CN118011651A - Beam shaper and manufacturing method thereof - Google Patents
Beam shaper and manufacturing method thereof Download PDFInfo
- Publication number
- CN118011651A CN118011651A CN202410300163.5A CN202410300163A CN118011651A CN 118011651 A CN118011651 A CN 118011651A CN 202410300163 A CN202410300163 A CN 202410300163A CN 118011651 A CN118011651 A CN 118011651A
- Authority
- CN
- China
- Prior art keywords
- super
- lens
- substrate
- structured
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 239000000758 substrate Substances 0.000 claims abstract description 71
- 238000000034 method Methods 0.000 claims abstract description 23
- 238000005530 etching Methods 0.000 claims description 28
- 238000010894 electron beam technology Methods 0.000 claims description 23
- 229920002120 photoresistant polymer Polymers 0.000 claims description 17
- 238000010884 ion-beam technique Methods 0.000 claims description 14
- 238000004140 cleaning Methods 0.000 claims description 6
- 239000013078 crystal Substances 0.000 claims description 6
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 238000005498 polishing Methods 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 239000012780 transparent material Substances 0.000 claims description 3
- 238000011161 development Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 12
- 238000012545 processing Methods 0.000 abstract description 8
- 238000005516 engineering process Methods 0.000 abstract description 5
- 239000003989 dielectric material Substances 0.000 description 8
- 238000002834 transmittance Methods 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 5
- 238000004088 simulation Methods 0.000 description 5
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 238000003491 array Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 210000004027 cell Anatomy 0.000 description 2
- 210000003850 cellular structure Anatomy 0.000 description 2
- 230000008602 contraction Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
- G02B27/0938—Using specific optical elements
- G02B27/095—Refractive optical elements
- G02B27/0955—Lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/002—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of materials engineered to provide properties not available in nature, e.g. metamaterials
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/0006—Arrays
- G02B3/0012—Arrays characterised by the manufacturing method
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Diffracting Gratings Or Hologram Optical Elements (AREA)
Abstract
The invention discloses a beam shaper and a manufacturing method thereof, which relate to the technical field of super-structured surfaces and comprise the following steps: comprises two super-structure lenses with different focal lengths and diameters; each super-structure lens comprises a transparent substrate for transmitting incident light and a plurality of dielectric columns etched on one side of the transparent substrate; one side of each super-structure lens with a plurality of dielectric columns is oppositely arranged, the axes of the super-structure lenses are positioned on the same straight line, and two focuses are mutually overlapped; the beam expander is arranged on the first super-structure lens, wherein the beam expander is arranged on the second super-structure lens when the focal length of the first super-structure lens is larger than that of the second super-structure lens according to the incidence direction of light; the beam expander and the beam contractor based on the single-medium super-structured lens provided by the invention are simple to process, are not limited by material types and complex processing technologies, are suitable for any transparent medium material, and have the advantages of miniaturization, low cost and high stability.
Description
Technical Field
The invention relates to the technical field of super-structured surfaces, in particular to a beam shaper and a manufacturing method thereof.
Background
In the optical field, beam expanders and beam contractors are commonly used beam shaping devices for changing the size and shape of a laser beam.
Conventional beam expanders and beam contractors typically employ a lens or mirror system to effect expansion or contraction of the beam. The traditional beam expander and beam contractor generally need to use a plurality of lenses or reflectors, so that the whole system is large in size, the miniaturization and integration are not facilitated, and the manufacturing cost and difficulty are increased; meanwhile, high precision is required for manufacturing and assembling the lens and the reflector, and the beam quality of the traditional beam expander and the traditional beam contractor is influenced by factors such as the surface quality of the lens or the reflector, optical errors, thermal stability and the like, and the factors may cause the problems of uneven energy distribution, unstable beam quality and the like of the light beam.
The super-structured surface lens developed in recent years is expected to be applied to beam expanding and shrinking systems to realize miniaturized and integrated beam operation. However, the typical super-structure lens needs to use a combination of different dielectric materials, especially the functional unit with high refractive index is inconsistent with the substrate material, which makes the processing procedure of the device complex, the processing efficiency is low, and the wide large-scale application is difficult to realize.
