阅读说明：本技术 一种大口径大视场双凹面反射镜望远镜光学系统 (Large-caliber large-view-field double-concave-surface reflector telescope optical system ) 是由 李正阳 王力帆 梁明 袁祥岩 李博 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种大口径大视场双凹面反射镜望远镜光学系统,包括两块双曲面反射镜,即双曲面主镜A、双曲面副镜B,且所述双曲面主镜A、双曲面副镜B均为凹面双曲面反射镜,在两块凹面双曲面反射镜之间设置有用于校正轴外光学像差的视场改正光学单元,所述光学系统沿光路方向依次设置为双曲面主镜A、双曲面副镜B、视场改正光学单元,所述光学系统无一次像面。本发明区别于传统反射式望远镜,采用双凹面反射镜对天体进行成像,具有长度短、体积小、重量轻的优点,而且大幅减少了副镜的面型检测难度,降低了副镜的面型检测成本。同时兼具大孔径、大视场的特点,大幅提高了望远镜的观测能力和探测效率。(The invention discloses a large-caliber large-view-field double-concave-surface reflector telescope optical system which comprises two hyperboloid reflectors, namely a hyperboloid primary reflector A and a hyperboloid secondary reflector B, wherein the hyperboloid primary reflector A and the hyperboloid secondary reflector B are both concave hyperboloid reflectors, a view field correction optical unit for correcting off-axis optical aberration is arranged between the two concave hyperboloid reflectors, the optical system is sequentially provided with the hyperboloid primary reflector A, the hyperboloid secondary reflector B and the view field correction optical unit along the optical path direction, and the optical system does not have a primary image surface. The invention is different from the traditional reflection telescope, adopts the double-concave reflector to image the celestial body, has the advantages of short length, small volume and light weight, greatly reduces the surface type detection difficulty of the auxiliary mirror and reduces the surface type detection cost of the auxiliary mirror. Meanwhile, the system has the characteristics of large aperture and large field of view, and greatly improves the observation capability and detection efficiency of the telescope.)

1. The utility model provides a two concave surface speculum telescope optical system of heavy-calibre heavy-field which characterized in that: including two hyperboloid reflectors, hyperboloid primary mirror A, hyperboloid secondary mirror B promptly, just hyperboloid primary mirror A, hyperboloid secondary mirror B are concave surface hyperboloid reflector, are provided with the field of view correction optical unit that is used for correcting off-axis optical aberration between two concave surface hyperboloid reflectors, optical system sets gradually to hyperboloid primary mirror A, hyperboloid secondary mirror B, field of view correction optical unit along the light path direction, optical system does not have a image plane.

2. The optical system of the large-caliber large-field biconcave mirror telescope according to claim 1, wherein: the field correction optical unit comprises a meniscus lens C, a meniscus lens D, a meniscus lens E, a meniscus lens F, a meniscus lens H, a meniscus lens I and a biconvex lens J which are sequentially arranged along the direction of the light path.

3. The optical system of the large-caliber large-field biconcave mirror telescope according to claim 2, wherein: an optical filter G is further provided between the meniscus lens F and the meniscus lens H.

4. The large-aperture large-field of view biconcave mirror telescope optical system of claim 3, wherein: the air space between the hyperboloid primary mirror A and the hyperboloid secondary mirror B is 4097mm +/-5%, the air space between the hyperboloid secondary mirror B and the meniscus lens C is 1606mm +/-5%, the air space between the meniscus lens C and the meniscus lens D is 100mm +/-5%, the air space between the meniscus lens D and the meniscus lens E is 140mm +/-5%, the air space between the meniscus lens E and the meniscus lens F is 190mm +/-5%, the air space between the meniscus lens F and the optical filter G is 401mm +/-5%, the air space between the optical filter G and the meniscus lens H is 487mm +/-5%, the air space between the meniscus lens H and the meniscus lens I is 75mm +/-5%, and the air space between the meniscus lens I and the biconvex lens J is 0.04mm +/-5%.

