CN114460676A - 1030nm sine type dielectric grating and manufacturing method thereof - Google Patents
1030nm sine type dielectric grating and manufacturing method thereof Download PDFInfo
- Publication number
- CN114460676A CN114460676A CN202210210169.4A CN202210210169A CN114460676A CN 114460676 A CN114460676 A CN 114460676A CN 202210210169 A CN202210210169 A CN 202210210169A CN 114460676 A CN114460676 A CN 114460676A
- Authority
- CN
- China
- Prior art keywords
- refractive
- layer
- grating
- dielectric
- index
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 25
- 239000000463 material Substances 0.000 claims abstract description 55
- 239000000758 substrate Substances 0.000 claims abstract description 12
- 238000005530 etching Methods 0.000 claims abstract description 9
- 229920002120 photoresistant polymer Polymers 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims abstract description 6
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 claims description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- 239000005350 fused silica glass Substances 0.000 claims description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 3
- 238000002834 transmittance Methods 0.000 claims description 3
- 230000010287 polarization Effects 0.000 abstract description 7
- 239000002184 metal Substances 0.000 description 7
- 238000002310 reflectometry Methods 0.000 description 7
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/18—Diffraction gratings
- G02B5/1809—Diffraction gratings with pitch less than or comparable to the wavelength
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/18—Diffraction gratings
- G02B5/1847—Manufacturing methods
- G02B5/1857—Manufacturing methods using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
Abstract
The invention relates to a 1030nm sine type medium grating and a manufacturing method thereof, wherein the grating comprises a top grating, a plurality of middle dielectric layers and a substrate; the top grating is made of a high-refractive-index film material, the middle multi-layer dielectric layer comprises a plurality of alternately superposed high-refractive-index material dielectric film layers and low-refractive-index material dielectric film layers, and the substrate is made of a low-refractive-index material; the slot shape of the top grating is sinusoidal. The manufacturing method comprises the steps that a high-refractive-index film layer is arranged above a middle multi-layer medium layer, the high-refractive-index film layer is made of high-refractive-index film materials, and the thickness of the high-refractive-index film layer is 0.5-0.6 mu m; arranging a layer of photoresist on the high-refractive-index film layer; the photoresist is made into a mask by a holographic interference system, and then etched into a top grating. The grating can ensure that two polarization states of TE and TM have extremely high diffraction efficiency under littrow incidence in the 1020-1040nm wave band, only one film layer needs to be etched during manufacturing, and the etching process has high redundancy.
Description
Technical Field
The invention relates to a 1030nm sine type dielectric grating and a manufacturing method thereof, belonging to the technical field of optical elements.
Background
In the field of high-power laser, a pulse compression grating is often used as a core optical element, and a metal grating, a metal dielectric film grating, a full-dielectric grating and the like can achieve high diffraction efficiency, however, the metal grating and the metal dielectric film grating are easily damaged by laser under high power due to the absorption characteristics of the metal grating and the metal dielectric film grating, and the metal grating has high diffraction efficiency only under TM polarization; the all-dielectric grating has the advantages of high diffraction efficiency and high damage threshold, and the diffraction polarization is irrelevant, so the all-dielectric grating is the first choice of the pulse compression grating, however, the conventional all-dielectric grating is rectangular or trapezoidal in groove shape, the film layers contained in the grating are two or more than two layers, the duty ratio of the grating is generally required to be controlled within a certain range, the depth of the grating groove is required to be accurately controlled, and the groove angle is required to be controlled, which brings much trouble to the processing of the grating.
For example, chinese patent application No. 201610239620.X discloses a 1064 nm polarization independent broadband high diffraction efficiency double-layer reflective all-dielectric grating. The grating can enable incident light of TE and TM two polarization modes to be incident at a littrow angle of-1 level, the reflection diffraction efficiency of-1 level is higher than 95% in a wavelength bandwidth of 80 nanometers (1020-1100 nanometers), the highest diffraction efficiency exceeds 99%, and the grating has diffraction efficiency of-1 level higher than 95% in a wider angular spectrum (about 5 degrees) and a wide azimuthal spectrum (plus or minus 15 degrees to plus or minus 20 degrees). The manufacturing of the grating needs to control the duty ratio and the grating groove depth, and needs to etch multiple layers of films, so that the processing difficulty of the grating is improved.
