Coaxial three-reflection wide-spectrum telescope optical system configuration

Abstract

The application provides a coaxial three-reflection wide-spectrum telescopic optical system configuration, and belongs to the technical field of optical systems, and specifically comprises a partial pupil primary mirror, a partial pupil secondary mirror, a first fold plane mirror, a partial pupil third mirror and a second fold plane mirror; the partial pupil primary mirror, the partial pupil secondary mirror and the first fold plane mirror constitute a wide-spectrum reflective objective lens group; the partial pupil third mirror and the second fold plane mirror constitute a wide-spectrum reflective ocular group; the first fold plane mirror, the partial pupil third mirror and the second fold plane mirror are located on the side of the partial pupil primary mirror away from the partial pupil secondary mirror; the optical path of the coaxial three-reflection wide-spectrum telescopic optical system passes through the partial pupil primary mirror, the partial pupil secondary mirror, the first fold plane mirror, the partial pupil third mirror and the second fold plane mirror in sequence along the optical axis. The application realizes the coaxial three-reflection wide-spectrum telescopic optical system configuration, and has the advantages of high magnification, no occlusion of the optical path, wide spectrum, high-quality imaging and compact spatial layout.

Description

Technical Field

[0001] This application relates to the field of optical systems, and in particular to a coaxial three-mirror broadband telescope optical system configuration. Background Technology

[0002] Depending on the distance of the target to be observed, optoelectronic observation and monitoring systems typically require optical systems with multiple focal lengths to detect, identify, and recognize targets at different distances, as well as for large-scale monitoring. Furthermore, because targets exhibit different characteristics in different spectral bands, the optical system needs to operate simultaneously in different spectral bands to improve the probability of target detection and identification. However, the types of wide-band transmission optical materials are limited, and the fabrication and processing of large-aperture optical materials are difficult. Therefore, wide-band optical systems generally adopt a reflective optical system configuration. The fact that reflectors do not introduce chromatic aberration is particularly advantageous for the design of wide-band optical systems. At the same time, the substrate material and aperture of the reflectors are not limited, and their fabrication is relatively easy to achieve.

[0003] Common reflective telescope optical system configurations can be divided into coaxial reflective telescope optical system configurations and off-axis reflective telescope optical system configurations. The advantage of a coaxial reflective telescope optical system configuration is its high magnification, but its disadvantage is the problem of central obstruction, which reduces the energy efficiency of the optical system and causes mid-frequency loss in the optical transfer function. Off-axis reflective telescope optical system configurations solve the central obstruction problem by using an off-axis approach, thus improving energy efficiency. However, the disadvantage of off-axis reflective telescope optical system configurations is their lower magnification, typically less than 6. × This is insufficient to meet the system's requirements. Currently, there is no effective solution that simultaneously possesses high telescope magnification and an unobstructed optical system. Summary of the Invention

[0004] In view of this, this application provides a coaxial three-mirror wide-spectrum telescope optical system configuration, which solves the problem that existing coaxial reflective telescope optical systems have high magnification but suffer from central obstruction, while off-axis three-mirror telescope optical systems have no obstruction but have low magnification. The coaxial three-mirror wide-spectrum telescope optical system configuration has the advantages of high magnification, unobstructed optical path, wide spectrum, high-quality imaging, and compact spatial layout.

[0005] The coaxial three-mirror broadband telescope optical system configuration provided in this application adopts the following technical solution:

[0006] A coaxial three-mirror broadband telescope optical system configuration includes a primary deflector mirror, a secondary deflector mirror, a first folding plane mirror, three deflector mirrors, and a second folding plane mirror;

[0007] The primary deflector, secondary deflector, and first folding plane mirror constitute a broadband reflective objective lens group; the three deflector lenses and the second folding plane mirror constitute a broadband reflective eyepiece group.

[0008] The first folding plane mirror, the three-mirror system, and the second folding plane mirror are located on the side of the primary mirror that is opposite to the secondary mirror.

[0009] The optical path of the coaxial three-mirror broadband telescope optical system passes sequentially along the optical axis through the primary deflector mirror, the secondary deflector mirror, the first folding plane mirror, the third deflector mirror, and the second folding plane mirror.

[0010] Optionally, the broadband reflective objective lens group and the broadband reflective eyepiece group constitute a Kepler-type telescope optical system with a central real focal point.

[0011] Optionally, the light-receiving surface of the primary deflector is a parabolic surface, the light-receiving surface of the secondary deflector is a hyperboloid, and the light-receiving surface of the tertiary deflector is a higher-order aspherical surface.

[0012] Optionally, the primary deflector, secondary deflector, and tertiary deflector are made of microcrystalline glass, fused silica, or silicon carbide.