Disclosure of Invention
Aiming at the defects that the prior art needs to use different dielectric materials to make the device processing procedure complex, the processing efficiency is low and the wide large-scale application is difficult to realize, the invention provides a beam shaper and a manufacturing method thereof, and adopts a single-medium super-structure lens to replace the traditional lens and the typical multi-material super-structure lens, so that the production and the application of a beam expander and a beam contractor are miniaturized and integrated, and are not limited by the types of materials, thereby promoting the super-structure surface technology to be practical and solving the problems existing in the prior art.
A beam shaper comprising two super-structured lenses of different focal length and diameter;
Each super-structure lens comprises a single-medium transparent substrate for transmitting incident light and a plurality of single-medium columns etched on one side of the transparent substrate, wherein the single-medium columns form a super-structure surface array and are used for realizing phase and amplitude modulation on light beams transmitted by the transparent substrate;
One sides of the two super-structured lenses, which are provided with a plurality of single-medium columns, are oppositely arranged, the axes of the super-structured lenses are positioned on the same straight line, and the two focuses are mutually overlapped; when the focal length of the super-structure lens on which the incident light is incident is larger than that of the emergent super-structure lens, the beam shaper is a beam contractor, and the beam expander is the opposite.
Further, the single-medium columns are all nano structures, and the single-medium columns and the single-medium transparent substrate are made of the same transparent material.
Further, the diameters of the single-medium columns are not uniform.
Further, a plurality of the dielectric pillars are periodically arranged on one side of the transparent substrate.
Further, a method for manufacturing the beam shaper comprises the following steps:
selecting two single-medium transparent substrates with different diameters and used for transmitting incident light;
Etching a plurality of single-medium columns on one side of each transparent substrate respectively to generate an ultra-structured surface array respectively, so as to form two ultra-structured surface lenses with different focal lengths;
One side of each super-structured lens etched with a plurality of single-medium columns is placed oppositely, the axes of the super-structured lenses are positioned on the same straight line, and focuses of the two super-structured lenses are overlapped with each other;
according to the direction of the incident light, when the focal length of the super-structure lens when the incident light is incident is larger than that of the super-structure lens when the incident light is emergent, the beam shaper is a beam contractor, and the beam expander is the opposite beam contractor.
Further, a plurality of single-medium columns are etched on one side of each transparent substrate by adopting an electron beam or focused ion beam etching method.
Further, the electron beam etching method EBL is used for etching a plurality of single dielectric pillars on one side of each transparent substrate, and specifically includes the following steps:
Selecting a lithium niobate crystal LN or any transparent crystal as a substrate, and cleaning the substrate;
Uniformly coating photoresist with a certain thickness on a substrate;
Using an electron beam exposure system to perform electron beam exposure on the substrate according to the designed pattern; the electron beam scans the surface of the photoresist, and the photoresist in the exposed area is solidified or degraded;
Immersing the exposed substrate into organic developer for development, and obtaining a plurality of single-medium columns on the surface of the substrate; wherein, the negative photoresist is solidified and can not be developed and dissolved, and the positive photoresist is degraded and developed and dissolved.
Further, the FIB etching method for etching a plurality of single-medium pillars on one side of each transparent substrate includes the following steps:
Selecting a lithium niobate crystal LN as a substrate, and sequentially polishing, cleaning, drying and surface metal spraying;
Placing the substrate on a sample stage of the FIB, and starting the FIB equipment to expose the substrate to an ion beam generated by the FIB;
etching a plurality of single-medium columns on the surface of the substrate by controlling parameters of the FIB equipment; parameters of the FIB device include voltage, beam current and etching time of the ion beam.
Further, the incident light passing through the beam expander is converted into emergent light with a diameter larger than that of the incident light, and the ratio of the diameter of the emergent light to the diameter of the incident light is the ratio of the focal length of the super-structure lens when the emergent light exits to the focal length of the super-structure lens when the incident light enters.
Further, the incident light passing through the beam contractor is converted into emergent light with a smaller diameter than the incident light, and the diameter ratio of the emergent light to the incident light is the ratio of the focal length of the super-structure lens when the emergent light exits to the focal length of the super-structure lens when the incident light enters.