Disclosure of Invention
In order to overcome the problems, the invention provides a 1030nm sine type medium grating and a manufacturing method thereof, the grating can enable two polarization states of TE and TM to have extremely high diffraction efficiency under littrow incidence in the wave band of 1020-1040nm, only one film layer needs to be etched during manufacturing, and the etching process has high redundancy. The manufacturing method can reduce reflection of 441nmS light, and is suitable for manufacturing a grating mask through a holographic system.
The technical scheme of the invention is as follows:
the first part
A1030 nm sine type dielectric grating comprises a top grating, a middle multilayer dielectric layer and a substrate; the top grating is made of a high-refractive-index film material, the middle multi-layer dielectric layer comprises a plurality of alternately superposed high-refractive-index material dielectric film layers and low-refractive-index material dielectric film layers, and the substrate is made of a low-refractive-index material; the groove shape of the top grating is sinusoidal.
Furthermore, the period of the top grating is 833nm, and the depth is 0.5-0.6 μm.
Furthermore, the film system structure of the middle multilayer dielectric layer is ^ M, wherein H is the high refractive index material dielectric film layer, L is the low refractive index material dielectric film layer, M is the alternation times, M is more than 8, and M isiThe thickness of the dielectric film layer of the high refractive index material of the ith layer is NiThe thickness of the dielectric film layer of the low refractive index material of the ith layer is shown.
Furthermore, the topmost layer of the middle multi-layer dielectric layer is the low-refractive-index material dielectric film layer, and the bottommost layer is the high-refractive-index material dielectric film layer.
Further, the material of the high refractive index material medium film layer is Ta2O5Or TiO2The material of the low-refractive-index material medium film layer is Si02。
Further, the material of the top grating is Ta2O5。
Further, the material of the substrate is fused quartz.
The second part
A method for manufacturing a 1030nm sinusoidal dielectric grating, which is used for manufacturing the 1030nm sinusoidal dielectric grating of any one of claims 2-6, and comprises the following steps:
a high-refractive-index film layer is arranged above the middle multi-layer medium layer, the high-refractive-index film layer is made of a high-refractive-index film material, and the thickness of the high-refractive-index film layer is 0.5-0.6 mu m;
the high-refractive-index film layer and the middle multilayer dielectric layer jointly form a high-transmittance film for S light with the wavelength of 441nm under 15-degree incidence and a high-reflection film for S light and P light with the wavelength of 1030nm under 38-degree incidence;
arranging a layer of photoresist above the high-refractive-index film layer;
making the photoresist into a mask by holographic interference system fabrication;
and etching the high-refractive-index film layer into the top grating.
The invention has the following beneficial effects:
1. under the incidence of TE and TM polarization states, in a wave band of 1020-1040nm and under the incidence of littrow, the diffraction efficiency of the grating is greater than 97 percent, and the highest diffraction efficiency is greater than 99 percent.
2. The grating is simple in structure of the film layer, only one film layer needs to be etched, so that the etching process is high in redundancy, and the grating is suitable for mass production.
3. The manufacturing method can reduce the reflectivity of S light with the 441nm waveband to be within 5 percent, and the reflectivity of P light with the 1020-1040nm waveband and S light to be within 2 percent, thereby effectively preventing the standing wave effect caused by overhigh reflectivity of the film layer.
4. The manufacturing method is used for preparing the sinusoidal grating, and the photoresist thickness and the top Ta layer2O5Approximately equivalently, the etching needs to be performed by only about 45-degree rotation, the etching depth is 0.5-0.6 μm, and the etching process has great redundancy, so that the grating is easy to manufacture.
Drawings
Fig. 1 is a schematic view of a film structure according to an embodiment of the invention.
Fig. 2 is a graph of S-ray reflectivity at 15 ° incidence for a film according to an embodiment of the present invention.
Fig. 3 is a graph of the reflectance of P-light and S-light at 38 ° incidence for a film layer according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a grating structure according to an embodiment of the present invention.
FIG. 5 is a graph of diffraction efficiency of a grating according to an embodiment of the present invention.
The reference numbers in the figures denote:
1. a top grating; 2. a middle multi-layer dielectric layer; 201. a high refractive index material dielectric film layer; 202. a dielectric film layer of a first refractive index material; 3. a substrate; 4. a high refractive index film layer.
Detailed Description
The invention is described in detail below with reference to the figures and the specific embodiments.
