CN211478691U - High-quality Bessel beam lens - Google Patents
High-quality Bessel beam lens Download PDFInfo
- Publication number
- CN211478691U CN211478691U CN202020014364.6U CN202020014364U CN211478691U CN 211478691 U CN211478691 U CN 211478691U CN 202020014364 U CN202020014364 U CN 202020014364U CN 211478691 U CN211478691 U CN 211478691U
- Authority
- CN
- China
- Prior art keywords
- lens
- film layer
- incident
- cone
- curved surface
- 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.)
- Active
Links
Images
Abstract
The utility model discloses a high-quality Bessel beam lens, which comprises a cone-shaped conical lens with a cambered surface at the top, wherein the surface area of the conical lens comprises a bottom plane, a side curved surface and a conical top curved surface, and the bottom plane is the bottom surface of the conical lens and is an incident surface on which laser is incident on the conical lens; the side curved surface is the side surface of the conical lens and is an emergent surface of the laser ray on the conical lens; the cone top curved surface is located the cone lens apex angle region, and the high anti-rete of having plated in the cone top curved surface outside. The technical scheme of the utility model be in the cone lens manufacturing process control cone lens through the control coating film go up emergent laser energy and distribute to reach and eliminate the cone lens apex angle influence, reduce Bessel light energy fluctuation, the diffraction influence when not having the introduction diaphragm simultaneously again, processing and convenient to use.
Description
Technical Field
The utility model relates to a laser beam machining lens technical field, concretely relates to high quality Bessel beam lens.
Background
At present, the application of cutting brittle materials such as glass, sapphire and the like by using the Bessel beam is wider and wider, the corresponding processing effect requirement is higher and higher, and the processing effect is directly related to the quality of the Bessel beam. The cone lens can generate approximate Bessel beams in a certain range, has higher diffraction efficiency, is an ideal device for generating the Bessel beams to perform laser processing, but because the cone angle position of the cone lens is an arc angle due to manufacturing errors, the energy consistency of the Bessel beams can be influenced by the arc angle, the processing effect is influenced, and a method which can effectively eliminate the influence of the defect of the top angle and is convenient to use is found to have practical value.
The bessel beams are generated by using a cone lens, an ideal cone lens is shown in fig. 1, and two directional wave fronts formed after parallel beams pass through are respectively parallel to the cone surface. The Bezier light beam is generated in the direction of the optical axis, the intensity curve of the light intensity along the transmission direction is smooth, and the light intensity can be considered as the ideal Bezier light beam with constant intensity along the transmission direction within a certain distance. The ideal axicon lens apex angle is the edges and corners, but axicon lens apex angle is great, is generally greater than 150, because manufacturing process limits, the axicon lens apex angle of actually processing out is the arc, and light through this arc point can interfere with the Bessel light that produces through other positions, produces intensity modulation to Bessel light beam, and the intensity change is no longer gentle on making the axial direction, but has certain shake.
Fig. 2 shows a cone lens with processing defects, in which after parallel light passes through the cone lens, an arc-shaped curved surface near the center of the cone lens converges a gaussian beam incident at a focal portion to make the gaussian beam closer to an optical axis, and a convergent near-spherical wave is formed behind an axon, so that an axial beam passing through the position is modulated, and thus, an intensity curve of a bessel beam is not smooth any more, but has a certain jitter, and the bessel beam is not an ideal bessel beam any more within a certain distance. In practical laser processing application, laser is in Gaussian distribution, the central incident energy is high, and axial intensity fluctuation is more obvious.
The existing solution is to add a diaphragm, but the diaphragm has the following defects: 1. the diaphragm needs to be matched with the arc size of the sharp corner, the size is small, and the manufacturing and assembling difficulty is high; 2. the introduction of the diaphragm can cause diffraction phenomena.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a structure scientific and reasonable can form the high quality Bessel beam lens of approximate ideal Bessel beam.
The utility model discloses a reach above-mentioned purpose, specifically can realize through following technical scheme:
a high-quality Bessel beam lens comprises a conical lens with a cambered surface at the top, wherein the surface area of the conical lens comprises a bottom plane, a side curved surface and a conical top curved surface, and the bottom plane is the bottom surface of the conical lens and is an incident surface on which laser is incident; the side curved surface is the side surface of the conical lens and is an emergent surface of the laser ray on the conical lens; the conic vertex curved surface is positioned in the vertex angle area of the conical lens, the outer side of the conic vertex curved surface is plated with a high-reflection film layer, and the thickness d of the high-reflection film layer is
d＝λ/2*n*cosα，
Wherein, λ is the wavelength of the incident light, n is the film refractive index of the highly reflective film layer, α is the incident angle of the light on the highly reflective film layer, and the incident angle is the included angle between the incident light and the normal of the incident surface of the highly reflective film layer.
