CN113485009A

CN113485009A - Super surface imaging device

Info

Publication number: CN113485009A
Application number: CN202010904854.8A
Authority: CN
Inventors: 杨萌; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-08
Anticipated expiration: 2040-04-24
Also published as: CN113485009B; CN113485007B; WO2021212811A1; CN113485007A; CN111352237A; CN113485008A; CN113485008B

Abstract

The present application provides a super-surface imaging device. The super-surface imaging device comprises a diaphragm, at least one super-surface lens and an imaging sensor, wherein the diaphragm is used for limiting an incident light beam; at least one super-surface lens is aligned with the diaphragm and provided with a plurality of phase compensation structures so as to perform deflection processing on the light beam limited by the diaphragm to perform phase compensation on the light beam; an imaging sensor converts the phase compensated light into an electrical signal proportional to a signal of the light. The super-surface lens is provided with a plurality of phase compensation structures, and the equivalent focal length of each phase compensation structure is gradually increased in a direction away from the center of the super-surface lens. The phase compensation of the phase compensation structure provided by the application can be changed according to the change of the chief ray angle, so that the super lens can have a certain field angle.

Description

Super surface imaging device

Divisional application statement

The application is a divisional application of a Chinese patent application with the invention name of 'a super-surface imaging device' filed on 24.4.2020 and the application number of 202010331976.2.

Technical Field

The present application relates to the field of optical devices, and more particularly, to a super-surface imaging apparatus.

Background

Lenses for imaging, transmission and the like in the existing camera shooting field are all made of transparent materials such as resin, plastic, glass and the like. Such lenses generally need to have larger dimensions because they introduce optical path differences through the gradual change in thickness, which results in focusing or diverging of the light. Capasso et al published a super-surface paper in Science journal 347 Vol 6228 at 3.2015 and have led to worldwide research on super-surface lenses.

The super-surface lens is different from the traditional lens in that the super-surface lens adopts a Pancharatnam-Berry phase difference which is introduced by a micro-nano scale structure and is relevant to the shape, so that the phase of scattered incident light can be randomly modulated to replace the optical path difference relied on by the traditional lens. Accordingly, the super-surface lens may form a substantially planar optical device that is easier to integrate, and may be greatly reduced in size relative to conventional lenses. Since the super-surface lens relies on diffractive optics rather than geometric optics in principle, the inherent aberrations of conventional lenses, such as spherical aberration, can be avoided from design, but instead, a new type of aberration is generated that is specific to diffractive optics.

The use of super-surface imaging in the prior art is limited to paraxial imaging, that is, a microscope lens is used to study the imaging of thin light parallel to the optical axis in the central field of view. In practical application scenarios, the lens must image all incident light rays within a certain field angle range on the sensor at the image plane, which is not limited to paraxial situation, and this necessitates the design of the application-oriented super-surface lens in consideration of normal imaging at multiple field angles.

Disclosure of Invention

One aspect of the present application provides a super-surface imaging apparatus. The super-surface imaging device can comprise a diaphragm, at least one super-surface lens and an imaging sensor, wherein the diaphragm is used for limiting an incident light beam; at least one super-surface mirror is aligned with the diaphragm and has a plurality of phase compensation structures to deflect the beam confined by the diaphragm for phase compensation thereof. The imaging sensor then converts the phase compensated light into an electrical signal proportional to the signal of the light. Wherein the phase compensation produced by each of the plurality of phase compensation structures varies with distance from the center of the diaphragm.

In one embodiment, the center of the diaphragm is aligned with the center of the super-surface mirror in the optical axis direction.

In one embodiment, the phase compensation varies with a decaying periodicity from the center of the super-surface lens in a radial direction of the super-surface lens.

In one embodiment, the angle of rotation that each of the plurality of phase compensation structures on the super-surface optic form with respect to either radial direction of the super-surface optic varies with distance from the center of the super-surface optic.

In one embodiment, the rotational angle of each of the plurality of phase compensation structures varies in a decaying periodicity from the center of the super-surface lens in a radial direction of the super-surface lens.

In one embodiment, the super-surface optic further comprises a transparent substrate, wherein the phase compensation structure is formed on the transparent substrate by a dielectric material.

In one embodiment, the dielectric material forming the phase compensation structure is an inorganic dielectric material having a refractive index different from a refractive index of a material forming the substrate.

In one embodiment, the inorganic dielectric material has a refractive index greater than a refractive index of a material forming the transparent substrate.

In one embodiment, the inorganic dielectric material comprises at least one of zinc sulfide, magnesium fluoride, titanium dioxide, zirconium oxide, silicon hydride, crystalline silicon, silicon nitride, amorphous silicon, gallium nitride, gallium phosphide, gallium arsenide.

In one embodiment, the material forming the transparent substrate is an inorganic material including one of conductive glass ITO, aluminum oxide, zinc oxide, magnesium fluoride, silicon dioxide.

In one embodiment, a material forming the transparent substrate is a resin-based organic transparent material.

