Infrared optical system and infrared optical lens

Abstract

The utility model discloses an infrared optical system and an infrared optical lens, the infrared optical system sequentially comprises a super lens and an aspherical lens from an object side to an image side, the surface, close to the object side, of the aspherical lens protrudes towards the image side, and the surface, away from the object side, of the aspherical lens protrudes towards the image side. The super lens meets the conditional expression that neff is larger than 0.8 and smaller than 3.6, and neff is the effective refractive index of the super lens; the infrared optical system meets the conditional expression: # imgabs0 #, L1 is the distance between the surface, close to the object side, of the super lens and the surface, away from the object side, of the aspherical lens, L is the total optical length of the infrared optical system, and when the value of # imgabs1 # is small, the mechanical length of an infrared optical lens corresponding to the infrared optical system can be relatively short, and the mechanical length of the infrared optical lens corresponding to the infrared optical system can be relatively short. The size of an infrared optical lens corresponding to the infrared optical system can be relatively small.

Description

Technical Field

[0001] The present application relates to the field of lenses, and in particular to an infrared optical system and an infrared optical lens. Background Art

[0002] The lens is generally composed of two parts: the optical system and the structural parts. Infrared lens, also known as infrared thermal imaging lens, generally refers to an imaging lens with a working wavelength of 8-14μm. Infrared lens can make up for the defects of visible light imaging lens, and can replace visible light imaging in fog, haze, rain, snow, night and other environments. It is widely used in security, automotive, military and other fields.

[0003] In the prior art, an infrared lens is usually composed of multiple lenses. Since the lens itself has a certain thickness and there is usually a preset distance between two adjacent lenses, the lens is relatively large. Utility Model Content

[0004] In response to the above technical problems, the embodiments of the present application provide an infrared optical system and an infrared optical lens, which aim to solve the problem of large size of the infrared optical system in the prior art.

[0005] According to one aspect of an embodiment of the present application, an infrared optical system is disclosed, wherein the infrared optical system includes, in order from the object side to the image side along the optical axis: a super lens and an aspheric lens; the surface of the aspheric lens close to the object side is convex toward the image side, and the surface of the aspheric lens away from the object side is convex toward the image side;

[0006] Wherein, the super lens satisfies the conditional formula: 0.8<n eff <3.6, where n eff is the equivalent refractive index of the metalens; the infrared optical system satisfies the following conditional formula: Wherein, L1 is the distance between the surface of the super lens close to the object side and the surface of the aspheric lens away from the object side, and L is the total optical length of the infrared optical system.

[0007] In some embodiments, the infrared optical system satisfies the following conditional formula in diopter D: 2.1D≤ΔΦ m ≤10.4D, where the ΔΦ m is the difference between the maximum and minimum optical power of the metalens in the working band.

[0008] In some embodiments, the infrared optical system satisfies the following condition: Among them, the f m is the focal length of the superlens, and f is the effective focal length of the infrared optical system.

[0009] In some embodiments, the infrared optical system satisfies the following condition: Among them, the T m is the thickness of the superlens, the T a is the thickness of the aspheric lens along the optical axis, the Φ m is the optical power provided by the metalens, the Φ a The optical power provided by the aspheric lens.

[0010] In some embodiments, the infrared optical system satisfies the following condition: Among them, the is the maximum phase value provided by the metalens, the r m is the effective area radius of the superlens.

[0011] In some embodiments, the metalens satisfies the following conditional formula: Among them, the n eff is the equivalent refractive index of the metalens, and the n t is the refractive index of the aspheric lens.

[0012] In some embodiments, the metalens satisfies the following conditional formula: Among them, the is the maximum spatial phase gradient of the metalens, is the maximum spatial phase gradient of the metalens.

[0013] In some embodiments, the metalens satisfies the following conditional formula: Wherein, the Δgd m is the maximum group delay difference provided by all the micro-nano structures of the metalens, the Δgd t is the maximum group delay difference provided by the aspheric lens.

[0014] A second aspect of an embodiment of the present application provides an infrared optical lens, comprising a lens barrel and the above-mentioned infrared optical system; the infrared optical system is arranged in the lens barrel.

[0015] In some embodiments, the lens barrel is provided with a first mounting through hole, and the lens barrel includes a main body and a supporting portion; the supporting portion is connected to one side of the main body along the optical axis direction, and a mounting hole is provided on a side of the supporting portion away from the main body;

[0016] The first mounting through hole includes a first hole segment and a second hole segment; the first hole segment is arranged in the main body; the second hole segment is arranged in the supporting portion, and the diameter of the second hole segment is smaller than the diameter of the first hole segment; the aspheric lens is accommodated in the first hole segment, the aspheric lens is connected to the main body, and the aspheric lens is abutted against the supporting portion; the super lens is accommodated in the mounting hole, and the super lens is connected to the supporting portion.

[0017] In some embodiments, the optical lens further includes a first pressure ring and a second pressure ring, wherein the first pressure ring is pressed onto the aspheric lens and connected to the main body; the second pressure ring is pressed onto the super lens and connected to the supporting portion.

[0018] In some embodiments, the lens barrel includes a main body and a supporting portion, the main body is provided with a second mounting through hole, the supporting portion is received in the second mounting through hole, and the supporting portion is connected to the main body;

[0019] The aspheric lens is accommodated in the second mounting through hole, the aspheric lens is connected to the main body, and the aspheric lens is abutted against the supporting portion; the super lens is located on one side of the aspheric lens along the axial direction of the second mounting through hole, and the super lens is connected to the main body.

[0020] In some embodiments, the optical lens further includes a buffer and a third pressure ring, wherein the buffer is disposed between the superlens and the aspheric lens; the third pressure ring is pressed onto the superlens, and the third pressure ring is connected to the main body.

[0021] The infrared optical system provided in the present application includes a super lens and an aspheric lens in order from the object side to the image side, the surface of the aspheric lens close to the object side is convex to the image side, and the surface of the aspheric lens away from the object side is convex to the image side, and the super lens satisfies the conditional formula: 0.8 < n eff <3.6, wherein the n eff is the equivalent refractive index of the metalens. The infrared optical system proposed in this application uses a combination of a metalens and an aspheric lens, which can significantly reduce the volume of the infrared optical system while meeting the imaging requirements, and can also reduce the production cost of the infrared optical system. The infrared optical system meets the following conditional formula: Wherein, L1 is the length between the surface of the metalens close to the object side and the surface of the aspheric lens away from the object side, and L is the total optical length of the infrared optical system. When the value is small, the mechanical length of the infrared optical lens corresponding to the infrared optical system can be relatively short, and the volume of the infrared optical lens corresponding to the infrared optical system can be relatively small. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0023] Figure 1 A schematic diagram of the architecture layout of an infrared optical system in an embodiment of the present application is shown.

[0024] Figure 2 A schematic diagram showing the performance output of an infrared optical system in an embodiment of the present application is shown.

[0025] Figure 3 The MTF field of view curve diagram of the infrared optical system in one embodiment of the present application is shown.

[0026] Figure 4 A schematic diagram showing the performance output of an infrared optical system in an embodiment of the present application is shown.

[0027] Figure 5 The MTF field of view curve diagram of the infrared optical system in one embodiment of the present application is shown.

[0028] Figure 6 A schematic diagram showing the performance output of an infrared optical system in an embodiment of the present application is shown.

[0029] Figure 7 The MTF field of view curve diagram of the infrared optical system in one embodiment of the present application is shown.

[0030] Figure 8 A schematic diagram showing the performance output of an infrared optical system in an embodiment of the present application is shown.

[0031] Fig. 9 The MTF field of view curve diagram of the infrared optical system in one embodiment of the present application is shown.

[0032] Fig.10 A schematic diagram showing the performance output of an infrared optical system in an embodiment of the present application is shown.

[0033] Fig.11 The MTF field of view curve diagram of the infrared optical system in one embodiment of the present application is shown.

[0034] Fig.12 A schematic diagram of the structure of an infrared optical lens in an embodiment of the present application is shown.

[0035] Fig.13 A schematic diagram of the structure of an infrared optical lens in an embodiment of the present application is shown.

[0036] Reference numerals

[0037] 100. Infrared optical system;

[0038] 1. Super lens; 11. Structural surface;

[0039] 2. Aspheric lens; 21. First curved surface; 22. Second curved surface;

[0040] 3. Optical protection parts;

[0041] A, object plane; B, image plane; S, optical axis;

[0042] 1000, infrared optical lens;

[0043] 200, lens barrel; 2001, main body; 2002, supporting portion; 2003, first mounting through hole; 2003a, first hole section; 2003b, second hole section; 2004, second mounting through hole; 2005, mounting hole;

[0044] 300, first pressing circle;

[0045] 400, second pressing circle;

[0046] 500, third pressing circle;

[0047] 600. Buffer parts. DETAILED DESCRIPTION

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present application will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0049] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application may be practiced while omitting one or more of the specific details, or other modules, components, etc. may be adopted. In other cases, known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the present application and making the various aspects of the present application unclear.

[0050] The present application provides an infrared optical system 100. The prior art that is closest to the specifications to be achieved by the present application is Chinese patent CN115079378A. Chinese patent CN115079378A discloses a short-focus, low-distortion, athermal infrared lens. The effective focal length of the lens is close to the effective focal length of the infrared optical system provided by the present application, but the total optical length of the lens reaches 38.75 mm, which is not conducive to the miniaturization of the lens.

[0051] See also Figure 1 , Figure 1 FIG. 1 shows a schematic diagram of the structure layout of an infrared optical system 100 in an embodiment of the present application, wherein the optical axis S is the center line of the light beam. Figure 1 In the figure, the left side of the leftmost lens is the object side, and the object plane A is located on the object side. The right side of the rightmost lens is the image side, and the image plane B is located on the image side. Therefore, the direction from the object plane A to the image plane B along the optical axis S is consistent with the direction from the object side to the image side along the optical axis S.

[0052] The infrared optical system 100 includes a super lens 1 and an aspherical lens 2 , and the super lens 1 and the aspherical lens 2 are arranged in sequence along the optical axis S from the object side to the image side.

[0053] The superlens 1 is an optical modulation device obtained by setting a structural surface 11 on a substrate. The structural surface 11 is composed of a plurality of micro-nano structures arranged, and a medium is filled between the micro-nano structures. The medium filled between the micro-nano structures includes but is not limited to air or other materials that are transparent in the working band of the superlens 1. According to the phase modulation method adopted, the various parameters of the micro-nano structure can be adaptively configured using a matching phase modulation formula, so that the superlens 1 can achieve the corresponding optical performance. The number of layers of the structural surface 11 can be one layer, two layers, or three layers or more, and the specific number of layers is not limited.

[0054] The structure surface 11 is arranged on the side of the substrate close to the aspheric lens 2, or the structure surface 11 is arranged on the side of the substrate far from the aspheric lens 2. It should be noted that although Figure 1 The middle structure surface 11 is located on the side of the substrate close to the aspheric lens 2 , but it should not be understood that the structure surface 11 can only be arranged on the side of the substrate close to the aspheric lens 2 .

[0055] The superlens 1 is used to provide optical focal length to converge light. The superlens 1 provides different focal lengths at different wavelengths. Therefore, the superlens 1 can converge the focus of each single wavelength light image plane at the same position, and has the function of correcting system chromatic aberration. The superlens 1 satisfies: 0.8<n eff <3.6, where n eff is the equivalent refractive index of the superlens 1. Further, the equivalent refractive index of the superlens 1 satisfies: 1<n eff <3.5.

[0056] The aspheric lens 2 has a first curved surface 21 and a second curved surface 22. Along the optical axis S from the object side to the image side, the first curved surface 21 and the second curved surface 22 are respectively located on both sides of the aspheric lens 2. The first curved surface 21 is close to the object side, and the first curved surface 21 is convex to the image side. The second curved surface 22 is close to the image side, and the second curved surface 22 is convex to the image side. The aspheric lens 2 is used to provide optical power.

[0057] The infrared optical system 100 satisfies the following conditional formula:

[0058]

[0059] Wherein, L1 is the distance between the surface of the metalens 1 close to the object side and the surface of the aspheric lens 2 far from the object side, and its unit is length unit. L is the total optical length of the infrared optical system 100, which is also known as TTL (Total Track Length), and its unit is length unit. Figure 1 In the infrared optical system 100 provided in the present application, L is the distance from the center of the surface of the metalens 1 close to the object side to the image plane. L and L1 have the same dimension, for example, both are millimeters.

[0060] for Since the length of L1 will directly affect the mechanical length of the infrared optical lens corresponding to the infrared optical system 100, The upper limit of the value represents the maximum proportion of the infrared optical lens corresponding to the infrared optical system 100 in the length of the optical path. The lower limit of the value represents the minimum proportion of the infrared optical lens corresponding to the infrared optical system 100 in the optical path, that is, The lower limit of the value of represents the limit of the compression lens length, When the value of is small, the mechanical length of the infrared optical lens corresponding to the infrared optical system 100 can be relatively short, and the volume of the infrared optical lens corresponding to the infrared optical system 100 can be relatively small.

[0061] In the present application, the metalens 1 provides optical power while correcting chromatic aberration, and the metalens 1 providing optical power and the aspheric lens 2 providing optical power correct the aberration together. Compared with the optical system composed of at least two refractive lenses in the prior art, the infrared optical system 100 proposed in the present application uses a combination of a metalens 1 and an aspheric lens 2, which can significantly reduce the volume of the infrared optical system 100 while meeting the imaging requirements, and can also reduce the production cost of the infrared optical system 100.

[0062] In some embodiments, the metalens 1 satisfies the following conditional formula:

[0063]

[0064] Among them, the is the maximum spatial phase gradient of the metalens at the central wavelength of the working band, is the maximum spatial phase gradient of the metalens at the central wavelength of the working band. It represents the range of focusing capabilities that the superlens 1 can provide, because the spatial phase gradient determines the ability of the superlens 1 to deflect the light beam. The upper limit of represents the maximum focusing range provided by the metalens 1, The lower limit of represents the minimum focusing range provided by the metalens 1.

[0065] In some embodiments, the metalens 1 satisfies the following conditional formula:

[0066]

[0067] Among them, Δgd m Δgd is the maximum group delay difference provided by all micro-nano structures of the superlens 1 at the central wavelength of the working band, and its unit is time unit. t It is the maximum group delay difference provided by the aspheric lens 2 at the central wavelength of the working band, and its unit is time unit. m and Δgd t The dimensions of are the same, for example, both are femtoseconds. In the infrared optical system 100, the super lens 1 needs to be dispersed and matched with the aspheric lens 2 to compensate for each other. It represents the compensation situation of the group delay in the infrared optical system 100. The upper limit of represents the maximum dispersion ratio provided by the metalens 1 in the infrared optical system 100, The lower limit of represents the minimum dispersion ratio provided by the metalens 1 in the infrared optical system 100.

[0068] In some embodiments, the metalens 1 satisfies the following conditional formula:

[0069]

[0070] Among them, n eff is the equivalent refractive index of the superlens 1, n t is the refractive index of the aspherical lens 2. represents the refractive index ratio of the superlens 1 and the aspherical lens 2 in the infrared optical system 100. The upper limit represents the maximum refractive index ratio that the metalens 1 in the infrared optical system 100 can provide. The upper limit of represents the minimum refractive index ratio required for the metalens 1 in the infrared optical system 100.

[0071] In some embodiments, the infrared optical system 100 satisfies the following conditional expression with D as the unit:

[0072] 2.1D≤ΔΦ m ≤10.4D

[0073] Since the super lens 1 has the function of correcting chromatic aberration, the optical power Φ of the super lens 1 is m will change with the change of the wavelength of the light beam, ΔΦ m is the maximum value of the optical focal length of the metalens 1 in the working band (Φ max ) and the minimum value (Φ min ), the unit of which is diopter, abbreviated as D.

[0074] For ΔΦ m , which reflects the ability of the super lens 1 to correct chromatic aberration. ΔΦ m The lower limit of represents the minimum chromatic aberration correction requirement of the infrared optical system 100 and its specific lens arrangement and structure for the metalens 1, ΔΦ m The upper limit of represents the maximum chromatic aberration correction capability that the metalens 1 can provide in the infrared optical system 100. m When the super lens 1 is used, it can provide a stronger light focusing ability.

[0075] In some embodiments, the infrared optical system 100 satisfies the following conditional formula:

[0076]

[0077] Among them, f m is the focal length of the metalens 1, and its unit is the length unit. f is the effective focal length of the infrared optical system 100, and its unit is the length unit. f and f m have the same dimension, for example, millimeters.