The scheme is further improved, the high-reflection film layer comprises N layers of dielectric high-reflection films, N is a natural number not less than 1, and the thickness d of the x-th layer of dielectric high-reflection filmxIs composed of
dx＝λ/2*nx*cosαx，
Wherein x is more than or equal to 1 and less than or equal to N, x is a natural number, lambda is the wavelength of incident light, and NxFilm layer refractive index of the x-th dielectric high-reflection film, αxThe incident angle of the light on the x-th dielectric high-reflection film is the included angle between the incident light and the normal of the incident surface of each dielectric high-reflection film, and the thickness of the high-reflection film layer 14 is the sum of the thicknesses of the N dielectric high-reflection film layers.
The scheme is further improved, and the side curved surface is plated with a first high-transmittance film layer.
The scheme is further improved, and the bottom plane and the side curved surface are not coated with films.
The scheme is further improved, and the bottom plane is plated with a second high-transmittance film layer.
The further improvement of the scheme also comprises a cylindrical lens, wherein the two ends of the cylindrical lens are respectively a first end surface and a second end surface, the first end surface and the bottom plane of the conical lens are integrated, and the second end surface is an incident surface of the laser ray on the cylindrical lens.
The scheme is further improved, and the second end face is plated with a third high-transmittance film layer.
In a further improvement of the above scheme, the second end surface is not coated with a film.
The technical scheme of the utility model be in the cone lens manufacturing process control cone lens through the control coating film go up emergent laser energy and distribute to reach and eliminate the cone lens apex angle influence, reduce Bessel light energy fluctuation, the diffraction influence when not having the introduction diaphragm simultaneously again, processing and convenient to use.
The cone lens can be selectively coated with an infrared and green light high-transmittance film or not coated with a film according to the wavelength of laser used in processing when in selection, the incident surface and the emergent surface of the cone lens are uniform and consistent in high transmittance, in order to eliminate the influence caused by the processing defect of the cone lens vertex angle, the light energy near the vertex angle needs to be reduced as much as possible, but the light energy near the vertex angle is strongest due to the Gaussian distribution of incident light, and the light energy near the cone top curved surface at the vertex angle of the cone lens is reduced by controlling the coating mode without influencing the light transmission of other parts. The incident bottom plane part and the emergent side curved surface part are plated with high-transmittance films or are not plated with films, the film thickness of each layer of the cone top curved surface multilayer dielectric high-reflection film is controlled by changing the film plating condition of the cone top curved surface part at the vertex angle of the cone lens, the optical path difference is enabled to be lambda/2, and the purpose of destructive transmission interference is achieved. The laser is reflected at the position of the conical top curved surface, and the light rays at other positions are transmitted, so that the laser is coherently superposed at the optical axis to generate a Bessel light beam, and the Bessel light eliminates intensity modulation caused by the irregular vertex angle of the conical lens. And because there is certain angle of incidence in the curved surface position of the conical top, the reflected light can be dispersed, will not return on the same way, thus guarantee the laser will not receive the reflection influence.
Drawings
FIG. 1 is a schematic diagram of the light beam incident of an ideal axicon lens;
FIG. 2 is an axicon lens with processing defects;
FIG. 3 is a schematic view of the cone lens structure of the present invention;
FIG. 4 is a schematic view of the incident light beam of the axicon lens of the present invention;
fig. 5 is a schematic view of an axicon lens structure according to embodiment 2 of the present invention;
fig. 6 is a schematic view of an axicon lens structure according to embodiment 3 of the present invention;
fig. 7 is a schematic view of an axicon lens structure according to embodiment 4 of the present invention;
fig. 8 is a schematic view of an axicon lens structure according to embodiment 5 of the present invention.
In the figure, 1, an axicon; 11. a bottom plane; 12. a side curved surface; 13. a cone top curved surface; 14. a high reflective film layer; 15. a first high-permeability film layer; 16. a second high-permeability film layer; 2. a cylindrical lens; 21. a first end face; 22. a second end face; 23. and a third high-permeability film layer.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
As shown in fig. 3, in embodiment 1, the high quality bessel beam lens of the present invention is a conical axicon lens 1, the surface of the axicon lens 1 includes a bottom plane 11, a side curved surface 12 and a cone top curved surface 13, the bottom plane 1 is the bottom surface of the axicon lens and is the incident surface on the laser incident axicon lens 1. The side curved surface 2 is a side surface of the axicon 1 and is an exit surface of the laser beam on the axicon 1. The cone top curved surface 13 is positioned in the top corner area of the cone lens 1, the cone top curved surface 13 and the side curved surface 2 are in smooth transition, the high reflection film layer 14 is plated on the outer side of the cone top curved surface 13, the thickness d of the high reflection film layer 14 is d ═ lambda/2 × n × cos alpha,
wherein λ is the wavelength of the incident light, n is the refractive index of the high reflective film layer, α is the incident angle of the light on the high reflective film layer, the incident angle is the angle between the incident light and the normal of the incident surface of the high reflective film layer 14, and the thickness of the high reflective film layer 14 is gradually reduced from the center to both sides. In this embodiment, the bottom plane 11 and the side curved surface 12 are not coated.
In another embodiment, the high-reflection film layer 14 comprises N layers of dielectric high-reflection films, N is a natural number greater than or equal to 1, and the thickness d of the x-th layer of dielectric high-reflection filmxIs composed of
dx＝λ/2*nx*cosαx，
Wherein x is more than or equal to 1 and less than or equal to N, x is a natural number, lambda is the wavelength of incident light, and NxFilm layer refractive index of the x-th dielectric high-reflection film, αxThe incident angle of the light ray on the x-th dielectric high-reflection film is the included angle between the incident light ray and the normal of the incident surface of each dielectric high-reflection film. The thickness of the high-reflection film layer 14 is the sum of the thicknesses of the N dielectric high-reflection film layers.
Fig. 4 shows the situation of the light of the laser passing through the axicon lens in fig. 3, the light passes through the side curved surface 12 and is coherently superposed on the optical axis to form an approximate ideal bessel beam, the light at the vertex curved surface 13 is reflected, and a certain angle exists between the reflection and the incident direction, so that the influence of the reflected light on the laser is avoided.
As shown in fig. 5, in the embodiment 2 of the present invention, a first high-permeability film layer 15 is plated on the side curved surface based on the structure of the embodiment 1. As shown in fig. 6, embodiment 3 is further improved on the basis of embodiment 1 or 2, and the bottom plane 11 is plated with a second high-permeability film layer 16.
Embodiment 4 is shown in fig. 7, and is a further improvement on the basis of embodiments 1 to 3, the lens of the present invention further includes a cylindrical lens 2, the two ends of the cylindrical lens 2 are respectively a first end face 21 and a second end face 22, the first end face 21 is connected with the bottom plane 11 of the axicon lens 1 as a whole, the second end face 22 is an incident face of the laser beam on the cylindrical lens 2, and the second end face 22 is not coated. As shown in fig. 8, in embodiment 5, on the basis of embodiment 4, further, the second end face 22 is plated with a third high-permeability film layer 23.
The utility model discloses a change 1 coating film condition of lens and restrain and make the defect, be the awl lens arc angle position at the vertex of a cone curved surface 13 of awl lens, this position is plated high anti-membrane, plates high transparent film or not coating film in base plane 11 and side curved surface 12 position. Plating a multi-layer dielectric high-reflection film at the position of the conical top curved surface 13, wherein n isxAnd dxRefractive index and thickness of the film layer, α respectivelyxThe incident angle of the x-th electric film layer and the thickness d of each film layerxNeed to satisfy the optical path difference of 2nx*dx*cosαxλ. As can be seen from the formula, the film thickness of the high-reflection film layer 14 varies according to the variation of the incident angle, and the specific thickness thereof can be obtained according to the formula.
The specific embodiments of the present invention are only for explaining the present invention, and are not intended to limit the present invention, and those skilled in the art can make modifications to the present embodiment as required without inventive contribution after reading the present specification, but all the embodiments are protected by patent laws within the scope of the claims of the present invention.
Claims (8)
1. A high-quality Bessel beam lens is characterized by comprising a conical axicon (1) with a cambered surface at the top, wherein the surface area of the axicon comprises a bottom plane (11), a side curved surface (12) and a conical top curved surface (13), and the bottom plane is the bottom surface of the axicon and is used as an incident surface for laser to be incident on the axicon; the side curved surface is the side surface of the conical lens and is an emergent surface of the laser ray on the conical lens; the cone top curved surface is positioned in the vertex angle area of the cone lens, a high reflection film layer (14) is plated on the outer side of the cone top curved surface, the thickness d of the high reflection film layer is lambda/2 n cos alpha,
wherein, λ is the wavelength of the incident light, n is the film refractive index of the highly reflective film layer, α is the incident angle of the light on the highly reflective film layer, and the incident angle is the included angle between the incident light and the normal of the incident surface of the highly reflective film layer.
2. The Bessel beam lens of claim 1, wherein the high-reflection film layer comprises N layers of dielectric high-reflection films, N is a natural number greater than or equal to 1, and the thickness d of the x-th layer of dielectric high-reflection filmxIs composed of
dx＝λ/2*nx*cosαx，
Wherein x is more than or equal to 1 and less than or equal to N, x is a natural number, lambda is the wavelength of incident light, and NxFilm layer refractive index of the x-th dielectric high-reflection film, αxThe incident angle of the light on the x-th dielectric high-reflection film is the included angle between the incident light and the normal of the incident surface of each dielectric high-reflection film, and the thickness of the high-reflection film layer 14 is the sum of the thicknesses of the N dielectric high-reflection film layers.
3. The high quality bessel beam lens according to claim 1, characterized in that the side curved surfaces are coated with a first high transmission film layer (15).
4. The high quality bessel beam lens of claim 1 wherein the base plane and the side curved surfaces are uncoated.
5. The high quality bessel beam lens according to claim 1, characterised in that the base plane is coated with a second high transmission film layer (16).
6. A high quality Bessel beam lens according to any one of claims 1 to 4, further comprising a cylindrical lens (2) having a first end surface (21) and a second end surface (22) at its two ends, the first end surface being integrally connected to the bottom surface of the axicon lens, and the second end surface being the incident surface of the laser beam on the cylindrical lens.
7. The high quality bessel beam lens according to claim 6, characterised in that the second end face is coated with a third high transmission film layer (23).
8. The high quality bessel beam lens of claim 6 wherein the second end face is uncoated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020014364.6U CN211478691U (en) | 2020-01-03 | 2020-01-03 | High-quality Bessel beam lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020014364.6U CN211478691U (en) | 2020-01-03 | 2020-01-03 | High-quality Bessel beam lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211478691U true CN211478691U (en) | 2020-09-11 |
Family
ID=72360060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020014364.6U Active CN211478691U (en) | 2020-01-03 | 2020-01-03 | High-quality Bessel beam lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211478691U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110967782A (en) * | 2020-01-03 | 2020-04-07 | 北京卓镭激光技术有限公司 | High-quality Bessel beam lens |
-
2020
- 2020-01-03 CN CN202020014364.6U patent/CN211478691U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110967782A (en) * | 2020-01-03 | 2020-04-07 | 北京卓镭激光技术有限公司 | High-quality Bessel beam lens |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10677992B2 (en) | Device for forming at least one focused beam in the near zone, from incident electromagnetic waves | |
| US7643719B1 (en) | Superlens and a method for making the same | |
| US11253952B2 (en) | Laser processing apparatus | |
| KR20070012371A (en) | Catadioptric imaging system for high numerical aperture imaging with deep ultraviolet light | |
| CN211478691U (en) | High-quality Bessel beam lens | |
| CN110967782A (en) | High-quality Bessel beam lens | |
| US4609258A (en) | Diode laser collimator | |
| CN102590962A (en) | Multiple unit semiconductor laser and optical fiber coupling system | |
| CN111266725B (en) | Laser processing device | |
| CN112612141A (en) | Optical system for shaping light beam | |
| US4219254A (en) | Corrective optics for higher order mode lasers | |
| CN207601356U (en) | A kind of optical fiber and semiconductor laser module | |
| TWI393919B (en) | Beam shaper | |
| CN218824795U (en) | Coupling device | |
| JP2003207724A (en) | System capable of changing wavelength and intensity of output light | |
| CN108196347A (en) | A kind of optical fiber, semiconductor laser module and fiber fabrication methods | |
| CN211653313U (en) | Total reflection polarization-maintaining turn-back prism | |
| CN110108642A (en) | A kind of total reflection White pond | |
| CN212160134U (en) | Polarization maintaining film for total reflection prism and total reflection prism | |
| CN212009179U (en) | Turn-back type laser polarization-maintaining total reflection prism | |
| JP7442082B2 (en) | optical mirror | |
| US20230140825A1 (en) | Beam splitter/combiner and projection apparatus | |
| US10795172B1 (en) | Apparatus and method of combining multiple laser beams using a negative focal length radial gradient index rod lens | |
| JP6822737B2 (en) | Asymmetric transparent film | |
| JIANG et al. | Design of Dual Hollow Beam Optical Antenna based on Fresnel Lens-Conical Lens Combination |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |