CN117434690A - Optical system and optical lens working in far infrared band - Google Patents

Optical system and optical lens working in far infrared band Download PDF

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Publication number
CN117434690A
CN117434690A CN202311351665.2A CN202311351665A CN117434690A CN 117434690 A CN117434690 A CN 117434690A CN 202311351665 A CN202311351665 A CN 202311351665A CN 117434690 A CN117434690 A CN 117434690A
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China
Prior art keywords
optical system
superlens
lens
wavelength
shows
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Pending
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CN202311351665.2A
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Chinese (zh)
Inventor
赵小波
郝成龙
谭凤泽
朱健
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Shenzhen Metalenx Technology Co Ltd
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Shenzhen Metalenx Technology Co Ltd
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Priority to CN202311351665.2A priority Critical patent/CN117434690A/en
Publication of CN117434690A publication Critical patent/CN117434690A/en
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
    • G02B13/003—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having two lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0055—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/008—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras designed for infrared light
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/06—Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/14—Optical objectives specially designed for the purposes specified below for use with infrared or ultraviolet radiation
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/0006—Arrays

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Lenses (AREA)

Abstract

The application provides an optical system and an optical lens working in a far infrared band. The optical system provided by the application, from the object plane of the optical system to the image plane of the optical system, sequentially comprises: superlenses, refractive lenses; the superlens comprises a substrate and a micro-nano structure arranged on the substrate; the micro-nano structure is arranged on the second surface of the superlens facing the image surface; an angle of incidence of the light ray on the second surface of the superlens is less than or equal to 45 °; the refractive lens faces the first surface of the object plane and is concave relative to the object plane; the refraction lens faces the second surface of the image surface and is convex relative to the image surface; the refractive power of the refractive lens is positive. The optical system provided by the application can simultaneously give consideration to a large field angle and high transmittance.

Description

Optical system and optical lens working in far infrared band
Technical Field
The present disclosure relates to the field of lenses, and in particular, to an optical system and an optical lens operating in a far infrared band.
Background
For an optical system operating in the far infrared band, in order to reduce the volume of the optical system, there has been proposed an optical system composed of a superlens and a refractive lens. However, in the proposed solution of the related art, it is difficult for the optical system to simultaneously achieve a large angle of view and a high transmittance.
Disclosure of Invention
An objective of the present application is to provide an optical system and an optical lens operating in a far infrared band, so that the optical system can simultaneously achieve a large field angle and high transmittance.
According to an aspect of an embodiment of the present application, an optical system operating in a far infrared band is disclosed, sequentially including, from an object plane of the optical system to an image plane of the optical system: superlenses, refractive lenses;
the superlens comprises a substrate and a micro-nano structure arranged on the substrate; the micro-nano structure is arranged on the second surface of the superlens facing the image surface; an angle of incidence of the light ray on the second surface of the superlens is less than or equal to 45 °;
the refractive lens faces the first surface of the object plane and is concave relative to the object plane; the refraction lens faces the second surface of the image surface and is convex relative to the image surface; the refractive power of the refractive lens is positive.
In an exemplary embodiment of the present application, the optical system satisfies the following condition:
wherein Fov is the field angle of the optical system in degrees; n is n 1 Is the refractive index of the superlens.
In an exemplary embodiment of the present application, the optical system satisfies the following condition:
Wherein k is a correction coefficient, and the unit is mm; sigma is the refractive index temperature coefficient of the refractive lens, and the unit is 1/°c; TTL is the total optical length of the optical system, and the unit is mm; f (f) 2 The effective focal length of the refractive lens is in mm.
In an exemplary embodiment of the present application, the optical system satisfies the following condition:
wherein c 1 Is the curvature of the first surface of the refractive lens, with the unit of 1/mm; c 2 Is the curvature of the second surface of the refractive lens in 1/mm; h is the thickness of the refraction lens, and the unit is mm; phi (phi) m The focal power of the superlens is 1/mm.
In an exemplary embodiment of the present application, the optical system satisfies the following condition:
wherein L is a distance from a first surface of the superlens facing the object side to a second surface of the refractive lens, and BFL is a distance from the second surface of the refractive lens to the image plane; l is the same unit as BFL.
In an exemplary embodiment of the present application, the micro-nano structure is a positive micro-nano structure, or a negative micro-nano structure.
In an exemplary embodiment of the present application, the optical system further includes: a diaphragm disposed adjacent to the superlens; the diaphragm is arranged on the surface of the superlens, or the diaphragm and the superlens are arranged at intervals.
In an exemplary embodiment of the present application, the optical system further includes: a protective glass; the protective glass is arranged between the refraction lens and the image surface.
According to an aspect of the embodiments of the present application, an optical lens operating in a far infrared band is disclosed, the optical lens including a lens barrel, an optical system as provided in any of the above embodiments;
the inner wall of the lens barrel is provided with a ladder-shaped structure; the super lens and the refraction lens are both supported on the step-shaped structure;
a connecting structure for fixing the superlens is arranged at the adjacent part of the superlens and the stepped structure; and a connecting structure for fixing the refraction lens is arranged at the adjacent part of the refraction lens and the stepped structure.
In an exemplary embodiment of the present application, the connection structure is provided by a pressing ring; or the connecting structure is obtained by setting in a dispensing mode.
In this embodiment of the present application, from an object plane of an optical system to an image plane of the optical system, the method sequentially includes: superlens, refractive lens. The refractive power of the refractive lens is positive, so that the refractive lens can perform a converging function on incident light, and then the light is gathered to an image plane for imaging. The micro-nano structure is arranged on the second surface of the super lens facing the image surface, and meanwhile, the incident angle of light on the second surface of the super lens is controlled to be smaller than or equal to 45 degrees, so that the light can be incident to the optical system at a large angle and obvious resonance can not be generated when the light passes through the super lens, and the optical system can simultaneously give consideration to a large field angle and high transmittance.
Other features and advantages of the present application will be apparent from the following detailed description, or may be learned in part by the practice of the application.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
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.
Fig. 1 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 2 shows a layout diagram of an optical lens operating in the far infrared band in an embodiment of the present application.
Fig. 3 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 4 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under normal temperature operating conditions.
Fig. 5 shows a column diagram of imaging points of the provided optical system in an ambient operating environment in an embodiment of the present application.
Fig. 6 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of-40 ℃.
FIG. 7 illustrates a column diagram of imaging points of a provided optical system in an operating environment at-40 ℃ in an embodiment of the present application.
Fig. 8 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of 80 ℃.
Fig. 9 shows a plot of imaging points of the provided optical system in an 80 ℃ operating environment in an embodiment of the present application.
Fig. 10 shows a field curvature diagram of a provided optical system in an embodiment of the present application.
Fig. 11 shows a distortion diagram of a provided optical system in an embodiment of the present application.
Fig. 12 shows an axial aberration diagram of a provided optical system in an embodiment of the present application.
Fig. 13 shows a vertical axis color difference diagram of a provided optical system in an embodiment of the present application.
Fig. 14 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 15 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under normal temperature operating conditions.
Fig. 16 shows an imaging point chart of the provided optical system in an embodiment of the present application in a normal temperature operation environment.
Fig. 17 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of-40 ℃.
Fig. 18 shows a plot of imaging points of the provided optical system in an operating environment of-40 ℃ in an embodiment of the present application.
Fig. 19 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of 80 ℃.
Fig. 20 shows a plot of imaging points of the provided optical system in an 80 ℃ operating environment in an embodiment of the present application.
Fig. 21 shows a field curvature diagram of a provided optical system in an embodiment of the present application.
Fig. 22 shows a distortion diagram of a provided optical system in an embodiment of the present application.
Fig. 23 shows an axial aberration diagram of a provided optical system in an embodiment of the present application.
Fig. 24 shows a vertical axis color difference diagram of the provided optical system in an embodiment of the present application.
Fig. 25 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 26 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under normal temperature operating conditions.