The invention provides a beam shaper and a manufacturing method thereof, which have the following beneficial effects:
Compared with the traditional bulk lens beam expander, beam contractor and the traditional multi-medium material super-structure surface beam expander and beam contractor, the invention adopts the super-structure lens of single medium to replace the traditional lens and the typical multi-material super-structure lens; the beam expander and the beam contractor based on the single-medium super-structure lens provided by the invention are simple to process, two super-structure lenses with different focal lengths and diameters are formed by the transparent substrate made of single-medium materials and the plurality of single-medium columns etched on one side of the transparent substrate, and the beam contractor is used when the focal length of the super-structure lens is larger than that of the super-structure lens when emergent light is incident according to the direction of incident light, and the beam contractor is used when the focal length of the super-structure lens is larger than that of emergent light.
Drawings
FIG. 1 is a schematic diagram of a single-medium super-lens structure according to an embodiment of the present invention;
FIG. 2 is a schematic view of a beam expander according to an embodiment of the present invention;
FIG. 3 is a schematic view of a beam reducer according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a sub-wavelength cell structure of an ultra-structured lens according to an embodiment of the present invention;
FIG. 5 is a graph showing the phase change and transmittance curves for different wavelengths and different cylinder diameters in an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.
The invention provides a beam shaper, which comprises two groups of super-structure surface lenses (super-structure lens 1 and super-structure lens 2) with different focal lengths and diameters, wherein the two super-structure surface lenses are formed by processing a single medium material, the focal lengths of the two super-structure surface lenses are overlapped together, and from the incident direction, the focal length of the first group of lenses is larger than that of the second group of lenses, and the first group of lenses are beam retractors, and the second group of lenses are beam retractors.
The working process of the beam shaper is as follows: when light rays with a certain diameter and a certain size in a specific wavelength range pass through the first group of super-structure lenses and are focused, then the light rays are diverged and then pass through the second super-structure lenses with different focal lengths and are converted into light rays with different diameters from the incident light rays, and therefore the purposes of beam expansion and beam contraction are achieved.
Two groups of mutually independent super-structured surface lenses respectively comprise super-structured surface arrays which are periodically arranged on a single medium transparent material sheet substrate and have different focal lengths and are formed by structural units with specific sizes and heights; the two groups of super-structure lenses are opposite, the axes are on the same straight line, focuses on the sides of the super-structure lenses are overlapped with each other, the super-structure surface is made of a single dielectric material, and the functional unit comprises a periodic artificial micro-nano structure.
The two groups of super-structured surface lens imaging units are formed by processing sub-wavelength microstructures on one side of a transparent substrate; the unprocessed microstructure side of the transparent substrate is used for transmitting incident light and supporting the sub-wavelength microstructure; the sub-wavelength microstructure is composed of a plurality of nano medium columns, and phase and amplitude modulation is realized on the light beam transmitted by the transparent substrate.
The invention provides a manufacturing method of a beam shaper, which comprises the following steps:
two transparent substrates of different diameter sizes are selected for transmission of incident light.
And respectively etching a plurality of dielectric columns on one side of each transparent substrate to respectively generate an ultra-structured surface array, thereby forming two ultra-structured surface lenses with different focal lengths. The method for etching the super-structure surface lens substrate by using the electron beam or the ion beam generates a first super-structure surface array with a specific focal length, which is periodically arranged, so as to form the super-structure lens with a certain focal length.
And (3) oppositely placing one sides of the two super-structured lenses etched with the plurality of nano-medium columns, wherein the axes of the two super-structured lenses are positioned on the same straight line, and the focuses of the two super-structured lenses are overlapped with each other.
According to the direction of the incident light, when the focal length of the super-structure lens is larger than that of the emergent super-structure lens when the incident light is incident, the super-structure lens is a beam expander, and the beam expander is the beam expander.
Wherein, forming the super-structured surface array comprises the following steps:
Selecting a dielectric material transparent to an operating band according to the operating band required by application;
and processing the designed sub-wavelength structure on the dielectric material sheet with ideal thickness by utilizing an electron beam etching technology or a focused ion beam etching technology to form the super-structured surface array.
