Broadband large-view-field low-distortion optical system

Abstract

The invention discloses a broadband large-view-field low-distortion optical system which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, an aperture diaphragm, a seventh bonding lens, an eighth bonding lens and a ninth lens which are sequentially arranged from an object space to an image space, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the aperture diaphragm, the seventh bonding lens, the eighth bonding lens and the ninth lens are sequentially arranged from the object space to the image space. The sixth lens forms a front lens group, the seventh balsaming lens, the eighth balsaming lens and the ninth lens form a rear lens group, the aperture diaphragm is located at the front focal plane of the rear lens group, and both the second lens and the sixth lens adopt aspheric surfaces. The optical system disclosed by the invention has the characteristics of large field of view, low distortion, wide band, long back intercept, excellent imaging quality, telecentric image space and the like, and is particularly suitable for the field of space remote sensing imaging.

Description

Technical Field

[0001] The invention belongs to the field of optical technology, and in particular relates to a wide-band, large-field-of-view, low-distortion optical system, which can be applied to aerospace remote sensing imaging. Background Art

[0002] In recent years, with the rapid development of remote sensing technology, wide-band, large-field-of-view, and wide-band remote sensing detection has become an important development trend of optical remote sensing instruments, and has broad application prospects in environmental monitoring, meteorological observation, resource surveys, marine remote sensing, etc. Therefore, it is of great significance to study wide-band and large-field-of-view optical systems.

[0003] For large field of view optical systems, in order to meet the needs of practical applications, they are usually required to have large field of view, long back intercept, low distortion, compact structure and other characteristics. Due to the sharp increase in aberrations caused by the increase in field of view, especially the difficulty in correcting distortion, aspheric surface balance distortion and astigmatism are usually introduced at a position far away from the field of view aperture. For example, a Chinese patent with application number CN112817119A discloses an optical lens for aerospace use, including the first lens to the tenth lens arranged in sequence from the object side to the image side, all lenses adopt a separate structure, wherein the first lens and the tenth lens adopt glass aspheric surface, with the characteristics of large field of view, image side telecentricity, good imaging quality, etc. However, the edge field of view distortion is about 40%, and the distortion value is large, which is difficult to apply to remote sensing instruments with high distortion requirements. The Xi'an Institute of Optics and Precision Mechanics of the Chinese Academy of Sciences proposed a large-field-of-view, low-distortion lens, which includes an anti-telecentric group, a double Gaussian group, and an output group coaxially arranged along the direction of light incidence. A total of three aspherical surfaces and two cemented groups are used. The maximum distortion is less than 4.7%, the overall dimensions are ≤Φ28×56mm, and the volume is small. It can achieve good imaging quality under temperature conditions of -40℃~60℃. However, the lens does not have the characteristics of image-side telecentricity, the edge illumination drops significantly, and the maximum field of view is only 115°, so there is still room for improvement. Summary of the invention

[0004] The present invention aims to solve the technical problems of large distortion and low edge illumination in existing large field of view optical systems, and to provide a wide-band, large field of view, low-distortion optical system, so as to achieve an imaging effect with large field of view angle, low distortion, wide band, long back intercept, image telecentricity and good imaging quality, so as to be more suitable for space remote sensing imaging.

[0005] In order to solve the above problems, the technical solutions provided by the present invention are as follows:

[0006] The invention discloses a wide-band, large-field-of-view, low-distortion optical system, which comprises: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, an aperture stop, a seventh cemented lens, an eighth cemented lens, and a ninth lens, which are coaxially arranged in sequence along the incident direction, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens constitute a front lens group, the seventh cemented lens, the eighth cemented lens, and the ninth lens constitute a rear lens group, and the aperture stop is located near the front focal plane of the rear lens group;

[0007] The first lens is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the first lens is in the range of [0.0025, 0.005];

[0008] The second lens is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the second lens is in the range of [0.01, 0.03];

[0009] The third lens is a biconvex lens, and the absolute value of the focal length of the third lens is in the range of [0.006, 0.01];

[0010] The fourth lens is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the fourth lens is in the range of [0.03, 0.05];

[0011] The fifth lens is a biconcave lens, and the absolute value of the focal length of the fifth lens is in the range of [0.02, 0.04];

[0012] The sixth lens is a biconvex lens, and the absolute value of the focal length of the sixth lens is in the range of [0.03, 0.05];

[0013] The seventh cemented lens is composed of a seventh cemented positive lens and a seventh cemented meniscus negative lens coaxially arranged in sequence along the incident direction of the light, and the absolute value of the focal length of the seventh cemented lens is in the range of [0.01, 0.04];

[0014] The eighth cemented lens is composed of an eighth cemented meniscus negative lens convex to the object side, an eighth cemented positive lens and an eighth cemented meniscus negative lens convex to the image side, which are coaxially arranged in sequence along the incident direction of the light, and the absolute value of the optical focus of the eighth cemented lens is in the range of [0.01, 0.04];

[0015] The ninth lens is a biconvex lens, and the absolute value of the focal length of the ninth lens is in the range of [0.02, 0.05].