Fig. 27 shows an imaging point chart of the provided optical system in an embodiment of the present application in a normal temperature operation environment.
Fig. 28 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of-40 ℃.
Fig. 29 shows a plot of imaging points of the provided optical system in an operating environment of-40 ℃ in an embodiment of the present application.
Fig. 30 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of 80 ℃.
Fig. 31 shows a plot of imaging points of the provided optical system in an 80 ℃ operating environment in an embodiment of the present application.
Fig. 32 shows a field curvature diagram of a provided optical system in an embodiment of the present application.
Fig. 33 shows a distortion diagram of a provided optical system in an embodiment of the present application.
Fig. 34 shows an axial aberration diagram of a provided optical system in an embodiment of the present application.
Fig. 35 shows a vertical axis color difference plot of the provided optical system in an embodiment of the present application.
Fig. 36 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 37 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under normal temperature operating conditions.
Fig. 38 shows an imaging point chart of the provided optical system in an embodiment of the present application in a normal temperature operation environment.
Fig. 39 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of-40 ℃.
FIG. 40 shows a plot of imaging points of the provided optical system in an operating environment at-40℃ in an embodiment of the present application.
Fig. 41 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of 80 ℃.
Fig. 42 shows a plot of imaging points of the provided optical system in an 80 ℃ operating environment in an embodiment of the present application.
Fig. 43 shows a field curvature diagram of a provided optical system in an embodiment of the present application.
Fig. 44 shows a distortion diagram of a provided optical system in an embodiment of the present application.
Fig. 45 shows an axial aberration diagram of a provided optical system in an embodiment of the present application.
Fig. 46 shows a vertical axis color difference plot of the provided optical system in an embodiment of the present application.
Fig. 47 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application.
Fig. 48 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under normal temperature operating conditions.
Fig. 49 shows an imaging point chart of the provided optical system in an embodiment of the present application in a normal temperature operation environment.
Fig. 50 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of-40 ℃.
FIG. 51 shows a plot of imaging points of the provided optical system in an operating environment at-40℃ in an embodiment of the present application.
Fig. 52 shows a graph of MTF versus field of view for an optical system provided in an embodiment of the present application under an operating environment of 80 ℃.
Fig. 53 shows a plot of imaging points of the provided optical system in an 80 ℃ operating environment in an embodiment of the present application.
Fig. 54 shows a field curvature diagram of a provided optical system in an embodiment of the present application.
Fig. 55 shows a distortion diagram of a provided optical system in an embodiment of the present application.
Fig. 56 shows an axial aberration diagram of a provided optical system in an embodiment of the present application.
Fig. 57 shows a vertical axis color difference plot of the provided optical system in an embodiment of the present application.
Description:
1-superlens; 2-refractive lenses; 3-an image plane of the optical system; the 4-superlens faces the second surface of the image plane; 5-protecting glass; 6-lens barrel; the abutting part of the 7-superlens and the stepped structure; the adjacency of the 8-refractive lens and the stepped structure; 9-void region.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. In the following description, numerous specific details are provided to give a thorough understanding of example embodiments of the present application. One skilled in the relevant art will recognize, however, that the aspects of the present application may be practiced without one or more of the specific details, or with other modules, components, etc. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the application.
For an optical system operating in the far infrared band, there has been proposed an optical system composed of a superlens and a refractive lens in the related art. Since the volume of the superlens is small compared to that of the refractive lens, the proposed solution of the related art reduces the volume of the optical system. However, in the proposed solution of the related art, when the optical system thereof has a large angle of view, light rays incident at a large angle generate significant resonance when passing through the superlens thereof, thereby causing a decrease in transmittance of the optical system thereof. As can be seen from the above, the optical system proposed by the related art has a drawback that it is difficult to achieve both a large angle of view and a high transmittance.
In view of overcoming the above-mentioned drawbacks of the related art, the present application provides an optical system operating in the far infrared band. Fig. 1 shows a layout diagram of an optical system operating in the far infrared band in an embodiment of the present application. In fig. 1, the object plane of the optical system is located on the left side of fig. 1, and the image plane 3 of the optical system is located on the right side of fig. 1; the position of the object plane is not shown in fig. 1 because it is not constant.
Referring to fig. 1, in the embodiment of the present application, from an object plane of an optical system to an image plane 3 of the optical system, the method sequentially includes: superlens 1, refractive lens 2.
In the embodiment of the application, the super lens 1 comprises a substrate and a super structure unit positioned on the surface of the substrate, wherein a micro-nano structure is arranged at the vertex and/or the center of the super structure unit; the filling material between the micro-nano structures is air or other material transparent in the working band. The superlens 1 is capable of providing the required phase of the optical system under the modulation of the light by the superstructural unit. After passing through the superlens 1, the light is incident on the refractive lens 2.
In the embodiment of the application, the refractive lens 2 faces the first surface of the object plane and is concave relative to the object plane; the refractive lens 2 faces the second surface of the image plane 3 and is convex with respect to the image plane 3. As can be seen, the refractive lens 2 has a meniscus shape facing the image plane 3 as a whole. The refractive power of the refractive lens 2 is positive, so that the refractive lens 2 can collect incident light, and the light is collected to the image surface 3 for imaging.
It should be noted that, through research and experiments by the present inventors, resonance occurs when light passes through the superlens, and the main reason is that the incident angle of the light is greater than 45 ° when the light is incident on the surface of the superlens on which the micro-nano structure is provided. Therefore, to avoid resonance of light passing through the superlens 1, it is necessary to control the incident angle of light to be less than or equal to 45 ° when the light is incident on the surface of the superlens 1 on which the micro-nano structure is provided.
Meanwhile, for the optical system to be provided in the application, the target requires the capability of allowing the light beam with a large angle to enter, namely, the target requires the incident angle of the light to be larger than 45 degrees when the light is incident on the first surface of the superlens 1 facing the object plane, so that the optical system to be provided in the application can have a large angle of view.
Therefore, in the embodiment of the present application, if the optical system needs to be capable of simultaneously achieving a large field angle and high transmittance, two conditions that the incident angle of the light beam is smaller than or equal to 45 ° when the light beam is incident on the surface of the superlens 1 on which the micro-nano structure is provided, and the incident angle of the light beam needs to be capable of being greater than 45 ° when the light beam is incident on the first surface of the superlens 1 facing the object plane need to be satisfied. If the micro-nano structure is arranged on the first surface of the superlens 1 facing the object plane, the two conditions cannot be satisfied simultaneously, i.e. the former condition is satisfied in order to have high transmittance, the latter condition cannot be satisfied, and a large field angle cannot be provided; the latter condition is satisfied in order to have a large angle of view, and the former condition cannot be satisfied, so that the high transmittance cannot be obtained.
Therefore, in the embodiment of the application, the micro-nano structure is arranged on the second surface 4 of the superlens 1 facing the image surface 3, and meanwhile, the incident angle of the light on the second surface 4 of the superlens 1 is controlled to be smaller than or equal to 45 degrees, so that the two conditions are simultaneously satisfied, the light can be incident to the optical system at a large angle, obvious resonance can not be generated when the light passes through the superlens 1, and the optical system can simultaneously consider a large field angle and high transmittance.
In one embodiment, the optical system provided herein satisfies the following conditions:
wherein Fov is the field angle of the optical system in degrees; n is n 1 Is the refractive index of the superlens 1.