In one embodiment, the distance of the super-surface mirror from the imaging sensor is less than the distance of the super-surface mirror from the diaphragm.

In one embodiment, the phase compensation structure is formed as a rectangular parallelepiped fin.

In one embodiment, the phase compensation structure is a rectangular parallelepiped fin having a height of 200 and 800nm and a length and width of 30-500 nm.

In one embodiment, the phase compensation structure is formed as a solid micro-nano structure of a cuboid, cylinder or hemisphere.

In one embodiment, a cuboid, cylinder or hemisphere hollow structure is further formed on the solid micro-nano structure.

Another aspect of the present application provides a super-surface imaging apparatus, comprising: the diaphragm is used for limiting the incident light beam; at least one super-surface lens which is aligned with the diaphragm and is provided with a plurality of phase compensation structures so as to perform deflection processing on the light beam limited by the diaphragm and perform phase compensation on the light beam; and an imaging sensor converting the phase-compensated light into an electrical signal proportional to a signal of the light. Wherein each of the super-surface lenses comprises: a first portion, located at the center of the super-surface optic, comprising a first plurality of phase compensation structures; and a second portion surrounding the first portion, including a second plurality of phase compensation structures, wherein the light beams phase-compensated by the first and second plurality of phase compensation structures are incident on the imaging sensor at non-overlapping first and second interference constructive positions, respectively.

In one embodiment, in the first portion, the phase shift changes introduced by the first plurality of phase compensation structures in directions towards and away from the center of the super-surface optic are symmetric.

In one embodiment, in the second portion, the phase shift variation introduced by the second plurality of phase compensation structures in directions towards and away from the center of the super-surface optic is asymmetric.

In one embodiment, the dielectric material forming the phase compensation structure is an inorganic dielectric material having a refractive index different from a refractive index of a material forming the transparent substrate.

In one embodiment, the distance between the super-surface mirror and the imaging sensor is less than the distance between the super-surface mirror and the diaphragm.

Another aspect of the present application provides a super-surface imaging apparatus, comprising: the diaphragm is used for limiting the incident light beam; at least one super-surface lens which is aligned with the diaphragm and is provided with a plurality of phase compensation structures so as to perform deflection processing on the light beam limited by the diaphragm and perform phase compensation on the light beam; and an imaging sensor that converts the phase-compensated light into an electrical signal proportional to a signal of the light; wherein the super-surface lens has a plurality of phase compensation structures, the equivalent focal length of which gradually increases in a direction away from the center of the super-surface lens.

Another aspect of the present application provides a super-surface imaging apparatus, comprising: the diaphragm is used for limiting the incident light beam; at least one super-surface lens which is aligned with the diaphragm and is provided with a plurality of phase compensation structures so as to perform deflection processing on the light beam limited by the diaphragm and perform phase compensation on the light beam; and an imaging sensor that converts the phase-compensated light into an electrical signal proportional to a signal of the light; wherein the super-surface optic has a plurality of phase compensation zones, each phase compensation zone comprising a plurality of phase compensation structures, and the phase compensation structures of at least one of the plurality of phase compensation zones introduce an asymmetric change in phase shift in a direction towards and away from the center of the super-surface optic. In one embodiment, the center of the diaphragm is aligned with the center of the super-surface mirror in the optical axis direction.

The phase compensation of the phase compensation structure in the prior art varies only in dependence on the distance r from the center of the lens. According to the application, the phase compensation of the phase compensation structure can be changed according to the change of the angle of the principal ray, and the requirement of paraxial imaging is not compensated for the incident angle of the principal ray, so that the super lens can have a certain field angle, and can be matched with a CMOS sensor comprising more than one pixel on an image surface in practical use. In addition, the present application is advantageous in that it can be integrated in a space-saving manner closer to CMOS.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 illustrates a super-surface imaging device according to an embodiment of the present application;

FIG. 2 illustrates a phase compensation structure according to an embodiment of the present application;

FIG. 3 illustrates a phase compensation schematic of a phase compensation structure according to an embodiment of the present application;

FIG. 4 shows a lens imaging a CRA zero beam according to an embodiment of the present application;

FIG. 5 shows a lens according to an embodiment of the present application imaging a beam of light with a CRA that is non-zero;

FIG. 6 illustrates a lens divided into a plurality of concentric zones according to an embodiment of the present application;

FIG. 7 shows a graph of the rotation angle φ of the phase compensating structure fins at a distance Δ r from the reference position in each region according to an embodiment of the present application;

FIG. 8 shows a graph of the rotation angle φ of a cuboid fin as a function of the center-to-edge distance r of a super surface according to an embodiment of the present application;

FIG. 9 shows a graph of the rotation angle φ of the phase compensating structure fins at a distance Δ r from the reference position in each region according to another embodiment of the present application;

FIG. 10 shows a graph of the rotation angle φ of a rectangular parallelepiped fin according to another embodiment of the present application as a function of the center-to-edge distance r of the super surface;

FIG. 11 shows a graph of the rotation angle φ of the phase compensating structure fins at a distance Δ r from the reference position in each region according to yet another embodiment of the present application;

FIG. 12 shows a graph of the rotation angle φ of a rectangular parallelepiped fin according to still another embodiment of the present application as a function of the center-to-edge distance r of the super surface.