[0013] Optionally, the first and second folding plane mirrors are made of fused silica or K9 optical glass.

[0014] Optionally, the broadband telescope optical system configuration has a focal length range of 1000mm to 1400mm and a magnification of 10. × The F-number of the optical system is f / 4 to f / 6.

[0015] Alternatively, the detectors suitable for the broadband telescope optical system configuration are a 1920×1080 visible light focal plane detector, a 640×512 shortwave detector, and a 640×512 cooled midwave infrared focal plane detector.

[0016] Among them, the 1920×1080 visible light focal plane detector has a spectral range of visible light and a wavelength of 0.4μm to 0.7μm; the 640×512 shortwave detector has a spectral range of shortwave and a wavelength of 0.9μm to 1.7μm; and the 640×512 cooled mid-wave infrared focal plane detector has a spectral range of mid-wave infrared and a wavelength of 3μm to 5μm.

[0017] In summary, this application includes the following beneficial technical effects:

[0018] By employing an optical system configuration with pupil offset and multiple mirrors folding the optical path, the central obstruction problem of the coaxial reflective optical system configuration is solved.

[0019] Because of the pupil offset design, the optical system is still a coaxial optical system and does not introduce off-axis aberrations, achieving a high telephoto magnification and overcoming the problem of low magnification in conventional off-axis three-mirror telephoto optical systems.

[0020] Both the telescope objective and eyepiece groups are reflective, the system has no chromatic aberration, and achieves high-quality imaging across a wide spectrum.

[0021] By utilizing optical surface types such as quadric surfaces and higher-order aspherical surfaces, the aberrations of the optical system were balanced, resulting in excellent image quality. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the optical path of the coaxial three-mirror broadband telescope optical system configuration of this application.

[0024] Figure 2 The optical transfer function diagram of the coaxial three-mirror broadband telescope optical system of this application is shown.

[0025] Figure 3 The diagram shows the short-wavelength optical transfer function of the coaxial three-mirror broadband telescope optical system of this application.

[0026] Figure 4 The image shows the infrared optical transfer function of the coaxial three-mirror broadband telescope optical system of this application.

[0027] Explanation of reference numerals in the attached diagram: 1. Primary deflector mirror; 2. Secondary deflector mirror; 3. First folding plane mirror; 4. Third deflector mirror; 5. Second folding plane mirror. Detailed Implementation

[0028] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0029] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0031] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0033] This application provides a coaxial three-mirror broadband telescope optical system configuration.

[0034] like Figures 1 to 4 As shown, a coaxial three-mirror broadband telescope optical system configuration includes a primary deflector mirror 1, a secondary deflector mirror 2, a first folding plane mirror 3, three deflector mirrors 4, and a second folding plane mirror 5.

[0035] The primary deflector 1, the secondary deflector 2, and the first folding plane mirror 3 constitute a broadband reflective objective lens group; the three deflector mirrors 4 and the second folding plane mirror 5 constitute a broadband reflective eyepiece group.

[0036] The first folding plane mirror, the deflecting pupil mirror 4, and the second folding plane mirror 5 are located on the side of the deflecting pupil primary mirror 1 that is opposite to the deflecting pupil secondary mirror 2.

[0037] The optical path of the coaxial three-mirror broadband telescope optical system passes sequentially along the optical axis through the primary pupil mirror 1, the secondary pupil mirror 2, the first folding plane mirror 3, the three pupil mirrors 4, and the second folding plane mirror 5.

[0038] The broadband reflective objective lens group and the broadband reflective eyepiece group constitute a Kepler-type telescope optical system with a central real focal point.

[0039] In this application, the optical path of the coaxial three-mirror broadband telescope optical system is formed by the primary pupil mirror 1, the secondary pupil mirror 2, the first folding plane mirror 3, the third pupil mirror 4, and the second folding plane mirror 5, arranged along the optical axis. This modified optical system configuration is based on the principles of reflective optics and aberration balance theory. It employs a pupil offset and multi-mirror folding optical path design method, achieving unobstructed broadband beams while obtaining high telescope magnification, high-quality imaging, and a compact spatial layout.

[0040] The broadband telescope optical system configuration has a focal length range of 1000mm to 1400mm and a magnification of 10. × The F-number of the optical system is f / 4 to f / 6.

[0041] The detectors suitable for the broadband telescope optical system configuration are a 1920×1080 visible light focal plane detector, a 640×512 short-wave detector, and a 640×512 cooled mid-wave infrared focal plane detector. Among them, the 1920×1080 visible light focal plane detector has a spectral range of visible light and a wavelength of 0.4μm to 0.7μm; the 640×512 short-wave detector has a spectral range of short-wave light and a wavelength of 0.9μm to 1.7μm; and the 640×512 cooled mid-wave infrared focal plane detector has a spectral range of mid-wave infrared and a wavelength of 3μm to 5μm.

[0042] The light-receiving surface of the primary deflector 1 is a parabolic surface, the light-receiving surface of the secondary deflector 2 is a hyperboloid, and the light-receiving surface of the tertiary deflector 4 is a high-order aspherical surface.

[0043] The primary depupil mirror 1, secondary depupil mirror 2, and tertiary depupil mirror 4 are made of microcrystalline glass, fused silica, or silicon carbide.

[0044] The first folding plane mirror 3 and the second folding plane mirror 5 are made of fused silica or K9 optical glass.

[0045] The embodiments of this application disclose the optical path optical parameters of a coaxial three-mirror broadband telescope optical system, as shown in Table 1.

[0046] Table 1. Optical Path Parameters of the Improved Coaxial Three-Mirror Wide-Spectrum Telescope Optical System (Unit: mm)

[0047]

[0048] The embodiments of this application also disclose the aspherical coefficients of the primary depolarizing mirror, the secondary depolarizing mirror, and the tertiary depolarizing mirror, as shown in Table 2.

[0049] Table 2 Aspherical Coefficients

[0050] Deviated pupil primary lens -1 —— —— —— —— Deplasmic secondary lens -2.12 Devior pupil three-lens 0 -1.5587E-8 4.3852E-12 -2.5750E-15 5.587E-19

[0051] The equation for an aspherical surface is:

[0052] Where: r is the distance from the optical axis; R is the radius of curvature at the vertex of the aspherical surface; k is the quadratic curve constant; A, B, C, and D are all aspherical coefficients.

[0053] The embodiments of this application also disclose the eccentricity and tilt of the first folding plane mirror, the second folding plane mirror, and the exit pupil, as shown in Table 3.

[0054] Table 3. Parameters of Eccentricity and Inclination

[0055] First folding plane mirror 0 63.27 Second folding plane mirror 0 26.73 Out of pupil 22.35 0

[0056] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A coaxial three-mirror broadband telescope optical system configuration, characterized in that, It consists of a primary deflector (1), a secondary deflector (2), a first folding plane mirror (3), a third deflector (4), and a second folding plane mirror (5); The primary deflector (1), secondary deflector (2), and first folding plane mirror (3) constitute a broadband reflective objective lens group; the three deflector lenses (4) and the second folding plane mirror (5) constitute a broadband reflective eyepiece group. The first folding plane mirror (3), the three-mirror deflector (4), and the second folding plane mirror (5) are located on the side of the primary mirror deflector (1) that is opposite to the secondary mirror deflector (2); The optical path of the coaxial three-mirror broadband telescope optical system passes through the primary pupil mirror (1), the secondary pupil mirror (2), the first folding plane mirror (3), the three pupil mirrors (4), and the second folding plane mirror (5) in sequence along the optical axis. The broadband reflective objective lens group and the broadband reflective eyepiece group constitute a Kepler-type telescope optical system with a central real focal point. The broadband telescope optical system configuration has a focal length range of 1000mm to 1400mm and a magnification of 10. × The optical system has an F-number of f / 4 to f / 6. The wide-spectrum telescope optical system configuration is suitable for detectors with a 1920×1080 visible light focal plane detector, a 640×512 short-wave detector, and a 640×512 cooled mid-wave infrared focal plane detector. Among them, the 1920×1080 visible light focal plane detector has a spectral range of visible light and a wavelength of 0.4μm to 0.7μm; the 640×512 shortwave detector has a spectral range of shortwave and a wavelength of 0.9μm to 1.7μm; and the 640×512 cooled mid-wave infrared focal plane detector has a spectral range of mid-wave infrared and a wavelength of 3μm to 5μm.

2. The coaxial three-mirror broadband telescope optical system configuration according to claim 1, characterized in that, The light-receiving surface of the primary pupil mirror (1) is a parabolic surface, the light-receiving surface of the secondary pupil mirror (2) is a hyperboloid, and the light-receiving surface of the tertiary pupil mirror (4) is a high-order aspherical surface.

3. The coaxial three-mirror broadband telescope optical system configuration according to claim 1, characterized in that, The primary depolarizing mirror (1), secondary depolarizing mirror (2), and tertiary depolarizing mirror (4) are made of microcrystalline glass, fused silica, or silicon carbide.

4. The coaxial three-mirror broadband telescope optical system configuration according to claim 1, characterized in that, The first folding plane mirror (3) and the second folding plane mirror (5) are made of fused silica or K9 optical glass.

Images