Example 1:
The invention provides a structure of a single-medium super-structure lens, as shown in the following figure 1, the single-medium super-structure lens of the embodiment constructs a surface array meeting specific phase change on an LN substrate, and the surface array comprises a plurality of microstructure units, namely a sub-wavelength cellular structure of the super-structure lens, as shown in figure 4, the geometric configuration is a cylinder, the unit period is 1.2 mu m, and the height is 1.2 mu m.
The microstructure unit of this embodiment has a size of a sub-wavelength, and a diameter in the visible light band is generally set to 0.2 μm to 1 μm.
The diameters of the microstructure units are different, and the duty ratio of the grating can be changed by adjusting the diameters of cylinders in the sub-wavelength cellular structure at different radiuses of the super-structured lens, so that different emergent phases are realized. Numerical simulation is performed on the super-structured surface unit (namely, an independent sub-wavelength cell structure) by using time domain finite difference numerical simulation software (FDTD), linear polarized parallel light or Gaussian light is used as excitation during simulation, periodic boundary conditions are set, the cylindrical diameter is scanned between 0.2 μm and 1 μm in the visible wavelength range, phase change and transmittance at different wavelengths and different cylindrical diameters can be obtained, as shown in fig. 5, the approximate wavelength range of incident light can be obtained through analysis of the transmittance (the transmittance is as large as possible and is close to one), and more specific wavelength (approximately at 1550 nm) is obtained through analysis of the phase change condition in the wavelength range (the phase change range is required to be approximately covered (0 to 2 pi) at a certain wavelength).
The phase retardation of the super-structured lens satisfies the following formula:
Wherein f is the focal length from the focal point of the super-constructed lens to the center point of the super-constructed lens, Refers to the phase retardation at the corresponding position of the super-structure lens structure unit; /(I)The phase corresponding to the geometric center position of the lambda super-structure lens with the wavelength of incident light; x refers to the x-axis coordinate at the corresponding position of the cylindrical structure, y refers to the y-axis coordinate at the corresponding position of the cylindrical structure, and λ is the incident wavelength.
The phase retardation formula can be used to obtain the phase change required at different radial positions of the super-lens (the whole period of 2 pi needs to be subtracted to obtain data of 0 to 2 pi). The MATLAB can be used to obtain images of phase changes at different radii on the lens.
Discretizing the image with the size of the structural unit (1.2 μm) to obtain the phase change of the structural unit at different radii of the lens. And converting the corresponding relation between the diameter and the phase of the cylinder of the structural unit obtained by utilizing simulation scanning before, and obtaining the diameter of the cylinder of the structural unit at different lens radiuses. By utilizing the corresponding relation obtained in the last step, a cylinder with a specific size can be built at a specific position on the lens, and then the single-medium super-structured surface super-structured lens with a specific incidence wavelength and a specific focal point and radius can be obtained.
The super-structured surface array formed by the above design has a condensing effect, and thus can be used as a convex lens.
By varying the values of the focus and radius, a different super-lens can be designed according to the above procedure.
Example 2:
The present invention proposes a method for fabricating the super-structured lens structure in embodiment 1, which includes focused ion beam etching (FIB) and electron beam Etching (EBL).
Wherein (1) focused ion beam etching (FIB) comprises the steps of:
Preparing a substrate: selecting near infrared transparent LN as a substrate, polishing, and improving the surface finish; then cleaning and drying, and performing surface metal spraying.
Designing a super-structure lens structure: the required super-structured lens structure is designed by using FDTD (according to the method of the embodiment 1), and the structural parameters are adjusted according to the actual requirements.
FIB etching: the substrate is placed on a sample stage of the FIB, the FIB equipment is turned on, and the substrate is exposed to the ion beam generated by the FIB. By controlling parameters of the FIB device, such as energy of the ion beam, etching time, etc., a desired super-structured lens structure is formed on the substrate surface.
Removing residues: after etching, the unprocessed part has a gold layer to form a diaphragm effect, and the processed part can be used for focusing the lens.
And (3) detection: and detecting the prepared super-structure lens by using an optical microscope or a scanning electron microscope to ensure that the structure meets the design requirement.
(2) The method for manufacturing the super-structure lens by using the electron beam etching technology EBL comprises the following steps of:
Preparing a base: an LN substrate is prepared, and the substrate is cleaned and processed to ensure clean surface and good flatness.
Designing a super-structure lens structure: the required super-structured lens structure is designed by using FDTD (according to the method of the embodiment 1), and the structural parameters are adjusted according to the actual requirements.
Coating electron beam photoresist: a photoresist (radiation sensitive polymer) is uniformly coated on a substrate to be processed to a certain thickness. The choice of photoresist depends on the particular characteristics and resolution desired.
Electron beam exposure: and using an electron beam exposure system to perform electron beam exposure according to the designed pattern, wherein in the exposure process, the highly focused electron beam scans the surface of the photoresist, so that the photoresist in the exposed area is solidified or degraded. The focusing and positioning capabilities of the electron beam are very high, and accurate exposure can be achieved on the nanometer scale.
Developing: and developing the exposed sample, immersing the substrate sample into an organic developing solution for developing, wherein the negative photoresist is cured due to electron beam exposure and cannot be dissolved by the developing solution, and the positive photoresist is degraded due to electron beam exposure and is dissolved by the developing solution. In this way, only the areas exposed to the electron beam remain. Thus obtaining the nano pattern with expected structure, which can be used for further metal deposition to construct surface plasmon nano devices.
And (3) removing a covering layer: the overburden is removed, typically using a chemical solvent or ion beam etching.
And (3) cleaning a substrate: the sample is thoroughly cleaned to remove any residue and ensure the purity of the lens surface.
Substrate inspection: the fabricated super-structured lens is inspected using a microscope or other characterization tool to ensure that its quality and performance meet requirements. The diameter of the super-structured lens is 25 μm and 50 μm respectively.
Example 3:
The invention provides a beam expander consisting of a single-medium super-structured surface, which is composed of a super-structured lens 1 and a super-structured lens 2 which are opposite to each other and have different focal lengths and diameters, as shown in fig. 2. The method for manufacturing the super-structure lens is as described in the first embodiment, and the super-structure lens 1 is made of a single dielectric material, the focal length of the super-structure lens is smaller than that of the super-structure lens 2, the axes of the two super-structure lenses are on the same straight line, the focuses of the two super-structure lenses are overlapped with each other in the middle of the two super-structure lenses, the super-structure surface arrays of the two lenses are arranged on the inner side, and the substrate is arranged on the outer side (relative to the overlapped focuses) to form a beam expander structure (specifically, a kepler structure).
The parallel light beam passes through the substrate of the super-structure lens 1, then is focused to a focus through the super-structure surface array on the super-structure lens 1, diverges, passes through the super-structure surface array of the super-structure lens 2, and then passes through the substrate to become parallel light with larger diameter than the incident light. The beam expansion ratio, that is, the ratio of the diameters of the outgoing light and the incoming light, is the ratio of the focal lengths of the super-lens 2 and the super-lens 1. The wavelength of the parallel light beam has a specific range, and after the medium is determined, the wavelength can be determined by the phase and transmittance requirements of the simulation scanning of the sub-wavelength unit structure of the super-structure surface of the beam expander.
Example 4:
The invention provides a beam reducer composed of a single-medium super-structure surface, as shown in figure 3, wherein the beam reducer structure comprises two super-structure lenses with the diameter of micrometers. The super-structure lens comprises a super-structure lens 1 and a super-structure lens 2 which are opposite to each other and have positive optical power and different in focal length and diameter, the focal length of the super-structure lens 1 is larger than that of the super-structure lens 2, the axes of the two super-structure lenses are on the same straight line, the focuses of the two super-structure lenses are overlapped with each other in the middle of the two super-structure lenses, the super-structure surface arrays of the two lenses are arranged on the inner side, and the substrate is arranged on the outer side (relative to the overlapped focuses) to form a beam contractor structure (particularly a kepler structure).
The parallel light beam passes through the substrate of the super-structure lens 1, then is focused to a focus through the super-structure surface array on the super-structure lens 1, diverges, passes through the super-structure surface array of the super-structure lens 2, and then passes through the substrate to be parallel light with smaller diameter than the incident light. The beam reduction ratio, i.e., the ratio of the diameters of the outgoing light and the incoming light, is the ratio of the focal lengths of the super-lens 2 and the super-lens 1. The wavelength of the parallel light beam has a specific range, and after the medium is determined, the wavelength can be determined by the phase and transmittance requirements of the simulation scanning of the sub-wavelength unit structure of the super-structure surface of the beam reducer.
