CN109473125B - Surface plasmon coding unit and surface plasmon coding chip - Google Patents
Surface plasmon coding unit and surface plasmon coding chip Download PDFInfo
- Publication number
- CN109473125B CN109473125B CN201811277032.0A CN201811277032A CN109473125B CN 109473125 B CN109473125 B CN 109473125B CN 201811277032 A CN201811277032 A CN 201811277032A CN 109473125 B CN109473125 B CN 109473125B
- Authority
- CN
- China
- Prior art keywords
- slit
- surface plasmon
- coding
- encoding
- signal receiving
- 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.)
- Expired - Fee Related
Links
- 229910052751 metal Inorganic materials 0.000 claims abstract description 50
- 239000002184 metal Substances 0.000 claims abstract description 50
- 239000000758 substrate Substances 0.000 claims abstract description 21
- 239000000463 material Substances 0.000 claims description 12
- 230000001902 propagating effect Effects 0.000 claims description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical group O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical group [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 7
- 229910052737 gold Inorganic materials 0.000 claims description 7
- 239000010931 gold Substances 0.000 claims description 7
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 229910052709 silver Inorganic materials 0.000 claims description 6
- 239000004332 silver Substances 0.000 claims description 6
- ORUIBWPALBXDOA-UHFFFAOYSA-L magnesium fluoride Chemical compound [F-].[F-].[Mg+2] ORUIBWPALBXDOA-UHFFFAOYSA-L 0.000 claims description 3
- 229910001635 magnesium fluoride Inorganic materials 0.000 claims description 3
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims 1
- 238000003860 storage Methods 0.000 abstract description 26
- 230000003287 optical effect Effects 0.000 description 17
- 230000001066 destructive effect Effects 0.000 description 9
- 238000000429 assembly Methods 0.000 description 6
- 230000000712 assembly Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000000313 electron-beam-induced deposition Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/0065—Recording, reproducing or erasing by using optical interference patterns, e.g. holograms
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
- G11B7/00772—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track on record carriers storing information in the form of optical interference patterns, e.g. holograms
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
- H03M7/001—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits characterised by the elements used
- H03M7/008—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits characterised by the elements used using opto-electronic devices
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Optical Integrated Circuits (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The invention discloses a surface plasmon coding unit and a surface plasmon coding chip. The surface plasmon encoding unit includes: the device comprises a transparent substrate and a metal layer arranged on one side of the transparent substrate; the metal layer comprises at least two groups of coding components; each encoding component comprises an encoding signal generating element, and the encoding signal generating element comprises a first slit and a second slit; each coding assembly further comprises a first coding signal receiving element and a second coding signal receiving element positioned on both sides of the coding signal generating element; each first coded signal receiving element and each second coded signal receiving element comprise a group of grating structures, and each group of grating structures comprises at least two grooves; an included angle between the extending direction of the groove and the extending direction of the first slit is not equal to 90 degrees, and the depth of the groove is smaller than the thickness of the metal layer. The surface plasmon coding unit provided by the embodiment can realize larger storage density.
Description
Technical Field
The embodiment of the invention relates to the technical field of optical storage, in particular to a surface plasmon coding unit and a surface plasmon coding chip.
Background
At present, along with digitization of information resources and rapid increase of information volume, a memory having a high storage density and a large storage capacity is increasingly favored by users. The optical storage technology has the advantages of high storage density, long storage life, high signal-to-noise ratio of information, low price of information bits and the like, and has a huge development prospect.
However, for conventional digital optical storage devices, such as optical discs and the like, light waves are generally used as information carriers, which makes the geometric size of the optical storage device limited by the diffraction limit of light, which is not favorable for further increasing the storage density of the optical storage device. In addition, one storage unit of the optical disc can hold only one binary information (0 or 1). This constraint makes it difficult for conventional digital optical storage to meet the demand for larger data storage.
Disclosure of Invention
The invention provides a surface plasmon coding unit and a surface plasmon coding chip, which are used for improving the storage density and the storage capacity of an optical storage technology.
In a first aspect, an embodiment of the present invention provides a surface plasmon encoding unit, including: the device comprises a transparent substrate and a metal layer arranged on one side of the transparent substrate;
the metal layer comprises at least two groups of coding components;
each coding component comprises a coding signal generating element, and the coding signal generating element comprises a first slit and a second slit which extend in the same direction; the size of the first slit is larger than that of the second slit along the direction perpendicular to the extending direction of the first slit; the first slit and the second slit penetrate through the metal layer;
each coding assembly further comprises a first coding signal receiving element and a second coding signal receiving element which are positioned on two sides of the coding signal generating element along the extending direction which is perpendicular to the first slit;
each of the first encoded signal receiving elements and each of the second encoded signal receiving elements comprises a set of grating structures, each set of grating structures comprising at least two grooves; an included angle between the extending direction of the groove and the extending direction of the first slit is not equal to 90 degrees, and the depth of the groove is smaller than the thickness of the metal layer.