Specifically, in the embodiment of the present application, the light incident on the optical system first enters the first surface of the superlens 1, is refracted, and then exits from the second surface 4 of the superlens 1. It will be appreciated that the angle of incidence of the light ray on the second surface 4 of the superlens 1 is equal to the angle of emergence of the light ray on the first surface of the superlens 1; therefore, the incidence angle of the control light ray on the second surface 4 of the superlens 1 is less than or equal to 45 °, i.e. the exit angle of the control light ray on the first surface of the superlens 1 is less than or equal to 45 °. The exit angle of the light ray on the first surface of the superlens 1 is denoted as θ 1 The conditions to be satisfied are: θ 1 ≤45°。
According to the refraction theorem:wherein 1 represents the refractive index of air. This allows the following: />
Thereby, the condition θ to be satisfied 1 Conversion to conditions at 45 DEG or lessThereby, the condition +.>
It should be noted that, in the optical system in the embodiment of the present application, since the lens surface that receives the light ray first is the first surface of the superlens 1, and the first surface of the superlens 1 is generally a plane, the incident angle of the light ray on the first surface of the superlens 1 needs to be smaller than 90 °; it follows that the field angle Fov of the optical system needs to be less than 180 °. Due to180 ° so that the field angle Fov of the optical system is less than 180 °, will be the conditionFurther conversion to Condition->
It follows that, in the case where the angle of view Fov required by the target is predetermined, the refractive index n of the superlens 1 is adjusted 1 The optical system can be made to satisfy the conditionThereby making the incident angle of the light rays on the second surface 4 of the superlens 1 less than or equal to 45 deg. while ensuring that the field angle Fov of the optical system is less than 180 deg..
It is further noted that when n 1 Reach toWhen (I)>Up to a maximum of 180 °; however, this does not mean n 1 Maximum can only be +.>In this embodiment, as shown in the following formula +.>When in use, let->Equal to 180 °, thereby ensuring that the field angle Fov is less than 180 °:
preferably, in one embodiment, the optical system provided herein satisfies the following conditions:
in the present embodiment, in the case where the angle of view Fov required by the target is predetermined, the refractive index n of the superlens 1 is adjusted 1 So that the optical system meets the conditionThereby making the incident angle of the light rays on the second surface 4 of the superlens 1 less than or equal to 30 deg. while ensuring that the field angle Fov of the optical system is less than 180 deg.. Similar to the above embodiment for the condition +.>The derivation of (2) is not described in detail here for the condition +.>Is a derivation of (3).
In one embodiment, the optical system provided herein satisfies the following conditions:
wherein k is a correction coefficient, and the unit is mm; sigma is the refractive index temperature coefficient of the refractive lens 2, and the unit is 1/DEGC; TTL (Total Track Length) is the total optical length of the optical system in mm; f (f) 2 Is the effective focal length of the refractive lens 2 in mm.
The refractive index temperature coefficient σ of the refractive lens 2 is mainly used to describe the speed at which the refractive index of the refractive lens 2 changes with ambient temperature. The larger σ, the greater the refractive index change degree of the refractive lens 2 at the same ambient temperature change degree; conversely, the smaller σ, the smaller the refractive index change degree of the refractive lens 2, which is the same as the ambient temperature change degree.
Since the superlens 1 is insensitive to temperature, there is little thermal difference effect, and therefore the thermal difference effect of the optical system provided in the present application is mainly caused by the refractive lens 2. Therefore, in order to passively eliminate the thermal difference in the optical system, in the present embodiment, the refractive index temperature coefficient σ of the refractive lens 2, the total optical length TTL of the optical system, and the effective focal length f of the refractive lens 2 are adjusted 2 And controlling.
Specifically, the larger σ, the greater the influence of the thermal difference on the optical system; the larger the TTL, the larger the influence of the thermal difference on the optical system; f (f) 2 The smaller the optical system is, the greater is the influence of the thermal difference. Since the influence of σ on the optical system is larger than the influence of TTL on the optical system, the correction coefficient for correcting σ in the present embodiment takes a value of 1×10 5 。
Further, by setting the upper limit value of the condition to 20.00, σ, TTL and f are restricted 2 The degree of influence of the heat difference on the optical system is achieved, so that the optical system can realize passive heat difference elimination. And by setting the lower limit value of the condition to 15.25, therebyEnsuring that the optical system has basic design conditions and that the refractive lens 2 has a reasonable effective focal length.
Preferably, in one embodiment, the optical system provided herein satisfies the following conditions:
in one embodiment, the optical system provided herein satisfies the following conditions:
wherein c 1 Is the curvature of the first surface of the refractive lens 2 in 1/mm; c 2 Is the curvature of the second surface of the refractive lens 2 in 1/mm; h is the thickness of the refractive lens 2 in mm; phi (phi) m The optical power of the superlens 1 is 1/mm.
c 1 、c 2 And H are parameters related to the optical power of the refractive lens 2. Thus, in the present embodiment, by this condition, the power distribution relationship between the superlens 1 and the refractive lens 2 can be restrained, while also restraining the outer shape and size of the refractive lens 2.
Specifically, by setting the upper limit value of this condition to 1.20, it is ensured that the superlens 1 can provide sufficient optical power, thereby enabling the superlens 1 to correct aberrations introduced in a large viewing place, particularly distortion and coma; meanwhile, the excessive curvature of the refraction lens 2 can be prevented, so that the processing difficulty of the refraction lens 2 is reduced; at the same time, the thickness of the refractive lens 2 can be prevented from being excessively large, thereby avoiding adverse effects on the transmittance and weight of the optical system.
Also, by setting the lower limit value of this condition to 0.25, the optical power provided by the superlens 1 is prevented from being excessively large, thereby avoiding the superlens 1 from introducing excessive negative dispersion; at the same time, it is ensured that the refractive lens 2 provides sufficient optical power, thereby ensuring that the positive dispersion provided by the refractive lens 2 is able to sufficiently compensate for the negative dispersion introduced by the superlens 1, thereby sufficiently correcting chromatic aberration of the optical system.
Preferably, in one embodiment, the optical system provided herein satisfies the following conditions:
in one embodiment, the optical system provided herein satisfies the following conditions:
wherein L is the distance from the first surface of the superlens 1 facing the object side to the second surface of the refractive lens 2, and BFL (Back Focal Length) is the distance from the second surface of the refractive lens 2 to the image plane 3; l and BFL are the same units (e.g., units are mm).
In this embodiment, by this condition, the optical total length of the optical system can be restrained while also satisfying the assembly requirement of the lens.
Specifically, by setting the upper limit value of this condition to 2.00, the lens total length L of the optical system (i.e., the distance between the foremost lens surface and the rearmost lens surface) is prevented from being excessively long, thereby preventing the volume of the optical system from being excessively large; at the same time, too short a back focal length of the optical system is avoided, thereby avoiding difficulty in assembling the lens. By setting the lower limit value of this condition to 0.90, the optical total length of the optical system is prevented from being excessively large due to the excessively long back focus, thereby preventing the optical system from being excessively bulky.
Preferably, in one embodiment, the optical system provided herein satisfies the following conditions:
in an embodiment, the micro-nano structure in the superlens 1 is a positive micro-nano structure, or a negative micro-nano structure.
In particular, the negative micro-nano structure is less susceptible to damage than the positive micro-nano structure in the process of assembling the optical system, thereby improving the structural safety of the superlens 1.
In one embodiment, the optical system provided herein further includes: a diaphragm disposed adjacent the superlens; the diaphragm is arranged on the surface of the superlens, or the diaphragm and the superlens are arranged at intervals.
In the present embodiment, a diaphragm is provided to limit the amount of light entering the optical system. The diaphragm may be provided on the first surface of the superlens 1 or on the second surface 4 of the superlens 1. Alternatively, the diaphragm may be provided at a distance from the superlens 1. When the diaphragm and the superlens 1 are arranged at intervals, structural members for connection, support and the like can be arranged between the diaphragm and the superlens 1, but other optical elements are not arranged.
In one embodiment, the optical system provided herein further includes: a cover glass 5; the cover glass 5 is provided between the refractive lens 2 and the image plane 3.
In the present embodiment, by providing the protection glass 5, the refractive lens 2 can be protected, thereby improving the structural safety of the refractive lens 2.