FIG. 13 shows a graph of the rotation angle φ of the phase compensating structure fins at a distance Δ r from the reference position in each region according to yet another embodiment of the present application;

FIG. 14 shows a graph of the rotation angle φ of a rectangular parallelepiped fin according to still another embodiment of the present application as a function of the center-to-edge distance r of the super surface.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that the expressions first, second, etc. in this specification are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first dielectric material discussed below may also be referred to as the second dielectric material without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of each component may have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

Throughout the specification, when an element such as a layer, region or substrate is described as being "on," "connected to" or "coupled to" another element, it can be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present between the element and the other element. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no other elements intervening between the element and the other element.

Spatially relative terms such as "above … …", "above", "below … …" and "below" may be used herein for descriptive convenience to describe one element's relationship to another element as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to other elements would then be "below" or "lower" relative to the other elements. Thus, the phrase "above … …" encompasses both an orientation of "above … …" and "below … …" depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this application should be interpreted accordingly.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears in the list of listed features, that statement modifies all features in the list rather than merely individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Additionally, the word "exemplary" is intended to mean exemplary or illustrative.

As used herein, the terms "approximately," "about," and the like are used as words of table approximation and not as words of table degree, and are intended to account for inherent deviations in measured or calculated values that can be appreciated by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In addition, unless explicitly defined or contradicted by context, the specific steps included in the methods described herein are not necessarily limited to the order described, but can be performed in any order or in parallel.

The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

FIG. 1 illustrates a super-surface imaging device 100 according to an embodiment of the present application. Referring to fig. 1, a simplified diagram of imaging an object 110 on a light axis is shown, with distances and scales being illustrative only. As shown, the super-surface imaging device 100 includes an aperture 120, at least one super-surface mirror 130, and a sensor 140, wherein the aperture 120, the at least one super-surface mirror 130, and the sensor 140 are arranged in sequence along an optical axis of the super-surface imaging device 100.

The diaphragm 120 limits the light beam, i.e., the light incident on the imaging device 100, to restrict the size of the incident light beam. Center O of diaphragm 120₁And the center O of the super-surface lens 130₂Substantially aligned in the optical axis direction. At least one super-surface mirror 130 is aligned with the aperture 120 and has a plurality of phase compensation structures 220 (see fig. 2 and 3) to deflect the beam after it is limited by the aperture 120 to compensate the phase of the beam. The phase compensation produced by each of the plurality of phase compensation structures 220 varies as its distance from the center of the diaphragm 120 varies. The imaging sensor 140 receives the light and converts the light signal into an electrical signal in a proportional relationship with the light signal, i.e., converts the phase-compensated light into an electrical signal proportional to the signal of the light from the object.

In an exemplary embodiment, each super-surface lens 130 may include: a first portion located in a central region of the super-surface lens, the first portion comprising a first plurality of phase compensation structures; and a second portion surrounding the first portion (i.e., the portion between the central region and the edge of the super-surface optic 130) that contains a second plurality of phase compensation structures, wherein the light beams that are phase compensated by the first and second plurality of phase compensation structures are incident on the imaging sensor at non-overlapping first and second interference constructive positions, respectively.

In the case of dividing the surface of the super-surface optic into a first portion and a second portion located in the central zone, the phase shift changes introduced by the first plurality of phase compensation structures in the first portion in directions towards and away from the center of the super-surface optic are symmetric; the second plurality of phase compensation structures of the second portion introduce an asymmetry in the phase shift variation in directions towards and away from the center of the super-surface optic.

Alternatively, the super-surface mirror 130 has the above-mentioned plurality of phase compensation structures with their equivalent focal lengths gradually increasing in a direction away from the center of the super-surface mirror 130.

Alternatively, the super surface optic 130 has a plurality of phase compensation zones, each phase compensation zone comprising a plurality of phase compensation structures, and wherein in at least one of the plurality of phase compensation zones, the phase compensation structures introduce an asymmetric change in phase shift in a direction towards and away from the center of the super surface optic.

The light emitted from different positions on the object 110 passes through the diaphragm 120 and the optical axis O₁-O₂The angles of the defined optical axes are different and will pass through the center O of the diaphragm 120 for ease of illustration₁Is defined as the chief ray angle CRA. A series of rays from the object 110 centered at a particular chief ray angle (rays 121,122, 123 and rays 131,132, 133 shown in fig. 1) will introduce a Pancharatnam-berry (pb) phase difference associated with the shape of the phase compensation structure through the phase compensation structure on the super-surface mirror 130 and create a location of interference constructive at a particular location on the sensor 140 to form an image point of the image 150.