Further, along a direction perpendicular to the extending direction of the first slit, the geometric centers of the code signal generating element, the first code signal receiving element and the second code signal receiving element in the same code assembly are located on the same straight line.
Furthermore, the metal layer comprises two groups of coding components, namely a first coding component and a second coding component;
along the extension direction of the first slit, the geometric center of the first slit of the first coding assembly is aligned with the geometric center of the second slit of the second coding assembly and the geometric center of the second slit of the first coding assembly is aligned with the geometric center of the first slit of the second coding assembly;
along the extending direction of the first slit, the geometric center of the first code signal receiving element of the first code assembly is aligned with the geometric center of the first code signal receiving element of the second code assembly and the geometric center of the second code signal receiving element of the first code assembly is aligned with the geometric center of the second code signal receiving element of the second code assembly.
Further, perpendicular to the extending direction of the first slit, the distance between the center of the first slit and the center of the second slit satisfies:
wherein d is a distance between a center of the first slit and a center of the second slit; m and j are non-negative integers; k is a radical ofsppIs a wave vector of plasmon propagating on the surface of the metal layer, and
k0is the corresponding wave vector of the incident light in vacuum,
λ0is the wavelength of the incident light in vacuum,mis the dielectric constant of the metal layer or layers,dis the dielectric constant of air.
Further, the extending direction of the grooves of each group of the grating structures is parallel to the extending direction of the first slits.
Further, the grating period d of the grating structuregSatisfies the following conditions:
further, along the extending direction perpendicular to the first slit, the widths of the first slit and the second slit are both smaller than 1/2 of the wavelength of the incident light.
Further, the width of the first slit and the width of the second slit are both greater than or equal to 50nm in a direction perpendicular to the extension direction of the first slit.
Further, along the extending direction of the first slit, the lengths of the first slit and the second slit are the same, and the length of the first slit and the length of the second slit are both greater than or equal to 0.5 μm and less than or equal to 10 μm.
Further, the material of the transparent substrate is silicon dioxide, aluminum oxide or magnesium fluoride.
Further, the metal layer is made of gold, silver or aluminum.
Further, the thickness of the metal layer is greater than or equal to 100nm and less than or equal to 450 nm.
Further, along the extension direction perpendicular to the first slit, the cross section of the groove is rectangular or circular.
In a second aspect, an embodiment of the present invention further provides a surface plasmon coding chip, including a plurality of surface plasmon coding units according to any one of the first aspects.
According to the surface plasmon coding unit provided by the embodiment of the invention, at least two groups of coding assemblies are arranged, each group of coding assemblies can store one group of binary information, the first coding signal receiving element and the second coding signal receiving element of each coding assembly can generate different coding information by changing the angle of incident light, and the two groups of coding assemblies can realize larger storage density. By arranging the first slit and the second slit which are different in width, each coding assembly can be guaranteed to generate complete destructive interference, and partial surface plasmon residual still exists after the destructive interference of the surface plasmon generated by the first slit and the second slit is avoided.
Drawings
FIG. 1 is a top view of a surface plasmon encoding unit provided by an embodiment of the invention;
FIG. 2 is a top view of another surface plasmon encoding unit provided by embodiments of the present invention;
FIG. 3 is a top view of another surface plasmon encoding unit provided by an embodiment of the present invention;
FIG. 4 is a cross-sectional view taken along AA' of FIG. 1;
FIG. 5 is a top view of still another surface plasmon encoding unit provided in an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a first slit and a second slit provided in an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In particular, Surface Plasmon Polaritons (SPPs) are considered as potential next-generation optical information carriers due to their excellent sub-wavelength scale electric field confinement and electric field enhancement effects. By utilizing the principle of surface plasmons, a plasmon coding unit can be prepared, and the plasmon coding unit can be used for information storage, optical communication and the like. When the plasmon encoding unit is used for information storage, the plasmon encoding unit stores binary information 0 when incident light is at a certain angle, and the plasmon encoding unit may store binary information 1 by changing the incident angle of the incident light. The plasmon coding unit is prepared by utilizing the principle of surface plasmon, so that an optical storage chip with smaller geometric dimension can be obtained, and the integration density of the optical storage chip can be improved. And, through angle multiplexing of incident light, each surface plasmon encoding unit thereof can be made to store two binary information at the same time.
In view of the above, the present embodiment provides a surface plasmon encoding unit, which can encode information according to the principle of surface plasmon.
Fig. 1 is a top view of a surface plasmon coding unit according to an embodiment of the present invention, fig. 2 is a top view of another surface plasmon coding unit according to an embodiment of the present invention, fig. 3 is a top view of still another surface plasmon coding unit according to an embodiment of the present invention, and fig. 4 is a cross-sectional view of fig. 1 along direction AA'. Specifically, referring to fig. 1 to 4, the surface plasmon encoding unit provided in this embodiment includes: a transparent substrate 20 and a metal layer 10 disposed on one side of the transparent substrate 20; the metal layer 10 comprises at least two groups of coding components 11; each encoding component 11 comprises an encoding signal generating element 12, and the encoding signal generating element 12 comprises a first slit 121 and a second slit 122 which extend in the same direction; the dimension of the first slit 121 is greater than the dimension of the second slit 122 in a direction Z perpendicular to the extension direction of the first slit 121; the first slit 121 and the second slit 122 penetrate through the metal layer 10; in the direction Z perpendicular to the extension direction of the first slit 121, each encoding component 11 further includes a first encoded signal receiving element 13 and a second encoded signal receiving element 14 located on both sides of the encoded signal generating element 12; each first coded signal receiving element 13 and each second coded signal receiving element 14 comprises a set of grating structures, each set of grating structures comprising at least two grooves 150; an included angle between the extending direction of the groove 150 and the extending direction Z of the first slit 121 is not equal to 90 °, and the depth of the groove 150 is smaller than the thickness of the metal layer 10.
The surface plasmon encoding unit provided by the present embodiment includes at least two sets of encoding components 11, each set of encoding components 11 includes a first slit 121 and a second slit 122, and when light is incident from a side of the transparent substrate 20 away from the metal layer 10, both the first slit 121 and the second slit 122 can generate a surface plasmon propagating in a direction Z perpendicular to the extending direction of the first slit 121. Since first encoded signal receiving element 13 and second encoded signal receiving element 14 are located on both sides of encoded signal generating element 12, both the surface plasmon generated by first slit 121 and the surface plasmon generated by second slit 122 may propagate in the direction of first encoded signal receiving element 13, and may also propagate in the direction of second encoded signal generating element 14. Therefore, by appropriately controlling the incident light, it is possible to cause each of the first and second encoded signal receiving elements 13 and 14 to receive a surface plasmon signal and convert the received surface plasmon into diffracted light, the propagation direction of which is perpendicular to the surface of the metal layer 10 and away from the transparent substrate. The diffracted light can be received by a diffracted light receiving element near the first encoded signal receiving element 13 or the second encoded signal receiving element 14, thereby realizing optical information encoding.
The surface plasmons generated due to the first slit 121 and the second slit 122 may interfere. By controlling the incident angle of the incident light, the surface plasmons generated by the first slit 121 and the surface plasmons generated by the second slit 122 can be caused to destructively or constructively interfere. Illustratively, if destructive interference occurs when the surface plasmons generated by the first slit 121 and the second slit 122 propagate in the direction of the first encoded signal generating element 13, the encoded component 11 cannot generate surface plasmons in the direction, the first encoded signal generating element 13 cannot receive the surface plasmons, and the encoded information generated by the first encoded signal generating element 13 is 0. If the surface plasmons generated by the first slit 121 and the second slit 122 do not destructively interfere when propagating in the direction of the second encoded signal generating element 14, the encoding component 11 may generate the surface plasmons in the direction, the second encoded signal generating element 14 may receive the surface plasmons, and the encoded information generated by the second encoded signal receiving element 14 is 1. Therefore, by controlling the angle of the incident light, it is possible to control whether the surface plasmon generated by the first slit 121 and the surface plasmon generated by the second slit 122 destructively interfere with each other, thereby controlling the encoding condition of each encoding component 11.
Further, when the surface plasmon propagates on the surface of the metal layer 10, the intensity is attenuated. If the widths of the first slit 121 and the second slit 122 in the direction perpendicular to the first slit 121 are equal, in a normal case, when two surface plasmons from two first slits 121 and two surface plasmons from the second slit 122 reach the same position on the metal layer 10, the surface plasmons generated by the first slit 121 and the surface plasmons generated by the second slit 122 are attenuated to different degrees and have different amplitudes. When the surface plasmon generated by the first slit 121 and the surface plasmon generated by the second slit 122 destructively interfere with each other, signals of the two surface plasmons cannot be completely cancelled, and after the two surface plasmons with different amplitudes destructively interfere with each other, the surface plasmon still with a certain intensity will be kept to continuously propagate to the first encoding signal receiving element 13 or the second encoding signal receiving element 14, so as to generate interference on normal information encoding. Therefore, by providing the first slit 121 and the second slit 122 having different widths, it can be ensured that the surface plasmons generated by the two slits can generate complete destructive interference.