The first part
Referring to fig. 4-5, a 1030nm sinusoidal dielectric grating includes a top grating 1, an intermediate multi-layer dielectric layer 2, and a substrate 3; the top grating 1 is made of a high-refractive-index film material, the middle multi-layer dielectric layer 2 comprises a plurality of alternately superposed high-refractive-index material dielectric film layers 201 and low-refractive-index material dielectric film layers 202, and the substrate 3 is made of a low-refractive-index material; the groove shape of the top grating 1 is sinusoidal. Compared with the existing all-dielectric grating, the grating contains only one layer of film, and the grating groove depth, duty ratio and groove shape do not need to be accurately controlled during manufacturing, so that the grating manufacturing difficulty is reduced.
Furthermore, the period of the top grating 1 is 833nm, and the depth is 0.5-0.6 μm.
Further, the film system structure of the middle multilayer dielectric layer 2 is MiHNiL ^ M, wherein H is the high refractive index material dielectric film 1201, L is the low refractive index material dielectric film 202, M is the alternation times, M is more than 8, MiThe thickness of the high refractive index material medium film layer 201 is the ith layer, NiIs the thickness of the ith layer of the low refractive index material dielectric film layer 202.
Further, the topmost layer of the middle multilayer dielectric layer 2 is the low refractive index material dielectric film layer 202, and the bottommost layer is the high refractive index material dielectric film layer 201.
Further, the material of the high refractive index material dielectric film layer 201 is Ta2O5Or TiO2The material of the low refractive index material dielectric film layer 202 is Si02。
Further, the material of the top grating 1 is Ta2O5。
Further the material of the substrate 3 is fused silica.
In one embodiment of the present invention, the material of the high refractive index material dielectric film layer 201 is Ta2O5The thickness of the top layer grating 1 is 565nm, and the structure of the middle multilayer dielectric layer 2 is shown in table 1:
TABLE 1 intermediate multilayer dielectric layer Structure
In the present embodiment, referring to fig. 5, the diffraction efficiency of the grating is incident in the littrow direction at the wavelength of 1020-1040nm, and the TE and TM diffraction efficiencies are greater than 97%.
The second part
Referring to fig. 1-3, a method of fabricating a 1030nm sinusoidal dielectric grating, for fabricating a 1030nm sinusoidal dielectric grating as described in the first section, comprising the steps of:
a high-refractive-index film layer 4 is arranged above the middle multilayer dielectric layer 2, the high-refractive-index film layer 4 is made of a high-refractive-index film material, and the thickness of the high-refractive-index film layer 4 is 0.5-0.6 mu m;
the high-refractive-index film layer 4 and the middle multilayer medium layer 2 jointly form a high-transmittance film for S light with the wavelength of 441nm under 15-degree incidence and a high-reflection film for S light and P light with the wavelength of 1030nm under 38-degree incidence;
a layer of photoresist is arranged above the high-refractive-index film layer 4;
making the photoresist into a mask by holographic interference system fabrication;
and etching the high-refractive-index film layer 4 into the top grating 1.
The holographic system adopts 441nm S polarized laser, the holographic interference angle of the 833nm period grating is 15 degrees, and in order to prevent the standing wave effect caused by the too high reflectivity of the film layer, the reflectivity of the S light needs to be reduced to be within 5 percent. Fig. 2 is a graph showing the reflectance of the high refractive index film layer 4 when the film layer has a thickness of 0.565 μm. Meanwhile, in order to improve the diffraction efficiency of the grating, the high refractive index film layer 4 and the middle multilayer medium layer form a high reflective film structure within a wavelength band of 1020-1040nm, so that the reflectivity of P light and S light with an incident angle of 30-45 degrees is greater than 98%, referring to fig. 3.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures made by using the contents of the specification and the drawings of the present invention or directly or indirectly applied to other related technical fields are included in the scope of the present invention.
Claims (8)
1. A1030 nm sine type dielectric grating is characterized by comprising a top grating (1), a middle multilayer dielectric layer (2) and a substrate (3); the top grating (1) is made of a high-refractive-index film material, the middle multi-layer dielectric layer (2) comprises a plurality of alternately superposed high-refractive-index dielectric film layers (201) and low-refractive-index dielectric film layers (202), and the substrate (3) is made of a low-refractive-index material; the groove shape of the top grating (1) is sinusoidal.
2. The 1030nm sinusoidal dielectric grating according to claim 1, wherein the top grating (1) has a period 833nm and a depth of 0.5-0.6 μm.