Fig. 2 and 3 respectively show schematic structures of a phase compensation structure 220 according to an embodiment of the present application. As shown, the super surface mirror 130 can include a substrate 210 and a plurality of phase compensation structures 220 on the substrate. The phase compensation structure 220 is formed on the transparent substrate 210 by a dielectric material. The material forming the substrate 210 may be an inorganic material such as conductive glass ITO, alumina, zinc oxide, magnesium fluoride, or silicon dioxide, or may be a resin-based organic transparent material. The dielectric material forming the phase compensation structure 220 may be an inorganic dielectric material mainly including at least one of inorganic dielectric materials such as zinc sulfide, magnesium fluoride, titanium dioxide, zirconium oxide, silicon hydride, crystalline silicon, silicon nitride, amorphous silicon, gallium nitride, gallium phosphide, gallium arsenide, and the like, but may also include an organic material such as PMMA, and the like. The refractive index of the material forming the phase compensation structure 220 is different from the refractive index of the material forming the substrate 210, and generally the refractive index of the material forming the phase compensation structure 220 is required to be high. The dimensions of the individual phase compensation structures 220 are similar to or smaller than the wavelength of light, and their maximum length or height may, for example, be in the range of 50nm to 2000nm, depending on the operating band. In the super-surface mirror 130, although a plurality of the above-described phase compensation structures 220 are arranged on the transparent substrate 210, since the dimensions of the phase compensation structures 220 are many orders of magnitude smaller than the substrate 210, the super-surface mirror 130 can still be considered to be a planar optical device, i.e., the super-surface mirror 130 is approximately flat.

According to an embodiment of the application, the distance between the super-surface mirror 130 and the imaging sensor 140 is smaller than the distance between the super-surface mirror and the diaphragm 120, enabling space-saving integration closer to CMOS. .

The phase compensation structures 220 may be rectangular parallelepiped fins, and as shown in fig. 2, each rectangular parallelepiped fin may be defined by a length L, a width W, and a height H. H may be in the range of 200-800nm depending on the material type, L may be in the range of 30-500nm depending on the material type and W may be in the range of 30-500nm depending on the material type, thereby disposing the phase compensation structure 220 on the super surface mirror 130 as much as possible. It will be appreciated by those skilled in the art that such a rectangular parallelepiped fin may act to phase incident light of circular polarization approximately like a half-wave plate, such that incident left-handed or right-handed circularly polarized light rotated by a fin rotation angle α emerges as right-handed or left-handed polarized light rotated by 2 α or-2 α, respectively, as shown in fig. 3. Therefore, different PB phase differences are introduced at different positions due to different rotation angles of the cuboid fins, and the focusing effect can be achieved by means of constructive interference of light rays of the PB phase differences at the designed focusing point. For example, the distance between the sensor 140 and the super-surface mirror 130 can be defined as the focal length f, and the rotation angle α of the phase compensation structure should be designed to satisfy the following condition under the limitation of paraxial imaging:

where λ is the wavelength, r is the distance of each cuboid fin from the center of the super-surface mirror 130, and k is an integer and preferably may be 0.

Those skilled in the art will also know eachThe single phase compensation structure is not limited to a cuboid fin, but solid micro-nano structures such as a cuboid, a cylinder and a hemisphere can be adopted, or hollow or partially hollow micro-nano structures with recesses or holes of the cuboid, the cylinder and the hemisphere are further arranged on the phase compensation structure to realize further fine adjustment of the phase, so that further effects of eliminating chromatic aberration, polarization sensitivity and the like are achieved. It should be particularly noted that the phase compensation structure may be formed by combining a plurality of solid or hollow micro-nano structures with different sizes to form a single phase compensation unit, and the further effects of eliminating chromatic aberration, polarization sensitivity and the like are achieved by using the combination of a plurality of phase compensation units. That is, the size, pitch, and rotation angle of the phase compensation structures 220 on the super-surface mirror 130 may be different from each other, and are not limited to the cases of fig. 2 to 3 that coincide with each other. If such a complex phase compensation structure is used, it is difficult to analytically calculate the size, pitch, rotation angle, etc. of the required phase compensation structure 220, and it is necessary to analyze the complex phase compensation structure using numerical simulation methods such as FDTD (finite difference time domain), finite element FEM, etc. only by satisfying the requirement

The phase compensation of (2) is sufficient.

For imaging over a wide band (or multiple wavelengths), λ in the above equation will vary. In this case, it is possible to simply combine the plurality of phase compensation structures 220 of different wavelengths with each other in different spatial positions, for example, to set the plurality of phase compensation structures 220 representing wavelengths as a group so that the focusing effects of different wavelengths are balanced to some extent, or to form the plurality of phase compensation structures representing wavelengths as different spatial portions of the super-surface lens. It is also possible to add a chromatic aberration compensation structure with introduced phase shift varying with wavelength on the basis of a phase compensation structure designed according to a certain participating wavelength, such as a resonance mode inside a nanostructure such as a fin structure or a combined resonance mode between nanostructures, so that the provided phase shift varies with wavelength, and since it is difficult to calculate which nanostructure or combination can provide such a phase shift varying with wavelength in an analytical manner, in the prior art, a structure providing the most suitable phase shift curve is generally selected by means of computer simulation after exhaustive enumeration of a plurality of possible structures.

