An infrared band optical system assembly and adjustment method and tooling eyepiece

Abstract

The invention discloses an infrared band optical system adjustment method and a tooling eyepiece, which belongs to the field of optical engineering; the tooling eyepiece is designed according to the parameters of a primary mirror component and a secondary mirror component; the primary mirror component is installed behind the secondary mirror component, and then transferred to the measurement optical path of a laser interferometer, and a first spherical reflector is placed behind the primary mirror component to construct an interference measurement optical path; the secondary mirror component is adjusted until the 0 field of view aberration of the imaging system satisfies that the wavefront RMS is not greater than 0.05λ; the first spherical reflector is removed, and the tooling eyepiece is installed in an eyepiece frame, and then the eyepiece frame is installed on the primary mirror component; a second spherical reflector is placed behind the primary mirror component to construct an interference measurement optical path; the position of the eyepiece frame relative to the primary mirror component is adjusted until the 0 field of view aberration of the imaging system satisfies that the wavefront RMS is not greater than 0.1λ; the tooling eyepiece is removed, installed in the eyepiece, and the system adjustment is completed. The invention realizes the precise adjustment of the eyepiece, and the adjustment precision is high, and ensures that the system has a high imaging quality after the adjustment is completed.

Description

Technical Field

[0001] The invention belongs to the field of optical engineering, and in particular relates to an infrared band optical system assembly and adjustment method and a tooling eyepiece. Background Art

[0002] The working wavelength of the commonly used laser interferometer at present is 0.6328μm, while the working band of the infrared band optical system is generally 1μm-1000μm, which makes it impossible to use the laser interferometer to perform quantitative inspection of the system aberration during the installation and adjustment of the infrared band optical system; in the prior art, the installation and adjustment of the infrared band optical system is to observe the system imaging screen, judge the aberration type existing in the system based on experience, and then perform blind adjustment, which is inefficient and it is difficult for the system imaging quality to meet the design requirements. Summary of the invention

[0003] Technical issues to be solved:

[0004] In order to avoid the shortcomings of the prior art, the present invention provides an infrared band optical system assembly and adjustment method and a tooling eyepiece, which solves the problems of the existing infrared band optical system's strong dependence on manual experience, large blindness in assembly and adjustment, and poor system imaging quality.

[0005] The technical solution of the present invention is: an infrared band optical system installation and adjustment method, characterized in that: the infrared band optical system comprises a primary mirror component, a secondary mirror component, an eyepiece frame and an eyepiece; light is incident on the primary mirror component and reflected to reach the secondary mirror component, is reflected again on the secondary mirror component and then incident on the eyepiece, and finally is refracted by the eyepiece to form an image;

[0006] The specific steps of the adjustment method are as follows:

[0007] Step 1: designing a tooling eyepiece according to the parameters of the primary mirror component and the secondary mirror component; when the tooling eyepiece is installed at the position where the eyepiece is to be processed, the imaging wavefront RMS of the optical system 0 field of view composed of the primary mirror component and the secondary mirror component is not greater than 0.05λ, λ=0.6328μm;

[0008] Step 2: Install the primary mirror component behind the secondary mirror component, and then transfer the two to the measurement optical path of the laser interferometer, place the first spherical reflector behind the primary mirror component, adjust the first spherical reflector so that its sphere center coincides with the 0 field of view focus of the optical system composed of the primary mirror component and the secondary mirror component, and construct an interference measurement optical path;

[0009] Step 3: According to the aberration type and value measured by the laser interferometer, the eccentricity and tilt of the secondary mirror component relative to the primary mirror component are adjusted;

[0010] Step 4: Repeat step 3 until the zero field of view aberration of the imaging system composed of the primary mirror component and the secondary mirror component satisfies that the wavefront RMS is not greater than 0.05λ, λ=632.8nm;

[0011] Step 5: Remove the first spherical reflector, install the tooling eyepiece into the eyepiece frame, and then install the eyepiece frame on the primary mirror component; place the second spherical reflector behind the primary mirror component, adjust the second spherical reflector so that its sphere center coincides with the 0 field of view focus of the optical system composed of the primary mirror component, the secondary mirror component, and the tooling eyepiece, and construct an interferometric measurement optical path;