The super-lens is composed of a single dielectric material, the functional unit and the substrate are made of the same transparent dielectric material, and the super-structure lens is combined into a beam expander and a beam shrinking device with specific size and beam expanding and shrinking ratio in the mode of an example III and an example IV.
The invention is mainly used for expanding or shrinking the parallel light beams with certain diameter and specific wavelength so as to change the diameter of the light beams with the diameter in the micrometer range. The beam expander and beam contractor structure adopts a single-medium super-structure lens (Metalens) to replace the traditional lens and the typical multi-material super-structure lens. The diameter and focal length of the super-structure lens determine the phase distribution of the surface, so that the arrangement mode of super-structure surface units is changed, and different optical characteristics can be reflected. For example: a super-structured lens having positive refractive power can be fabricated. Therefore, the focal length of the super-structure lens is not determined by the refractive index and the curvature radius of materials in the traditional lens, and the focal length and the diameter of the super-structure lens can be greatly reduced (in micron level), so that the size of the beam expander and the beam contractor which are formed by two super-structure lenses with different diameters and focal lengths (the diameters are different, the diameters are not required, and the diameters are generally different) is very small, thereby enabling the production and the application of the beam expander and the beam contractor to be miniaturized and integrated, and being applicable to any transparent medium material.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (10)
1. A beam shaper comprising two super-structured lenses of different focal lengths and diameters;
Each super-structure lens comprises a single-medium transparent substrate for transmitting incident light and a plurality of single-medium columns etched on one side of the transparent substrate, wherein the single-medium columns form a super-structure surface array and are used for realizing phase and amplitude modulation on light beams transmitted by the transparent substrate;
One sides of the two super-structured lenses, which are provided with a plurality of single-medium columns, are oppositely arranged, the axes of the super-structured lenses are positioned on the same straight line, and the two focuses are mutually overlapped; when the focal length of the super-structure lens on which the incident light is incident is larger than that of the emergent super-structure lens, the beam shaper is a beam contractor, and the beam expander is the opposite.
2. The beam shaper according to claim 1, wherein a plurality of the single dielectric pillars are each nano-structured and the single dielectric pillars are of a same transparent material as the single dielectric transparent substrate.
3. A beam shaper according to claim 1, wherein a plurality of said single dielectric posts are non-uniform in diameter.
4. The beam shaper according to claim 1, wherein a plurality of the single dielectric pillars are periodically arranged on one side of the transparent substrate.
5. A method of manufacturing a beam shaper as claimed in any of claims 1 to 4, comprising the steps of:
selecting two single-medium transparent substrates with different diameters and used for transmitting incident light;
Etching a plurality of single-medium columns on one side of each transparent substrate respectively to generate an ultra-structured surface array respectively, so as to form two ultra-structured surface lenses with different focal lengths;
One side of each super-structured lens etched with a plurality of single-medium columns is placed oppositely, the axes of the super-structured lenses are positioned on the same straight line, and focuses of the two super-structured lenses are overlapped with each other;
according to the direction of the incident light, when the focal length of the super-structure lens when the incident light is incident is larger than that of the super-structure lens when the incident light is emergent, the beam shaper is a beam contractor, and the beam expander is the opposite beam contractor.
6. The method of claim 5, wherein a plurality of single dielectric pillars are etched on one side of each transparent substrate by electron beam or focused ion beam etching.
7. The method for manufacturing a beam shaper according to claim 6, wherein the EBL etching a plurality of single dielectric pillars on one side of each transparent substrate by using an electron beam etching method comprises the following steps:
Selecting a lithium niobate crystal LN or any transparent crystal as a substrate, and cleaning the substrate;
Uniformly coating photoresist with a certain thickness on a substrate;
Using an electron beam exposure system to perform electron beam exposure on the substrate according to the designed pattern; the electron beam scans the surface of the photoresist, and the photoresist in the exposed area is solidified or degraded;
Immersing the exposed substrate into organic developer for development, and obtaining a plurality of single-medium columns on the surface of the substrate; wherein, the negative photoresist is solidified and can not be developed and dissolved, and the positive photoresist is degraded and developed and dissolved.
8. The method of fabricating a beam shaper according to claim 6, wherein the FIB etching a plurality of single dielectric pillars on one side of each transparent substrate by using a focused ion beam etching method, comprises the following steps:
Selecting a lithium niobate crystal LN as a substrate, and sequentially polishing, cleaning, drying and surface metal spraying;
Placing the substrate on a sample stage of the FIB, and starting the FIB equipment to expose the substrate to an ion beam generated by the FIB;
etching a plurality of single-medium columns on the surface of the substrate by controlling parameters of the FIB equipment; parameters of the FIB device include voltage, beam current and etching time of the ion beam.
9. The method according to claim 5, wherein the incident light passing through the beam expander is converted into outgoing light having a larger diameter than the incident light, and the ratio of the diameter of the outgoing light to the diameter of the incoming light is the ratio of the focal length of the super-lens at the time of outgoing light to the focal length of the super-lens at the time of incoming light.
10. The method of claim 5, wherein the incident light passing through the beam shaper is converted into outgoing light with a smaller diameter than the incident light, and the ratio of the diameter of the outgoing light to the diameter of the incoming light is the ratio of the focal length of the super-lens when the outgoing light is outgoing to the focal length of the super-lens when the incoming light is incoming.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410300163.5A CN118011651A (en) | 2024-03-15 | 2024-03-15 | Beam shaper and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410300163.5A CN118011651A (en) | 2024-03-15 | 2024-03-15 | Beam shaper and manufacturing method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118011651A true CN118011651A (en) | 2024-05-10 |
Family
ID=90956483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410300163.5A Pending CN118011651A (en) | 2024-03-15 | 2024-03-15 | Beam shaper and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118011651A (en) |
-
2024
- 2024-03-15 CN CN202410300163.5A patent/CN118011651A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11550084B2 (en) | Low-contrast metasurfaces | |
| US5007709A (en) | Diffraction grating and manufacturing method thereof | |
| WO2006047480A2 (en) | Method and apparatus of making highly repetitive micro-pattern using laser writer | |
| CN113640905B (en) | Polarization-independent achromatic superlens based on calculation wavefront coding | |
| JP2008164553A (en) | X-ray condensing method using phase recovery method, and device thereof | |
| Hisanaga et al. | Fabrication of 3-dimensionally shaped Si diaphragm dynamic focusing mirror | |
| CN111596462B (en) | Multi-orbital angular momentum light beam generator and preparation method thereof | |
| Ayyagari et al. | Hybrid multiphase Fresnel lenses on silicon wafers for terahertz frequencies | |
| CN117518447A (en) | Three-dimensional microscopic imaging method and device based on super-structured lens | |
| CN118011651A (en) | Beam shaper and manufacturing method thereof | |
| Zeitner et al. | The potential of e-beam lithography for micro-and nano-optics on large areas | |
| CN114879355B (en) | Telescope structure and manufacturing method thereof | |
| Zeitner et al. | Advanced lithography for micro-optics | |
| Zhu et al. | Free-Form Micro-Lens Array Fabrication via Laser Micro-Lens Array Lithography. | |
| Smith et al. | Rapid Fabrication of Large Area Diffractive Axicons for Astronomical Applications | |
| US12007695B2 (en) | Rapid large-scale fabrication of metasurfaces with complex unit cells | |
| CN117406317A (en) | Two-dimensional plane grating manufacturing method based on wafer chuck positioning system of photoetching machine | |
| Xu et al. | Research on automatic detection method for surface defects of large-size gratings | |
| CN117784532A (en) | Preparation system and preparation method of large-area phase-type calculation hologram | |
| US20210271102A1 (en) | Freeform surface having a diffractive pattern and a method and system for forming a defractive pattern on a freeform surface | |
| Jandura et al. | Preparation of Fresnel zone plate for LED application using laser lithography | |
| Britten et al. | Diffractive optics for the NIF | |
| CN118409374A (en) | Manufacturing method of micro-lens array based on digital mask lithography technology | |
| CN117930404A (en) | Polarization-independent all-medium multifocal super-structured lens based on optical sparse aperture | |
| Weible et al. | Metrology of refractive microlens arrays |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |