the coating machine so that the vacuum degree of the vacuum chamber in the coating machine reaches 10-4Pa;

[0059] S3: Use APC to control the auxiliary gas flow rate;

[0060] S4: Using a high-voltage electron gun and a Hall ion source-assisted method, the evaporation rate of the raw materials of the high-refractive-index dielectric film layer is controlled at 0.25nm / s-0.35nm / s, so that a more stable refractive index and a uniform refractive index on the surface can be obtained.

[0061] S5: Control the current of the electron gun to control the evaporation rate of the metal film to 0.05nm / s-0.15nm / s, so that the metal film has good stability and density;

[0062] S6: Control the current of the electron gun so that the evaporation rate of the single-layer high-refractive-index dielectric anti-reflection film of the outer film is controlled at 0.25nm / s-0.35nm / s to ensure the firmness and film quality of the anti-reflection film;

[0063] S7: controlling the substrate temperature below 60° C. to prevent oxidation of the metal layer at high temperature;

[0064] S8: using an ion source to ionize Ar gas, under the action of a large electric field, bombarding the substrate, so that the coating material quickly reaches the substrate for coating, so as to improve the density of the film layer;

[0065] S9: Control the coating umbrella stand for the coating machine on which the substrate is placed to rotate at a constant speed during coating, so that the coating material of the substrate is evenly distributed;

[0066] S10: After the coating is completed, the substrate must remain still in the coating chamber for 1 hour to allow the substrate to cool down to room temperature and release stress.

[0067] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A novel light splitting film for a light splitting prism, characterized in that: It includes an outer membrane and a middle membrane arranged above and below; The middle layer film includes metal films and high refractive index medium film layers arranged alternately; The middle layer film is used to be arranged between the substrate and the outer layer film; the film layer in contact with the substrate is the high refractive index medium film layer; The outer film is a single-layer low-refractive-index medium anti-reflection film.

2. The novel light splitting film for a light splitting prism according to claim 1, characterized in that: The substrate is fused quartz.

3. The novel light splitting film for a light splitting prism according to claim 1, characterized in that: The periodic number of the high refractive index medium film layer is not less than 3.

4. The novel light splitting film for a light splitting prism according to claim 1, characterized in that: The single-layer low-refractive-index medium anti-reflection film is TiO2.

5. The novel light splitting film for light splitting prism according to claim 1, characterized in that: The middle layer film includes the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer and the outer film in order from the side adjacent to the substrate to the side away from the substrate; the thickness of the first dielectric film layer is 33.27nm; the thickness of the first metal layer is 11.69nm; the thickness of the second dielectric film layer is 69.94nm; the thickness of the second metal layer is 12.16nm; the thickness of the third dielectric film layer is 69.76nm; the thickness of the third metal layer is 11.64nm; the thickness of the outer film is 33.08nm; The first dielectric film layer, the second dielectric film layer and the third dielectric film layer are made of TiO2, the first metal film, the second metal film and the third metal film are made of metal material Ag, and the outer film is made of Ti3O5; Alternatively, the middle layer film comprises, from the side adjacent to the substrate to the side away from the substrate, the first dielectric film layer, the first metal layer, the second dielectric film layer, the second metal layer, the third dielectric film layer, the third metal layer, the fourth dielectric layer, the fourth metal layer and the outer film in order; the thickness of the first dielectric film layer is 37.71nm; the thickness of the first metal layer is 10.08nm; the thickness of the second dielectric film layer is 81.34nm; the thickness of the second metal layer is 11.15nm; the thickness of the third dielectric film layer is 64.64nm; the thickness of the third metal layer is 2.38nm; the thickness of the fourth dielectric film layer is 25.58nm; the thickness of the fourth metal layer is 8nm; the thickness of the outer film is 35.49nm; The first dielectric film layer, the second dielectric film layer, the third dielectric film layer and the fourth dielectric film layer are made of Ta2O5, the first metal film, the second metal film, the third metal film and the fourth metal film are made of metal material Ag, and the outer film is made of Ta2O5.

6. The novel light splitting film for light splitting prism according to claim 1, characterized in that: The high refractive index dielectric film layer is made of a mixture of one or more materials selected from TiO2, Ta2O5 and NB2O5.

7. The novel light splitting film for light splitting prism according to claim 1, characterized in that: The metal film is Ag.

8. The novel light splitting film for light splitting prism according to claim 1, characterized in that: The outer layer film is TiO2, Ti3O5 or Ta2O5.

9. The novel light splitting film for light splitting prism according to claim 1, characterized in that: The transmittance of the novel beam splitting film to visible light within the wavelength range of 415-615nm is above 80%, and the transmittance to near infrared light within the wavelength range of 940-1500nm is less than 20%.

10. The method for manufacturing a novel light splitting film for a light splitting prism according to claim 1, characterized in that: The manufacturing steps include: S1: The substrate is cleaned by multi-slot ultrasonic cleaning, and after heat drying, is placed in a dedicated umbrella stand of a coating machine, and is placed in an umbrella stand of the coating machine; S2: Use a mechanical pump and a diffusion pump to quickly evacuate the vacuum chamber of the coating machine so that the vacuum degree of the vacuum chamber in the coating machine reaches 10-4Pa; S3: Use APC to control the auxiliary gas flow rate; S4: Using a high-voltage electron gun and a Hall ion source-assisted method, the evaporation rate of the raw material of the high-refractive index dielectric film layer is controlled at 0.25nm / s-0.35nm / s; S5: Control the current of the electron gun so that the evaporation rate of the metal film is controlled at 0.05nm / s-0.15nm / s; S6: Control the current of the electron gun so that the evaporation rate of the single-layer high-refractive-index dielectric anti-reflection film of the outer film is controlled at 0.25nm / s-0.35nm / s; S7: Control the substrate temperature below 60°C; S8: using an ion source to ionize Ar gas, under the action of a large electric field, bombarding the substrate, so that the coating material quickly reaches the substrate for coating, thereby improving the density of the film layer; S9: Control the coating umbrella stand for the coating machine on which the substrate is placed to rotate at a constant speed during coating, so that the coating material of the substrate is evenly distributed; S10: After the coating is completed, the substrate must remain still in the coating chamber for 1 hour to allow the substrate to cool down to room temperature and release stress.

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