Additive Manufacturing of Metalenses

Abstract

A method for manufacturing an optical element is disclosed. The method includes the following steps: forming a first material layer on a substrate, forming a plurality of cavities in the first material layer by an imprinting process, and forming a second material layer in the plurality of cavities to form an optical metasurface. An optical element manufactured according to the method, an optical device including the optical element, and an optical device such as a cellular phone, a camera, an image recording device, or a video recording device are also disclosed.

Description

Technical Field

[0001] The present disclosure relates to a method of manufacturing an optical element, particularly where the optical element is a metalens for use in an optical device. Background Art

[0002] Conventional optical lenses, such as convex, concave or meniscus refractive lenses, can be bulky, expensive, and require complex processes to manufacture. In addition, the optical ability of such lenses to affect incident radiation can be limited.

[0003] Compared to such conventional lenses, the use of optical elements including meta-surfaces is becoming increasingly common in optical systems.

[0004] Metasurfaces typically include multiple nanostructures, such as structures having nanoscale dimensions in the range of tens or hundreds of nanometers. Such nanostructures are typically arranged in a specific pattern to have a defined effect on incident radiation. That is, the specific nanostructure pattern and / or nanostructure dimensions that form the metasurface can be defined to change the characteristics of the incident radiation. Metasurfaces designed to change incident radiation typically include nanostructures with dimensions within or less than the wavelength of the incident radiation.

[0005] Flat lenses based on metasurfaces are referred to in the art as “metalenses.” Metalenses can be configured, for example, to operate as convex lenses, concave lenses, prisms, or to change the phase of incident radiation, etc.

[0006] Due to the extremely small size of the nanostructures used to form the metasurface, the fabrication of metalenses can be technically challenging. That is, due to the small size of the nanostructures, metalenses formed by conventional photolithography techniques can be susceptible to manufacturing defects, potentially resulting in optical aberrations and / or undesirable or unpredictable optical properties in use.

[0007] Furthermore, limitations of existing lithographic techniques using the specific materials required to form metalenses may effectively limit the practical minimum size and / or geometry of the nanostructures of a metalens.

[0008] Therefore, an object of at least one embodiment of at least one aspect of the present disclosure is to eliminate or at least alleviate at least one of the above-mentioned disadvantages of the prior art. Summary of the invention

[0009] The present disclosure relates to a method of manufacturing an optical element, in particular wherein the optical element is a metalens for use in an optical device. The present disclosure also relates more generally to optical devices and apparatus including optical devices, such as cellular phones, cameras, image recording devices; and / or video recording devices.

[0010] According to a first aspect of the present disclosure, a method for manufacturing an optical element is provided, the method comprising the following steps: forming a first material layer on a substrate; forming a plurality of cavities in the first material layer by an imprinting process; and forming a second material layer in the plurality of cavities to form an optical metasurface.

[0011] Advantageously, fabricating an optical element by imprinting a first material layer to form a plurality of cavities can result in the formation of structures of an optical metasurface having very well-defined sidewalls. That is, the sidewalls of any posts, beams, ridges, wings, and / or mesas formed by the second material layer in the plurality of cavities can be, for example, substantially 90 degrees or close to 90 degrees relative to the surface of the substrate. That is, the sidewalls of any such structure can be oriented substantially vertically relative to the horizontal plane of the upper surface of the substrate.

[0012] Furthermore, by following such a method, any such structure may be formed without the need for an etching step, such as a wet etch or a plasma etch, which may result in a structure without well-defined sidewalls, for example due to non-perfect anisotropic etching or the like.

[0013] In certain embodiments, the second material may include a refractive index greater than that of the substrate. For example, the refractive index of the second material may be 0.5, 1.0, or more greater than that of the substrate.

[0014] In certain embodiments, the second material may include a refractive index that is less than the refractive index of the substrate. For example, the refractive index of the second material may be 0.5, 1.0, or more less than the refractive index of the substrate.

[0015] In certain embodiments, the second material may include a refractive index greater than 1.5. In certain embodiments, the second material may include a refractive index greater than 2. The second material may include a refractive index greater than 2.5. The second material may include a refractive index between 2 and 3.5.

[0016] The embossing process may include embossing the plurality of cavities directly into the first material layer.

[0017] The imprinting process may include imprinting a pattern corresponding to the plurality of cavities into a mask layer. The mask layer may be formed on the first material layer. The method may include subsequently etching the first material layer to form the plurality of cavities.

[0018] The step of forming the second material layer may include selectively growing the second material.

[0019] The step of forming the second material layer may include selectively depositing the second material.

[0020] Advantageously, the imprint process can work in conjunction with the selective growth / deposition process to form structures in the cavity with very well-defined sidewalls.

[0021] The method may include a subsequent step of removing the first material layer from the substrate such that the second material layer defines a plurality of posts, beams, ridges, wings and / or mesas extending from the substrate.

[0022] The step of forming the second material layer may include applying a coating to the first material layer.

[0023] The second material layer may form a substantially planar surface over the first material layer and the plurality of cavities.

[0024] The second material layer may form a layer of substantially uniform thickness over the first material layer.

[0025] The second material layer may form a layer that conforms to the contours of the cavity in the first material layer.