[0016] The wide-band, large-field-of-view, low-distortion optical system described in the present invention is also characterized in that: the first lens is made of fused quartz material; and the second lens is made of radiation-resistant heavy crown glass material.

[0017] Furthermore, the refractive index of the second lens is in the range of [1.60, 1.70], and the dispersion is in the range of [50, 65];

[0018] The refractive index of the third lens is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60];

[0019] The refractive index of the fourth lens is in the range of [1.70, 1.80], and the dispersion is in the range of [40, 55];

[0020] The refractive index of the fifth lens is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28];

[0021] The refractive index of the sixth lens is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28];

[0022] The refractive index of the seventh cemented positive lens is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90];

[0023] The refractive index of the seventh cemented meniscus negative lens is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60];

[0024] The refractive index of the eighth cemented meniscus negative lens is in the range of [1.70, 1.75], and the dispersion is in the range of [30, 40];

[0025] The refractive index of the eighth cemented positive lens is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90];

[0026] The refractive index of the eighth cemented meniscus negative lens is in the range of [1.80, 1.85], and the dispersion is in the range of [40, 50];

[0027] The refractive index of the ninth lens is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90].

[0028] Furthermore, the second lens and the sixth lens are both aspherical.

[0029] Furthermore, the equation of the aspheric surface is constructed using equation (1):

[0030] (1)

[0031] In formula (1), z is the aspheric height, c is the vertex curvature of the aspheric surface, y is the aperture of the aspheric surface, k is the cone coefficient, A4 is the fourth-order aspheric coefficient, A6 is the sixth-order aspheric coefficient, A8 is the eighth-order aspheric coefficient, and A 10 is the 10th-order aspheric coefficient.

[0032] Furthermore, the operating band is from visible light to near infrared.

[0033] Furthermore, the clear aperture of the first lens (1) is less than 200 mm.

[0034] Furthermore, the incident angle of the chief ray of all fields of view on the focal plane is less than 3°.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1. In the present invention, both the second lens and the sixth lens adopt a single-sided aspheric surface, which reduces the pressure of single-piece aspheric surface correction distortion and astigmatism aberration, solves the problem of difficulty in aspheric surface processing caused by excessive depth of sagittal height of a single aspheric surface, meets the current aspheric surface processing technology, and has strong engineering feasibility.

[0037] 2. The present invention solves the chromatic aberration problem caused by the wide-band optical system by using low-refractive-index and low-dispersion materials, and the maximum lateral chromatic aberration is less than 20um. In addition, by constraining the incident angle of the main light of the edge field of view, quasi-image telecentricity is achieved, and the illumination uniformity of the edge field of view is improved. The back intercept of the optical system of the present invention is greater than 25mm, which reserves enough space for the detector installation.

[0038] 3. In the present invention, the first lens and the second lens are made of quartz and radiation-resistant heavy crown glass materials respectively, both of which are radiation-resistant materials. Compared with the traditional optical system in which only the first lens is made of quartz, the radiation resistance of the space environment is further improved, and it is particularly suitable for optical remote sensing instruments in orbital environments with large total space radiation doses such as medium orbit and medium-high orbit. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of the wide-band, large-field-of-view, low-distortion optical system of the present invention;

[0040] Figure 2 It is a modulation transfer function (MTF) curve of the wide-band, large-field-of-view, low-distortion optical system of the present invention;

[0041] Figure 3 The field curvature and distortion curves of the wide-band, large-field-of-view, low-distortion optical system of the present invention;

[0042] Figure 4The lateral chromatic aberration curve of the wide-band, large-field-of-view, low-distortion optical system of the present invention;

[0043] Numbers in the figure: L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; S-aperture stop; L7-seventh cemented lens; L700-seventh cemented positive lens; L701-seventh cemented negative lens; L8-eighth cemented lens; L800-eighth cemented negative lens convex to the object side; L801-eighth cemented positive lens; L802-eighth cemented negative lens convex to the image side; L9-ninth cemented lens. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings.

[0045] like Figure 1 The figure shows a schematic diagram of the structure of the wide-band, large-field-of-view, low-distortion optical system of the present invention. The optical system includes 12 lenses, 2 of which are aspherical, and the rest are spherical, and adopts an anti-telephoto structure with negative-positive focal power distribution. Specifically, it includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an aperture stop S, a seventh cemented lens L7, an eighth cemented lens L8, and a ninth lens L9, which are coaxially arranged in sequence along the incident direction. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 constitute a front lens group, the seventh cemented lens L7, the eighth cemented lens L8, and the ninth lens L9 constitute a rear lens group, and the aperture stop S is located near the front focal plane of the rear lens group.

[0046] The first lens L1 is a negative meniscus lens convex to the object side, and the absolute value of the focal length is in the range of [0.0025, 0.005]. In the embodiment of the present invention, the absolute value of the focal length is preferably 0.0031, or other focal length values ​​within the focal length range are preferred;

[0047] The second lens L2 is a negative meniscus lens convex to the object side, and the absolute value of the optical focal length is in the range of [0.01, 0.03]. In the embodiment of the present invention, the absolute value of the optical focal length is preferably 0.017, or other optical focal length values ​​within the optical focal length range are preferred;

[0048] The third lens L3 is a biconvex lens, and the absolute value of the focal length is in the range of [0.006, 0.01]. In the embodiment of the present invention, the absolute value of the focal length is preferably 0.007, or other focal length values ​​within the focal length range are preferred;

[0049] The fourth lens L4 is a negative meniscus lens convex toward the object side, and the absolute value of the focal length is in the range of [0.03, 0.05]. In the embodiment of the present invention, the absolute value of the focal length is preferably 0.034, or other focal length values ​​within the focal length range are preferred;

[0050] The fifth lens L5 is a biconcave lens, and the absolute value of the focal length is in the range of [0.02, 0.04]. In the embodiment of the present invention, the absolute value of the focal length is preferably 0.024, or other focal length values ​​within the focal length range are preferred.

[0051] The sixth lens L6 is a biconvex lens, and the absolute value of the optical focal length is in the range of [0.03, 0.05]. In the embodiment of the present invention, the absolute value of the optical focal length is preferably 0.034, or other optical focal length values ​​within the optical focal length range are preferred.

[0052] The seventh cemented lens L7 is composed of a seventh cemented positive lens L700 and a seventh cemented meniscus negative lens L701 which are coaxially arranged in sequence along the incident direction of the light. The absolute value of the focal length is in the range of [0.01, 0.04]. In the embodiment of the present invention, the absolute value of the focal length is preferably 0.019, or a focal length value within another focal length range is preferably selected.

[0053] The eighth cemented lens L8 is composed of an eighth cemented meniscus negative lens L800 convex to the object side, an eighth cemented positive lens L801 and an eighth cemented meniscus negative lens L802 convex to the image side, which are coaxially arranged in sequence along the incident direction of the light. The absolute value of the optical focal length is in the range of [0.01, 0.04]. In the embodiment of the present invention, the absolute value of the optical focal length is preferably 0.015, or an optical focal length value within other optical focal length ranges is preferably used;

[0054] The ninth lens L9 is a biconvex lens, and the absolute value of the optical focal length is in the range of [0.02, 0.05]. In the embodiment of the present invention, the absolute value of the optical focal length is preferably 0.025, or other optical focal length values ​​within the optical focal length range are preferred.

[0055] In this embodiment, the first lens L1 is made of fused quartz; the second lens L2 is made of radiation-resistant heavy crown glass material, with a refractive index value range of [1.60, 1.70] and a dispersion value range of [50, 65]. In this embodiment of the present invention, H-ZK6 glass material is preferred, with a refractive index of 1.613 and a dispersion of 58.577, or radiation-resistant glass materials within other refractive index ranges and dispersion ranges are preferred;

[0056] The refractive index of the third lens L3 is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60]. In the embodiment of the present invention, the glass material of the N-KZFS2 model is preferably used, with a refractive index of 1.558 and a dispersion of 54.008, or glass materials within other refractive index ranges and dispersion ranges are preferably used;

[0057] The refractive index of the fourth lens L4 is in the range of [1.70, 1.80], and the dispersion is in the range of [40, 55]. In the embodiment of the present invention, a glass material of type H-LAF3B is preferably used, whose refractive index is 1.744 and dispersion is 44.904, or a glass material within other refractive index ranges and dispersion ranges is preferably used;

