# US 12,761,397 B2 · Optical element and optical design method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,397 B2 - Document ID: US12761397B2 - Status: Granted - Kind: B2 - Application number: 18/650,809 - Filed: 2024-04-30 - Published: 2024-11-07 - Granted: 2026-10-13 - Earliest claimed: 2023-05-02 - Assignees: Kowa Company, Ltd. - Applicants: KOWA COMPANY, Ltd. - Inventors: Kentaro Iwami; Hideki Ina; Jun Maruyama - Web page: https://patentgrep.com/patent/US12761397B2 ## CPC - G02B 1/002: {made of materials engineered to provide properties not available in nature, e.g. metamaterials} - G02B 3/00: Simple or compound lenses - G02B 27/0012: {Optical design, e.g. procedures, algorithms, optimisation routines} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical element includes: a metalens having a finely shaped surface on which a fine pattern is formed based on a shape of a meta-atom and a bonded surface formed in a flat shape; and a bonding lens having a feature equivalent to an existing lens and being bonded to the bonded surface. For example, the bonding lens includes: a first glass material bonded to the bonded surface; and a second glass material separated from the bonded surface and bonded to the first glass material. For example, an optical design method includes: a setting step of setting, based on optical design of a configuration including binary optics replacing a feature of the metalens, a first step pattern of the binary optics; a first calculation step; and a first identification step. ## Claims ### Claim 1 An optical element comprising: a metalens having a finely shaped surface on which a fine pattern is formed based on a shape of a meta-atom and a bonded surface formed in a flat shape; and a bonding lens having a feature equivalent to an existing lens and being bonded to the bonded surface, wherein the bonding lens includes: a first glass material bonded to the bonded surface; and a second glass material separated from the bonded surface and bonded to the first glass material. ### Claim 2 An optical design method for designing an optical element comprising a metalens having a finely shaped surface on which a fine pattern is formed based on a shape of a meta-atom and a bonded surface formed in a flat shape, and a bonding lens having a feature equivalent to an existing lens and being bonded to the bonded surface, the method comprising: a first restrictive condition step of identifying conditions for a diffractive optical element and the bonding lens that satisfy: B ⁢ 1 ∝ λ 0 ( N ⁢ 1 - N ⁢ 2 ) / ( R × ( λ 1 - λ 2 ) ) , wherein: B1 is a phase coefficient used to model the diffractive optical element by an equivalent refraction method using optical design software; λ0 is a normalized wavelength of the diffractive optical element; λ1 is a first correction target wavelength to be subjected to axial chromatic aberration correction; λ2 is a second correction target wavelength to be subjected to axial chromatic aberration correction; N1 is a first refractive index of the bonding lens for the first correction target wavelength; N2 is a second refractive index of the bonding lens for the second correction target wavelength; and R is a radius of curvature of a convex surface of the bonding lens. ### Claim 3 (depends on 2) The optical design method according to claim 2, further comprising: a setting step of setting, based on optical design of a configuration including binary optics included in one diffractive optical element replacing a feature of the metalens, a first step pattern of the binary optics; a first calculation step of calculating first phase data indicating a phase relationship with respect to the shape of the meta-atom based on a preset first wavelength; and a first identification step of calculating a first phase pattern from the first step pattern and identifying the fine pattern corresponding to the first phase pattern with reference to the first phase data. ### Claim 4 (depends on 3) The optical design method according to claim 3, wherein the setting step includes setting the first step pattern based on optical design of a configuration in which the binary optics and a conventional lens for initial setting are combined. ### Claim 5 (depends on 4) The optical design method according to claim 4, further comprising: a second calculation step of calculating second phase data different from the first phase data based on a preset second wavelength different from the preset first wavelength; a second identification step of identifying a second phase pattern corresponding to the fine pattern with reference to the second phase data; and a design step of designing the bonding lens based on the first phase pattern and the second phase pattern. ### Claim 6 (depends on 5) The optical design method according to claim 5, wherein the design step includes identifying a second step pattern corresponding to the second phase pattern, and designing the bonding lens based on the second step pattern. ### Claim 7 (depends on 3) The optical design method according to claim 3, wherein the first calculation step includes calculating the first phase data using a vector model optical simulation. ### Claim 8 An optical design method for designing an optical element comprising a metalens having a finely shaped surface on which a fine pattern is formed based on a shape of a meta-atom and a bonded surface formed in a flat shape, and a bonding lens having a feature equivalent to an existing lens and being bonded to the bonded surface, the method comprising: a second restrictive condition step of identifying conditions for a diffractive optical element and the bonding lens that satisfy: B ⁢ 1 ∝ λ 0 ( φ p ⁢ c ⁢ 2 - φ p ⁢ c ⁢ 1 ) / ( - λ 1 ( 1 - e ′ ⁢ φ pc ⁢ 1 ) + λ 2 ( 1 - e ′ ⁢ φ p ⁢ c ⁢ 2 ) ) , wherein: B1 is a phase coefficient used to model the diffractive optical element by an equivalent refraction method using optical design software; λ0 is a normalized wavelength of the diffractive optical element; λ1 is a first correction target wavelength to be subjected to axial chromatic aberration correction; λ2 is a second correction target wavelength to be subjected to axial chromatic aberration correction; φpc1 is a reciprocal of focal length of the bonding lens; φpc2 is a reciprocal of focal length of the diffractive optical element; and e′ is a geometric optical distance between the diffractive optical element and the bonding lens.