5. The optical system of the large-caliber large-field biconcave mirror telescope according to claim 1, wherein: the large caliber is more than 1 meter, and the large view field is a view field with a diameter of more than 3 degrees.

6. The optical system of the large-caliber large-field biconcave mirror telescope according to claim 1, wherein: the optical system adopts a reflective optical architecture.

Technical Field

The invention relates to an optical system of an astronomical optical telescope, in particular to an optical system of a large-caliber large-view-field biconcave reflector telescope.

Background

With the gradual and deep exploration and research of the universe, a telescope with higher resolution and stronger detection capability is required to be equipped for more accurate detection of the universe. In terms of large ground-based telescopes, the common structural forms of the optical systems are Cassegrain system (Cassegrain system), Ritchey-creatry optical system, primary focus optical system and grignard-elevation system (grignard system), wherein secondary mirrors of the Cassegrain system and the Ritchey-creatry optical system are convex mirrors, a phase plate with a larger caliber is required to be equipped for detection in the surface type detection process, the detection principle schematic diagram is shown in fig. 1, the detection system comprises an interferometer 11, a standard objective 12, a phase compensation mirror 13 and a secondary mirror 14 to be detected, a reflection-type standard spherical mirror with a large caliber is required to be prepared in the detection process, the construction of a detection optical path is complicated, the adjustment is difficult, the telescope manufacturing cost is increased, the primary and secondary mirrors of the grignard system are both double-concave surfaces, but the secondary mirrors are required to carry out secondary imaging on the focus converged by the primary mirrors, namely, the optical path length is increased, the lens barrel is very long, the field of view is very small (i.e. has an angularly graded field of view) and as shown in figure 2 the system shows a parabolic primary mirror 16, an ellipsoidal secondary mirror 17, and a primary image plane 18.

Disclosure of Invention

The purpose of the invention is as follows: in view of the above problems, the present invention provides an optical system of an astronomical telescope with a large-aperture large-field-of-view biconcave mirror.

The invention is realized by adopting the following scheme:

the utility model provides a two concave surface speculum telescope optical system of heavy-calibre heavy-field, includes two hyperboloid speculums, hyperboloid primary mirror A, hyperboloid secondary mirror B promptly, just hyperboloid primary mirror A, hyperboloid secondary mirror B are concave surface hyperboloid speculums, are provided with the visual field correction optical unit that is used for proofreading and correct off-axis optical aberration between two concave surface hyperboloid speculums, optical system sets gradually to hyperboloid primary mirror A, hyperboloid secondary mirror B, visual field correction optical unit along the light path direction, optical system does not have a image plane.

Further, the field correction optical unit includes a meniscus lens C, a meniscus lens D, a meniscus lens E, a meniscus lens F, a meniscus lens H, a meniscus lens I, and a biconvex lens J, which are sequentially arranged along the optical path direction.

Further, an optical filter G is disposed between the meniscus lens F and the meniscus lens H.

Further, the air space between the hyperboloid primary mirror a and the hyperboloid secondary mirror B is 4097mm ± 5%, the air space between the hyperboloid secondary mirror B and the meniscus lens C is 1606mm ± 5%, the air space between the meniscus lens C and the meniscus lens D is 100mm ± 5%, the air space between the meniscus lens D and the meniscus lens E is 140mm ± 5%, the air space between the meniscus lens E and the meniscus lens F is 190mm ± 5%, the air space between the meniscus lens F and the optical filter G is 401mm ± 5%, the air space between the optical filter G and the meniscus lens H is 487mm ± 5%, the air space between the meniscus lens H and the meniscus lens I is 75mm ± 5%, and the air space between the meniscus lens I and the biconvex lens J is 0.04mm ± 5%.

Further, the large caliber is more than 1 meter, and the large view field is a view field with a diameter of more than 3 degrees.

Further, the optical system adopts a reflective optical architecture.