[0026] The method may include the subsequent step of forming a third material layer over the second material layer.

[0027] The third material may include a different refractive index than the second material.

[0028] The third material layer may conform to the contours of the second material layer.

[0029] The second material may include a refractive index greater than the refractive index of the first material.

[0030] The cavities may be formed in a substantially concentric arrangement.

[0031] The plurality of cavities may be arranged in a pattern of substantially concentric groups.

[0032] The second material layer may comprise a thickness of less than 100 nm.

[0033] The plurality of cavities may be arranged at intervals of less than 500 nm.

[0034] The plurality of cavities may include different orientations in a plane defined by the substrate.

[0035] The method may include a prior step of forming a seed layer on the substrate.

[0036] The seed layer may include a second material.

[0037] The step of forming the second material layer may include at least one of: atomic layer deposition; chemical vapor deposition; physical vapor deposition; and / or epitaxial growth.

[0038] The first material and / or the second material and / or the third material may include at least one of: gallium nitride, silicon nitride or titanium oxide.

[0039] According to a second aspect of the present disclosure, there is provided an optical element manufactured according to the method of the first aspect.

[0040] The optical element may include or be configured as a metalens.

[0041] The optical element may be configured to operate in at least a portion of the visible light range.

[0042] The optical element may be configured for operation in at least a portion of the near infrared range, for example, for operation at radiation including wavelengths between approximately 0.75 microns and 1.4 microns.

[0043] The optical element may be configured to operate in at least a portion of the following: a short wavelength infrared range; a mid wavelength infrared range; a long wavelength infrared range; and / or a far infrared range; According to a third aspect of the present disclosure, an optical device is provided, comprising at least one optical element according to the second aspect. At least one optical device may also include a radiation sensor and / or a radiation source. At least one optical element may be configured to be used with a radiation sensor and / or a radiation source.

[0044] The at least one optical element may be configured to at least one of: change the phase of incident radiation; filter incident radiation; focus incident radiation; disperse incident radiation.

[0045] The optical device may include a plurality of optical elements. The plurality of optical elements may include optical elements having different configurations. That is, at least one of the plurality of optical elements may be configured differently from at least another of the plurality of optical elements.

[0046] According to a fourth aspect of the present disclosure, there is provided an apparatus comprising the optical device according to the third aspect. The apparatus may comprise at least one of the following: a cellular phone, a camera, an image recording device; and / or a video recording device.

[0047] The above summary of the invention is intended to be merely illustrative and not restrictive. The present disclosure includes one or more corresponding aspects, embodiments or features, either alone or in various combinations, whether or not specifically stated (including claimed) in that combination or alone. It should be understood that the features defined above or related to any specific embodiment of the present disclosure below according to any aspect of the present disclosure may be used alone or in combination with any other defined features in any other aspect or embodiment, or form another aspect or embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] These and other aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, which show:

[0049] Figure 1a -d is a method of forming an optical element according to the first embodiment of the present disclosure;

[0050] Figure 2a -c is a method for forming an optical element according to a second embodiment of the present disclosure;

[0051] Figure 3a -d is a method of forming an optical element according to a third embodiment of the present disclosure;

[0052] Figure 4a -g is a method of forming an optical element according to a fourth embodiment of the present disclosure;

[0053] Figure 5a -c is a method of forming an optical element according to a fifth embodiment of the present disclosure;

[0054] Figure 6 is a method of forming an optical element according to a sixth embodiment of the present disclosure;

[0055] Figure 7a -d is an optical device according to an embodiment of the present disclosure; and

[0056] Figure 8 is a device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] Figure 1a to Figure 1d A method of manufacturing an optical element according to a first embodiment of the present disclosure is described.

[0058] In the first step, a first material layer 105 is formed on a substrate 110. The first material layer 105 may include a curable material. For example, the curable material may be an ultraviolet (UV) radiation curable material or a heat curable material.

[0059] In an optional prior step, a seed layer may be formed on the substrate 110. The seed layer may be formed, for example, by atomic layer deposition; chemical vapor deposition, physical vapor deposition, and / or epitaxial growth. The seed layer may include a material suitable for forming (e.g., epitaxially growing, etc.) a second material thereon, wherein the second material is described in more detail below. The seed layer may include a second material. In another method, the substrate 110 may be provided as an "epitaxial ready" substrate, such as a substrate 110 that has been pre-treated with a seed layer.

[0060] In this particular embodiment, the substrate 110 comprises silicon. In another embodiment, the substrate 110 may comprise, for example, fused silica, sapphire, or any glass, such as a silica-based glass.

[0061] The first material may include a polymer, such as a thermoplastic polymer or the like.

[0062] The first material layer 105 may be formed by spin coating the substrate 110 or deposited on the substrate 110. In some embodiments, the first material layer 105 may be deposited onto the substrate 110, for example, by evaporation. In some embodiments, the substrate 110 may be dipped or otherwise immersed in the first material, wherein the first material is in a liquid state, to form the first material layer 105 on the substrate 110.

[0063] The first material layer 105 may be applied in a liquid state to the substrate 110. For example, before applying the first material layer 105 to the substrate 110, the first material may be heated until the first material is converted into a liquid state.

[0064] The first material layer 105 may include a resist material.