[0012] Step 6: According to the aberration type and value measured by the laser interferometer, adjust the position of the eyepiece frame relative to the primary mirror assembly;

[0013] Step 7: Repeat step 6 until the zero field aberration of the imaging system composed of the primary mirror component, the secondary mirror component and the tooling eyepiece satisfies that the wavefront RMS is not greater than 0.1λ, λ=632.8nm;

[0014] Step 8: Remove the tooling eyepiece and install the eyepiece to complete the system adjustment.

[0015] A further technical solution of the present invention is that the material of the eyepiece tooling is selected to allow the transmission of light with a wavelength of 632.8 nm emitted by the laser interferometer.

[0016] A further technical solution of the present invention is that when the tooling eyepiece is installed at the position of the eyepiece, the imaging wavefront RMS of the optical system 0 field of view composed of the primary mirror component and the secondary mirror component is no more than 0.1λ, λ=0.6328μm.

[0017] A further technical solution of the present invention is that the optical axis of the tooling eyepiece coincides with the outer circle axis thereof, and the outer circle diameter of the tooling eyepiece is the same as the outer circle diameter of the eyepiece.

[0018] A further technical solution of the present invention is that the reflective film coated on the primary mirror component and the secondary mirror component has a reflectivity of not less than 10% at a wavelength of 0.6328 μm.

[0019] A further technical solution of the present invention is that the ratio of the curvature radius R1 of the first spherical reflector to the aperture D1 is smaller than the F number of the current optical system, that is, the optical system without the eyepiece fixture installed.

[0020] A further technical solution of the present invention is that the ratio of the curvature radius R2 of the second spherical reflector to the aperture D2 is smaller than the F number of the current optical system, that is, the optical system equipped with the eyepiece tooling.

[0021] A tooling eyepiece, characterized in that: the optical parameters are: the radius of curvature of the first surface is -13.9443mm, the radius of curvature of the second surface is -1.357mm; the center thickness is 2.6448mm, and the aperture is 0.2mm.

[0022] A further technical solution of the present invention is that the material of the tooling eyepiece is HK9LGT.

[0023] Beneficial Effects

[0024] The beneficial effects of the present invention are:

[0025] 1) The present invention adopts a method of in-situ replacement of tooling eyepieces, which solves the problem that the infrared catadioptric hybrid optical system cannot be adjusted using a laser interferometer. The eyepiece adjustment can be completed quickly according to the aberration type and value measured by the laser interferometer, with high efficiency;

[0026] 2) The present invention realizes precise adjustment of the eyepiece with high adjustment accuracy, thus ensuring that the system has high imaging quality after adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the assembly and adjustment of the secondary mirror component;

[0028] Figure 2 This is a schematic diagram of adjusting the eyepiece frame using a tooling eyepiece;

[0029] Figure 3 This is a schematic diagram of the eyepiece after installation and adjustment;

[0030] Explanation of the reference numerals: 1. Laser interferometer; 2. Secondary mirror assembly; 3. Primary mirror assembly; 4. First spherical reflector; 5. Second spherical reflector; 6. Eyepiece frame; 7. Tooling eyepiece; 8. Eyepiece. DETAILED DESCRIPTION

[0031] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0032] Reference Figure 1-3 An infrared band optical system in the present embodiment shown includes a primary mirror component 3, a secondary mirror component 2, an eyepiece frame 6 and an eyepiece 8; the light transmission mode of the infrared band optical system is as follows: the incident light is reflected on the primary mirror and then incident on the secondary mirror, and then reflected again on the secondary mirror and then incident on the eyepiece 8, and finally refracted by the eyepiece 8 to form an image; the optical axis of the eyepiece 8 coincides with the axis of its outer circle, and the outer circle diameter of the eyepiece 8 is the same as the inner circle diameter of the eyepiece frame 6; the reflective film coated on the primary mirror and the secondary mirror has a reflectivity of not less than 10% for a wavelength of 0.6328μm.