Compared with the prior art, the invention has the following beneficial effects:

the large-aperture large-view-field astronomical telescope optical system adopts a reflective optical architecture, is different from the traditional reflective telescope, adopts the double-concave reflector to image the celestial body, has the advantages of short length, small volume and light weight, greatly reduces the surface type detection difficulty of the auxiliary mirror and reduces the surface type detection cost of the auxiliary mirror. Meanwhile, the system has the characteristics of large aperture and large field of view, and greatly improves the observation capability and detection efficiency of the telescope.

Drawings

FIG. 1 is a schematic diagram of a detection optical path of a conventional reflection telescope.

Fig. 2 is a schematic diagram of the small field of view principle of a conventional reflection telescope.

FIG. 3 is a diagram of an optical system architecture in an embodiment of the present invention.

Fig. 4 is a schematic diagram of the detection of the optical system in the embodiment of the present invention.

FIG. 5 is a diagram (dot-column diagram) showing the image quality of the optical system under the full field of view in the present invention.

FIG. 6 is a schematic diagram of a Guest Star Telescope Telescope simulation according to the present invention.

The labels in the figure are: 1. a hyperboloid primary mirror A; 2. a hyperboloid secondary mirror B; 3. a meniscus lens C; 4. a meniscus lens D; 5. a meniscus lens E; 6. a meniscus lens F; 7. a filter G; 8. a meniscus lens H; 9. a meniscus lens I; 10. a biconvex lens J; 11. an interferometer; 12. a standard objective lens; 13. a phase compensation mirror; 14. a secondary mirror to be tested; 15. a compensation lens; 16. a parabolic primary mirror; 17. an ellipsoidal secondary mirror; 18. and (5) primary image surface.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings.

The embodiment provides an optical system of a large-aperture large-field-of-view biconcave telescope, and the architecture diagram of the optical system is shown in figure 3. The optical system comprises two hyperboloid reflectors, namely a hyperboloid main reflector A1 and a hyperboloid auxiliary reflector B2, wherein the hyperboloid main reflector A1 and the hyperboloid auxiliary reflector B2 are both concave hyperboloid reflectors, a field-of-view correction optical unit for correcting off-axis optical aberration is arranged between the two concave hyperboloid reflectors, the optical system is sequentially provided with the hyperboloid main reflector A1, the hyperboloid auxiliary reflector B2 and the field-of-view correction optical unit along the optical path direction, and the optical system does not have a primary image surface. The large-aperture large-view-field astronomical telescope optical system of the embodiment adopts a reflection type optical architecture, is different from a traditional reflection type telescope (such as a Gregorian astronomical telescope, an auxiliary mirror of the telescope is a concave surface and has a primary image surface, so that a lens barrel needs to be made very long), adopts a double-concave surface reflector to image an astronomical body, has the advantages of short length, small volume and light weight, greatly reduces the surface type detection difficulty of the auxiliary mirror, and has a detection schematic diagram shown as figure 4, wherein an interferometer 11, a standard objective 12, an auxiliary mirror 14 to be detected and a compensating lens 15 are displayed in the diagram, so that the surface type detection cost of the auxiliary mirror is reduced; meanwhile, the telescope has the characteristics of large caliber (more than 1 meter caliber) and large view field (more than 3 degrees of view field in diameter), and greatly improves the observation capability and detection efficiency of the telescope.

In this embodiment, a preferable embodiment of the field correction optical unit includes a meniscus lens C3, a meniscus lens D4, a meniscus lens E5, a meniscus lens F6, a filter G7, a meniscus lens H8, a meniscus lens I9, a biconvex lens J10, and the entire optical system includes two concave hyperboloid mirrors, seven field correcting mirrors, and one filter. The optical system is sequentially provided with a hyperboloid main mirror A1, a hyperboloid secondary mirror B2, a meniscus lens C3, a meniscus lens D4, a meniscus lens E5, a meniscus lens F6, an optical filter G7, a meniscus lens H8, a meniscus lens I9 and a biconvex lens J10 along the optical path direction.

The primary mirror A is a hyperboloid reflector with the caliber of 4000 mm. The secondary mirror B is a concave hyperboloid reflector, seven correcting mirror groups are arranged to correct off-axis optical aberration in order to improve the optical image quality under a large field of view of the telescope optical system, and in addition, an optical filter F is arranged to screen image spots of specific wave bands in order to improve the photometric accuracy. The optical path structure improves the assembly performance of an optical system, reduces the optical detection cost, and when the optical path is designed, the secondary mirror B adopts a concave surface type, so that the size of the phase compensator is greatly reduced, and the surface type detection is convenient.

The lens adopts a reflective optical structure, integrates a deformation structure of a Ritchey-Cregory and Grignard-fruit system structure as a basic prototype of the system, and realizes imaging of a celestial body on the premise that the secondary mirror is designed to be a concave surface, so that the weight and the length of the lens cone are effectively controlled. The entrance pupil aperture of the lens is 4000mm, and the lens has the advantages of light, small and compact structure, short length, small size and light weight under the conditions of meeting the light energy and ensuring the image quality, and has the characteristics of large aperture and large view field.

The optical system adopts seven transmission lenses as a correcting lens group to achieve good optical image quality. In consideration of the difficulty of the gluing process of the large-caliber lens, the large-caliber lens does not adopt a gluing set. In the optimization design, the operation number and the weight are reasonably selected, so that various aberrations are effectively controlled. Considering the processing difficulty of the large-aperture lens, part of air space is enlarged during design, and the optical filter is arranged in the middle of the correcting lens group, so that the sizes of the 2 lenses in the rear group are greatly reduced.

In this embodiment, the air space between the hyperboloid primary mirror a and the hyperboloid secondary mirror B is 4097mm, the air space between the hyperboloid secondary mirror B and the meniscus lens C is 1606mm, the air space between the meniscus lens C and the meniscus lens D is 100mm, the air space between the meniscus lens D and the meniscus lens E is 140mm, the air space between the meniscus lens E and the meniscus lens F is 190mm, the air space between the meniscus lens F and the optical filter G is 401mm, the air space between the optical filter G and the meniscus lens H is 487mm, the air space between the meniscus lens H and the meniscus lens I is 75mm, and the air space between the meniscus lens I and the biconvex lens J is 0.04 mm. The air interval data may vary by ± 5%.

The optical system composed of the lens achieves the following optical indexes:

1. focal length: f ═ 7106 mm;

2. relative pore diameter: D/F is 1/1.78;

3. the field angle: 4 ° (-2 °);

4. designing a wave band: 380-700 nm;

5. spot of field RMS: 0 ° field spot RMS of 5.4 μm and 2 ° field spot RMS of 6.7 μm (see fig. 5 in particular);

6. total length of lens barrel: 4300 mm.

The optical system of the large-caliber large-view-field astronomical optical telescope has the advantages that:

(1) the secondary mirror adopts a concave hyperboloid reflector, so that the surface type detection is convenient, and the manufacturing cost is saved;

(2) the deformation structure of the Ritchey-Cregory and Grignard-fruit system structure is used as the basic prototype of the system, and the imaging of the object celestial body is realized on the premise that the secondary mirror is designed to be a concave surface, so that the weight and the length of the lens are effectively controlled.

(3) Considering the processing difficulty of the large-aperture lens, part of air space is enlarged during design, and the optical filter is arranged in the middle of the correcting lens group, so that the sizes of the 2 lenses in the middle and rear groups are greatly reduced.

The embodiment is applied to the Guest Star Telescope project at present, and a Telescope physical simulation schematic diagram is shown in FIG. 6.

In summary, the invention is a large-aperture large-view-field biconcave mirror telescope optical system. The system adopts the double-concave reflector to image the celestial body in the design process, has the advantages of short length, small volume and light weight, greatly reduces the face type detection difficulty of the secondary mirror and reduces the face type detection cost of the secondary mirror. Meanwhile, the system has the characteristics of large aperture and large field of view, and greatly improves the observation capability and detection efficiency of the telescope.

The above description is only an example of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.