[0058] The refractive index of the fifth lens L5 is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28]. In the embodiment of the present invention, a glass material of type N-SF10 is preferred, whose refractive index is 1.785 and dispersion is 25.68, or a glass material within other refractive index ranges and dispersion ranges is preferred;

[0059] The refractive index of the sixth lens L6 is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28]. In the embodiment of the present invention, a glass material of type N-SF10 is preferred, whose refractive index is 1.785 and dispersion is 25.68, or a glass material within other refractive index ranges and dispersion ranges is preferred;

[0060] The refractive index of the seventh cemented positive lens L700 is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90]. In the embodiment of the present invention, the glass material of the H-FK61 model is preferably used, and the refractive index is 1.497, and the dispersion is 81.613, or other glass materials within the refractive index range and the dispersion range are preferably used;

[0061] The refractive index of the seventh cemented meniscus negative lens L701 is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60]. In the embodiment of the present invention, the glass material of the N-KZFS2 model is preferably used, and the refractive index is 1.558, and the dispersion is 54.008, or other glass materials within the refractive index range and the dispersion range are preferably used;

[0062] The refractive index of the eighth cemented meniscus negative lens (L800) is in the range of [1.70, 1.75], and the dispersion is in the range of [30, 40]. In the embodiment of the present invention, the glass material of the N-KZFS8 model is preferred, and the refractive index is 1.720, and the dispersion is 34.700, or the glass material within other refractive index ranges and dispersion ranges is preferred;

[0063] The refractive index of the eighth cemented positive lens L801 is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90]. In the embodiment of the present invention, the glass material of the H-FK61 model is preferably used, and the refractive index is 1.497, and the dispersion is 81.613, or other glass materials within the refractive index range and the dispersion range are preferably used;

[0064] The refractive index of L802 of the eighth cemented meniscus negative lens is in the range of [1.80, 1.85], and the dispersion is in the range of [40, 50]. In the embodiment of the invention, the glass material of the N-LASF41 model is preferred, and the refractive index is 1.835 and the dispersion is 43.129, or other glass materials within the refractive index range and the dispersion range are preferred;

[0065] The refractive index of the ninth lens L9 is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90]. In the embodiment of the present invention, a glass material of the H-FK61 model is preferably used, whose refractive index is 1.497 and the dispersion is 81.613, or a glass material within other refractive index ranges and dispersion ranges is preferably used.

[0066] The surface parameters of all lenses in the embodiment of the present invention are as follows:

[0067]

[0068] In the embodiment of the present invention, the surface of the second lens L2 facing the image side and the surface of the sixth lens L6 facing the object side are both aspherical surfaces, and the aspherical surface equations are:

[0069]

[0070] Among them, z is the aspheric surface sag, c is the aspheric surface vertex curvature, y is the aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A 10 is the 10th-order aspheric coefficient.

[0071] In this embodiment, the two aspheric coefficients are as follows:

[0072]

[0073] The effective focal length of the optical system of this embodiment is The full field of view angle is 119°, the working band is 550-910nm, the relative aperture is 1:4.5, the total optical length is 235mm, the clear aperture of the first lens is 180mm, and the incident angle of the edge field chief light on the image plane is 2.5°, achieving a large field of view and image telecentricity. The edge field image plane illumination is better than 85%. The optical system of this embodiment can be applied to space remote sensing fields such as the front optical system of a satellite-borne high-resolution and wide-coverage imaging spectrometer and a multi-angle and multi-spectral polarization camera.

[0074] like Figure 2The figure shows the modulation transfer function (MTF) curve of the wide-band, large-field-of-view, low-distortion optical system of this embodiment. The abscissa in the figure represents the spatial frequency in line pairs per millimeter (lp / mm), and the ordinate represents the MTF value. The figure shows that at a spatial frequency of 20lp / mm, the MTF of the maximum field of view is greater than 0.70, indicating that the optical system has good imaging quality on the entire image plane.

[0075] like Figure 3 The left figure in FIG. 1 shows the field curvature curve of the wide-band, large-field-of-view, low-distortion optical system of this embodiment. The horizontal axis is the field curvature and the vertical axis is the normalized field of view. The figure shows that the maximum field curvature of the embodiment of the present invention is less than 0.3 mm. Figure 3 The right figure in the figure shows the distortion curve of the wide-band, large-field-of-view, low-distortion optical system of this embodiment. The horizontal axis is the relative distortion and the vertical axis is the normalized field of view. The figure shows that the distortion of all fields of view of the embodiments of the present invention is less than 2%.

[0076] like Figure 4 The figure shows the lateral chromatic aberration curve of the wide-band, large-field-of-view, low-distortion optical system of this embodiment, where the horizontal axis represents the lateral chromatic aberration and the vertical axis represents the normalized field of view. The figure shows that the lateral chromatic aberration of the embodiment of the present invention is less than 16um, which provides a strong guarantee for the spectral registration of optical remote sensing instruments.

Claims

1. A wide-band, large-field-of-view, low-distortion optical system, characterized in that: include: A first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), an aperture stop (S), a seventh cemented lens (L7), an eighth cemented lens (L8), and a ninth lens (L9) are coaxially arranged in sequence along the incident direction, wherein the first lens (L1), the second lens (L2), the third lens (L3), the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) constitute a front lens group, the seventh cemented lens (L7), the eighth cemented lens (L8), and the ninth lens (L9) constitute a rear lens group, and the aperture stop (S) is located near the front focal plane of the rear lens group; The first lens (L1) is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the first lens (L1) is in the range of [0.0025, 0.005]; The second lens (L2) is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the second lens (L2) is in the range of [0.01, 0.03]; The third lens (L3) is a biconvex lens, and the absolute value of the focal length of the third lens (L3) is in the range of [0.006, 0.01]; The fourth lens (L4) is a negative meniscus lens convex toward the object, and the absolute value of the focal length of the fourth lens (L4) is in the range of [0.03, 0.05]; The fifth lens (L5) is a biconcave lens, and the absolute value of the focal length of the fifth lens (L5) is in the range of [0.02, 0.04]; The sixth lens (L6) is a biconvex lens, and the absolute value of the focal length of the sixth lens (L6) is in the range of [0.03, 0.05]; The seventh cemented lens (L7) is composed of a seventh cemented positive lens (L700) and a seventh cemented meniscus negative lens (L701) which are coaxially arranged in sequence along the incident direction of light, and the absolute value of the focal length of the seventh cemented lens (L7) is in the range of [0.01, 0.04]; The eighth cemented lens (L8) is composed of an eighth cemented meniscus negative lens (L800) convex to the object side, an eighth cemented positive lens (L801) and an eighth cemented meniscus negative lens (L802) convex to the image side, which are coaxially arranged in sequence along the incident direction of light, and the absolute value of the optical focus of the eighth cemented lens (L8) is in the range of [0.01, 0.04]; The ninth lens (L9) is a biconvex lens, and the absolute value of the focal length of the ninth lens (L9) is in the range of [0.02, 0.05].

2. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The first lens (L1) is made of fused quartz material; the second lens (L2) is made of radiation-resistant heavy crown glass material.

3. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The refractive index of the second lens (L2) is in the range of [1.60, 1.70], and the dispersion is in the range of [50, 65]; The refractive index of the third lens (L3) is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60]; The refractive index of the fourth lens (L4) is in the range of [1.70, 1.80], and the dispersion is in the range of [40, 55]; The refractive index of the fifth lens (L5) is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28]; The refractive index of the sixth lens (L6) is in the range of [1.75, 1.85], and the dispersion is in the range of [20, 28]; The refractive index of the seventh cemented positive lens (L700) is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90]; The refractive index of the seventh cemented meniscus negative lens (L701) is in the range of [1.50, 1.65], and the dispersion is in the range of [50, 60]; The refractive index of the eighth cemented meniscus negative lens (L800) is in the range of [1.70, 1.75], and the dispersion is in the range of [30, 40]; The refractive index of the eighth cemented positive lens (L801) is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90]; The refractive index of the eighth cemented meniscus negative lens (L802) is in the range of [1.80, 1.85], and the dispersion is in the range of [40, 50]; The refractive index of the ninth lens (L9) is in the range of [1.45, 1.55], and the dispersion is in the range of [75, 90].

4. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The second lens (L2) and the sixth lens (L6) are both aspherical.

5. The wide-band, large-field-of-view, low-distortion optical system according to claim 4, characterized in that: The equation of the aspheric surface is constructed using equation (1): (1) In formula (1), z is the aspheric height, c is the vertex curvature of the aspheric surface, y is the aperture of the aspheric surface, k is the cone coefficient, A4 is the fourth-order aspheric coefficient, A6 is the sixth-order aspheric coefficient, A8 is the eighth-order aspheric coefficient, and A 10 is the 10th-order aspheric coefficient.

6. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The operating band is from visible light to near infrared.

7. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The clear aperture of the first lens (1) is less than 200 mm.

8. The wide-band, large-field-of-view, low-distortion optical system according to claim 1, characterized in that: The incident angle of the chief ray at the focal plane for all fields of view is less than 3°.

Images