[0078] for The value of represents the focal length proportion of the superlens 1 in the system, reflecting the role of the superlens 1 in focusing. The upper limit represents the minimum light focusing ability that the metalens 1 needs to provide in the infrared optical system 100. The lower limit of represents the maximum light focusing ability that the metalens 1 needs to provide in the infrared optical system 100.

[0079] In some embodiments, the infrared optical system 100 satisfies the following conditional formula:

[0080]

[0081] Among them, MTF aveis the average modulation transfer function value corresponding to the full field of view at the cutoff frequency, that is, MTF ave is the mean value of the modulation transfer function (MTF) of the whole field of view at the cutoff frequency. The modulation transfer function is also called the spatial contrast transfer function and the spatial frequency contrast sensitivity function. It reflects the ability of the optical system to transfer the modulation degree of sinusoidal objects of various frequencies as a function of spatial frequency. L is the total optical length of the infrared optical system 100, in millimeters. The specific measurement method of L can be referred to above, and the measurement method will not be described in this article.

[0082] for The value of reflects the effect of compressing the volume and improving the image quality of the infrared optical system 100. The larger the value, the smaller the volume of the infrared optical system 100 and the better the image quality of the infrared optical system 100. The lower limit of represents the basic control capability of the infrared optical system 100 on the image quality in the case of compressed volume. The upper limit represents the ultimate control capability of the infrared optical system 100 on the image quality under the condition of compressed volume. Between 0.043 and 0.051, the infrared optical system 100 can output better image quality while having a relatively small volume.

[0083] In some embodiments, the infrared optical system 100 satisfies the following conditional formula:

[0084]

[0085] Among them, T m is the thickness of the metalens 1, in millimeters. a is the thickness of the aspheric lens 2 along the optical axis S, that is, T a is the center thickness of the aspheric lens 2, in millimeters. m is the optical power provided by the super lens 1. Φ a is the focal length provided by the aspherical lens 2, Φ a The unit is D.

[0086] for The value of is the difference between the optical focal length of the metalens 1 at a unit thickness and the optical focal length of the aspheric lens 2 at a unit thickness, which reflects the thickness advantage of the metalens 1 in the infrared optical system 100 compared with the aspheric lens 2 when providing the same optical focal length. Specifically, the metalens 1 can still provide a larger optical focal length at a lower thickness, so that the volume of the infrared optical system 100 can be significantly reduced.

[0087] The lower limit of the value of represents a situation in which the metalens 1 provides the minimum optical power per unit thickness and the aspherical lens 2 provides the maximum optical power per unit thickness in the infrared optical system 100 . The upper limit of the value of represents a situation in which the metalens 1 provides the maximum optical power per unit thickness and the aspherical lens 2 provides the minimum optical power per unit thickness in the infrared optical system 100 .

[0088] In some embodiments, the infrared optical system 100 satisfies the following conditional formula:

[0089]

[0090] in, is the maximum phase value provided by the superlens 1, The unit of is p, where p represents a radian of 2π. m is the effective area radius of the metalens 1, which is also called the net aperture, i.e., the maximum radius of the area through which the light beam passes. It should be noted that when the metalens 1 is a double-sided metalens, when the two structural surfaces 11 When the two structural surfaces 11 are equal, any one of them can be selected. If they are not equal, choose The larger structural surface 11 is calculated.

[0091] for The lower limit represents the maximum phase value per unit radius that the metalens 1 needs to provide when achieving the target optical performance and compressing the volume in the infrared optical system 100. That is, when the target optical performance is to be achieved and the volume is compressed in the infrared optical system 100, the maximum phase value per unit radius of the metalens 1 should be greater than 4.06p / mm. The upper limit represents the maximum phase value per unit radius that the metalens 1 can provide in the infrared optical system 100. The maximum value of .

[0092] See also Figure 1In some embodiments, the infrared optical system 100 further includes an optical protector 3, which can transmit light, and is located along the optical axis S on the side of the aspheric lens 2 away from the super lens 1, that is, the infrared optical system 100 along the optical axis S from the object side to the image side is sequentially composed of the super lens 1, the aspheric lens 2 and the optical protector 3.

[0093] The optical protection member 3 may be in the form of protective glass, but the material of the optical protection member 3 is not limited to silicon. For example, the material of the optical protection member 3 may also be germanium.

[0094] The present application exemplarily provides five infrared optical systems 100 that meet usage requirements in five embodiments. Next, the infrared optical system 100 provided by each embodiment of the present application is introduced in detail.

[0095] Example 1

[0096] Figure 2 The schematic diagram of the architecture layout of the infrared optical system 100 operating in the far-infrared band in the embodiment 1 provided by the present application is shown. Figure 2 The performance of the infrared optical system 100 output in Example 1 of the present application is also shown. Figure 2 Combined with Figure 1 In Example 1, the infrared optical system 100 includes, in order from the object side to the image side along the optical axis S: a super lens 1, an aspherical lens 2 and an optical protection member 3.

[0097] Table 1. Some parameters of infrared optical system 100

[0098] System Parameters data Total optical length (TTL) 6.38mm Field of view (2ω) 69.1° F-number 1.1 Effective focal length 3.11mm Working band 8~12μm

[0099] As can be seen from Table 1, the infrared optical system 100 in this embodiment has an operating band of 8 to 12 μm, which meets the working requirements of the far-infrared band. The F number (aperture) of the infrared optical system 100 is 1.1, which can greatly increase the amount of light entering the infrared optical system 100, and collect as much energy as possible entering the infrared optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. At the same time, the infrared optical system 100 has a large field of view angle of 69.1°. At the same time, the total optical length is only 6.38 mm, which fully meets the requirements of the infrared optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0100] Starting from the object plane, along the optical axis S from the object side to the image side, each surface in the optical system is numbered, and the parameters of each surface are summarized to obtain the following Table 2.

[0101] Table 2. Parameters of various surfaces in the infrared optical system 100 provided in Example 1

[0102] Surface serial number Surface type Radius of curvature thickness Material 1 Physical surface unlimited - - 2 Spherical unlimited 0.38mm Silicon 3 Structural surface unlimited 0.93mm - 4 Aspheric -5.06mm 1.53mm IRG206 5 Aspheric -3.45mm 2.85mm - 6 Spherical unlimited 0.60mm Silicon 7 Spherical unlimited 0.10mm - 8 Image plane unlimited - -

[0103] For each surface in Table 2, surface 1 is the object surface. Surface 2 is the surface of the metalens 1 close to the object side, and surface 3 is the surface of the metalens 1 away from the object side. Since the micro-nano structure is provided on the surface of the metalens 1 away from the object side, it is recorded as the structural surface. Surface 4 is the surface of the aspheric lens 2 close to the object side, and surface 5 is the surface of the aspheric lens 2 away from the object side. Surface 6 is the surface of the optical protection member 3 close to the object side, and surface 7 is the surface of the optical protection member 3 away from the object side. Surface 8 is the image surface.

[0104] As can be seen from Table 2, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, the distance between surface 1 and surface 2 is uncertain, and the material between surface 1 and surface 2 is air. Surface 2 is a spherical surface, the distance between surface 2 and surface 3 is 0.38 mm, and the material between surface 2 and surface 3 is silicon. Surface 3 is structural surface 11, which is a plane, the distance between surface 3 and surface 4 is 0.93 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is -5.06 mm, the distance between surface 4 and surface 5 is 1.53 mm, and the material between surface 4 and surface 5 is IRG206, which is the brand of chalcogenide glass lenses. The specific parameters of IRG206 can be found in relevant materials. The radius of curvature of surface 5 is -3.45 mm, the distance between surface 5 and surface 6 is 2.85 mm, and the material between surface 5 and surface 6 is air. Surface 6 is a spherical surface, the distance between surface 6 and surface 7 is 0.60 mm, and the material between surface 6 and surface 7 is silicon. Surface 7 is a spherical surface, the distance between surface 7 and surface 8 is 0.10 mm, and the material between surface 7 and surface 8 is air. Surface 8 is a plane.

[0105] Surface 3 and surface 4 are even-order aspheric surfaces, and their surface shapes satisfy the following relationship:

[0106]

[0107] Among them, Z(r) is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of r along the optical axis; c is the surface curvature of the aspherical surface, c=1 / R, R is the radius of curvature of the aspherical surface; k is the cone coefficient; A, B, C, and D are aspherical coefficients.