In practice, since the pixels at various positions on the sensor 140 can be used for imaging, not just a small area near the optical axis, it is required to simultaneously image different incident light rays at different positions on the plane of the sensor 140, and the above analysis cannot be limited to the special case of paraxial incidence. As shown in fig. 1, CRA of the light beams 121, 122, 123 shown by the dotted lines is 0, which corresponds to the paraxial imaging described above. However, the CRA of the beams 131, 132, and 133 shown by the solid lines is not zero, and the imaging positions required for the beams of the CRA are also different from the imaging positions of the paraxial beams 121, 122, and 123, and in this case, the phase compensation required to be satisfied will also vary. As shown in fig. 5, since the lens is used to image an external scene with a distance far greater than the focal length in most cases, the incident beamlets can be regarded as parallel light, and the required phase compensation becomes:

wherein,

wherein, the lambda is the wavelength,

f is the distance (i.e. focal length) between the sensor 140 and the super surface mirror 130,

f' is the distance traveled by the chief ray from the super-surface optic 130 to the sensor 140,

ar is the distance of the phase compensating structure from the intersection of the chief ray with the super-surface optic 130,

θ＝arccos(f/f’)。

it can be seen that the phase compensation is related to both f' and CRA, i.e. will vary according to the change in distance of the center of the diaphragm 120. The super-surface imaging device can be adapted to sensors with different sizes by selecting f'. If makeWith the fin-shaped phase compensation structure, the angle of rotation of the fin should be as in the above formula

1/2, wherein, for left-handed incident light, the angle of rotation is

Positive 1/2, for right-handed polarized light, the angle of rotation is

Negative 1/2. The direction of rotation is opposite for different circular polarizations. The above equation is equivalent to the paraxial case only in the case of CRA ═ 0, while the difference between the phase compensation required for CRA between 0 and 90 ° and the paraxial case will increase.

In a simplified embodiment, the focus point may be located at a position where the extension of the principal ray intersects the image plane where the sensor is located:

where f/cosCRA may be defined as the equivalent focal length, i.e., the equivalent focal length should gradually increase in the radial direction of the super-surface optic 130.

To satisfy the above formula, the super-surface lens 130 can be divided into a plurality of regions, which are not overlapped with each other and are designed according to a range of CRA. Or may partially overlap each other such that the response to CRA changes continuously in the radial direction of the lens.

As shown in FIG. 6, the super-surface lens 130 may be divided into a plurality of concentric zones according to the CRA, each zone designed according to a different CRA in the above formula. The shape of each area is not limited to the above-described ring shape, but may be divided according to the shape of the super surface mirror 130 itself, such as a rectangle, a polygon, an irregular shape, and the like. The super-surface mirror 130 may be further divided into a plurality of grids according to areas in the coordinate system, and different phase compensation structures may be arranged in different grids according to the corresponding CRA and Δ r and the above formula. The size or width of each concentric region may be determined based on the actual micro-machining capability.

Example 1

In one example, assuming a CRA of up to 30 ° and a wavelength of 500nm, a total of 6 concentric annular regions are arranged, each region having a width (e.g., r in fig. 6)₁、r₂、r₃、r₄And r₅) And the diaphragm radius is 20 microns, the distance between the diaphragm and the super-surface mirror is 200 microns, and f is 50 microns, the rotation angle phi of the phase compensation structure fin at the distance delta r relative to the corresponding reference position in each area is shown in table 1 and fig. 7 respectively.

Specifically, in the present example, for an area with a CRA of 0 °, the reference position is the center O of the super-surface lens 130₂(ii) a For the region with the CRA of 5 °, the boundary between the region with the reference position of 5 ° and the region with the CRA of 0 °; for the region with the CRA of 10 °, the boundary between the region with the reference position of 10 ° and the region with the CRA of 5 °; for the region with the CRA of 15 °, the boundary between the region with the reference position of 15 ° and the region with the CRA of 10 °; for the region with the CRA of 20 °, the boundary between the region with the reference position of 20 ° and the region with the CRA of 15 °; for the region with the CRA of 25 °, the boundary between the region with the reference position of 25 ° and the region with the CRA of 20 °; in the region having a CRA of 30 °, the boundary between the region having a reference position of 30 ° and the region having a CRA of 25 °.

TABLE 1 rotation angle φ of phase compensating structural fins at a distance Δ r from the center in each zone

One of the significant differences is that for the case of CRA ═ 0 °, the change in Φ is symmetric in the positive and negative directions; whereas for the case where the CRA is not equal to 0 °, the amount of variation in phi in the positive direction (i.e., in the direction away from the center of the super surface lens 130) starts to be larger than the amount of variation in phi in the negative direction (i.e., in the direction closer to the center of the super surface lens 130) at the same distance from the reference position of each area, and the difference in the amounts of variation in the positive and negative directions also tends to increase as the CRA increases.

If the distance r from the center to the edge of the super surface is taken as the standard, the rotation angles of the corresponding rectangular parallelepiped fins can be extracted from the above table and listed together as shown in table 2 and fig. 8.