[0065] The first material layer 105 may be formed on a portion (eg, an upper surface) of a surface of the substrate 110. In some embodiments, the first material layer 105 may be formed on all or substantially all of a surface of the substrate 110.

[0066] I'm here too Figure 1a In the next step depicted in FIG, a plurality of cavities 115 are formed in the first material layer 105 by an imprinting process.

[0067] The plurality of cavities 115 may be formed by imprinting the plurality of cavities 115 directly into the first material layer 105. For example, the plurality of cavities 115 may be formed by an imprinting process, such as a nanoimprint lithography process as described in more detail below.

[0068] In one example embodiment, the plurality of cavities 115 may be formed by a thermoplastic nanoimprint lithography process. That is, the first material layer 105 is coated onto the substrate 110, and then a mold (not shown) including a predefined topological pattern is pressed onto the first material layer 105. The first material layer 105 is then heated directly and / or heated via the substrate 110 and / or heated via the mold, so that the first material layer 105 softens. The topological pattern on the mold is then pressed into the softened first material layer 105, thereby transferring a pattern corresponding to the predefined topological pattern of the mold to the first material layer 105. Figure 1a As shown, the pattern corresponding to the predefined topological pattern includes a plurality of cavities 115. After the first material layer 105 has sufficiently cooled, the mold may be separated from the first material layer 105.

[0069] In another exemplary embodiment, the plurality of cavities 115 are formed by a photo-nanoimprint lithography process. That is, a first material layer 105 is applied to the substrate 110, wherein the first material layer 105 comprises a photocurable material. At this stage, the first material layer 105 may be in a substantially ductile, softened or liquid state. Then, a mold comprising a predefined topological pattern is pressed onto the first material layer 105. The first material layer is subsequently cured by exposure to radiation, such as ultraviolet (UV) radiation. The mold may be, for example, transparent to radiation having a wavelength suitable for curing the first material layer 105. After the first material is cured, the mold may be separated from the first material layer 105.

[0070] like Figure 1a As shown, a residual layer 120 or scum including the first material may be present in at least one of the plurality of cavities 115 .

[0071] In example embodiments, the residual layer 120 may be removed from the substrate 110 by a plasma descum process, such as a descum process using oxygen plasma or high-power argon plasma. As a result of the descum process, portions of the substrate 110 corresponding to the plurality of cavities 115 are exposed, such as Figure 1b That is, part of the upper surface of the substrate 110 will be exposed, as shown in FIG. Figure 1b shown.

[0072] The plurality of cavities 115 may be formed in a defined arrangement, for example with a defined geometry and orientation, such that the resulting metasurface formed by the cavities (as described below with respect to Figure 1c and 1d 115 may have a desired effect on the incident radiation. For example, in one embodiment, the plurality of cavities 115 may be provided in a substantially concentric arrangement and / or the plurality of cavities 115 may be arranged in a pattern of substantially concentric groups.

[0073] In one example embodiment, the plurality of cavities 115 may be arranged at intervals less than 1 micrometer. In another embodiment, the plurality of cavities 115 may be arranged at intervals less than 500 nanometers.

[0074] In one example embodiment, the first material layer 105 may have a thickness less than 500 nanometers. In another example embodiment, the first material layer 105 may have a thickness less than 100 nanometers.

[0075] exist Figure 1c In the next step shown, a second material layer 125 is formed in the plurality of cavities 115 to form an optical metasurface. The second material may include a high refractive index. For example, the second material may include a refractive index of 2 or greater.

[0076] In one embodiment, the second material layer 125 includes gallium nitride. In other embodiments, the second material layer 125 may include silicon, silicon dioxide, silicon nitride, titanium oxide, etc.

[0077] The first material and / or the second material can be transparent or substantially transparent to radiation having a wavelength in the visible range and / or the near infrared range (e.g., approximately 380 to 740 nanometers). Additionally and / or alternatively, the first material and / or the second material can be transparent or substantially transparent to radiation having a wavelength in the UV, near infrared, short, medium or long wavelength infrared or far infrared range. In certain embodiments, the dimensions of the plurality of cavities 115 (e.g., lateral and / or vertical dimensions and / or spacing between cavities) can be smaller than the wavelength of radiation to which the first and / or second material is transparent.

[0078] In one embodiment, the second material layer 125 is formed by a selective growth process. Figure 1c As shown, the selective growth process ensures that the second material layer 125 is formed on the exposed portions of the substrate 110 , but generally not on the remaining portions of the first material layer 105 .

[0079] The selective growth process of the second material layer 125 may include a selective chemical vapor deposition process. In other embodiments, other deposition processes may be used. For example, the selective growth process of the second material layer 125 may alternatively or additionally include a physical vapor deposition and / or epitaxial growth process.

[0080] exist Figure 1d In another optional step shown, the first material layer 105 can be stripped, such as by chemical stripping, to expose a portion of the substrate 110. Figure 1d In an exemplary embodiment, the first material layer 105 is removed from the substrate 110 such that the second material layer 125 defines a plurality of posts, beams, ridges, wings, and / or mesas extending from the substrate 110 .

[0081] Advantageously, the process of imprinting the first material layer 105 to form the plurality of cavities 115 and the subsequent process of selectively growing the second material layer 125 in the plurality of cavities 115 results in a plurality of posts, beams, ridges, wings and / or mesas extending from the substrate 110 having very well-defined sidewalls. That is, the sidewalls of any post, beam, ridge, wing and / or mesa may be, for example, substantially 90 degrees or close to 90 degrees relative to the surface of the substrate 110. That is, the sidewalls of any post, beam, ridge, wing and / or mesa may be oriented substantially vertically relative to the horizontal plane of the upper surface of the substrate 110.

[0082] Beneficially, by complying with Figure 1a to Figure 1d Describe and / or Figure 1a to Figure 1dA method is described for forming pillars, beams, ridges, wings and / or mesas without using an etching process (e.g., wet etching or plasma etching) that may otherwise result in the pillars, beams, ridges, wings and / or mesas not having well-defined sidewalls, such as non-perfect anisotropic etching.

[0083] In further embodiments (not shown), additional coatings or layers may subsequently be deposited over the second material layer 125, wherein the additional coatings and / or layers may include a refractive index that is significantly different than the refractive index of the second material.

[0084] Figure 1d The optical element depicted in is a metalens.

[0085] Figure 2a to Figure 2c A second embodiment of a method of manufacturing an optical element according to the present disclosure is depicted.

[0086] In the first step, a first material layer 205 is formed on a substrate 210. The first material layer 205 may include a curable material. For example, the curable material may be an ultraviolet (UV) radiation curable material or a heat curable material.

[0087] In the same Figure 2a In the next step depicted, a plurality of cavities 215 are formed in the first material layer 205 by an imprinting process.

[0088] In the next step, the residual layer 220 may be removed from the substrate 210 by, for example, a plasma descum process.

[0089] Figure 2a and Figure 2b The steps shown in the Figure 1a and Figure 1b The steps of the described embodiment are therefore not described in further detail for the sake of brevity. The imprint process used to form the plurality of cavities 215 may be, for example, a thermoplastic nanoimprint lithography or a photo nanoimprint lithography process, as described above.

[0090] exist Figure 2c In the next step shown, a second material layer 225 is formed in the plurality of cavities 215 to form an optical metasurface. In this particular embodiment, the second material layer 225 is applied as a coating to the first material layer 205. Figure 2c As shown, the second material layer 225 can form a substantially planar surface 230 over the first material layer 205 and the plurality of cavities 215 .

[0091] In some embodiments, the second material has a refractive index that is significantly different from the refractive index of the first material. For example, in one embodiment, the second material can have a refractive index that differs from the refractive index of the first material by at least 1. In some embodiments, the second material can have a refractive index that differs from the refractive index of the first material by 1.5, 2, 2.5, or more.

[0092] The second material layer 225 may be formed at least in part by, for example, atomic layer deposition, chemical vapor deposition, physical vapor deposition and / or epitaxial growth. Additionally and / or alternatively, the second material layer 225 may be formed at least in part by spin coating the second material layer 225 onto the first material layer 205 .

[0093] About Figure 1a to Figure 1d In contrast to the described embodiment, the second material layer 225 is not selectively grown, and therefore, the second material layer 225 is formed on the first material layer 205 and in the plurality of cavities 215 formed in the first material layer 205 , for example, on the exposed portion of the substrate 210 .

[0094] The flat surface 230 may be particularly suitable for mounting additional optical components, such as those shown in FIG. Figure 5b Described in more detail.

[0095] Figure 2c The optical element depicted in is a metalens.

[0096] Figures 3a to 3d Another embodiment of a method of manufacturing an optical element according to an embodiment of the present disclosure is depicted.

[0097] Figure 3a and Figure 3b The steps shown in the Figure 1a and Figure 1b The steps of the described embodiment are therefore not described in further detail. The imprint process for forming the plurality of cavities 315 in the first material layer 305 on the substrate 310 may be, for example, a thermoplastic nanoimprint lithography or a photo nanoimprint lithography process, as described above.

[0098] exist Figure 3c In the next step shown, a second material layer 325 is formed in the plurality of cavities 315 to form an optical metasurface. In this particular embodiment, the second material layer 325 is applied as a conformal coating to the first material layer 305. That is, the second material layer 325 conforms to the contours, such as geometric and / or topographic contours, of the underlying first material layer 305.

[0099] The second material layer 325 can be formed by, for example, atomic layer deposition, chemical vapor deposition, physical vapor deposition and / or epitaxial growth. Figure 1a to Figure 1dIn contrast to the described embodiment, the second material layer 325 is not selectively grown, and therefore, the second material layer 325 is formed on the first material layer 305 and in the plurality of cavities 315 formed in the first material layer 205 , for example, on the exposed portion of the substrate 310 .

[0100] In one embodiment, the second material layer 325 may be substantially uniformly formed on the first material layer 305 and in the plurality of cavities 315 formed in the first material layer 305. That is, the second material layer 325 may include a substantially uniform thickness.

[0101] The second material layer 325 may include a plurality of cavities 330 corresponding to the plurality of cavities 315 in the first material layer 325. That is, because the second material layer substantially conforms to the geometric contours of the first material layer 325, the second material layer 325 includes cavities, such as Figure 3c shown.

[0102] In an optional additional step, a third material layer 335 may be formed over the second material layer 325, such as Figure 3d . The third material layer 325 may be formed by any one of spin coating, atomic layer deposition, chemical vapor deposition, physical vapor deposition, and / or epitaxial growth. The third material layer 335 may fill the plurality of cavities 330 in the second material layer 325. The third material layer 335 may form a substantially flat surface 340 above the second material layer 325 and the plurality of cavities 330.

[0103] The third material may be selected to include a different refractive index than the second and / or first material. For example, in some embodiments, the third material may have a refractive index that differs from the refractive index of the second and / or first material by 1 or more.

[0104] The flat surface 340 may be particularly suitable for mounting additional optical components, such as those shown in FIG. Figure 5c Described in more detail.

[0105] Figure 3d The optical element depicted in is a metalens.

[0106] Figure 4a to Figure 4g A method of manufacturing an optical element according to another embodiment of the present disclosure is depicted.

[0107] exist Figure 4aIn the optional first step shown, a seed layer 450 is formed on the substrate 410. The seed layer 450 can be formed, for example, by atomic layer deposition, chemical vapor deposition, physical vapor deposition and / or epitaxial growth. The seed layer 450 may include a material suitable for forming (e.g., epitaxially growing, etc.) a second material thereon, wherein the second material is described in more detail below. The seed layer 450 may include a second material. In a particular method, the substrate can be provided as an "epitaxial ready" substrate, such as a substrate that has been pre-treated with a seed layer.

[0108] exist Figure 4b In the next step depicted in , a first material layer 405 is formed on the substrate 410. Figure 4b In the example embodiment depicted in , the first material layer 405 is formed on the seed layer 450, which may optionally be present as described above. The first material layer 405 may include, for example, silicon and / or silicon dioxide. In other embodiments, the first material may include gallium nitride, silicon nitride, titanium oxide, etc.

[0109] like Figure 4c As depicted in FIG. 4 , a mask layer 455 may be formed on the first material layer 405. The mask layer 455 may include a polymer, such as a thermoplastic polymer or the like.

[0110] The first material layer 405 may be formed or deposited on the substrate 410 (or the seed layer 450) by spin coating the substrate 410. In some embodiments, the first material layer 405 may be deposited (e.g., by evaporation) on the substrate 410 (or the seed layer 450), for example, by atomic layer deposition, chemical vapor deposition, physical vapor deposition, and / or epitaxial growth.

[0111] The mask layer 455 may be formed or deposited on the first material layer 405 by spin coating the first material layer 405. Alternatively, the mask layer 455 may be deposited on the first material layer 405, for example, by atomic layer deposition, chemical vapor deposition, physical vapor deposition, and / or epitaxial growth.

[0112] like Figure 4c As depicted, a plurality of cavities 415 may be formed in the mask layer 455 by an imprint process. The imprint process may be, for example, a thermoplastic nanoimprint lithography process or a photo nanoimprint lithography process. Such processes have been described above with respect to Figure 1a has been described, and will not be described in further detail at this time.

[0113] like Figure 4dAs depicted in FIG. 4 , the residual layer 420 (e.g., scum of the residual layer 420 or the mask layer 455) can be removed from the first material layer 405 by a plasma descum process (e.g., a descum process using oxygen plasma or high-power argon plasma, etc.). As a result of the descum process, portions of the first material layer 405 corresponding to the plurality of cavities 415 will be exposed, as shown in FIG. Figure 4d That is, part of the upper surface of the first material layer 405 will be exposed, as shown in FIG. Figure 4d shown.

[0114] exist Figure 4e In a subsequent step as depicted in FIG. 4 , an etching process (e.g., wet etching or plasma etching) may be used to etch a plurality of cavities 460 into the first material layer 405, wherein the plurality of cavities 460 are defined by the plurality of cavities 415 formed in the mask layer 455. The mask layer 455 may then be stripped (e.g., chemically stripped) to produce a Figure 4e If desired, a further descum process may be performed to remove any residual layer or scum (not shown) comprising the first material that may be present in at least one of the plurality of cavities 460 .

[0115] like Figure 4f The remaining steps of the selective growth of the second material layer 425 as depicted in Figure 4g The optional step of peeling off the first material layer 405 depicted in Figure 1c and Figure 1d The steps described above are not described in further detail for the sake of brevity. It should also be understood that in another embodiment, the coating may be applied to Figure 4e The structure shown in the previous reference Figure 2c Similarly, it should also be understood that in yet another alternative embodiment, a conformal coating may be applied to Figure 4e The structure shown in , as previously referenced Figure 3c and Figure 3d described.

[0116] Figure 4g The optical element depicted in is a metalens.

[0117] Figure 5a to Figure 5c A method of forming an optical device according to an embodiment of the present disclosure is described. Figure 5a An optical element 570 is depicted. For purposes of illustration only, the optical element 570 corresponds to Figures 3a to 3d It should be understood that in other embodiments, different metalenses may be used instead or in addition, such as those described in reference Figure 1d , Figure 2c or Figure 4g Any description in and / or Figure 1d , Figure 2c or Figure 4g Any of the metalenses depicted in .

[0118] Optical element 570 may be coupled to and / or combined with additional optical components 575, such as Figure 5b As shown. Figure 5b In the example embodiment shown, the additional optical component 575 is a lens. The additional optical component 575 has been adhered or otherwise coupled to the lower surface of the optical element 570. It should be understood that in other embodiments, the additional optical component 575 can be adhered or otherwise coupled to the lower surface of the optical element 570.

[0119] The additional optical component 575 may be, for example, a microlens array (MLA), a diffuser, a diffractive optical element (DOE), a Fresnel lens, a refractive lens, or the like.

[0120] exist Figure 5c In another example embodiment shown, the optical element 570 can be coupled to and / or combined with a plurality of additional optical components 575, 580. In the example shown, the optical element 570 is combined with a lower optical component 575 adhered or otherwise coupled to a lower surface of the optical element 570 and an upper optical component 580 adhered or otherwise coupled to an upper surface of the optical element 570.

[0121] Figure 6 A flow chart corresponding to a method of manufacturing an optical element is depicted. A first step 600 includes forming a first material layer on a substrate. A subsequent step 605 includes forming a plurality of cavities in the first material layer by an imprinting process. A subsequent step 610 includes forming a second material layer in the plurality of cavities to form an optical metasurface.

[0122] Figure 7a An optical device, generally designated 700, is depicted in accordance with an embodiment of the present disclosure. Optical device 700 includes an optical element 705. Optical element 705 may be, for example, a reference Figure 1d , Figure 2c , Figure 3d , Figure 4g , Figure 5a , Figure 6 b. Figure 5a , Figure 5b or Figure 5c An optical element as described in any one of the above.

[0123] The example optical device 700 includes a radiation source 710. The radiation source 710 may include a light emitting diode.

[0124] The radiation source 710 and the optical element 705 are supported by a support member 715. It should be understood that in other embodiments, the support member 715 can have a different configuration. For example, the support member 715 can include one or more spacing elements for spacing the radiation source 710 from the optical element 705.

[0125] In still other embodiments, the radiation source 710 and the optical element 705 may be directly coupled, such as being held in close proximity to each other by a support member 715. In still other embodiments, the optical device 700 may not include a support member 715, but rather the radiation source 710 and the optical element 705 may be directly coupled, such as by adhesion or other means. In still other embodiments, the optical element 705 may be formed directly on the radiation source 710.

[0126] Radiation source 710 may be configured to emit radiation 720. Figure 7a In the exemplary embodiment of FIG. 7 , radiation source 710 is disposed relative to optical element 705 such that radiation 720 emitted by radiation source 710 is incident on optical element 705 .

[0127] The optical element 705 can alter the incident radiation 720, resulting in emitted radiation 725 emitted by the optical device 700. For example, the optical element 705 can be configured to change the phase of the incident radiation 720. In other embodiments, the optical element 705 can be configured to at least one of filter, focus, or disperse the incident radiation 720, additionally or alternatively.

[0128] Figure 7b An optical device, generally designated 750, is depicted according to another embodiment of the present disclosure. The optical device 750 includes an optical element 755. The optical element 755 may be, for example, as described with reference to Figure 1d , Figure 2c , Figure 3d , Figure 4g , Figure 5a , Figure 5b , Figure 5c Any one of the optical elements described in .

[0129] The example optical device 750 includes a radiation sensor 760. The radiation sensor 760 may include, for example, a photodiode. The radiation sensor 760 may include an active pixel sensor. The radiation sensor 760 may include a sensor array.

[0130] The radiation sensor 760 and the optical element 765 are supported by the support member 765. It should be understood that in other embodiments, the support member 765 can have a different configuration. For example, the support member 765 can include one or more spacing elements for spacing the radiation sensor 760 from the optical element 755.

[0131] In still other embodiments, radiation sensor 760 and optical element 755 may be directly coupled, such as held adjacent to each other by support member 765. In still other embodiments, optical device 750 may not include support member 765, and radiation sensor 760 and optical element 755 may be directly coupled, such as by bonding or other means. In still other embodiments, optical element 755 may be formed directly on radiation sensor 760.

[0132] The optical element 705 can be configured to modify the radiation 725 incident on the optical element 705. For example, the optical element 705 can be configured to modify the radiation 725 such that the radiation 770 incident on the radiation sensor 760 exhibits different characteristics than the radiation 775 incident on the optical element 705. For example, the optical element 755 can be configured to change the phase of the incident radiation 775. In other embodiments, the optical element 705 can alternatively or additionally be configured to at least one of filter, focus, or disperse the incident radiation 775. In a particular embodiment, the optical element 755 can be configured to focus the radiation 775 such that the focal point of the radiation 770 is incident on the radiation sensor 760.

[0133] Figure 7c An optical device, generally designated 800, is depicted in accordance with an embodiment of the present disclosure. Optical device 800 includes an optical element 805. Optical element 805 may be, for example, a reference Figure 1d , Figure 2c , Figure 3d , Figure 4g , Figure 5a , Figure 6 b. Figure 5a , Figure 5b or Figure 5c An optical element as described in any one of the above.

[0134] The example optical device 800 includes a radiation source 810. The radiation source 810 may include a light emitting diode.

[0135] The example optical device 800 includes a radiation sensor 840. The radiation sensor 840 may include, for example, a photodiode. The radiation sensor 840 may include an active pixel sensor. The radiation sensor 840 may include a sensor array.

[0136] The radiation source 810, the radiation sensor 840, and / or the optical element 805 can be supported by a support member 815. It should be understood that in other embodiments, the support member 815 can have a different configuration. For example, the support member 815 can include one or more spacing elements for spacing the radiation source 810 and / or the radiation sensor 840 from the optical element 805.

[0137] Radiation source 810 may be configured to emit radiation 820. Figure 7c In the exemplary embodiment of FIG. 8 , radiation source 810 is disposed relative to optical element 805 such that radiation 820 emitted by radiation source 810 is incident on optical element 805 .

[0138] The optical element 805 can alter the incident radiation 820, resulting in emitted radiation 825 emitted by the optical device 800. For example, the optical element 805 can be configured to change the phase of the incident radiation 820. In other embodiments, the optical element 805 can be configured to at least one of filter, focus, or disperse the incident radiation 820, additionally or alternatively.

[0139] Additionally or alternatively, the optical element 805 may reflect at least a portion of the incident radiation. The reflected portion 830 of the incident radiation may be sensed by the radiation sensor 840.

[0140] Additionally or alternatively, the optical element 805 can be configured to modify radiation 835 incident on the optical element 805 from outside the optical device 800. For example, the optical element 805 can be configured to modify the radiation 835 so that the radiation 830 incident on the radiation sensor 840 exhibits different characteristics than the radiation 835 incident on the optical element 805 from outside the optical device 800. For example, the optical element 805 can be configured to change the phase of the incident radiation 835. In other embodiments, the optical element 805 can alternatively or additionally be configured to at least one of filter, focus, or disperse the incident radiation 835. In a particular embodiment, the optical element 805 can be configured to focus the radiation 835 so that the focus of the radiation 830 is incident on the radiation sensor 840.

[0141] Figure 7d An optical device, generally designated 850, is depicted according to another embodiment of the present disclosure. The optical device 850 includes a first optical element 855 and a second optical element 860 formed on a common substrate 865. The first optical element 855 and the second optical element 860 may be, for example, as described in reference Figure 1d , Figure 2c , Figure 3d , Figure 4g , Figure 5a , Figure 5b , Figure 5c Any one of the optical elements described in .

[0142] That is, in the embodiments of the present disclosure, by forming multiple optical metasurfaces on a common substrate, multiple optical elements can be formed on a common substrate. The multiple optical metasurfaces may include one or more optical metasurfaces having the same characteristics. The multiple optical metasurfaces may include one or more optical metasurfaces having different characteristics.

[0143] For example purposes only, Figure 7d Also included is a radiation sensor 870 and a radiation source 875, which have the same Figures 7a to 7c Features and functions have been described.

[0144] For purposes of example only, the first optical element 855 and the second optical element 860 are depicted as being disposed (e.g., formed) on a lower surface of a common substrate 865. It should be understood that one or more metasurfaces may alternatively and / or additionally be disposed (e.g., formed) on an upper surface of the common substrate 865. Similarly, Figure 7a , Figure 7b and Figure 7c The optical elements 705, 755, 705 depicted in the drawings may include a metasurface disposed on an upper surface and / or a lower surface of the optical elements 705, 755, 805.

[0145] Figure 8 An apparatus is depicted that includes an optical device 905, generally designated 900. The optical device 905 may be, for example, as described with reference to Figures 7a to 7d Optical devices 700, 750, 800, 850 are described.

[0146] The optical device 905 is communicatively coupled to a processor circuit 910. The processor circuit 910 is configured to receive signals from the optical device 905 and / or provide signals and / or power to the optical device 905. For purposes of example only, the apparatus 900 is a cellular telephone. It should be understood that in other examples, the apparatus 900 may be a digital camera, a security camera, a laptop or tablet device, an image recording device, etc.

[0147] Applicants disclose separately each individual feature described herein and any combination of two or more such features, as long as these features or combinations can be performed according to the common general knowledge of those skilled in the art based on the specification as a whole, regardless of whether these features or combinations of features solve any problems disclosed herein, and are not limited to the scope of the claims. Applicants point out that various aspects of the present disclosure may consist of any such individual features or combinations of features. In view of the foregoing description, it will be apparent to those skilled in the art that various modifications may be made within the scope of the present disclosure.

[0148] Those skilled in the art will appreciate that in the foregoing description and the appended claims, positional terms such as "above," "along," "side," etc., are made with reference to conceptual illustrations such as those shown in the accompanying drawings. These terms are used for ease of reference and are not intended to be limiting. Therefore, these terms should be understood to refer to an object when in an orientation as shown in the accompanying drawings.

[0149] Although the present disclosure has been described in terms of specific embodiments as described above, it should be understood that these embodiments are illustrative only and that the claims are not limited to those embodiments. Those skilled in the art will be able to make modifications and substitutions in light of the present disclosure, which modifications and substitutions are considered to fall within the scope of the appended claims. Each feature disclosed or shown in this specification may be combined in any embodiment, either alone or in any appropriate combination with any other features disclosed or shown herein.

[0150] Reference numerals list

[0151] 105 First material layer

[0152] 110 substrate

[0153] 115 Multiple cavities

[0154] 120 Residual layer

[0155] 125 Second material layer

[0156] 205 First Material Layer

[0157] 210 substrate

[0158] 215 Multiple cavities

[0159] 220 Residual layer

[0160] 225 Second material layer

[0161] 230 Plane Surface

[0162] 305 First material layer

[0163] 310 base plate

[0164] 315 Multiple cavities

[0165] 325 Second Material Layer

[0166] More than 330 cavities

[0167] 335 Third Material Layer

[0168] 340 Flat Surface

[0169] 405 First Material Layer

[0170] 410 base plate

[0171] 415 Multiple cavities

[0172] 420 Residual Layer

[0173] 425 Second Material Layer

[0174] 450 Seed Layer

[0175] 455 Mask layer

[0176] More than 460 cavities

[0177] 570 Optical Components

[0178] 575 Optical components

[0179] 580 Optical Components

[0180] 600 First Step

[0181] 605 Next Steps

[0182] 610 Next Steps

[0183] 700 Optical Equipment

[0184] 705 Optical Components

[0185] 710 Radiation Source

[0186] 715 Supporting member

[0187] 720 Radiation

[0188] 725 Radiation

[0189] 750 Optical equipment

[0190] 755 Optical Components

[0191] 760 Radiation Sensor

[0192] 765 Supporting member

[0193] 770 Radiation

[0194] 775 Radiation

[0195] 800 Optical Equipment

[0196] 805 Optical Components

[0197] 810 Radiation Source

[0198] 840 Radiation Sensor

[0199] 815 Supporting member

[0200] 820 Incident Radiation

[0201] 825 Emitting Radiation

[0202] 830 Reflection part

[0203] 835 Radiation

[0204] 850 Optical equipment

[0205] 855 First Optical Element

[0206] 860 Second optical element

[0207] 865 Public substrate

[0208] 870 Radiation Sensor

[0209] 875 Radiation Source

[0210] 900 Devices

[0211] 905 Optical Equipment

[0212] 910 Processor Circuit

Claims

1. A method for manufacturing an optical element, the method comprising the following steps: forming a layer of a first material on a substrate; forming a plurality of cavities in the layer of the first material by an embossing process; forming a layer of a second material in the plurality of cavities to form an optical metasurface; as well as forming a layer of a third material over the layer of the second material, the layer of the third material conforming to a contour of the layer of the second material; The third material has a different refractive index than the second material.

2. The method according to claim 1, wherein the embossing process comprises: embossing the plurality of cavities directly into the layer of the first material; or A pattern corresponding to the plurality of cavities is imprinted into a mask layer formed on the layer of the first material, and the layer of the first material is subsequently etched to form the plurality of cavities. 3 . The method of claim 1 , wherein the step of forming a layer of the second material comprises selectively growing or selectively depositing the second material.

4. A method according to claim 3, comprising the subsequent step of removing the layer of the first material from the substrate such that the layer of the second material defines a plurality of posts, beams, ridges, wings and / or mesas extending from the substrate.

5. The method of claim 1, wherein the step of forming a layer of the second material comprises applying a coating to the layer of the first material.

6. The method of claim 5, wherein the layer of the second material forms: a substantially flat surface overlying the layer of the first material and the plurality of cavities; and / or a layer of substantially uniform thickness over the layer of said first material; and / or A layer conforms to the contour of the cavity in the layer of the first material. The method of claim 1 , wherein the second material has a refractive index greater than a refractive index of the first material. The method of claim 1 , wherein the second material has a refractive index greater than 2.

9. The method of claim 1, wherein the plurality of cavities are formed in a substantially concentric arrangement and / or the plurality of cavities are arranged in a pattern of substantially concentric groups.

10. The method of claim 1, wherein at least one of the following: The layer of the second material has a thickness of less than 100 nanometers; The plurality of cavities are arranged at intervals less than 500 nanometers; The plurality of cavities have different orientations in a plane defined by the substrate.

11. The method of claim 1 , wherein the step of forming a layer of the second material comprises at least one of: atomic layer deposition; chemical vapor deposition; physical vapor deposition; and / or epitaxial growth. 12 . The method of claim 1 , wherein the first material and / or the second material comprises gallium nitride, silicon nitride, or titanium oxide.

13. The method of claim 12, wherein the third material comprises gallium nitride, silicon nitride, or titanium oxide.

14. The method according to claim 1, further comprising: A seed layer is formed on the substrate. The method of claim 14 , wherein the seed layer comprises the second material.

16. An optical element manufactured according to the method of any one of claims 1 to 15.

17. The optical element of claim 16, configured as a metalens.

18. An optical element according to claim 16 or 17, wherein the optical element is configured to operate in at least a part of the visible range and / or the near infrared range.

19. An optical device comprising at least one optical element according to claim 16, the optical device further comprising a radiation sensor and / or a radiation source, wherein the at least one optical element is configured to be used together with the radiation sensor and / or the radiation source.

20. An apparatus comprising the optical device according to claim 19, wherein: The apparatus is at least one of: a cellular telephone, a camera, an image recording device; and / or a video recording device.

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