[0033] Reference Figure 1 and Figure 2 The specific operation steps of the infrared band optical system installation method of this embodiment are as follows:

[0034] The specific operation steps of the above infrared band optical system installation and adjustment method are as follows:

[0035] Step 1: According to the parameters of the eyepiece such as the radius of curvature, thickness, and material, a tooling eyepiece 7 is designed. The optical material of the tooling eyepiece 7 allows the light of the laser interferometer 1 to be transmitted. When the tooling eyepiece 7 is installed at the position of the eyepiece 8, the imaging wavefront RMS of the optical system 0 formed by the primary mirror component 3 and the secondary mirror component 2 is not greater than 0.1λ, λ=0.6328μm; the optical axis of the tooling eyepiece 7 coincides with its outer circular axis, and the caliber of the tooling eyepiece 7 is the same as that of the eyepiece 8. The optical system parameters of an embodiment that meets the above requirements are shown in Tables 1 and 2. Table 1 shows the optical system parameters of the eyepiece, and Table 2 shows the optical system parameters of the tooling eyepiece.

[0036] Table 1 Eyepiece parameters

[0037]

[0038] Table 2 Tooling eyepiece parameters

[0039]

[0040] Step 2: Install the primary mirror component 3 on the secondary mirror component 2, transfer the two to the measurement optical path of the laser interferometer 1, place the first spherical reflector 4 behind the primary mirror component 3, adjust the first spherical reflector 4 so that its sphere center coincides with the focal point of the field of view of the optical system 0 composed of the primary mirror component 3 and the secondary mirror component 2, and construct an interference measurement optical path;

[0041] Step 3: According to the aberration type and value measured by the laser interferometer 1, the eccentricity and tilt of the secondary mirror component 2 relative to the primary mirror component 3 are adjusted;

[0042] Step 4: Repeat the above step 3 until the field aberration of the imaging system 0 composed of the primary mirror component 3 and the secondary mirror component 2 satisfies that the wavefront RMS is not greater than 0.05λ, λ=632.8nm;

[0043] Step 5: remove the first spherical reflector 4, install the tooling eyepiece 7 into the eyepiece frame 6, install the eyepiece frame 6 on the primary mirror component 3, place the second spherical reflector 5 behind the primary mirror component 3, adjust the second spherical reflector 5 so that its sphere center coincides with the field of view focus of the optical system 0 composed of the primary mirror component 3, the secondary mirror component 2 and the tooling eyepiece 7, and construct an interference measurement optical path;

[0044] Step 6: According to the aberration type and value measured by the laser interferometer, the position of the eyepiece frame 6 relative to the primary mirror component 3 is adjusted;

[0045] Step 7: Repeat the above step 6 until the zero field aberration of the imaging system composed of the primary mirror component 3, the secondary mirror component 2 and the tooling eyepiece 7 satisfies that the wavefront RMS is not greater than 0.1λ, λ=632.8nm;

[0046] Step 8: Since the optical axes of the eyepiece 8 and the tooling eyepiece 7 coincide with their outer circular axes, the apertures are the same as the inner diameter of the eyepiece frame 6, and the tooling eyepiece 7 is installed at the theoretical position of the eyepiece 8 in the eyepiece frame 6, at this time, the tooling eyepiece 7 is removed and directly installed into the eyepiece 8 to ensure that the eyepiece 8 is in its theoretical position, completing the system adjustment.

[0047] Note: The material of the eyepiece only allows the transmission of light with a wavelength within the bandwidth of 2μm-1000μm. The wavelength of the light emitted by the laser interferometer is 632.8nm, which is not within the bandwidth allowed by the eyepiece material. Therefore, it cannot be directly installed in the eyepiece for adjustment using the laser interferometer. If it is directly installed in the eyepiece, since the eyepiece material does not allow the transmission of the 632.8nm wavelength light emitted by the laser interferometer, it is impossible to use the laser interferometer to measure the wavefront of the optical system composed of the primary mirror component, the secondary mirror component, and the eyepiece.

[0048] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for assembling an infrared optical system, characterized in that: The infrared band optical system comprises a primary mirror component, a secondary mirror component, an eyepiece frame and an eyepiece; light is incident on the primary mirror component and reflected to reach the secondary mirror component, and then reflected again on the secondary mirror component before being incident on the eyepiece, and finally refracted by the eyepiece to form an image; the first surface of the eyepiece has a curvature radius of 41.6847 mm and an aperture of 0.2 mm; the second surface has a curvature radius of -5.3697 mm and an aperture of 0.2 mm; the center thickness is 3.9733 mm, and the material is SILICON; The specific steps of the adjustment method are as follows: Step 1: Design a tooling eyepiece according to the parameters of the primary mirror component and the secondary mirror component; when the tooling eyepiece is installed at the position where the eyepiece is to be processed, the imaging wavefront RMS of the optical system 0 field of view composed of the primary mirror component and the secondary mirror component is not greater than 0.05 λ, λ=0.6328 μm; the radius of curvature of the first surface of the tooling eyepiece is -13.9443 mm, and the caliber is 0.2 mm; the radius of curvature of the second surface is -1.357 mm, and the caliber is 0.2 mm; the center thickness is 2.6448 mm, and the material is HK9LGT; Step 2: Install the primary mirror component behind the secondary mirror component, and then transfer the two to the measurement optical path of the laser interferometer, place the first spherical reflector behind the primary mirror component, adjust the first spherical reflector so that its sphere center coincides with the 0 field of view focus of the optical system composed of the primary mirror component and the secondary mirror component, and construct an interference measurement optical path; Step 3: According to the aberration type and value measured by the laser interferometer, the eccentricity and tilt of the secondary mirror component relative to the primary mirror component are adjusted; Step 4: Repeat step 3 until the zero field aberration of the imaging system composed of the primary mirror component and the secondary mirror component satisfies that the wavefront RMS is not greater than 0.05 λ, λ=0.6328 μm; Step 5: Remove the first spherical reflector, install the tooling eyepiece into the eyepiece frame, and then install the eyepiece frame on the primary mirror component; place the second spherical reflector behind the primary mirror component, adjust the second spherical reflector so that its sphere center coincides with the 0 field of view focus of the optical system composed of the primary mirror component, the secondary mirror component, and the tooling eyepiece, and construct an interferometric measurement optical path; Step 6: According to the aberration type and value measured by the laser interferometer, adjust the position of the eyepiece frame relative to the primary mirror assembly; Step 7: Repeat step 6 until the zero field aberration of the imaging system composed of the primary mirror component, the secondary mirror component and the tooling eyepiece satisfies that the wavefront RMS is not greater than 0.1 λ, λ=0.6328 μm; Step 8: Remove the tooling eyepiece and install the eyepiece to complete the system adjustment.

2. The infrared band optical system assembly and adjustment method according to claim 1, characterized in that: The material of the tooling eyepiece is selected to allow the transmission of light with a wavelength of 0.6328 μm emitted by the laser interferometer.

3. The infrared band optical system assembly and adjustment method according to claim 1, characterized in that: The optical axis of the tooling eyepiece coincides with the outer circle axis of the tooling eyepiece, and the outer circle diameter of the tooling eyepiece is the same as the outer circle diameter of the eyepiece.

4. The infrared band optical system assembly and adjustment method according to claim 1, characterized in that: The reflectivity of the reflective film coated on the primary mirror component and the secondary mirror component at a wavelength of 0.6328 μm is not less than 10%.

5. The infrared band optical system assembly and adjustment method according to claim 1, characterized in that: The ratio of the curvature radius R1 to the aperture D1 of the first spherical reflector is smaller than the F number of the current optical system, that is, the optical system without the eyepiece fixture installed.

6. The infrared band optical system assembly and adjustment method according to claim 1, characterized in that: The ratio of the curvature radius R2 to the aperture D2 of the second spherical reflector is smaller than the F number of the current optical system, that is, the optical system equipped with the eyepiece tooling.

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