TABLE 2 variation of the rotation angle phi of the cuboid fins with r

Example 2

In another example, assuming a CRA of 30 ° at maximum and a wavelength of 700 nm, 6 concentric annular regions are arranged, each having a width and a stop radius of 20 microns, a stop distance of 200 microns from the super-surface mirror, and f of 50 microns, the rotation angle Φ of the phase compensation structure fin at a distance Δ r in each region with respect to the corresponding reference position is shown in table 3 and fig. 9, respectively. In the present embodiment, the reference position is defined similarly to embodiment 1.

TABLE 3 rotation angle φ of phase compensating structural fins at distance Δ r from center in each zone

If the distance r from the center to the edge of the super surface is taken as the standard, the rotation angles of the corresponding rectangular parallelepiped fins can be extracted from the above table and listed together as shown in table 4 and fig. 10.

TABLE 4 variation of the rotation angle phi of the rectangular parallelepiped fin with r

r(μm)	φ(°)	r(μm)	φ(°)	r(μm)	φ(°)	r(μm)	φ(°)
								0	0	35	-117.018	70	-117.138	105	0
1	-2.57117	36	-86.3583	71	-153.572	106	-1.92891
								2	-10.2816	37	-60.2311	72	-195.06	107	-7.77403
3	-23.1221	38	-38.7091	73	-241.631	108	-17.6224
								4	-41.0772	39	-21.8614	74	-199.121	109	-31.5602
5	-64.1258	40	-9.75365	75	-162.466	110	-49.6722
								6	-92.2405	41	-2.4474	76	-129.297	111	-72.0418
7	-125.389	42	0	77	-99.7016	112	-98.7505
								8	-163.531	43	-2.4642	78	-73.769	113	-129.878
9	-206.625	44	-9.8879	79	-51.5871	114	-165.5
								10	-254.622	45	-22.3139	80	-33.2439	115	-205.692
11	-247.546	46	-39.7797	81	-18.8272	116	-152.982
								12	-201.204	47	-62.317	82	-8.42388	117	-125.015
13	-159.499	48	-89.9521	83	-2.1199	118	-99.6536
								14	-122.497	49	-122.705	84	0	119	-76.9736
15	-90.2626	50	-160.591	85	-2.14733	120	-57.0527
								16	-62.8558	51	-203.616	86	-8.64316	121	-39.9702
17	-40.3318	52	-251.784	87	-19.5666	122	-25.8067
								18	-22.7412	53	-218.992	88	-34.9941	123	-14.644
19	-10.1296	54	-178.483	89	-54.9994	124	-6.5656
								20	-2.53753	55	-141.884	90	-79.6531	125	-1.65576
21	0	56	-109.28	91	-109.022	126	0
								22	-2.54636	57	-80.7595	92	-143.17	127	-1.68469
23	-10.2001	58	-56.406	93	-182.154	128	-6.79694
								24	-22.9789	59	-36.3032	94	-226.031	129	-15.4245
25	-40.8942	60	-20.533	95	-176.782	130	-27.6553
								26	-63.9514	61	-9.17479	96	-144.367	131	-43.5778
27	-92.1498	62	-2.3057	97	-114.999	132	-63.2802
								28	-125.482	63	0	98	-88.7615	133	-86.8504
29	-163.936	64	-2.32887	99	-65.7396	134	-114.376
								30	-207.492	65	-9.36001	100	-46.0193	135	-145.943
31	-256.125	66	-21.1574	101	-29.6875	136	-181.638
								32	-235.426	67	-37.7808	102	-16.8316
33	-191.631	68	-59.2858	103	-7.53954
								34	-152.135	69	-85.723	104	-1.89958

Example 3

In yet another example, assuming a CRA of 30 ° at maximum and a wavelength of 500nm, 6 concentric annular regions are arranged, each having a width and a stop radius of 20 microns, a stop distance of 200 microns from the super-surface mirror, and f of 60 microns, the rotation angle Φ of the phase compensation structure fin at a distance Δ r in each region with respect to the corresponding reference position is shown in table 5 and fig. 11, respectively. In the present embodiment, the reference position is defined similarly to embodiment 1.

TABLE 5 rotation angle φ of phase compensating structural fins at distance Δ r from center in each zone

Example 1	CRA＝0°	CRA＝5°	CRA＝10°	CRA＝15°	CRA＝20°	CRA＝25°	CRA＝30°
								Δr(μm)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)
10	-297.945	-298.853	-292.926	-280.288	-261.449	-237.298	-209.068
								9	-241.648	-242.038	-236.89	-226.339	-210.831	-191.112	-168.19
8	-191.154	-191.187	-186.846	-178.266	-165.824	-150.126	-131.978
								7	-146.503	-146.317	-142.785	-136.033	-126.367	-114.264	-100.347
6	-107.731	-107.438	-104.693	-99.6001	-92.399	-83.4492	-73.2107
								5	-74.8702	-74.5583	-72.5473	-68.9212	-63.8542	-57.6016	-50.4845
4	-47.9468	-47.6777	-46.3246	-43.9479	-40.6643	-36.6403	-32.0824
								3	-26.9831	-26.7927	-25.9949	-24.6273	-22.7582	-20.4832	-17.9185
2	-11.9967	-11.8947	-11.524	-10.9029	-10.0628	-9.04702	-7.9071
								1	-2.99979	-2.96998	-2.87334	-2.71481	-2.50258	-2.24755	-1.96264
0	0	0	0	0	0	0	0
								-1	-2.99979	-2.96139	-2.85701	-2.69228	-2.47591	-2.21904	-1.93452
-2	-11.9967	-11.8261	-11.3934	-10.7227	-9.8496	-8.819	-7.68216
								-3	-26.9831	-26.5614	-25.5546	-24.0198	-22.0391	-19.7141	-17.1596
-4	-47.9468	-47.1301	-45.2824	-42.5097	-38.9611	-34.8184	-30.2843
								-5	-74.8702	-73.4908	-70.5152	-66.1164	-60.5318	-54.0463	-46.9746
-6	-107.731	-105.598	-101.188	-94.762	-86.6663	-77.3124	-67.15
								-7	-146.503	-143.401	-137.234	-128.367	-117.279	-104.532	-90.7307
-8	-191.154	-186.848	-178.583	-166.85	-152.285	-135.62	-117.638
								-9	-241.648	-235.881	-225.161	-210.13	-191.599	-170.493	-147.796
-10	-297.945	-290.44	-276.894	-258.122	-235.133	-209.067	-181.126

If the distance r from the center to the edge of the super surface is taken as a criterion, the required rotation angle of the rectangular parallelepiped fin can be extracted from the above table and listed together as shown in table 6 and fig. 12.

TABLE 6 variation of the rotation angle phi of the rectangular parallelepiped fin with r

Example 4

In yet another example, assuming that CRA is 36 ° at maximum and wavelength is 500nm, 6 concentric annular regions are arranged, each having a width and a stop radius of 20 microns, a stop distance from the super-surface mirror of 200 microns, and f is 50 microns, the rotation angle Φ of the phase compensation structure fin at a distance Δ r from the corresponding reference position in each region should be as shown in table 7 and fig. 13. In the present embodiment, the reference position is defined similarly to embodiment 1.

TABLE 7 rotation angle φ of phase compensating structural fins at distance Δ r from center in each zone

Example 1	CRA＝0°	CRA＝6°	CRA＝12°	CRA＝18°	CRA＝24°	CRA＝30°	CRA＝36°
								Δr(μm)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)	φ(°)
10	-356.47	-358.019	-347.77	-326.042	-294.132	-254.294	-209.567
								9	-289.276	-289.937	-281.04	-262.928	-236.731	-204.321	-168.163
8	-228.944	-228.994	-221.498	-206.793	-185.832	-160.126	-131.624
								7	-175.544	-175.219	-169.125	-157.574	-141.335	-121.591	-99.8272
6	-129.137	-128.629	-123.895	-115.199	-103.138	-88.5923	-72.6514
								5	-89.7761	-89.2367	-85.7723	-79.5933	-71.1319	-61.0089	-49.9761
4	-57.5081	-57.0431	-54.7147	-50.6733	-45.207	-38.7174	-31.6824
								3	-32.3709	-32.0419	-30.6707	-28.3504	-25.2489	-21.5942	-17.6527
2	-14.3942	-14.2182	-13.5819	-12.5306	-11.1412	-9.51571	-7.77139
								1	-3.59964	-3.54819	-3.38256	-3.11491	-2.76504	-2.35856	-1.92445
0	0	0	0	0	0	0	0
								-1	-3.59964	-3.53347	-3.35516	-3.07851	-2.72425	-2.31806	-1.88819
-2	-14.3942	-14.1005	-13.3629	-12.2396	-10.815	-9.19183	-7.48136
								-3	-32.3709	-31.6454	-29.9324	-27.3693	-24.149	-20.5017	-16.6741
-4	-57.5081	-56.105	-52.9678	-48.3512	-42.6026	-36.1293	-29.3633
								-5	-89.7761	-87.4093	-82.3684	-75.0665	-66.0522	-55.9583	-45.4482
-6	-129.137	-125.481	-118.029	-107.395	-94.3747	-79.8738	-64.8304
								-7	-175.544	-170.239	-159.841	-145.214	-127.448	-107.763	-87.4141
-8	-228.944	-221.592	-207.693	-188.402	-165.15	-139.515	-113.106
								-9	-289.276	-279.448	-261.469	-236.835	-207.36	-175.021	-141.814
-10	-356.47	-343.706	-321.052	-290.39	-253.959	-214.175	-173.451

If the distance r from the center to the edge of the super surface is taken as a criterion, the required rotation angle of the rectangular parallelepiped fin can be extracted from the above table and listed together as shown in table 8 and fig. 14.

TABLE 8 variation of the rotation angle phi of the rectangular parallelepiped fin with r

r(μm)	φ(°)	r(μm)	φ(°)	r(μm)	φ(°)	r(μm)	φ(°)
								0	0	35	-159.841	70	-157.574	105	0
1	-3.59964	36	-118.029	71	-206.793	106	-2.35856
								2	-14.3942	37	-82.3684	72	-262.928	107	-9.51571
3	-32.3709	38	-52.9678	73	-326.042	108	-21.5942
								4	-57.5081	39	-29.9324	74	-253.959	109	-38.7174
5	-89.7761	40	-13.3629	75	-207.36	110	-61.0089
								6	-129.137	41	-3.35516	76	-165.15	111	-88.5923
7	-175.544	42	0	77	-127.448	112	-121.591
								8	-228.944	43	-3.38256	78	-94.3747	113	-160.126
9	-289.276	44	-13.5819	79	-66.0522	114	-204.321
								10	-356.47	45	-30.6707	80	-42.6026	115	-254.294
11	-343.706	46	-54.7147	81	-24.149	116	-173.451
								12	-279.448	47	-85.7723	82	-10.815	117	-141.814
13	-221.592	48	-123.895	83	-2.72425	118	-113.106
								14	-170.239	49	-169.125	84	0	119	-87.4141
15	-125.481	50	-221.498	85	-2.76504	120	-64.8304
								16	-87.4093	51	-281.04	86	-11.1412	121	-45.4482
17	-56.105	52	-347.77	87	-25.2489	122	-29.3633
								18	-31.6454	53	-290.39	88	-45.207	123	-16.6741
19	-14.1005	54	-236.835	89	-71.1319	124	-7.48136
								20	-3.53347	55	-188.402	90	-103.138	125	-1.88819
21	0	56	-145.214	91	-141.335	126	0
								22	-3.54819	57	-107.395	92	-185.832	127	-1.92445
23	-14.2182	58	-75.0665	93	-236.731	128	-7.77139
								24	-32.0419	59	-48.3512	94	-294.132	129	-17.6527
25	-57.0431	60	-27.3693	95	-214.175	130	-31.6824
								26	-89.2367	61	-12.2396	96	-175.021	131	-49.9761
27	-128.629	62	-3.07851	97	-139.515	132	-72.6514
								28	-175.219	63	0	98	-107.763	133	-99.8272
29	-228.994	64	-3.11491	99	-79.8738	134	-131.624
								30	-289.937	65	-12.5306	100	-55.9583	135	-168.163
31	-358.019	66	-28.3504	101	-36.1293	136	-209.567
								32	-321.052	67	-50.6733	102	-20.5017
33	-261.469	68	-79.5933	103	-9.19183
								34	-207.693	69	-115.199	104	-2.31806

The description of the present application has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the application in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in the art. For example, one skilled in the art can use other semiconductor processes to fabricate superlenses under the teachings of the present disclosure. The embodiment was chosen and described in order to best explain the principles of the application and the practical application, and to enable others of ordinary skill in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A super-surface imaging apparatus, the super-surface imaging apparatus comprising:

the diaphragm is used for limiting the incident light beam;

at least one super-surface lens aligned with the diaphragm and having a plurality of phase compensation structures to deflect the light beam limited by the diaphragm for phase compensation thereof; and

an imaging sensor that converts the phase-compensated light into an electrical signal proportional to a signal of the light;

wherein the super-surface lens has a plurality of phase compensation structures, and the equivalent focal length of the phase compensation structures gradually increases in a direction away from the center of the super-surface lens.

2. The super surface imaging device of claim 1, wherein a center of the stop is aligned with a center of the super surface mirror in an optical axis direction.

3. The super surface imaging device as claimed in claim 2, wherein the phase compensation varies with a decaying periodicity from the center of the super surface lens in a radial direction of the super surface lens.

4. The super surface imaging device of any one of claims 1 to 3, wherein the super surface mirror further comprises a transparent substrate, wherein the phase compensation structure is formed on the transparent substrate by a dielectric material.

5. The super surface imaging device according to claim 4, wherein the dielectric material forming the phase compensation structure is an inorganic dielectric material having a refractive index different from a refractive index of a material forming the transparent substrate.

6. The super surface imaging apparatus according to claim 5, wherein the inorganic dielectric material has a refractive index greater than a refractive index of a material forming the transparent substrate.

7. The super surface imaging device of claim 5, wherein the inorganic dielectric material comprises at least one of zinc sulfide, magnesium fluoride, titanium dioxide, zirconium oxide, silicon hydride, crystalline silicon, silicon nitride, amorphous silicon, gallium nitride, gallium phosphide, gallium arsenide.

8. The super surface imaging device according to claim 5, wherein the material forming the transparent substrate is an inorganic material comprising one of conductive glass ITO, alumina, zinc oxide, magnesium fluoride, silicon dioxide.

9. The super surface imaging device according to claim 5, wherein a material forming the transparent substrate is a resin-based organic transparent material.

10. The super surface imaging device as claimed in claim 5, wherein the distance of the super surface mirror from the imaging sensor is less than the distance of the super surface mirror from the diaphragm.