[0108] Table 3. Aspheric coefficients in the infrared optical system provided in Example 1

[0109] Surface serial number K 4 times 6 times 8 times 10 times 12 times 14 times 16 times 3 1.78E+00 -3.70E-03 -7.96E-04 4.17E-04 -1.14E-03 7.09E-04 -1.70E-04 1.54E-05 4 -2.27E-01 -1.59E-03 3.80E-04 -4.01E-04 3.64E-05 1.93E-05 -5.15E-06 3.68E-07

[0110] Please refer to Table 3. The fourth-order aspheric coefficient of surface 3 is -3.70E-03, that is, A is equal to -3.70E-03. The values ​​of B, C, and D of surface 3 can be queried through Table 3 according to the above method. The values ​​of A, B, C, and D of surface 4 can also be obtained through Table 3.

[0111] See also Figure 3 , Figure 3 The MTF field of view curve of the infrared optical system 100 working in the infrared band in Example 1 provided by the present application is shown. MTF is also called modulation transfer function, which is an important indicator used to describe the imaging quality of an optical system. The larger the MTF value, the better the imaging quality. Figure 3 , Figure 3 The sagittal curve S1 and the meridional curve T1 of the MTF of 5.25lp / mm spatial frequency as the field of view changes, the sagittal image curve S2 and the meridional curve T2 of the MTF of 10.5lp / mm spatial frequency as the field of view changes, the sagittal image curve S3 and the meridional curve T3 of the MTF of 21lp / mm spatial frequency as the field of view changes, and the sagittal curve S4 and the meridional curve T4 of the MTF of 42lp / mm spatial frequency as the field of view change are listed. It can be seen from the above eight curves that although the edge image quality of the infrared optical system 100 is poor, the MTF within the 33.55° field of view is always greater than 0.2. Therefore, the center image quality of the infrared optical system 100 is better. Among them, Figure 3 The Y field of view in the figure represents the field of view in the Y-axis direction.

[0112] Example 2

[0113] Figure 4 The schematic diagram of the architecture layout of the infrared optical system 100 working in the far-infrared band in the second embodiment provided by the present application is shown. Figure 4 The performance of the infrared optical system 100 output in Example 2 of the present application is shown. Figure 4 Combined with Figure 1 In Example 2, the infrared optical system 100 includes, in order from the object side to the image side along the optical axis S: a super lens 1, an aspherical lens 2 and an optical protection member 3.

[0114] Table 4. Some parameters of infrared optical system

[0115] System Parameters data Total optical length (TTL) 6.36mm Field of view (2ω) 61.9° F-number 1.1 Effective focal length 3.4mm Working band 8~12μm

[0116] As can be seen from Table 4, the infrared optical system 100 in this embodiment has an operating band of 8 to 12 μm, which meets the working requirements of the far-infrared band. The F number (aperture) of the infrared optical system 100 is 1.1, which can greatly increase the amount of light entering the infrared optical system 100, and collect as much energy as possible entering the infrared optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. At the same time, the infrared optical system 100 has a large field of view angle of 61.9°. At the same time, the total optical length is only 6.36 mm, which fully meets the requirements of the infrared optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0117] Starting from the object plane, along the optical axis S from the object side to the image side, each surface in the optical system is numbered, and the parameters of each surface are summarized to obtain the following Table 5.

[0118] Table 5. Parameters of various surfaces in the infrared optical system provided in Example 2

[0119] Surface serial number Surface type Radius of curvature thickness Material 1 Physical surface unlimited - - 2 Spherical unlimited 0.38mm Silicon 3 Structural surface unlimited 1.17mm - 4 Aspheric -5.93mm 1.21mm IRG206 5 Aspheric -3.72mm 3.01mm - 6 Spherical unlimited 0.60mm Silicon 7 Spherical unlimited 0mm - 8 Image plane unlimited - -

[0120] For each surface in Table 5, surface 1 is the object surface. Surface 2 is the surface of the metalens 1 close to the object side, and surface 3 is the surface of the metalens 1 away from the object side. Since the micro-nano structure is provided on the surface of the metalens 1 away from the object side, it is recorded as the structural surface. Surface 4 is the surface of the aspheric lens 2 close to the object side, and surface 5 is the surface of the aspheric lens 2 away from the object side. Surface 6 is the surface of the optical protection member 3 close to the object side, and surface 7 is the surface of the optical protection member 3 away from the object side. Surface 8 is the image surface.

[0121] As can be seen from Table 5, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, the distance between surface 1 and surface 2 is uncertain, and the material between surface 1 and surface 2 is air. Surface 2 is a spherical surface, the distance between surface 2 and surface 3 is 0.38 mm, and the material between surface 2 and surface 3 is silicon. Surface 3 is structural surface 11, which is a plane, the distance between surface 3 and surface 4 is 1.17 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is -5.93 mm, the distance between surface 4 and surface 5 is 1.21 mm, and the material between surface 4 and surface 5 is IRG206. The radius of curvature of surface 5 is -3.72 mm, the distance between surface 5 and surface 6 is 3.01 mm, and the material between surface 5 and surface 6 is air. Surface 6 is a spherical surface, the distance between surface 6 and surface 7 is 0.60 mm, and the material between surface 6 and surface 7 is silicon. Surface 7 is a spherical surface, and the distance between surface 7 and surface 8 is 0 mm. Surface 8 is a plane.

[0122] Surface 3 and surface 4 are even-order aspheric surfaces, and their surface shapes can be determined by the formula provided in the above embodiment.

[0123] Table 6. Aspheric coefficients in the infrared optical system provided in Example 2

[0124] Surface serial number K 4 times 6 times 8 times 10 times 12 times 14 times 16 times 3 2.20E+00 1.67E-03 -2.66E-03 1.66E-03 -4.64E-04 3.60E-05 1.23E-05 -1.82E-06 4 -3.03E-01 -5.68E-04 1.69E-04 -1.88E-04 3.00E-05 3.82E-06 -1.73E-06 1.95E-07

[0125] See also Figure 5 , Figure 5 The MTF field of view curve of the infrared optical system 100 working in the infrared band in Example 2 provided by the present application is shown. MTF is also called modulation transfer function, which is an important indicator used to describe the imaging quality of an optical system. The larger the MTF value, the better the imaging quality. Figure 5 , Figure 5 The sagittal curve S1 and the meridional curve T1 of the MTF of 5.25lp / mm spatial frequency as the field of view changes, the sagittal image curve S2 and the meridional curve T2 of the MTF of 10.5lp / mm spatial frequency as the field of view changes, the sagittal image curve S3 and the meridional curve T3 of the MTF of 21lp / mm spatial frequency as the field of view changes, and the sagittal curve S4 and the meridional curve T4 of the MTF of 42lp / mm spatial frequency as the field of view change are listed. It can be seen from the above eight curves that although the image quality of the infrared optical system 100 is poor at the edges, the MTF within the 28° field of view is always greater than 0.2. Therefore, the image quality of the center of the infrared optical system 100 is better. Among them, Figure 5 The Y field of view in the figure represents the field of view in the Y-axis direction.

[0126] Example 3

[0127] Figure 6 The schematic diagram of the architecture layout of the infrared optical system 100 operating in the far-infrared band in the third embodiment provided by the present application is shown. Figure 6 The performance of the infrared optical system 100 output in Example 3 of the present application is shown. Figure 6 Combined with Figure 1 In Example 3, the infrared optical system 100 includes, in order from the object side to the image side along the optical axis S: a super lens 1, an aspherical lens 2 and an optical protection member 3.

[0128] Table 7. Some parameters of infrared optical system

[0129] System Parameters data Total optical length (TTL) 8.7mm Field of view (2ω) 70.1° F-number 1 Effective focal length 3.18mm Working band 8~12μm

[0130] As can be seen from Table 7, the infrared optical system 100 in this embodiment has an operating band of 8 to 12 μm, which meets the working requirements of the far-infrared band. The F number (aperture) of the infrared optical system 100 is 1, which can greatly increase the amount of light entering the infrared optical system 100, and collect as much energy as possible entering the infrared optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. At the same time, the infrared optical system 100 has a large field of view angle of 70.1°. At the same time, the total optical length is only 8.7 mm, which fully meets the requirements of the infrared optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0131] Starting from the object plane, along the optical axis S from the object side to the image side, each surface in the optical system is numbered, and the parameters of each surface are summarized to obtain the following Table 8.

[0132] Table 8. Parameters of various surfaces in the infrared optical system provided in Example 3

[0133] Surface serial number Surface type Radius of curvature thickness Material 1 Physical surface unlimited - - 2 Spherical unlimited 0.38mm Silicon 3 Structural surface unlimited 0.5mm - 4 Aspheric -5.40mm 3.44mm IRG209 5 Aspheric -4.55mm 3.07mm - 6 Spherical unlimited 0.60mm Silicon 7 Spherical unlimited 0.1mm - 8 Image plane unlimited - -

[0134] For each surface in Table 8, surface 1 is the object surface. Surface 2 is the surface of the metalens 1 close to the object side, and surface 3 is the surface of the metalens 1 away from the object side. Since the micro-nano structure is provided on the surface of the metalens 1 away from the object side, it is recorded as the structural surface. Surface 4 is the surface of the aspheric lens 2 close to the object side, and surface 5 is the surface of the aspheric lens 2 away from the object side. Surface 6 is the surface of the optical protection member 3 close to the object side, and surface 7 is the surface of the optical protection member 3 away from the object side. Surface 8 is the image surface.

[0135] As can be seen from Table 8, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, the distance between surface 1 and surface 2 is uncertain, and the material between surface 1 and surface 2 is air. Surface 2 is a spherical surface, the distance between surface 2 and surface 3 is 0.38 mm, and the material between surface 2 and surface 3 is silicon. Surface 3 is structural surface 11, which is a plane, the distance between surface 3 and surface 4 is 0.5 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is -5.40 mm, the distance between surface 4 and surface 5 is 3.44 mm, and the material between surface 4 and surface 5 is IRG209, which is the brand of chalcogenide glass lenses. The specific parameters of IRG209 can be found in relevant materials. The radius of curvature of surface 5 is -4.55 mm, the distance between surface 5 and surface 6 is 3.07 mm, and the material between surface 5 and surface 6 is air. Surface 6 is a spherical surface, the distance between surface 6 and surface 7 is 0.60 mm, and the material between surface 6 and surface 7 is silicon. Surface 7 is a spherical surface, the distance between surface 7 and surface 8 is 0.1 mm. Surface 8 is a plane.

[0136] Surface 3 and surface 4 are even-order aspheric surfaces, and their surface shapes can be determined by the formula provided in the above embodiment.

[0137] Table 9. Aspheric coefficients in the infrared optical system provided in Example 3

[0138] Surface serial number K 4 times 6 times 8 times 10 times 12 times 14 times 16 times 3 9.30E+00 -1.06E-02 1.15E-02 -9.31E-03 4.62E-03 -1.34E-03 1.91E-04 -6.55E-06 4 3.87E-01 -7.22E-04 4.17E-04 -1.16E-04 1.78E-05 -1.58E-06 7.56E-08 -1.52E-09

[0139] See also Figure 7 , Figure 7 The MTF field of view curve of the infrared optical system 100 working in the infrared band in Example 3 provided by the present application is shown. MTF is also called modulation transfer function, which is an important indicator used to describe the imaging quality of an optical system. The larger the MTF value, the better the imaging quality. Figure 7 , Figure 7 The sagittal curve S1 and the meridional curve T1 of the MTF of 5.25lp / mm spatial frequency with field of view, the sagittal image curve S2 and the meridional curve T2 of the MTF of 10.5lp / mm spatial frequency with field of view, the sagittal image curve S3 and the meridional curve T3 of the MTF of 21lp / mm spatial frequency with field of view, and the sagittal curve S4 and the meridional curve T4 of the MTF of 42lp / mm spatial frequency with field of view are listed. It can be seen from the above eight curves that the MTF of the infrared optical system 100 within the half field of view of 35.05° is almost always greater than 0.3, so the image quality of the infrared optical system 100 is good. Among them, Figure 7 The Y field of view in the figure represents the field of view in the Y-axis direction.

[0140] Example 4

[0141] Figure 8 FIG. 1 shows a schematic diagram of the architecture layout of an infrared optical system 100 operating in the far-infrared band in Example 4 provided in the present application. Figure 8 The performance of the infrared optical system 100 output in Example 4 of the present application is also shown. Figure 8 Combined with Figure 1 In Example 4, the infrared optical system 100 includes, in order from the object side to the image side along the optical axis S: a super lens 1, an aspherical lens 2 and an optical protection member 3.

[0142] Table 10. Some parameters of infrared optical system

[0143] System Parameters data Total optical length (TTL) 7.82mm Field of view (2ω) 70.2° F-number 1 Effective focal length 3.126mm Working band 8~12μm

[0144] As can be seen from Table 10, the infrared optical system 100 in this embodiment has an operating band of 8 to 12 μm, which meets the working requirements of the far-infrared band. The F number (aperture) of the infrared optical system 100 is 1, which can greatly increase the amount of light entering the infrared optical system 100, and collect as much energy as possible entering the infrared optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. At the same time, the infrared optical system 100 has a large field of view angle of 70.2°. At the same time, the total optical length is only 7.82 mm, which fully meets the requirements of the infrared optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0145] Starting from the object plane, along the optical axis S from the object side to the image side, each surface in the optical system is numbered, and the parameters of each surface are summarized to obtain the following Table 11.

[0146] Table 11. Parameters of various surfaces in the infrared optical system provided in Example 4

[0147]

[0148]

[0149] For each surface in Table 11, surface 1 is the object surface. Surface 2 is the surface of the metalens 1 close to the object side, and surface 3 is the surface of the metalens 1 away from the object side. Since the micro-nano structure is provided on the surface of the metalens 1 away from the object side, it is recorded as the structural surface. Surface 4 is the surface of the aspheric lens 2 close to the object side, and surface 5 is the surface of the aspheric lens 2 away from the object side. Surface 6 is the surface of the optical protection member 3 close to the object side, and surface 7 is the surface of the optical protection member 3 away from the object side. Surface 8 is the image surface.

[0150] As can be seen from Table 11, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, the distance between surface 1 and surface 2 is uncertain, and the material between surface 1 and surface 2 is air. Surface 2 is a spherical surface, the distance between surface 2 and surface 3 is 0.38 mm, and the material between surface 2 and surface 3 is silicon. Surface 3 is structural surface 11, which is a plane, the distance between surface 3 and surface 4 is 0.54 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is -5.94 mm, the distance between surface 4 and surface 5 is 2.84 mm, and the material between surface 4 and surface 5 is IRG206. The radius of curvature of surface 5 is -3.99 mm, the distance between surface 5 and surface 6 is 3.39 mm, and the material between surface 5 and surface 6 is air. Surface 6 is a spherical surface, the distance between surface 6 and surface 7 is 0.60 mm, and the material between surface 6 and surface 7 is silicon. Surface 7 is a spherical surface, and the distance between surface 7 and surface 8 is 0.09 mm. The surface 8 is flat.

[0151] Surface 3 and surface 4 are even-order aspheric surfaces, and their surface shapes can be determined by the formula provided in the above embodiment.

[0152] Table 12. Aspheric coefficients in the infrared optical system provided in Example 4

[0153] Surface serial number K 4 times 6 times 8 times 10 times 12 times 14 times 16 times 3 3.95E+00 -1.53E-02 1.07E-02 -6.67E-03 8.08E-04 7.09E-04 -3.09E-04 3.27E-05 4 -3.89E-01 -3.34E-05 -9.59E-04 3.19E-04 -6.71E-05 7.29E-06 -3.92E-07 6.94E-09

[0154] See also Fig. 9 , Fig. 9 The MTF field of view curve of the infrared optical system 100 working in the infrared band in Example 4 provided by the present application is shown. MTF is also called modulation transfer function, which is an important indicator used to describe the imaging quality of an optical system. The larger the MTF value, the better the imaging quality. Fig. 9 , Fig. 9 The sagittal curve S1 and the meridional curve T1 of the MTF of 5.25lp / mm spatial frequency as the field of view changes, the sagittal image curve S2 and the meridional curve T2 of the MTF of 10.5lp / mm spatial frequency as the field of view changes, the sagittal image curve S3 and the meridional curve T3 of the MTF of 21lp / mm spatial frequency as the field of view changes, and the sagittal curve S4 and the meridional curve T4 of the MTF of 42lp / mm spatial frequency as the field of view change are listed. It can be seen from the above eight curves that the MTF of the infrared optical system 100 within the half field of view of 35.1° is always greater than 0.2, so the image quality of the infrared optical system 100 is better. Among them, Fig. 9 The Y field of view in the figure represents the field of view in the Y-axis direction.

[0155] Example 5

[0156] Fig.10 The schematic diagram of the architecture layout of the infrared optical system 100 operating in the far-infrared band in Example 5 provided by the present application is shown. Fig.10 The performance of the infrared optical system 100 output in Example 5 of the present application is also shown. Fig.10 Combined with Figure 1 In Example 5, the infrared optical system 100 includes, in order from the object side to the image side along the optical axis S: a super lens 1, an aspherical lens 2 and an optical protection member 3.

[0157] Table 13. Some parameters of infrared optical system

[0158] System Parameters data Total optical length (TTL) 7.28mm Field of view (2ω) 70.2° F-number 1 Effective focal length 3.12mm Working band 8~12μm

[0159] As can be seen from Table 13, the infrared optical system 100 in this embodiment has an operating band of 8 to 12 μm, which meets the working requirements of the far-infrared band. The F number (aperture) of the infrared optical system 100 is 1, which can greatly increase the amount of light entering the infrared optical system 100, and collect as much energy as possible entering the infrared optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. At the same time, the infrared optical system 100 has a large field of view angle of 70.2°. At the same time, the total optical length is only 7.28 mm, which fully meets the requirements of the infrared optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0160] Starting from the object plane, along the optical axis S from the object side to the image side, each surface in the optical system is numbered, and the parameters of each surface are summarized to obtain the following Table 14.

[0161] Table 14. Parameters of various surfaces in the infrared optical system provided in Example 5

[0162]

[0163]

[0164] For each surface in Table 14, surface 1 is the object surface. Surface 2 is the surface of the metalens 1 close to the object side, and surface 3 is the surface of the metalens 1 away from the object side. Since the surface of the metalens 1 close to the object side and the surface away from the object side are both provided with micro-nano structures, surface 2 and surface 3 are both recorded as structural surfaces. Surface 4 is the surface of the aspheric lens 2 close to the object side, and surface 5 is the surface of the aspheric lens 2 away from the object side. Surface 6 is the surface of the optical protection member 3 close to the object side, and surface 7 is the surface of the optical protection member 3 away from the object side. Surface 8 is the image surface.

[0165] As can be seen from Table 14, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, the distance between surface 1 and surface 2 is uncertain, and the material between surface 1 and surface 2 is air. Surface 2 is a plane, the distance between surface 2 and surface 3 is 0.38 mm, and the material between surface 2 and surface 3 is silicon. Surface 3 is structural surface 11, which is a plane, the distance between surface 3 and surface 4 is 0.49 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is -7.14 mm, the distance between surface 4 and surface 5 is 2.81 mm, and the material between surface 4 and surface 5 is IRG206. The radius of curvature of surface 5 is -4.35 mm, the distance between surface 5 and surface 6 is 2.90 mm, and the material between surface 5 and surface 6 is air. Surface 6 is a spherical surface, the distance between surface 6 and surface 7 is 0.60 mm, and the material between surface 6 and surface 7 is silicon. Surface 7 is a spherical surface, and the distance between surface 7 and surface 8 is 0.11 mm. The surface 8 is flat.

[0166] Surface 3 and surface 4 are even-order aspheric surfaces, and their surface shapes can be determined by the formula provided in the above embodiment.

[0167] Table 15. Aspheric coefficients in the infrared optical system provided in Example 5

[0168] Surface serial number K 4 times 6 times 8 times 10 times 12 times 14 times 16 times 3 2.17E+00 -6.65E-03 8.01E-03 -6.14E-03 1.07E-03 6.91E-04 -3.07E-04 3.67E-05 4 -9.85E-01 4.84E-04 -1.15E-03 3.25E-04 -5.79E-05 7.29E-06 -7.38E-07 4.42E-08

[0169] See also Fig.11 , Fig.11 The MTF field of view curve of the infrared optical system 100 working in the infrared band in Example 5 provided by the present application is shown. MTF is also called modulation transfer function, which is an important indicator used to describe the imaging quality of an optical system. The larger the MTF value, the better the imaging quality. Fig.11 , Fig.11 The sagittal curve S1 and the meridional curve T1 of the MTF of 5.25lp / mm spatial frequency as the field of view changes, the sagittal image curve S2 and the meridional curve T2 of the MTF of 10.5lp / mm spatial frequency as the field of view changes, the sagittal image curve S3 and the meridional curve T3 of the MTF of 21lp / mm spatial frequency as the field of view changes, and the sagittal curve S4 and the meridional curve T4 of the MTF of 42lp / mm spatial frequency as the field of view change are listed. It can be seen from the above eight curves that the MTF of the infrared optical system 100 within the half field of view of 35.1° is always greater than 0.2, so the image quality of the infrared optical system 100 is better. Among them, Fig.11 The Y field of view in the figure represents the field of view in the Y-axis direction.

[0170] After summarizing the various parameters of the infrared optical system 100 provided by the above five embodiments, the following Table 16 is obtained. The display of Table 16 is mainly used to illustrate that the various conditions satisfied by the infrared optical system 100 provided by the present application are all verified and supported by experiments.

[0171] Table 16. Parameters of the infrared optical system 100 provided in various embodiments

[0172]

[0173]

[0174] The present application also provides an infrared optical lens 1000, which includes a lens barrel 200 and the infrared optical system 100, wherein the structure of the infrared optical system 100 can be referred to above and will not be described herein. The lens barrel 200 is used to provide an installation base for the infrared optical system 100, and the infrared optical system 100 is disposed in the lens barrel 200.

[0175] The present application provides three different infrared optical lens 1000 structures by way of example. Next, the infrared optical lens 1000 provided by each embodiment of the present application is described in detail. In the following three embodiments, no optical protection member 3 is provided. The optical protection member 3 may be provided in the infrared optical lens 1000. The optical protection member 3 may also be provided on the outside of the image sensor of the electronic device (not shown) using the infrared optical lens 1000. The image sensor includes but is not limited to CMOS (Complementary Metal Oxide Semiconductor, referred to as CMOS, complementary metal oxide semiconductor) and CCD (Charge Coupled Device, referred to as CCD, charge coupled device).

[0176] Example 1

[0177] See also Fig.12 Combined with Figure 1 The lens barrel 200 is provided with a first mounting through hole 2003, and the first mounting through hole 2003 is used to receive at least a part of the infrared optical system 100. The lens barrel 200 includes a main body 2001 and a supporting part 2002, and the main body 2001 is a main body 2001 of the lens barrel 200, and the main body 2001 is substantially cylindrical, and the axial direction of the main body 2001 is parallel to or coincides with the optical axis S.

[0178] The supporting portion 2002 is roughly cylindrical, and the supporting portion 2002 is connected to a side of the main body 2001 along the optical axis S, that is, the supporting portion 2002 is connected to a side of the main body 2001 axially. The diameter of the supporting portion 2002 is unequal to the diameter of the main body 2001, so that the cross section of the lens barrel 200 along the axial direction is stepped. In the present embodiment, the diameter of the supporting portion 2002 is less than the diameter of the main body 2001, so that the cross section of the lens barrel 200 is stepped. In the present embodiment, the diameter of the supporting portion 2002 is greater than the diameter of the main body 2001, so that the cross section of the lens barrel 200 is stepped. The supporting portion 2002 is provided with a mounting hole 2005 away from a side of the main body 2001, and the mounting hole 2005 is coaxial with the first mounting through hole 2003.

[0179] The first mounting through hole 2003 includes a first hole section 2003a and a second hole section 2003b. The first hole section 2003a is arranged on the main body 2001. The second hole section 2003b is arranged on the supporting portion 2002, the second hole section 2003b is connected with the first hole section 2003a, and the second hole section 2003b is coaxial with the first hole section 2003a. The diameter of the second hole section 2003b is smaller than the diameter of the first hole section 2003a, so that the first mounting through hole 2003 is a stepped hole, and the transition point between the first hole section 2003a and the second hole section 2003b is the sudden change point of the aperture of the first mounting through hole 2003.

[0180] The aspheric lens 2 is received in the first hole section 2003a, and the aspheric lens 2 is connected to the main body 2001 to fix the aspheric lens 2. The aspheric lens 2 abuts against the supporting portion 2002, and since the transition between the first hole section 2003a and the second hole section 2003b is in a step shape, the aspheric lens 2 abuts against the supporting portion 2002, and the aspheric lens 2 can be limited along one side of the optical axis, which can reduce the probability of the aspheric lens 2 loosening.

[0181] Regarding the connection method between the aspheric lens 2 and the main body 2001, the connection method between the aspheric lens 2 and the main body 2001 includes but is not limited to thread connection and bonding. Specifically:

[0182] (1) When the aspheric lens 2 is threadedly connected to the main body 2001, the inner wall of the first hole section 2003a of the main body 2001 is provided with a first internal thread (not shown), and the outer edge of the aspheric lens 2 is provided with a first external thread (not shown) matched with the first internal thread. During installation, the aspheric lens 2 is first placed in a preset position in the first hole section 2003a, so that the aspheric lens 2 is threadedly connected to the main body 2001, and the aspheric lens 2 is in contact with the supporting portion 2002.

[0183] (2) When the aspheric lens 2 is bonded to the main body 2001, the adhesive is first applied to the outer edge of the aspheric lens 2, and then the aspheric lens 2 is placed in a preset position in the first hole section 2003a, so that the aspheric lens 2 and the main body 2001 are bonded by the adhesive, and the aspheric lens 2 abuts against the supporting portion 2002. Alternatively, the adhesive is first applied to a preset position on the inner wall of the first hole section 2003a, and then the aspheric lens 2 is placed in the first hole section 2003a, so that the aspheric lens 2 and the main body 2001 are connected, and the aspheric lens 2 abuts against the supporting portion 2002.

[0184] Regarding the diameter of the first hole segment 2003a, the diameter of the first hole segment 2003a near the supporting portion 2002 is smaller than the diameter of the first hole segment 2003a away from the supporting portion 2002, thereby facilitating the aspheric lens 2 to enter the preset position in the first hole segment 2003a.

[0185] See also Fig.12 The infrared optical lens 1000 also includes a first pressure ring 300, which is roughly annular. The first pressure ring 300 is accommodated in the first hole section 2003a, and the first pressure ring 300 is pressed on the aspheric lens 2, which can limit the aspheric lens 2 along the other side of the optical axis. The first pressure ring 300 cooperates with the supporting portion 2002 to completely fix the aspheric lens 2 and prevent the aspheric lens 2 from loosening.

[0186] Regarding the connection method between the first pressing ring 300 and the main body 2001, the connection method between the first pressing ring 300 and the main body 2001 includes but is not limited to thread connection and bonding. Specifically:

[0187] (1) When the first pressing ring 300 is threadedly connected to the main body 2001, a second internal thread (not shown) is provided at one end of the inner wall of the first hole section 2003a away from the supporting portion 2002, and a second external thread (not shown) is provided on the outer edge of the first pressing ring 300 to match the second internal thread. During installation, the first pressing ring 300 is screwed into a preset position in the first hole section 2003a, so that the first pressing ring 300 is threadedly connected to the main body 2001, and the first pressing ring 300 is pressed onto the aspheric lens 2.

[0188] (2) When the first pressing ring 300 is bonded to the main body 2001, adhesive is first applied to the outer edge of the first pressing ring 300, and then the first pressing ring 300 is placed in a preset position in the first hole section 2003a, so that the first pressing ring 300 and the main body 2001 are bonded by the adhesive, and the first pressing ring 300 is pressed against the aspheric lens 2. Alternatively, adhesive is first applied to a preset position on the inner wall of the first hole section 2003a, and then the first pressing ring 300 is screwed into the first hole section 2003a, so that the first pressing ring 300 and the main body 2001 are bonded, and the first pressing ring 300 is pressed against the aspheric lens 2.

[0189] The side of the first pressing ring 300 away from the aspheric lens 2 does not protrude from the main body 2001. Specifically, the side of the first pressing ring 300 away from the aspheric lens 2 is flush with the side of the main body 2001 away from the supporting portion 2002, or the side of the first pressing ring 300 away from the aspheric lens 2 is located on the inner side of the side of the main body 2001 away from the supporting portion 2002. The side of the first pressing ring 300 away from the aspheric lens 2 does not protrude from the main body 2001, which can avoid increasing the length of the infrared optical lens 1000.

[0190] The super lens 1 is received in the mounting hole 2005 , and the super lens 1 abuts against the supporting portion 2002 to fix the super lens 1 .

[0191] Regarding the connection method between the metalens 1 and the supporting part 2002, the connection method between the metalens 1 and the supporting part 2002 includes but is not limited to thread connection and bonding. Specifically:

[0192] (1) When the metalens 1 is threadedly connected to the supporting portion 2002, the inner wall of the mounting hole 2005 is provided with a third internal thread (not shown), and the outer edge of the metalens 1 is provided with a third external thread (not shown) adapted to the third internal thread. During installation, the metalens 1 is first placed in a preset position in the mounting hole 2005 so that the metalens 1 is threadedly connected to the supporting portion 2002.

[0193] (2) When the metalens 1 is bonded to the supporting portion 2002, an adhesive is first applied to the outer edge of the metalens 1, and then the metalens 1 is placed in a preset position in the mounting hole 2005 to bond the metalens 1 to the supporting portion 2002. Alternatively, an adhesive is first applied to a preset position on the inner wall of the mounting hole 2005, and then the metalens 1 is placed in the mounting hole 2005 to bond the metalens 1 to the supporting portion 2002.

[0194] The metalens 1 and the aspheric lens 2 can be installed in the same manner, for example, the metalens 1 and the aspheric lens 2 are both fixed by threaded connection, or the metalens 1 and the aspheric lens 2 are both fixed by bonding. The metalens 1 and the aspheric lens 2 can also be installed in different manners, for example, the metalens 1 is fixed by threaded connection, and the aspheric lens 2 is fixed by bonding. Alternatively, the metalens 1 is fixed by bonding, and the aspheric lens 2 is fixed by threaded connection.

[0195] See also Fig.12 The infrared optical lens 1000 also includes a second pressing ring 400, which is roughly annular. The second pressing ring 400 is connected to the supporting portion 2002, and the second pressing ring 400 is pressed on the super lens 1 to fix the super lens 1 along the optical axis S to prevent the super lens 1 from loosening.

[0196] Regarding the connection method between the second pressing ring 400 and the supporting portion 2002, the connection method between the second pressing ring 400 and the supporting portion 2002 includes but is not limited to threaded connection and bonding. Specifically:

[0197] (1) When the second pressing ring 400 is threadedly connected to the supporting portion 2002, the outer edge of the supporting portion 2002 is provided with a fourth external thread (not shown), and the inner edge of the second pressing ring 400 is provided with a fourth internal thread (not shown) adapted to the fourth external thread. During installation, the second pressing ring 400 is first covered on the supporting portion 2002, and then the second pressing ring 400 is rotated to screw the second pressing ring 400 to a preset position, so that the second pressing ring 400 is threadedly connected to the supporting portion 2002, and the second pressing ring 400 is pressed on the metalens 1.

[0198] (2) When the second pressing ring 400 is bonded to the supporting portion 2002, an adhesive is first applied to the inner edge of the second pressing ring 400, and then the first pressing ring 300 is covered on the supporting portion 2002, so that the second pressing ring 400 and the supporting portion 2002 are bonded by the adhesive, and the second pressing ring 400 is pressed against the metalens 1. Alternatively, an adhesive is first applied to the outer edge of the supporting portion 2002, and then the first pressing ring 300 is covered on the supporting portion 2002, so that the second pressing ring 400 and the supporting portion 2002 are bonded, and the second pressing ring 400 is pressed against the metalens 1.

[0199] The outer optical lens 1000 further includes a seal (not shown), which is disposed at the connection between the super lens 1 and the lens barrel 200, the connection between the aspherical lens 2 and the lens barrel 200, the connection between the first pressing ring 300 and the lens barrel 200, and the connection between the second pressing ring 400 and the lens barrel 200, so as to improve the sealing performance of the infrared optical lens 1000 and reduce the probability of water and dust entering the infrared optical lens 1000. The seal includes but is not limited to a seal ring, a sealing strip, and a sealant.

[0200] The installation method of the infrared optical lens 1000 in this embodiment is roughly as follows: Fig.12 First, the aspheric lens 2 is installed at a preset position, and the aspheric lens 2 is connected to the main body 2001, and then the first pressing ring 300 is installed, the first pressing ring 300 is connected to the main body 2001, and the first pressing ring 300 is pressed on the aspheric lens 2. Then the super lens 1 is installed in the installation hole 2005, the super lens 1 is connected to the supporting part 2002, and finally the second pressing ring 400 is installed, the second pressing ring 400 is connected to the supporting part 2002, and the second pressing ring 400 is pressed on the super lens 1. Among them, the installation order of the aspheric lens 2 and the super lens 1 can be exchanged, that is, the super lens 1 is installed first and then the aspheric lens 2 is installed.

[0201] Example 2

[0202] See also Fig.13 Combined with Figure 1 The lens barrel 200 is provided with a second mounting through hole 2004, the second mounting through hole 2004 is used to receive at least a part of the infrared optical system 100, and the axial direction of the second mounting through hole 2004 is parallel to or coincides with the optical axis S. The lens barrel 200 includes a main body 2001 and a supporting part 2002, the main body 2001 is a main body 2001 of the lens barrel 200, the main body 2001 is substantially cylindrical, the axial direction of the main body 2001 is parallel to or coincides with the optical axis S, and the second mounting through hole 2004 is located in the main body 2001.

[0203] The supporting portion 2002 is received in the second mounting through hole 2004, the supporting portion 2002 is connected to the hole wall of the second mounting through hole 2004, and the supporting portion 2002 is used to provide support for the aspheric lens 2 along the axial direction of the second mounting hole 2005. As for the specific shape of the supporting portion 2002, the supporting portion 2002 can be annular. The supporting portion 2002 can also be composed of at least two protrusions arranged at intervals, and the cross-sections of each protrusion along the radial direction of the lens barrel 200 should be located in the same plane.

[0204] The aspheric lens 2 is received in the second mounting through hole 2004, and the aspheric lens 2 is connected to the main body 2001 to fix the aspheric lens 2. The aspheric lens 2 is in contact with the supporting portion 2002 to limit the aspheric lens 2 along one side of the axial direction of the second mounting through hole 2004. The mounting method of the aspheric lens 2 can be referred to above, and will not be elaborated in this article.

[0205] The super lens 1 is received in the second mounting through hole 2004, and the super lens 1 is located on one side of the aspheric lens 2. The super lens 1 is connected to the main body 2001 to fix the super lens 1, and the super lens 1 is in contact with the aspheric lens 2.

[0206] Limiting the metalens 1 along one side of the axial direction of the second mounting through hole 2004 can reduce the probability of loosening of the metalens 1. The mounting method of the metalens 1 can refer to the above, and will not be elaborated in this article.

[0207] See also Fig.13 The infrared optical lens also includes a buffer 600 and a third pressure ring 500. The buffer 600 is roughly annular. The buffer 600 is sandwiched between the super lens 1 and the aspheric lens 2 so that the super lens 1 abuts against the aspheric lens 2. The specific form of the buffer 600 includes but is not limited to a gasket. The third pressure ring 500 is roughly annular. The third pressure ring 500 covers the super lens 1 and is connected to the main body 2001 to completely restrict the super lens 1 and the aspheric lens 2, which can reduce the probability of the aspheric lens 2 and the super lens 1 loosening. When the third pressure ring 500 is connected to the main body 2001, the third pressure ring 500 covers the main body 2001. The fixing method of the third pressure ring 500 includes but is not limited to threaded connection and bonding. The specific installation method of the third pressure ring 500 can refer to the fixing method of the first pressure ring 300 or the second pressure ring 400 mentioned above.

[0208] The installation method of the infrared optical lens 1000 in this embodiment is roughly as follows: Fig.13 First, the aspheric lens 2 is installed at a preset position in the second installation through hole 2004, so that the aspheric lens 2 is connected to the main body 2001, and the aspheric lens 2 is abutted against the supporting portion 2002. Then, the buffer 600 is placed in the second installation through hole 2004, and then the super lens 1 is placed in a preset position, and the super lens 1 is bonded to the main body 2001. Finally, the third pressing ring 500 is covered and connected to the main body 2001.

[0209] Example 3

[0210] The lens barrel 200 is provided with a third mounting through hole (not shown), and the third mounting through hole is used to accommodate the infrared optical system 100, and the axial direction of the third mounting through hole is parallel to or coincides with the optical axis S. The super lens 1 and the aspheric lens 2 are both accommodated in the third mounting through hole, and the super lens 1 and the aspheric lens 2 are both bonded to the hole wall of the third mounting through hole to achieve fixation.

[0211] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.

Claims

1. An infrared optical system, characterized in that: The infrared optical system comprises, in order from the object side to the image side along the optical axis: a super lens and an aspheric lens; the surface of the aspheric lens close to the object side is convex toward the image side, and the surface of the aspheric lens away from the object side is convex toward the image side; Wherein, the super lens satisfies the conditional formula: 0.8<n eff <3.6, wherein the n eff is the equivalent refractive index of the metalens; the infrared optical system satisfies the following conditional formula: Wherein, L1 is the distance between the surface of the super lens close to the object side and the surface of the aspheric lens away from the object side, and L is the total optical length of the infrared optical system.

2. The infrared optical system according to claim 1, characterized in that: The infrared optical system satisfies the following condition: 2.1D≤ΔΦ m ≤10.4D, where the ΔΦ m is the difference between the maximum and minimum optical power of the metalens in the working band.

3. The infrared optical system according to claim 1, characterized in that: The infrared optical system satisfies the following conditional formula: Among them, the f m is the focal length of the superlens, and f is the effective focal length of the infrared optical system.

4. The infrared optical system according to claim 1, characterized in that: The infrared optical system satisfies the following conditional formula: Among them, the T m is the thickness of the superlens, the T a is the thickness of the aspheric lens along the optical axis, the Φ m is the optical power provided by the metalens, the Φ a is the optical power provided by the aspheric lens.

5. The infrared optical system according to claim 1, characterized in that: The infrared optical system satisfies the following conditional formula: Among them, the is the maximum phase value provided by the metalens, the r m is the effective area radius of the superlens.

6. The infrared optical system according to claim 1, characterized in that: The metalens satisfies the following conditional formula: Among them, the n eff is the equivalent refractive index of the metalens, and the n t is the refractive index of the aspheric lens.

7. The infrared optical system according to claim 1, characterized in that: The metalens satisfies the following conditional formula: Among them, the is the maximum spatial phase gradient of the metalens, is the maximum spatial phase gradient of the metalens.

8. The infrared optical system according to claim 1, characterized in that: The metalens satisfies the following conditional formula: Wherein, the Δgd m is the maximum group delay difference provided by all the micro-nano structures of the metalens, the Δgd t is the maximum group delay difference provided by the aspheric lens.

9. An infrared optical lens, characterized in that: include: A lens barrel and an infrared optical system as described in any one of claims 1 to 8; the infrared optical system is arranged in the lens barrel.

10. The infrared optical lens according to claim 9, characterized in that: The lens barrel is provided with a first mounting through hole, and the lens barrel comprises a main body and a supporting part; the supporting part is connected to one side of the main body along the optical axis direction, and a mounting hole is provided on a side of the supporting part away from the main body; The first mounting through hole includes a first hole segment and a second hole segment; the first hole segment is arranged in the main body; the second hole segment is arranged in the supporting portion, and the diameter of the second hole segment is smaller than the diameter of the first hole segment; the aspheric lens is accommodated in the first hole segment, the aspheric lens is connected to the main body, and the aspheric lens is abutted against the supporting portion; the super lens is accommodated in the mounting hole, and the super lens is connected to the supporting portion.

11. The infrared optical lens according to claim 10, characterized in that: The optical lens further includes a first pressing ring and a second pressing ring, wherein the first pressing ring is pressed onto the aspheric lens and connected to the main body; the second pressing ring is pressed onto the super lens and connected to the supporting portion.

12. The infrared optical lens according to claim 9, characterized in that: The lens barrel comprises a main body and a supporting part, the main body is provided with a second mounting through hole, the supporting part is received in the second mounting through hole, and the supporting part is connected to the main body; The aspheric lens is accommodated in the second mounting through hole, the aspheric lens is connected to the main body, and the aspheric lens is abutted against the supporting portion; the super lens is located on one side of the aspheric lens along the axial direction of the second mounting through hole, and the super lens is connected to the main body.

13. The infrared optical lens according to claim 12, characterized in that: The optical lens further includes a buffer and a third pressing ring, wherein the buffer is arranged between the super lens and the aspheric lens; the third pressing ring is pressed onto the super lens, and the third pressing ring is connected to the main body.

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