In one embodiment, the present application also provides an optical lens operating in the far infrared band. The optical lens comprises a lens barrel and the optical system provided by any embodiment. Fig. 2 shows a layout diagram of an optical lens operating in the far infrared band in an embodiment of the present application. Referring to fig. 2, in the optical lens provided in the present application, an inner wall of the lens barrel 6 is provided with a step structure, and the superlens 1 and the refractive lens 2 are both supported by the step structure. Preferably, the stepped structure comprises at least two steps for the superlens 1 and the refractive lens 2 to rest on at different steps.
In addition, a connection structure for fixing the superlens 1 is provided at the adjacent part 7 of the superlens 1 and the stepped structure, mainly for improving the structural firmness of the superlens 1. Similarly, a connection structure for fixing the refractive lens 2 is provided at the adjacent portion 8 of the refractive lens 2 and the stepped structure, mainly for improving the structural firmness of the refractive lens 2. The two-part connecting structure not only has the fixing function, but also has the waterproof and dustproof functions.
In an embodiment, the connection structure for fixing the superlens 1 and the connection structure for fixing the refractive lens 2 may be set by a pressing ring or may be set by a dispensing method.
The connection structure for fixing the superlens 1 and the connection structure for fixing the refractive lens 2 may be provided in the same manner or may be provided in a different manner. That is, the two connecting structures can be both arranged by adopting a pressing ring mode, can be both arranged by adopting a dispensing mode, can be both arranged by adopting a pressing ring mode, and can be both arranged by adopting a dispensing mode.
Referring to fig. 2, in one embodiment, during assembly of the optical lens, there may be a void region 9 between the superlens 1, the refractive lens 2 and the stepped structure. To ensure the tightness of the optical lens, the hollow area 9 may be sealed in a dispensing manner.
TABLE 1 target demand for various system parameters of optical system
System parameters Data
Optical total length (TTL) ≤3.8mm
Angle of view 120°(±3％)
Distortion of <50％
F number ≤1.1
MTF ＞0.15@1F 42cyc/mm
Operating band 8～12μm
Table 1 shows the target requirements for various system parameters for the optical system to be provided in one embodiment. Specifically, in one embodiment, the optical system target to be provided operates in the far infrared band, i.e., 8-12 μm band; the optical total length target is less than or equal to 3.8mm; the view angle target reaches 120 degrees, allowing 3% floating up and down; the imaging distortion degree target is less than 50%; f number target is less than or equal to 1.1; and, for an MTF of the full field of view range at a cut-off frequency of 42cyc/mm (period/millimeter), the target is greater than 0.15. Among them, MTF (Modulation Transfer Function), also called modulation transfer function, is an important index for describing the imaging quality of the optical system. The closer the MTF value is to the diffraction limit, the better the imaging quality.
Targeting the target requirements shown in table 1, the present application illustratively provides 5 optical systems satisfying the target requirements shown in table 1 in 5 embodiments. Next, the 5 optical systems provided in the present application will be described in detail.
Example 1
Fig. 3 shows a layout structure diagram of the optical system operating in the far infrared band provided in embodiment 1. Referring to fig. 3, the optical system provided in this embodiment sequentially includes, from an object plane to an image plane: superlens, diaphragm, refractive lens and protecting glass. The diaphragm is arranged on the second surface of the superlens facing the image surface.
TABLE 2 System parameters of the optical System provided in example 1
System parameters Data
Optical total length (TTL) 3.2mm
Angle of view 122.6°
F number 1.1
Effective focal length 0.92mm
Operating band 8～12μm
As can be seen from table 2, the optical system provided in this example works in the 8-12 μm band; the total optical length of the optical system is 3.2mm and is smaller than 3.8mm of the target requirement, so that the requirement of the optical system on miniaturization is fully met; the view angle is 122.6 degrees and is larger than 120 degrees of the target requirement, so that the requirement of the optical system on a large view angle is fully met; the F number is 1.1 and is equal to 1.1 of the target requirement, and the requirement of the optical system on the light inlet quantity is basically met.
Each surface in the optical system provided in this embodiment is labeled in the direction from the object plane to the image plane, and the parameters of each surface are summarized to obtain table 3 shown below.
TABLE 3 parameters of the various surfaces in the optical system provided in example 1
Surface serial number Surface type Radius of curvature Thickness of (L) Material
1 Object plane Infinite number of cases - -
2 Spherical surface Infinite number of cases 0.30mm Silicon
3 Super surface (diaphragm) Infinite number of cases 0.10mm -
4 Spherical surface -4.23mm 1.45mm Silicon
5 Spherical surface -2.00mm 0.75mm -
6 Spherical surface Infinite number of cases 0.50mm Silicon
7 Spherical surface Infinite number of cases 0.10mm -
8 Image plane Infinite number of cases - -
Wherein the surface 1 is an object plane. The surface 2 is the first surface of the superlens facing the object plane. The surface 3 is a second surface of the superlens facing the image surface; the micro-nano structure is arranged on the second surface of the super lens, so that the super lens is marked as a super surface; and the diaphragm is coplanar with the second surface of the superlens. The surface 4 is the first surface of the refractive lens facing the object plane. The surface 5 is a second surface of the refractive lens facing the image plane. The surface 6 is the first surface of the cover glass facing the object plane. The surface 7 is the second surface of the cover glass facing the image plane. The surface 8 is an image plane.
As can be seen from table 3, the radius of curvature of the surface 1 is infinite (i.e. it is planar), the distance between it and the surface 2 is variable, and the material between it and the surface 2 is air. The surface 2 is planar, the distance between it and the surface 3 is 0.30mm, and the material between it and the surface 3 is silicon. The surface 3 is planar and has a distance of 0.10mm from the surface 4 and the material from the surface 4 is air. The radius of curvature of the surface 4 is-4.23 mm, the distance between the surface and the surface 5 is 1.45mm, and the material between the surface and the surface 5 is silicon. The radius of curvature of the surface 5 is-2.00 mm, the distance between the surface and the surface 6 is 0.75mm, and the material between the surface and the surface 6 is air. The surface 6 is planar and has a distance of 0.50mm from the surface 7 and the material from the surface 7 is silicon. The surface 7 is planar and has a distance of 0.10mm from the surface 8 and the material from the surface 8 is air. The surface 8 is planar.
Fig. 4 shows a graph of MTF versus field of view for the optical system provided in example 1 under normal temperature operating conditions. Wherein, the normal temperature generally refers to 20 ℃ or 25 ℃. The horizontal axis of FIG. 4 represents the field of view in degrees in the Y-axis direction; the vertical axis represents the MTF value. In fig. 4, T represents a meridian direction curve, and S represents a sagittal direction curve; the meridian curve T1 and the sagittal curve S1 correspond to a spatial frequency of 5.00cyc/mm, the meridian curve T2 and the sagittal curve S2 correspond to a spatial frequency of 10.00cyc/mm, the meridian curve T3 and the sagittal curve S3 correspond to a spatial frequency of 15.00cyc/mm, the meridian curve T4 and the sagittal curve S4 correspond to a spatial frequency of 20.00cyc/mm, the meridian curve T5 and the sagittal curve S5 correspond to a spatial frequency of 30.00cyc/mm, the meridian curve T6 and the sagittal curve S6 correspond to a cut-off frequency of 42.00cyc/mm.
As can be seen from fig. 4, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.2, that is, always greater than 0.15 of the target requirement, thereby indicating that the optical system has excellent imaging quality in the full field range under the normal temperature working environment. The MTF of the 0.8 view field range at the cut-off frequency of 42.00cyc/mm does not change obviously with the increase of the view field angle, so that the imaging definition and uniformity of the optical system in the 0.8 view field range are excellent in the normal temperature working environment. The difference between the meridional curve T and the sagittal curve S corresponding to the same spatial frequency is small, and this means that the optical system is excellent in astigmatism control in a normal temperature operating environment. The difference between the MTF value of each curve at the minimum field and the MTF value at the maximum field is small, thereby indicating that the optical system has good field curvature control in a normal temperature operating environment.
Fig. 5 shows a column diagram of imaging points of the optical system provided in embodiment 1 in a normal temperature operating environment. Fig. 5 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 5, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm, thereby demonstrating that the optical system has excellent imaging quality in the wavelength band of 8 to 12 μm in a normal temperature operating environment.
Fig. 6 shows a graph of MTF versus field of view for the optical system provided in example 1 under an operating environment of-40 ℃. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 6 will not be repeated here.
As can be seen from fig. 6, the MTF of the full field of view range at the cut-off frequency of 42.00cyc/mm is always greater than 0.2, i.e. is always greater than 0.15 of the target requirement, thus demonstrating that the optical system has excellent imaging quality in the full field of view range under the working environment of-40 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 6 will not be described again.
Fig. 7 shows a plot of imaging points of the optical system provided in example 1 in an operating environment at-40 ℃. FIG. 7 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 7, the optical system provided in this embodiment has relatively dense imaging spots at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength in a working environment of-40 ℃, thereby demonstrating that the optical system has excellent imaging quality at 8-12 μm wavelength bands in a working environment of-40 ℃.
Fig. 8 shows a graph of MTF versus field of view for the optical system provided in example 1 under an operating environment of 80 ℃. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 8 will not be repeated here.
As can be seen from fig. 8, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.2, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system has excellent imaging quality in the full field range under the working environment of 80 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 8 will not be described again.
Fig. 9 shows a plot of imaging points of the optical system provided in example 1 in an operating environment at 80 ℃. Fig. 9 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 9, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm in an operating environment at 80 ℃, thereby demonstrating that the optical system has excellent imaging quality at the wavelength band of 8 to 12 μm in an operating environment at 80 ℃.
As can be seen from fig. 4 to 9, the optical system provided in this embodiment can always maintain excellent imaging quality in the 8-12 μm band at a temperature range of-40 to 80 ℃, thereby demonstrating that the optical system sufficiently realizes passive athermalization.
Fig. 10 shows a field diagram of the optical system provided in embodiment 1. The horizontal axis of fig. 10 represents the distance deviation between the actual focal point of the light ray and the image plane in mm; the vertical axis represents the normalized field of view along the positive Y-axis direction. In FIG. 10, T 8 A field curvature curve representing the meridian direction corresponding to the 8 μm wavelength S 8 A field curvature curve representing the sagittal direction corresponding to a wavelength of 8 μm, T 10 A field curvature curve representing the meridian direction corresponding to the wavelength of 10 μm, S 10 A field curvature curve representing a sagittal direction corresponding to a wavelength of 10 μm, T 12 A field curvature curve representing a meridian direction corresponding to a wavelength of 12 μm, S 12 A field curvature curve representing the sagittal direction corresponding to a wavelength of 12 μm.
As can be seen from fig. 10, the curvature of field of the optical system is smaller than 0.30mm at each wavelength in the 8-12 μm band, thereby indicating that the curvature of field of the optical system is smaller.
Fig. 11 shows a distortion chart of the optical system provided in embodiment 1. The horizontal axis of fig. 11 represents the degree of distortion of the image in percent; the vertical axis represents the normalized field of view along the positive Y-axis direction. Fig. 11 shows distortion curves for three wavelengths of 8 μm, 10 μm, 12 μm, respectively, except that the three distortion curves are nearly completely coincident due to being too close together.
As can be seen from fig. 11, the distortion of the optical system is less than 50% at each wavelength in the 8-12 μm band, and the target requirement of the optical system for distortion is fully satisfied.
Fig. 12 shows an axial aberration diagram of the optical system provided in embodiment 1. The horizontal axis of FIG. 12 represents the spherical aberration in mm; the vertical axis represents normalized pupil coordinates, without units. In FIG. 12, p 8 Represents the axial aberration curve, p, at a wavelength of 8 μm 10 Represents the axial aberration curve, p, at a wavelength of 10 μm 12 Representing the axial aberration curve at a wavelength of 12 μm.
As can be seen from fig. 12, at each wavelength in the 8-12 μm band, the axial aberration of the optical system is always less than 0.045mm, thereby indicating that the spherical aberration of the optical system is small; and p is 8 、p 10 And p 12 The three axial aberration curves are denser, thus indicating that the chromatic aberration of the optical system is smaller.
Fig. 13 shows a vertical axis chromatic aberration diagram of the optical system provided in embodiment 1. The horizontal axis of fig. 13 represents the amount of deviation in μm of the image point position at other wavelengths compared to the image point position at the center wavelength of the operating band; the vertical axis represents the field of view in degrees. In fig. 13, the outermost two-sided curve depicts the range of diameter of airy disk; the curves at the two outermost sides are removed, and three curves from left to right are as follows: vertical axis color difference curve F corresponding to 8 mu m wavelength 8 Vertical axis color difference curve F corresponding to 10 mu m wavelength 10 A vertical axis color difference curve F corresponding to 12 mu m wavelength 12 。
As can be seen from fig. 13, at each wavelength in the 8-12 μm band, the chromatic aberration of the optical system on the homeotropic axis is within the range of the airy disk diameter, and there is a large margin, thereby indicating that the chromatic aberration of the optical system has been well compensated.
Example 2
Fig. 14 shows a layout structure diagram of an optical system operating in the far infrared band provided in embodiment 2. Referring to fig. 14, the optical system provided in this embodiment includes, in order from an object plane to an image plane: superlens, diaphragm, refractive lens and protecting glass. The diaphragm is arranged on the second surface of the superlens facing the image surface.
TABLE 4 System parameters of the optical System provided in example 2
As can be seen from Table 4, the optical system provided in this example works in the 8-12 μm band; the total optical length of the optical system is 3.15mm and is smaller than 3.8mm of the target requirement, so that the requirement of the optical system on miniaturization is fully met; the view angle is 122.6 degrees and is larger than 120 degrees of the target requirement, so that the requirement of the optical system on a large view angle is fully met; the F number is 1.1 and is equal to 1.1 of the target requirement, and the requirement of the optical system on the light inlet quantity is basically met.
Each surface in the optical system provided in this embodiment is labeled in the direction from the object plane to the image plane, and the parameters of each surface are summarized to obtain table 5 shown below.
TABLE 5 parameters of the various surfaces in the optical system provided in example 2
Surface serial number Surface type Radius of curvature Thickness of (L) Material
1 Object plane Infinite number of cases - -
2 Spherical surface Infinite number of cases 0.30mm Silicon
3 Super surface (diaphragm) Infinite number of cases 0.10mm -
4 Spherical surface -3.82mm 1.40mm Silicon
5 Spherical surface -1.97mm 0.75mm -
6 Spherical surface Infinite number of cases 0.50mm Silicon
7 Spherical surface Infinite number of cases 0.10mm -
8 Image plane Infinite number of cases - -
As such, table 3 is described and Table 5 is not repeated here.
Fig. 15 shows a graph of MTF versus field of view for the optical system provided in example 2 under normal temperature operating conditions. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 15 will not be repeated here.
As can be seen from fig. 15, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.19, that is, always greater than 0.15 of the target requirement, thereby indicating that the optical system is excellent in imaging quality in the full field range under the normal temperature operating environment. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 15 will not be described again.
Fig. 16 shows a chart of imaging points of the optical system provided in embodiment 2 in a normal temperature operating environment. FIG. 16 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 16, the optical system provided in this embodiment has a relatively dense imaging light spot at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm, thereby demonstrating that the optical system has excellent imaging quality in the wavelength band of 8 to 12 μm in a normal temperature operating environment.
Fig. 17 shows a graph of MTF versus field of view for the optical system provided in example 2 under an operating environment of-40 ℃. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 17 will not be repeated here.
As can be seen from fig. 17, the MTF of the full field of view range at the cutoff frequency of 42.00cyc/mm is always greater than 0.18, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system has excellent imaging quality in the full field of view range under the working environment of-40 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 17 will not be described again.
Fig. 18 shows a plot of imaging points of the optical system provided in example 2 in an operating environment at-40 ℃. Fig. 18 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 18, the optical system provided in this embodiment has relatively dense imaging spots at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength in a working environment of-40 ℃, thereby demonstrating that the optical system has excellent imaging quality at 8-12 μm wavelength bands in a working environment of-40 ℃.
Fig. 19 shows a graph of MTF versus field of view for the optical system provided in example 2 under an operating environment of 80 ℃. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 19 will not be repeated here.
As can be seen from fig. 19, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.19, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system is excellent in imaging quality in the full field range under an operating environment of 80 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 19 will not be described again.
Fig. 20 shows a plot of imaging points of the optical system provided in example 2 in an operating environment at 80 ℃. Fig. 20 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 20, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm in an operating environment at 80 ℃, thereby demonstrating that the optical system has excellent imaging quality at the wavelength band of 8 to 12 μm in an operating environment at 80 ℃.
As can be seen from a combination of fig. 15 to 20, the optical system provided in this embodiment can always maintain excellent imaging quality in the 8-12 μm band at a temperature range of-40 to 80 ℃, thereby demonstrating that the optical system sufficiently realizes passive athermalization.
Fig. 21 shows a field profile of the optical system provided in embodiment 2. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 10 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 21 will not be repeated here.
As can be seen from fig. 21, the curvature of field of the optical system is smaller than 0.35mm at each wavelength in the 8-12 μm band, thereby indicating that the curvature of field of the optical system is smaller.
Fig. 22 shows a distortion chart of the optical system provided in embodiment 2. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 11 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 22 will not be repeated here.
As can be seen from fig. 22, the distortion of the optical system is less than 50% at each wavelength in the 8-12 μm band, and the target requirement of the optical system for distortion is fully satisfied.
Fig. 23 shows an axial aberration diagram of the optical system provided in embodiment 2. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 12 and the meaning represented by each curve, the meaning represented by the horizontal axis and the vertical axis of fig. 23 and the meaning represented by each curve will not be repeated here.
As can be seen from fig. 23, at each wavelength in the 8-12 μm band, the axial aberration of the optical system is always less than 0.09mm, thereby indicating that the spherical aberration of the optical system is small; and p is 8 、p 10 And p 12 The three axial aberration curves are denser, thus indicating that the chromatic aberration of the optical system is smaller.
Fig. 24 shows a vertical axis chromatic aberration diagram of the optical system provided in embodiment 2. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 13 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 24 will not be repeated here.
As can be seen from fig. 24, at each wavelength in the 8-12 μm band, the chromatic aberration of the optical system on the homeotropic axis is within the range of the airy disk diameter, and there is a large margin, thereby indicating that the chromatic aberration of the optical system has been well compensated.
Example 3
Fig. 25 shows a layout structure diagram of an optical system operating in the far infrared band provided in embodiment 3. Referring to fig. 25, the optical system provided in this embodiment includes, in order from an object plane to an image plane: superlens, diaphragm, refractive lens and protecting glass. The diaphragm is arranged on the second surface of the superlens facing the image surface.
TABLE 6 System parameters of the optical System provided in example 3
System parameters Data
Optical total length (TTL) 3.24mm
Angle of view 122.7°
F number 1.08
Effective focal length 0.92mm
Operating band 8～12μm
As can be seen from Table 4, the optical system provided in this example works in the 8-12 μm band; the total optical length of the optical system is 3.24mm and is smaller than 3.8mm of the target requirement, so that the requirement of the optical system on miniaturization is fully met; the view angle is 122.7 degrees and is larger than 120 degrees of the target requirement, so that the requirement of the optical system on a large view angle is fully met; the F number is 1.08 and is smaller than 1.1 of the target requirement, and the requirement of the optical system on the light inlet quantity is fully met.
Each surface in the optical system provided in this embodiment is labeled in the direction from the object plane to the image plane, and the parameters of each surface are summarized to obtain table 7 shown below.
TABLE 7 parameters of the various surfaces in the optical system provided in example 3
Surface serial number Surface type Radius of curvature Thickness of (L) Material
1 Object plane Infinite number of cases - -
2 Spherical surface Infinite number of cases 0.30mm Silicon
3 Super surface (diaphragm) Infinite number of cases 0.09mm -
4 Spherical surface -4.10mm 1.50mm Silicon
5 Spherical surface -2.02mm 0.75mm -
6 Spherical surface Infinite number of cases 0.50mm Silicon
7 Spherical surface Infinite number of cases 0.10mm -
8 Image plane Infinite number of cases - -
As such, table 3 is described and Table 7 is not repeated here.
Fig. 26 shows a graph of MTF versus field of view for the optical system provided in example 3 under normal temperature operating conditions. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 26 will not be repeated here.
As can be seen from fig. 26, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.19, that is, always greater than 0.15 of the target requirement, thereby indicating that the optical system is excellent in imaging quality in the full field range under the normal temperature operating environment. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 26 will not be described again.
Fig. 27 shows a chart of imaging points of the optical system provided in embodiment 3 in a normal temperature operating environment. FIG. 27 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 27, the optical system provided in this embodiment has a relatively dense imaging light spot at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm, thereby demonstrating that the optical system has excellent imaging quality in the wavelength band of 8 to 12 μm under normal temperature working environment.
Fig. 28 shows a graph of MTF versus field of view for the optical system provided in example 3 under an operating environment of-40 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 28 will not be repeated here.
As can be seen from fig. 28, the MTF of the full field of view range at the cutoff frequency of 42.00cyc/mm is always greater than 0.18, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system has excellent imaging quality in the full field of view range under the working environment of-40 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 28 will not be described again.
Fig. 29 shows a plot of imaging points of the optical system provided in example 3 in an operating environment at-40 ℃. Fig. 29 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 29, the optical system provided in this embodiment has relatively dense imaging spots at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength in a working environment of-40 ℃, thereby demonstrating that the optical system has excellent imaging quality at 8-12 μm wavelength bands in a working environment of-40 ℃.
Fig. 30 shows a graph of MTF versus field of view for the optical system provided in example 3 under an operating environment of 80 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 30 will not be repeated here.
As can be seen from fig. 30, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.19, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system is excellent in imaging quality in the full field range under the working environment of 80 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 30 will not be described again.
Fig. 31 shows a plot of imaging points of the optical system provided in example 3 in an operating environment at 80 ℃. FIG. 31 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 31, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm in an operating environment at 80 ℃, thereby demonstrating that the optical system has excellent imaging quality at the wavelength band of 8 to 12 μm in an operating environment at 80 ℃.
As can be seen from fig. 26 to 31, the optical system provided in this embodiment can always maintain excellent imaging quality in the 8-12 μm band at a temperature range of-40 to 80 ℃, thereby demonstrating that the optical system sufficiently realizes passive athermalization.
Fig. 32 shows a field profile of the optical system provided in embodiment 3. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 10, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 32 will not be repeated here.
As can be seen from fig. 32, the curvature of field of the optical system is smaller than 0.30mm at each wavelength in the 8-12 μm band, thereby indicating that the curvature of field of the optical system is smaller.
Fig. 33 shows a distortion chart of the optical system provided in embodiment 3. Similar to the description of the meaning represented by the horizontal axis and the vertical axis of fig. 11 and the meaning represented by each curve, the meaning represented by the horizontal axis and the meaning represented by each curve of fig. 33 will not be repeated here.
As can be seen from fig. 33, the distortion of the optical system is less than 50% at each wavelength in the 8-12 μm band, and the target requirement of the optical system for distortion is fully satisfied.
Fig. 34 shows an axial aberration diagram of the optical system provided in embodiment 3. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 12, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 34 will not be repeated here.
As can be seen from fig. 34, at each wavelength in the 8-12 μm band, the axial aberration of the optical system is always less than 0.07mm, thereby indicating that the spherical aberration of the optical system is small; and p is 8 、p 10 And p 12 The three axial aberration curves are denser, thus indicating that the chromatic aberration of the optical system is smaller.
Fig. 35 shows a vertical axis chromatic aberration diagram of the optical system provided in embodiment 1. Similar to the description of the meaning represented by the horizontal and vertical axes of fig. 13 and the meaning represented by each curve, the meaning represented by the horizontal and vertical axes of fig. 35 and the meaning represented by each curve will not be repeated here.
As can be seen from fig. 35, at each wavelength in the 8-12 μm band, the chromatic aberration of the optical system on the homeotropic axis is within the range of the airy disk diameter, and there is a large margin, thereby indicating that the chromatic aberration of the optical system has been well compensated.
Example 4
Fig. 36 shows a layout structure diagram of an optical system operating in the far infrared band provided in embodiment 4. Referring to fig. 36, the optical system provided in this embodiment includes, in order from an object plane to an image plane: diaphragm, superlens, refractive lens, and protective glass. Wherein, diaphragm and superlens interval setting.
TABLE 8 System parameters of the optical System provided in example 4
System parameters Data
Optical total length (TTL) 3.24mm
Angle of view 118°
F number 1.09
Effective focal length 0.92mm
Operating band 8～12μm
As can be seen from table 8, the optical system provided in this example works in the 8-12 μm band; the total optical length of the optical system is 3.24mm and is smaller than 3.8mm of the target requirement, so that the requirement of the optical system on miniaturization is fully met; the view angle is 118 degrees, and the view angle is within the range of 3% of 120-degree drop of the target requirement, so that the requirement of the optical system on a large view angle is basically met; the F number is 1.09 and less than 1.1 of the target requirement, and the requirement of the optical system on the light inlet quantity is fully met.
Each surface in the optical system provided in this embodiment is labeled in the direction from the object plane to the image plane, and the parameters of each surface are summarized to obtain table 9 shown below.
TABLE 9 parameters of the various surfaces in the optical system provided in example 4
As with Table 3, no further description of Table 9 is provided herein.
Fig. 37 shows a graph of MTF versus field of view for the optical system provided in example 4 under normal temperature operating conditions. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 37 will not be repeated here.
As can be seen from fig. 37, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.16, that is, always greater than 0.15 of the target requirement, thereby indicating that the optical system is excellent in imaging quality in the full field range under the normal temperature operating environment. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 37 will not be described again.
Fig. 38 shows a chart of imaging points of the optical system provided in embodiment 4 in a normal temperature operating environment. Fig. 38 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 38, the optical system provided in this embodiment has a relatively dense imaging light spot at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm, thereby demonstrating that the optical system has excellent imaging quality in the wavelength band of 8 to 12 μm in a normal temperature operating environment.
Fig. 39 shows a graph of MTF versus field of view for the optical system provided in example 4 under an operating environment of-40 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 39 will not be repeated here.
As can be seen from fig. 39, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.15 of the target requirement, thus demonstrating that the optical system has excellent imaging quality in the full field range under the-40 ℃ working environment. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 39 will not be described again.
Fig. 40 shows a plot of imaging points for the optical system provided in example 4 in an operating environment at-40 ℃. Fig. 40 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 40, the optical system provided in this embodiment has relatively dense imaging spots at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength in a working environment of-40 ℃, thereby demonstrating that the optical system has excellent imaging quality at 8-12 μm wavelength bands in a working environment of-40 ℃.
Fig. 41 shows a graph of MTF versus field of view for the optical system provided in example 4 under an operating environment of 80 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 41 will not be repeated here.
As can be seen from fig. 41, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.18, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system is excellent in imaging quality in the full field range under an operating environment of 80 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 41 will not be described again.
Fig. 42 shows a plot of imaging points of the optical system provided in example 3 in an operating environment at 80 ℃. FIG. 42 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 42, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm, and the wavelength of 12 μm in an operating environment at 80 ℃, thereby demonstrating that the optical system has excellent imaging quality at the wavelength band of 8 to 12 μm in an operating environment at 80 ℃.
As can be seen from fig. 37 to 42, the optical system provided in this embodiment can always maintain excellent imaging quality in the 8-12 μm band at a temperature range of-40 to 80 ℃, thereby demonstrating that the optical system sufficiently realizes passive athermalization.
Fig. 43 shows a field profile of the optical system provided in embodiment 4. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 10, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 43 will not be repeated here.
As can be seen from fig. 43, the curvature of field of the optical system is smaller than 0.35mm at each wavelength in the 8-12 μm band, thereby indicating that the curvature of field of the optical system is smaller.
Fig. 44 shows a distortion chart of the optical system provided in embodiment 4. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 11, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 44 will not be repeated here.
As can be seen from fig. 44, the distortion of the optical system is less than 50% at each wavelength in the 8-12 μm band, which fully satisfies the target requirement of the optical system for distortion.
Fig. 45 shows an axial aberration diagram of the optical system provided in embodiment 4. Similar to the description of the meaning represented by the horizontal and vertical axes of fig. 12 and the meaning represented by each curve, the meaning represented by the horizontal and vertical axes of fig. 45 and the meaning represented by each curve will not be repeated here.
As can be seen from fig. 45, the axial aberration of the optical system is always less than 0.1mm at each wavelength in the 8-12 μm band, thereby indicating that the spherical aberration of the optical system is small.
Fig. 46 shows a vertical axis color difference chart of the optical system provided in example 4. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 13, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 46 will not be repeated here.
As can be seen from fig. 46, at each wavelength in the 8-12 μm band, the chromatic aberration of the optical system on the homeotropic axis is within the range of the airy disk diameter, and there is a large margin, thereby indicating that the chromatic aberration of the optical system has been well compensated.
Example 5
Fig. 47 shows a layout structure diagram of an optical system operating in the far infrared band provided in embodiment 5. Referring to fig. 47, the optical system provided in this embodiment sequentially includes, from an object plane to an image plane: superlens, diaphragm, refractive lens and protecting glass. Wherein, diaphragm and superlens interval setting.
TABLE 10 System parameters of the optical System provided in example 5
System parameters Data
Optical total length (TTL) 2.90mm
Angle of view 122.7°
F number 1.1
Effective focal length 0.92mm
Operating band 8～12μm
As can be seen from table 10, the optical system provided in this example works in the 8-12 μm band; the total optical length of the optical system is 2.90mm and is smaller than 3.8mm of the target requirement, so that the requirement of the optical system on miniaturization is fully met; the view angle is 122.7 degrees and is larger than 120 degrees of the target requirement, so that the requirement of the optical system on a large view angle is fully met; the F number is 1.1 and is equal to 1.1 of the target requirement, and the requirement of the optical system on the light inlet quantity is basically met.
Each surface in the optical system provided in this embodiment is labeled in the direction from the object plane to the image plane, and the parameters of each surface are summarized to obtain table 11 shown below.
TABLE 11 parameters of the various surfaces in the optical system provided in example 5
Surface serial number Surface type Radius of curvature Thickness of (L) Material
1 Object plane Infinite number of cases - -
2 Spherical surface Infinite number of cases 0.30mm Silicon
3 Super surface Infinite number of cases 0.11mm -
4 Diaphragm Infinite number of cases 0.19mm -
5 Spherical surface -4.97mm 1.00mm Silicon
6 Spherical surface -1.90mm 0.70mm -
7 Spherical surface Infinite number of cases 0.50mm Silicon
8 Spherical surface Infinite number of cases 0.10mm -
9 Image plane Infinite number of cases - -
As with Table 3, no further description of Table 11 is provided herein.
Fig. 48 shows a graph of MTF versus field of view for the optical system provided in example 5 under normal temperature operating conditions. Similar to the description of the meaning represented by the horizontal and vertical axes of fig. 4 and the meaning represented by each curve, the meaning represented by the horizontal and vertical axes of fig. 48 and the meaning represented by each curve will not be repeated here.
As can be seen from fig. 48, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.17, that is, always greater than 0.15 of the target requirement, thereby indicating that the optical system is excellent in imaging quality in the full field range under the normal temperature operating environment. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 48 will not be described again.
Fig. 49 shows a chart of imaging points of the optical system provided in embodiment 5 in a normal temperature operating environment. Fig. 49 shows a column of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 49, the optical system provided in this embodiment has a relatively dense imaging light spot at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm, thereby demonstrating that the optical system has excellent imaging quality in the wavelength band of 8 to 12 μm in a normal temperature operating environment.
Fig. 50 shows a graph of MTF versus field of view for the optical system provided in example 5 under an operating environment of-40 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 4, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 50 will not be repeated here.
As can be seen from fig. 50, the MTF of the full field of view range at the cutoff frequency of 42.00cyc/mm is always greater than 0.19, i.e., always greater than 0.15 of the target requirement, thereby demonstrating that the optical system has excellent imaging quality in the full field of view range under the working environment of-40 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 50 will not be described again.
FIG. 51 shows a plot of imaging points for the optical system provided in example 5 in an operating environment at-40 ℃. FIG. 51 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 51, the optical system provided in this embodiment has relatively dense imaging spots at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength in a working environment of-40 ℃, thereby demonstrating that the optical system has excellent imaging quality at 8-12 μm wavelength bands in a working environment of-40 ℃.
Fig. 52 shows a graph of MTF versus field of view for the optical system provided in example 5 under an operating environment of 80 ℃. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by the curves in fig. 4, the meaning represented by the horizontal axis and the meaning represented by the curves in fig. 52 will not be repeated here.
As can be seen from fig. 52, the MTF of the full field range at the cut-off frequency of 42.00cyc/mm is always greater than 0.15 of the target requirement, thus demonstrating that the optical system is excellent in imaging quality in the full field range under the working environment of 80 ℃. Similar to the interpretation of the performance of the other aspects of the optical system reflected in fig. 4, the performance of the other aspects of the optical system reflected in fig. 52 will not be described again.
Fig. 53 shows a plot of imaging points of the optical system provided in example 5 in an operating environment at 80 ℃. FIG. 53 shows a plot of imaging points at 8 μm wavelength, 10 μm wavelength and 12 μm wavelength. As can be seen from fig. 53, the optical system provided in this embodiment has relatively dense imaging spots at the wavelength of 8 μm, the wavelength of 10 μm and the wavelength of 12 μm in an operating environment at 80 ℃, thereby demonstrating that the optical system has excellent imaging quality at the wavelength band of 8 to 12 μm in an operating environment at 80 ℃.
As can be seen from fig. 48 to 53, the optical system provided in this embodiment can always maintain excellent imaging quality in the 8-12 μm band at a temperature range of-40 to 80 ℃, thereby demonstrating that the optical system sufficiently realizes passive athermalization.
Fig. 54 shows a field profile of the optical system provided in example 5. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 10, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 54 will not be repeated here.
As can be seen from fig. 54, at each wavelength in the 8-12 μm band, the curvature of field of the optical system is smaller than 0.30mm, thereby indicating that the curvature of field of the optical system is smaller.
Fig. 55 shows a distortion chart of the optical system provided in embodiment 5. Similar to the description of the meaning represented by the horizontal and vertical axes of fig. 11 and the meaning represented by each curve, the meaning represented by the horizontal and vertical axes of fig. 55 and the meaning represented by each curve will not be repeated here.
As can be seen from fig. 55, the distortion of the optical system is less than 50% at each wavelength in the 8-12 μm band, and the target requirement of the optical system for distortion is fully satisfied.
Fig. 56 shows an axial aberration diagram of the optical system provided in embodiment 5. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 12, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 56 will not be repeated here.
As can be seen from fig. 56, the axial aberration of the optical system is always less than 0.03mm at each wavelength in the 8-12 μm band, thereby indicating that the spherical aberration of the optical system is small.
Fig. 57 shows a vertical axis color difference chart of the optical system provided in example 5. Similar to the description of the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 13, the meaning represented by the horizontal axis and the meaning represented by each curve in fig. 57 will not be repeated here.
As can be seen from fig. 57, at each wavelength in the 8-12 μm band, the chromatic aberration of the optical system on the homeotropic axis is within the range of the airy disk diameter, and there is a large margin, thereby indicating that the chromatic aberration of the optical system has been well compensated.
The parameters of the optical system provided in the above 5 embodiments were summarized to obtain table 12 shown below. The table 12 is mainly used for illustrating various conditions satisfied by the optical system provided in the present application, and all conditions are experimentally verified and supported.
TABLE 12 parameters of the optical systems provided by the embodiments
Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

Claims (10)

1. An optical system operating in the far infrared band, comprising, in order from an object plane of the optical system to an image plane of the optical system: superlenses, refractive lenses;
The superlens comprises a substrate and a micro-nano structure arranged on the substrate; the micro-nano structure is arranged on the second surface of the superlens facing the image surface; an angle of incidence of the light ray on the second surface of the superlens is less than or equal to 45 °;
the refractive lens faces the first surface of the object plane and is concave relative to the object plane; the refraction lens faces the second surface of the image surface and is convex relative to the image surface; the refractive power of the refractive lens is positive.
2. The optical system of claim 1, wherein the optical system satisfies the following condition:
wherein Fov is the field angle of the optical system in degrees; n is n 1 Is the refractive index of the superlens.
3. The optical system of claim 1, wherein the optical system satisfies the following condition:
wherein k is a correction coefficient, and the unit is mm; sigma is the refractive index temperature coefficient of the refractive lens, and the unit is 1/°c; TTL is the total optical length of the optical system, and the unit is mm; f (f) 2 The effective focal length of the refractive lens is in mm.
4. The optical system of claim 1, wherein the optical system satisfies the following condition:
Wherein c 1 Is the curvature of the first surface of the refractive lens, with the unit of 1/mm; c 2 Is the curvature of the second surface of the refractive lens in 1/mm; h is the thickness of the refraction lens, and the unit is mm; phi (phi) m The focal power of the superlens is 1/mm.
5. The optical system of claim 1, wherein the optical system satisfies the following condition:
wherein L is a distance from a first surface of the superlens facing the object side to a second surface of the refractive lens, and BFL is a distance from the second surface of the refractive lens to the image plane; l is the same unit as BFL.
6. The optical system of claim 1, wherein the micro-nano structure is a positive micro-nano structure or a negative micro-nano structure.
7. The optical system of claim 1, wherein the optical system further comprises: a diaphragm disposed adjacent to the superlens; the diaphragm is arranged on the surface of the superlens, or the diaphragm and the superlens are arranged at intervals.
8. The optical system of claim 1, wherein the optical system further comprises: a protective glass; the protective glass is arranged between the refraction lens and the image surface.
9. An optical lens operating in the far infrared band, characterized in that it comprises a barrel, an optical system according to any one of claims 1-8;
the inner wall of the lens barrel is provided with a ladder-shaped structure; the super lens and the refraction lens are both supported on the step-shaped structure;
a connecting structure for fixing the superlens is arranged at the adjacent part of the superlens and the stepped structure; and a connecting structure for fixing the refraction lens is arranged at the adjacent part of the refraction lens and the stepped structure.
10. The optical lens of claim 9, wherein the connection structure is provided by a pressing ring; or the connecting structure is obtained by setting in a dispensing mode.
CN202311351665.2A 2023-10-18 2023-10-18 Optical system and optical lens working in far infrared band Pending CN117434690A (en)

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Application Number Priority Date Filing Date Title
CN202311351665.2A CN117434690A (en) 2023-10-18 2023-10-18 Optical system and optical lens working in far infrared band

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311351665.2A CN117434690A (en) 2023-10-18 2023-10-18 Optical system and optical lens working in far infrared band

Publications (1)

Publication Number Publication Date
CN117434690A true CN117434690A (en) 2024-01-23

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