3. The 1030nm sinusoidal dielectric grating as defined in claim 2, wherein said intermediate multilayer dielectric layer (2) has a film system structure of (M)iHNiL) ^ M, wherein H is the high refractive index material medium film layer (201), L is the low refractive index material medium film layer (202), M is the alternation times, M is more than 8, MiThe thickness N of the ith high refractive index material medium film layer (201)iThe thickness of the ith low-refractive index material medium film layer (202) is shown.
4. The 1030nm sinusoidal dielectric grating as defined in claim 3, wherein the top most layer of said intermediate multilayer dielectric layer (2) is said low refractive index dielectric film layer (202) and the bottom most layer is said high refractive index dielectric film layer (201).
5. The 1030nm sinusoidal dielectric grating as defined in claim 2, wherein said high index material dielectric film layer (201) is Ta2O5Or TiO2The material of the low-refractive-index material dielectric film layer (202) is Si02。
6. The 1030nm sinusoidal dielectric grating as claimed in claim 2, wherein the material of the top grating (1) is Ta2O5。
7. The 1030nm sinusoidal dielectric grating according to claim 2, wherein the material of the substrate (3) is fused silica.
8. A method for manufacturing a 1030nm sinusoidal dielectric grating, which is used for manufacturing the 1030nm sinusoidal dielectric grating of any one of claims 2-7, and is characterized by comprising the following steps:
a high-refractive-index film layer (4) is arranged above the middle multilayer dielectric layer (2), the high-refractive-index film layer (4) is made of a high-refractive-index film material, and the thickness of the high-refractive-index film layer (4) is 0.5-0.6 mu m;
the high-refractive-index film layer (4) and the middle multilayer dielectric layer (2) jointly form a high-transmittance film for S light with the wavelength of 441nm under 15-degree incidence and a high-reflection film for S light and P light with the wavelength of 1030nm under 38-degree incidence;
arranging a layer of photoresist above the high-refractive-index film layer (4);
making the photoresist into a mask by holographic interference system fabrication;
and etching the high-refractive-index film layer (4) into the top grating (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210210169.4A CN114460676B (en) | 2022-03-03 | 2022-03-03 | 1030nm sinusoidal medium grating and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210210169.4A CN114460676B (en) | 2022-03-03 | 2022-03-03 | 1030nm sinusoidal medium grating and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114460676A true CN114460676A (en) | 2022-05-10 |
| CN114460676B CN114460676B (en) | 2024-01-09 |
Family
ID=81417217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210210169.4A Active CN114460676B (en) | 2022-03-03 | 2022-03-03 | 1030nm sinusoidal medium grating and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114460676B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080049328A1 (en) * | 2006-08-25 | 2008-02-28 | Haixin Zhou | Tunable diffraction grating having electro-optic material and method for operating same |
| JP2008081555A (en) * | 2006-09-26 | 2008-04-10 | Toyo Tire & Rubber Co Ltd | Polyol composition for rigid polyurethane foam, method for producing rigid polyurethane foam, and method for applying heat insulation to low-temperature tank |
| CN101718883A (en) * | 2009-12-09 | 2010-06-02 | 中国科学院上海光学精密机械研究所 | High-density deeply etched sinusoidal and channeled grating polarization beam splitter |
| US20110102877A1 (en) * | 2008-07-04 | 2011-05-05 | Universite Jean-Monnet | Diffractive polarizing mirror device |
| CN102289014A (en) * | 2011-09-16 | 2011-12-21 | 中国科学院上海光学精密机械研究所 | Metal dielectric film reflection polarization beam splitting grating for waveband of 1,053 nanometers |
| US20120300302A1 (en) * | 2009-12-17 | 2012-11-29 | CNRS(Centre National de la Recherche Scientifique) | Optimized dielectric reflective diffraction grating |
| US20150309220A1 (en) * | 2014-04-28 | 2015-10-29 | Finisar Corporation | Reflective diffraction gratings employing efficiency enhancement or etch barrier layers |
| CN105891925A (en) * | 2016-04-18 | 2016-08-24 | 中国科学院上海光学精密机械研究所 | 1064-nanometer polarization-independent broadband high diffraction efficiency double-layer reflection type all-dielectric raster |
| CN110989061A (en) * | 2019-11-08 | 2020-04-10 | 中国科学院福建物质结构研究所 | All-dielectric polarization-independent total internal reflection grating and manufacturing method thereof |
| CN113064227A (en) * | 2021-03-23 | 2021-07-02 | 中国科学院微电子研究所 | Preparation method of sinusoidal grating |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008081555A1 (en) * | 2007-01-05 | 2008-07-10 | Shimadzu Corporation | Manufacturing method for blaze type diffraction grating |
-
2022
- 2022-03-03 CN CN202210210169.4A patent/CN114460676B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080049328A1 (en) * | 2006-08-25 | 2008-02-28 | Haixin Zhou | Tunable diffraction grating having electro-optic material and method for operating same |
| JP2008081555A (en) * | 2006-09-26 | 2008-04-10 | Toyo Tire & Rubber Co Ltd | Polyol composition for rigid polyurethane foam, method for producing rigid polyurethane foam, and method for applying heat insulation to low-temperature tank |
| US20110102877A1 (en) * | 2008-07-04 | 2011-05-05 | Universite Jean-Monnet | Diffractive polarizing mirror device |
| CN101718883A (en) * | 2009-12-09 | 2010-06-02 | 中国科学院上海光学精密机械研究所 | High-density deeply etched sinusoidal and channeled grating polarization beam splitter |
| US20120300302A1 (en) * | 2009-12-17 | 2012-11-29 | CNRS(Centre National de la Recherche Scientifique) | Optimized dielectric reflective diffraction grating |
| CN102289014A (en) * | 2011-09-16 | 2011-12-21 | 中国科学院上海光学精密机械研究所 | Metal dielectric film reflection polarization beam splitting grating for waveband of 1,053 nanometers |
| US20150309220A1 (en) * | 2014-04-28 | 2015-10-29 | Finisar Corporation | Reflective diffraction gratings employing efficiency enhancement or etch barrier layers |
| CN105891925A (en) * | 2016-04-18 | 2016-08-24 | 中国科学院上海光学精密机械研究所 | 1064-nanometer polarization-independent broadband high diffraction efficiency double-layer reflection type all-dielectric raster |
| CN110989061A (en) * | 2019-11-08 | 2020-04-10 | 中国科学院福建物质结构研究所 | All-dielectric polarization-independent total internal reflection grating and manufacturing method thereof |
| CN113064227A (en) * | 2021-03-23 | 2021-07-02 | 中国科学院微电子研究所 | Preparation method of sinusoidal grating |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114460676B (en) | 2024-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7688512B2 (en) | Transmissive diffraction grating, and spectral separation element and spectroscope using the same | |
| CN108008478B (en) | Polarization selection reflection type grating based on metal multilayer dielectric film | |
| US6122103A (en) | Broadband wire grid polarizer for the visible spectrum | |
| US6850366B2 (en) | Multi-cavity optical filter | |
| US6958859B2 (en) | Grating device with high diffraction efficiency | |
| WO2013105210A1 (en) | Optical multilayer film | |
| EP1552328A2 (en) | Spectral filter for green and longer wavelengths | |
| CN111162110A (en) | Organic light-emitting display panel, manufacturing method thereof and display device | |
| WO2015168182A1 (en) | Reflective diffraction gratings employing efficiency enhancement or etch barrier layers | |
| CN111769425A (en) | All-dielectric reflective spectrum beam-combining grating for 1064 nanometer waveband | |
| US20100091369A1 (en) | Double-layer grating | |
| CN115421295A (en) | Design method of super lens, super lens and processing technology | |
| JP3913765B1 (en) | Polarization phase difference plate | |
| CN102313920B (en) | Wide spectrum metal multilayer dielectric grating based on non-normalized film structure | |
| US20040240064A1 (en) | Optical filter and method of manufacturing thereof | |
| CN114460676B (en) | 1030nm sinusoidal medium grating and manufacturing method thereof | |
| US20100208346A1 (en) | Multilayer Dielectric Transmission Gratings Having Maximal Transmitted Diffraction Efficiency | |
| CN207440322U (en) | A kind of 800 nano waveband broadband reflection type diffraction grating | |
| JP2003279707A (en) | Structure of antireflection film to one-dimensional photonic crystal and its forming method | |
| CN114879282A (en) | Laser protective film based on medium super surface and preparation method thereof | |
| CN102157894A (en) | Axisymmetric polarization resonator mirror based on grating | |
| US20220359794A1 (en) | Light-emitting diode structure | |
| CN114859453B (en) | Random polarization beam combining grating based on continuous interface all-dielectric film | |
| US11927780B2 (en) | Dielectric grating apparatus | |
| TWI820663B (en) | High diffraction efficiency and wide spectrum dielectric grating structure |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |