# US 2022/0120410 A1 · Light source including effective refractive index controlling pattern > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0120410 A1 - Document ID: US20220120410A1 - Status: Published application - Kind: A1 - Application number: 17/459,519 - Filed: 2021-08-27 - Published: 2022-04-21 - Earliest claimed: 2020-10-16 - Assignees: University-Industry Cooperation Group of Kyung Hee University; Hexasolution Co., Ltd. - Applicants: Universit-Industry Cooperation Group of Kyung Hee University; Hexasolution Co., Ltd. - Inventors: Sun-Kyung Kim; Young Bin Kim; Dukkyu Bae; Gaeul Cho - Web page: https://patentgrep.com/patent/US20220120410A1 ## CPC - H10H 20/819: characterised by their shape, e.g. curved or truncated substrates - G02B 3/0087: {with index gradient} - G02B 5/1809: {with pitch less than or comparable to the wavelength} - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/855: Optical field-shaping means, e.g. lenses - H10H 20/872: {Periodic patterns for optical field-shaping, e.g. photonic bandgap structures} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Provided is a light source. The light source includes a substrate, a light emitting layer provided on the substrate and configured to emit light, and a plurality of unit structures provided on the light emitting layer, wherein the unit structures are arranged along a radial direction and a tangential direction to form an effective refractive index controlling pattern, wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures, wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer, wherein the effective refractive index controlling pattern has rotational symmetry. ## Claims ### Claim 1 A light source comprising: a substrate; a light emitting layer provided on the substrate and configured to emit light; and a plurality of unit structures provided on the light emitting layer, wherein the unit structures are arranged along a radial direction and a tangential direction to form an effective refractive index controlling pattern, wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures, wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer, wherein the effective refractive index controlling pattern has rotational symmetry. ### Claim 2 (depends on 1) The light source of claim 1, wherein a density of the unit structures changes in the radial direction. ### Claim 3 (depends on 2) The light source of claim 2, wherein the density of the unit structures monotonically increases, monotonically decreases, or increases or decreases repeatedly along the radial direction. ### Claim 4 (depends on 1) The light source of claim 1, wherein in the effective refractive index controlling pattern, the first variable is constant. ### Claim 5 (depends on 4) The light source of claim 4, wherein in the effective refractive index controlling pattern, the second variable increases along the radial direction. ### Claim 6 (depends on 4) The light source of claim 4, wherein in the effective refractive index controlling pattern, the second variable decreases along the radial direction. ### Claim 7 (depends on 1) The light source of claim 1, wherein in the effective refractive index controlling pattern, the third variable is smaller than the central wavelength of the light. ### Claim 8 (depends on 7) The light source of claim 7, wherein in the effective refractive index controlling pattern, the first variable decreases along the radial direction. ### Claim 9 (depends on 7) The light source of claim 7, wherein in the effective refractive index controlling pattern, the first variable increases along the radial direction. ### Claim 10 (depends on 1) The light source of claim 1, wherein a height of each of the unit structures is determined according to the fourth variable. ### Claim 11 A light source comprising: a substrate; a light emitting layer provided on the substrate and configured to emit light; a plurality of unit structures provided on the light emitting layer; a barrier layer covering the unit structures; and a planarization layer covering the unit structures and the barrier layer, wherein the unit structures are arranged along a radial direction and a tangential direction to form an effective refractive index controlling pattern, wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures, wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer, wherein the effective refractive index controlling pattern has rotational symmetry. ### Claim 12 (depends on 11) The light source of claim 11, wherein the unit structures comprise a material having a lower refractive index or the same as that of the planarization layer. ### Claim 13 (depends on 12) The light source of claim 12, wherein each of the unit structures has a cavity structure including a gas. ### Claim 14 (depends on 11) The light source of claim 11, wherein the refractive index of the barrier layer is greater than or equal to a refractive index of the unit structures, and is smaller than or equal to a refractive index of the planarization layer. ### Claim 15 (depends on 11) The light source of claim 11, wherein a height of each of the unit structures has a size greater than or equal to a threshold value determined according to the following [Equation 1]. Δn×tc=2π×λ [Equation 1] Δn is the fourth variable, tc is the threshold value, and λ is the central wavelength of the light emitted from the light emitting layer. ### Claim 16 (depends on 11) The light source of claim 11, further comprising a semiconductor layer between the light emitting layer and the unit structures, wherein the substrate and the semiconductor layer each comprise a doped semiconductor material, wherein the light emitting layer comprises a semiconductor material having at least one of a quantum well structure, a quantum wire structure, or a quantum dot structure. ### Claim 17 (depends on 11) The light source of claim 11, wherein the light emitting layer comprises a color conversion material causing fluorescence or phosphorescence. ### Claim 18 A light source comprising: a substrate; a light emitting layer provided on the substrate and configured to emit light; and a plurality of lenses provided on the light emitting layer, wherein the lenses are disposed repeatedly and are arranged to fill a plane, wherein the lenses each have an effective refractive index controlling pattern including a plurality of unit structures arranged along a radial direction and a tangential direction, wherein the effective refractive index controlling pattern is configured to control the effective refractive index through a first variable defined by a width of each of the unit structures, a second variable defined as a period in which the unit structures are arranged in the tangential direction, a third variable defined as a period in which the unit structures adjacent in the radial direction are arranged, and a fourth variable defined as a difference between a refractive index of the unit structures and a refractive index of a material surrounding the unit structures, wherein the first variable is smaller than a central wavelength of the light emitted from the light emitting layer, wherein the effective refractive index controlling pattern has rotational symmetry. ### Claim 19 (depends on 18) The light source of claim 18, wherein each of the unit structures has a cavity structure including a gas. ### Claim 20 (depends on 18) The light source of claim 18, wherein in the effective refractive index controlling pattern of each of the lenses, a density of the unit structures monotonically increases, monotonically decreases, or increases or decreases repeatedly along the radial direction.