It should be noted that fig. 1-3 each illustrate the structure and function of the surface plasmon coding unit by taking two sets of coding assemblies as an example. However, it should be noted that the surface plasmon encoding unit provided in the present embodiment may also include three or more encoding components 11. Also, fig. 1 to 3 only exemplarily show three possible positional relationships between the encoding components 11, but it should be understood that this does not constitute a limitation to the structure of the surface plasmon encoding unit of the present application.
Since each encoding component 11 can store one set of binary information, the surface plasmon encoding unit provided in the present embodiment of fig. 1 to 3 can store two sets of encoded information, and thus the surface plasmon encoding unit provided in the present embodiment can have a large storage capacity. When the surface plasmon encoding unit provided by the present embodiment includes three or more encoding components 11, the surface plasmon encoding unit can have a larger storage capacity.
The surface plasmon coding unit provided by this embodiment, by setting at least two sets of coding assemblies, each set of coding assembly can store a set of binary information, by changing the angle of incident light, the first coding signal receiving element and the second coding signal receiving element of each coding assembly can generate different coding information, and the two sets of coding assemblies can realize a larger storage density. By arranging the first slit and the second slit which are different in width, each coding assembly can be guaranteed to generate complete destructive interference, and partial surface plasmon residual still exists after the destructive interference of the surface plasmon generated by the first slit and the second slit is avoided.
Alternatively, the geometric centers of the code signal generating element 12, the first code signal receiving element 13 and the second code signal receiving element 14 in the same code assembly 11 are located on the same straight line in the direction perpendicular to the extending direction of the first slit 121. Specifically, such an arrangement can ensure that the surface plasmon generated near the geometric center position of first code generating element 12 can be transmitted to near the geometric center position of first code signal receiving element 13 and/or second code signal receiving element 14. When the surface plasmon is transmitted to the first encoded signal receiving element 13 or the second encoded signal receiving element 14, it can be ensured that the surface plasmon received by the first encoded signal receiving element 13 or the second encoded signal receiving element 14 has a large intensity.
Fig. 5 is a top view of still another surface plasmon encoding unit according to an embodiment of the present invention. Optionally, referring to fig. 5, the metal layer includes two sets of encoding components, namely a first encoding component 111 and a second encoding component 112; along the extending direction Z perpendicular to the first slit 121, the first slit 121 and the second slit 122 of the first encoding component 111 are aligned with the second slit 122 and the first slit 121 of the second encoding component 112, respectively; along a direction perpendicular to the extending direction of the first slit 121, the first and second coded signal receiving elements 13 and 14 of the first coding component 111 are aligned with the first and second coded signal receiving elements 13 and 14 of the second coding component 112, respectively.
Specifically, still taking the surface plasmon coding unit including two sets of coding components as an example, when the surface plasmon coding unit is irradiated with the same light beam, the incident angles of the light beams received by the first coding component 111 and the second coding component 112 are the same, and since the positions of the two slits in the first coding component 111 and the second coding component 112 are set differently, the first coding component 111 and the second coding component 112 can generate different coding information. In the case that the first slit 121 in the first encoding component 111 is aligned with the second slit 122 in the second encoding component 112, by aligning the first encoding signal receiving element 13 of the first encoding component 111 with the first encoding signal receiving element 13 of the second encoding component 112, it can be ensured that the distance between the first slit 121 of the first encoding component 111 and the first encoding signal receiving element 13 of the first encoding component 111 is equal to the distance between the second slit 122 of the second encoding component 112 and the first encoding signal receiving element 13 of the second encoding component 112. When the same light beam is incident, the intensities of the surface plasmons received by the first encoded signal receiving element 13 of the first encoding element 111 and the first encoded signal receiving element 13 of the second encoding element 112 can be made substantially equal. Similarly, in the case that the second slit 122 of the first encoding component 111 is aligned with the first slit 121 of the second encoding component 112, by aligning the second encoded signal receiving element 14 of the first encoding component 111 with the second encoded signal receiving element 14 of the second encoding component 112, it can be ensured that the distance between the second slit 122 of the first encoding component 111 and the second encoded signal receiving element 14 of the first encoding component 111 is equal to the distance between the first slit 121 of the second encoding component 112 and the second encoded signal receiving element 14 of the second encoding component 112. When the same light beam is incident, the intensities of the surface plasmons received by the second encoded signal receiving element 14 of the first encoding component 111 and the second encoded signal receiving element 14 of the second encoding component 112 can be made substantially the same.
Alternatively, the material of the transparent substrate 20 in fig. 5 is selected to be quartz, the material of the metal layer 10 is selected to be gold, and the thickness of the metal layer 10 is set to be 230 nm. Along the extending direction Z perpendicular to the first slit 121, the width of the first encoding signal receiving element 13 is set to be 90nm, and the width of the second encoding signal receiving element 14 is set to be 150 nm; the depths of the first slit 121 and the second slit 122 are each set to 230nm, and the distance between the first slit 121 and the second slit 122 is set to 757 nm. The lengths of the first slit 121 and the second slit 122 in the extending direction Z of the first slit 121 are set to 10 μm. The grating structures of the first and second code signal receiving elements 13 and 14 are each set to 606nm in period, 50nm in depth, and 10 μm in length in the direction perpendicular to the extending direction of the first slit 121. By selecting incident light with vacuum wavelength of 633nm and changing the incident angle of the incident light, different coded information can be obtained.
Illustratively, when the angle of the incident light is 26 °, the surface plasmons generated by the first slit 121 and the second slit 122 of the first encoding component 111 and transmitted toward the first encoding signal receiving component 13 of the first encoding component 111 may constructively interfere, and thus, the first encoding component 111 may generate the surface plasmons transmitted toward the first encoding signal receiving component 13 of the first encoding component 111. The surface plasmons generated by first slit 121 and second slit 122 of first encoding component 111 and propagating towards second encoding signal receiving component 14 of second encoding component 112 may destructively interfere, and thus, the surface plasmons generated by first encoding component 111 and propagating towards second encoding signal receiving component 14 of first encoding component 111 may not be generated. Therefore, the first encoding signal receiving component 13 of the first encoding component 111 can generate the encoding signal 1 upon receiving the surface plasmon; since the second encoded signal receiving element 14 of the first encoding component 111 cannot receive the surface plasmons, the second encoded signal receiving element 14 of the first encoding component 111 generates an encoded signal 0. Similarly, the surface plasmons generated by the first slit 121 and the second slit 122 of the second encoding component 112 and transmitted toward the first encoding signal receiving component 13 of the second encoding component 112 can generate destructive interference, and therefore, the second encoding component 112 does not generate surface plasmons transmitted toward the first encoding signal receiving component 13 of the second encoding component 112. Thus, the first encoded signal receiving element 13 of the second encoding component 112 generates an encoded signal 0. The first slit 121 and the second slit 122 of the second encoding component 112 may generate constructive interference of surface plasmons transmitted toward the second encoded signal receiving component 14 of the second encoding component 112, and the second encoding component 112 may generate surface plasmons transmitted toward the second encoded signal receiving component 14 of the second encoding component 112. Accordingly, the second encoded signal receiving component 14 of the second encoding component 112 may generate the encoded signal 1 upon receiving the surface plasmons. Therefore, when the angle of incident light is 26 °, the surface plasmon encoding unit can generate encoded information of binary "1001".
When the angle of the incident light is 16 °, according to a similar principle, the first encoded signal receiving element 13 of the first encoding component 111, the first encoded signal receiving element 13 of the second encoding component 112, and the second encoded signal receiving element 14 of the second encoding component 112 can be made to generate the encoded signal 1, and the second encoded signal receiving element 14 of the first encoding component 111 can be made to generate the encoded signal 0. Therefore, when the angle of incident light is 16 °, the surface plasmon encoding unit can generate encoded information of binary "1011".
When the angle of the incident light is 36.8 °, according to a similar principle, the first encoded signal receiving element 13 of the first encoding component 111, the second encoded signal receiving element 14 of the first encoding component 111, and the second encoded signal receiving element 14 of the second encoding component 112 can be made to generate the encoded signal 1, and the first encoded signal receiving element 13 of the second encoding component 112 can be made to generate the encoded signal 0. Therefore, when the angle of incident light is 16 °, the surface plasmon encoding unit can generate encoded information of binary "1101".
When the angle of the incident light is 13 °, according to a similar principle, the first encoded signal receiving element 13 of the first encoding component 111, the second encoded signal receiving element 14 of the first encoding component 111, the first encoded signal receiving element 13 of the second encoding component 112, and the second encoded signal receiving element 14 of the second encoding component 112 can be made to simultaneously generate the encoded signal 1. Therefore, when the angle of incident light is 13 °, the entire surface plasmon encoding unit can generate encoded information of binary "1111".
It can be understood that the 4 kinds of encoded information described above are only part of the encoding function of the surface plasmon encoding unit provided by the present embodiment; the surface plasmon encoding unit may also generate other encoded information if the angle of the incident light is further changed. It should be noted that, in the above embodiment, 4 kinds of incident lights with different angles are listed, and when the coded signal 1 is generated, the first coded signal receiving element 13 and the second coded signal receiving element 14 both receive surface plasmons where constructive interference occurs, and by providing a device with such a structure, the first coded signal receiving element 13 and the second coded signal receiving element 14 both can receive surface plasmons with relatively large intensity, thereby ensuring the coding quality. It should be understood that, in general, when the surface plasmons generated by the first slit 121 and the second slit 122 do not completely destructively interfere, the first encoding signal receiving element 13 or the second encoding signal receiving element 14 may also receive the surface plasmons with a certain intensity, thereby obtaining the encoding signal 1; however, the intensity of the surface plasmon at this time is relatively weak, which is disadvantageous for improving the encoding quality.
Fig. 6 is a schematic structural diagram of a first slit and a second slit provided in an embodiment of the present invention. Alternatively, referring to fig. 6, perpendicular to the extending direction Z of the first slit 121, a distance between the center of the first slit 121 and the center of the second slit 122 satisfies:
where d is the distance between the center of the first slit 121 and the center of the second slit 122; m and j are non-negative integers; k is a radical ofsppIs a wave vector of surface plasmon propagating on the surface of the metal layer, and
k0is the corresponding wave vector of the incident light in vacuum,
λ0is the wavelength of the incident light in vacuum,mis the dielectric constant of the metal layer or layers,dis the dielectric constant of air.
Specifically, when m and j are both non-negative integers, (2m +2j +1) π is an odd multiple of π, and k issppIs determined by the wave vector k of the incident light in the vacuum correspondence0Material of metal layermAnd dielectric constant of airdIn setting the distance between the center of the first slit 121 and the center of the second slit 122, the above-described factors may be referred to.
Optionally, with continued reference to fig. 1, the extending direction of the grooves 150 of each group of grating structures is parallel to the extending direction Z of the first slits 121. Specifically, when the extending direction of the groove 150 is parallel to the extending direction Z of the first slit 121, the transmission direction of the surface plasmon is perpendicular to the extending direction of the groove 150, and when the surface plasmons constructively interfere, the surface plasmon having the maximum intensity is received by the first encoded signal receiving component 13 or the second encoded signal receiving element 14.
Optionally, the grating period d of the grating structuregSatisfies the following conditions:
specifically, when the period of the grating structure satisfies the above relationship, the length of the period of the grating structure is generally equal to the wavelength of the surface plasmon, and therefore, the wave vector matching condition can be satisfied, so that the surface plasmon can be efficiently converted into diffracted light and output when propagating to the grating structure, the propagation direction of the diffracted light is perpendicular to the metal layer 10, and the diffracted light propagates in a direction away from the transparent substrate 20. Grating period dgThe value of (b) is related to the wave vector of the surface plasmon propagating on the surface of the metal layer. Note that, in order to maintain the receiving effect of the grating structure on the surface plasmon, the minimum distance between two adjacent grooves 150 may be set to be greater than or equal to 50 nm.
Optionally, the widths of the first slit 121 and the second slit 122 are smaller than 1/2 of the wavelength of the incident light along the extending direction Z perpendicular to the first slit. Illustratively, under the influence of diffraction limit, for the first slit 121 and the second slit 122 in the same encoding component 11, if the width of the first slit 121 exceeds 1/2 of the wavelength of the incident light, the loss of the surface plasmon from the second slit 122 when passing through the upper surface of the first slit 121 may be very large, even resulting in the failure of the encoding component 11 to operate normally.
Optionally, the widths of the first slit 121 and the second slit 122 are both greater than or equal to 50nm in the direction Z perpendicular to the extension direction of the first slit 121.
Specifically, the distance between the center of the first slit 121 and the center of the second slit 122 is ensured to satisfy
In the case of (1), the width of the first slit 121 is set to be larger than or equal toEqual to 50nm, and the width of the second slit 122 is made smaller than that of the first slit 121, so that when the surface plasmons of the metal layer 10 are excited by ultraviolet light, visible light, and infrared light, the diffraction limit can be avoided. In addition, if the wavelength of incident light is relatively large, the widths of the first slit 121 and the second slit 122 may be increased accordingly to improve the signal intensity of the surface plasmon. Illustratively, if the wavelength of the incident light is 195nm, the width of the first slit 121 may be selected to be 80nm, and the width of the second slit 122 may be made smaller than the width of the first slit 121. If the wavelength of the incident light is infrared light of 1000nm, the width of the first slit 121 may be selected to be 400nm to obtain a surface plasmon having a relatively large signal intensity.
Optionally, the lengths of the first slit 121 and the second slit 122 are the same along the extending direction Z of the first slit 121, and both the first slit 121 and the second slit 122 are greater than or equal to 0.5 μm and less than or equal to 10 μm. In general, in the extending direction Z of the first slit 121, when the lengths of the first slit 121 and the second slit 122 are large, the intensity of the surface plasmon that can be generated is large. Under the condition of meeting the requirement of the surface plasmon intensity, the length value of the second slit 122 can be comprehensively considered according to the factors such as the size of the surface plasmon encoding unit. It is understood that the length values of the first slit 121 and the second slit 122 provided in this embodiment are only preferred embodiments, and are not limited to the length values of the first slit 121 and the second slit 122.
Alternatively, if the light transmittance of the transparent substrate 20 is too low, the attenuation of light in the transparent substrate 20 is severe, and the incident light cannot even reach the surface of the metal layer 10 through the transparent substrate 20; if the optical transmittance of the transparent substrate 20 is too high, the intensity of the generated surface plasmon is too large to be useful for practical use, and the intensity of the light wave reaching the surface of the metal layer 20 can be controlled by selecting an appropriate optical signal attenuator. In the case where the light transmittance is satisfied, the present embodiment does not specifically limit the material selection of the transparent substrate 20. Alternatively, the material of the transparent substrate 20 is silicon dioxide, aluminum oxide, magnesium fluoride, or the like; by selecting the above three materials as the transparent substrate 20, the intensity of the light wave reaching the surface of the metal layer 10 can be made within a relatively desirable range without using an optical signal attenuator.
Optionally, the material of the metal layer 10 is gold, silver or aluminum. In particular, light can relatively easily excite surface plasmons on the surface of gold, silver or aluminum to realize information encoding. In general, gold, silver, or aluminum can generate surface plasmons under irradiation of ultraviolet light, visible light, and infrared light, and is a relatively excellent excitation material for surface plasmons.
Alternatively, when the material of the metal layer 10 is gold, silver or aluminum, electron beam deposition or magnetron sputtering deposition may be selected to prepare the metal layer 10. When the first slit 121, the second slit 122, and the groove 150 are formed in the metal layer 10, a focused ion beam process, an electron beam exposure process, or a dry etching process may be selected, or a combination of a plurality of processes may be simultaneously selected.
Optionally, the thickness of the metal layer is greater than or equal to 100nm and less than or equal to 450 nm. Specifically, if the thickness of the metal layer 10 is too small, the difficulty in preparing the groove 150 having a certain depth is large, and the groove 150 is likely to penetrate through the metal layer 10; if the thickness of the metal layer 10 is too large, the intensity of the surface plasmon generated on the surface of the metal layer is correspondingly reduced, the intensity of the required incident light is large, and when the incident light is formed by excitation, energy is consumed, which is not favorable for saving cost.
Alternatively, referring to fig. 4, the cross section of the groove 150 is rectangular or circular along the direction perpendicular to the extending direction of the first slit 121. Specifically, fig. 4 illustrates a groove 150 having a rectangular cross section, where the groove 150 having a rectangular or circular cross section has a strong ability to receive surface plasmons, and can generate diffracted light with a large intensity, so as to obtain a relatively reliable encoding result. It should be noted that, in the case of meeting the coding requirement, the shape of the cross section of the groove 150 is not particularly required in this embodiment, and the groove 150 may have other shapes.
Based on the same inventive concept, the embodiment also provides a plasmon encoding chip, which comprises a plurality of surface plasmon encoding units described in any of the above embodiments. Alternatively, a plurality of surface plasmon coding units can be connected in series or in parallel to achieve a larger amount of information storage.
The surface plasmon coding chip provided by this embodiment, by setting at least two sets of coding components on each surface plasmon coding unit, each set of coding components can store one set of binary information, by changing the angle of incident light, the first coding signal receiving element and the second coding signal receiving element of each coding component can generate different coding information, and the two sets of coding components can realize larger storage density. By arranging the first slit and the second slit which are different in width, each coding assembly can be guaranteed to generate complete destructive interference, and partial surface plasmon residual still exists after the destructive interference of the surface plasmon generated by the first slit and the second slit is avoided.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (14)
1. A surface plasmon encoding unit, comprising: the device comprises a transparent substrate and a metal layer arranged on one side of the transparent substrate;
the metal layer comprises at least two groups of coding components;
each coding component comprises a coding signal generating element, and the coding signal generating element comprises a first slit and a second slit which extend in the same direction; the size of the first slit is larger than that of the second slit along the direction perpendicular to the extending direction of the first slit; the first slit and the second slit penetrate through the metal layer;
each coding assembly further comprises a first coding signal receiving element and a second coding signal receiving element which are positioned on two sides of the coding signal generating element along the extending direction which is perpendicular to the first slit;
each of the first encoded signal receiving elements and each of the second encoded signal receiving elements comprises a set of grating structures, each set of grating structures comprising at least two grooves; an included angle between the extending direction of the groove and the extending direction of the first slit is not equal to 90 degrees, and the depth of the groove is smaller than the thickness of the metal layer.
2. The surface plasmon encoding unit of claim 1, wherein the geometric centers of said encoding signal generating element, said first encoding signal receiving element and said second encoding signal receiving element in the same encoding assembly are located on the same straight line along a direction perpendicular to the extension direction of said first slit.
3. The surface plasmon encoding unit of claim 1, wherein the metal layer comprises two sets of encoding components, a first encoding component and a second encoding component respectively;
along the extension direction of the first slit, the geometric center of the first slit of the first coding assembly is aligned with the geometric center of the second slit of the second coding assembly and the geometric center of the second slit of the first coding assembly is aligned with the geometric center of the first slit of the second coding assembly;
along the extending direction of the first slit, the geometric center of the first code signal receiving element of the first code assembly is aligned with the geometric center of the first code signal receiving element of the second code assembly and the geometric center of the second code signal receiving element of the first code assembly is aligned with the geometric center of the second code signal receiving element of the second code assembly.
4. The surface plasmon encoding unit of claim 1, wherein, perpendicular to the direction of extension of the first slit, the distance between the center of the first slit and the center of the second slit satisfies:
wherein d is a distance between a center of the first slit and a center of the second slit; m and j are non-negative integers; k is a radical ofsppIs a wave vector of plasmon propagating on the surface of the metal layer, and
k0is the corresponding wave vector of the incident light in vacuum,
λ0is the wavelength of the incident light in vacuum,mis the dielectric constant of the metal layer or layers,dis the dielectric constant of air.
5. The surface plasmon encoding unit of claim 1 wherein the grooves of each set of said grating structures all extend parallel to the direction of extension of said first slit.
6. The surface plasmon encoding unit of claim 5, wherein the grating period d of said grating structuregSatisfies the following conditions:
7. the surface plasmon encoding unit of claim 1, wherein the width of each of said first slit and said second slit, in a direction perpendicular to the extension of said first slit, is less than 1/2 of the wavelength of the incident light.
8. The surface plasmon encoding unit of claim 1, wherein the width of each of the first and second slits in a direction perpendicular to the extension direction of the first slit is greater than or equal to 50 nm.
9. The surface plasmon encoding unit of claim 1, wherein the length of the first slit and the length of the second slit are the same along the extension direction of the first slit, and wherein the length of the first slit and the length of the second slit are both greater than or equal to 0.5 μ ι η and less than or equal to 10 μ ι η.
10. The surface plasmon encoding unit of claim 1, wherein the material of said transparent substrate is silica, alumina or magnesium fluoride.
11. The surface plasmon encoding unit of claim 1, wherein the material of the metal layer is gold, silver, or aluminum.
12. The surface plasmon encoding unit of claim 1, wherein the metal layer has a thickness greater than or equal to 100nm and less than or equal to 450 nm.
13. The surface plasmon encoding unit of claim 3, wherein the cross section of said groove is rectangular or circular in a direction perpendicular to the extension direction of said first slit.
14. A plasmon encoding chip comprising a plurality of surface plasmon encoding units according to any of claims 1-13.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811277032.0A CN109473125B (en) | 2018-10-30 | 2018-10-30 | Surface plasmon coding unit and surface plasmon coding chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811277032.0A CN109473125B (en) | 2018-10-30 | 2018-10-30 | Surface plasmon coding unit and surface plasmon coding chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109473125A CN109473125A (en) | 2019-03-15 |
| CN109473125B true CN109473125B (en) | 2020-08-04 |
Family
ID=65666671
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811277032.0A Expired - Fee Related CN109473125B (en) | 2018-10-30 | 2018-10-30 | Surface plasmon coding unit and surface plasmon coding chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109473125B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110031924B (en) * | 2019-04-28 | 2021-07-23 | 长春理工大学 | Method and system for realizing tunable surface plasmon frequency division |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0318808D0 (en) * | 2003-08-11 | 2003-09-10 | Toshiba Res Europ Ltd | An encoded carrier |
| CN101256246A (en) * | 2008-03-31 | 2008-09-03 | 浙江大学 | Miniature array spectral filter based on metallic surface plasma excimer |
| CN101858998B (en) * | 2010-05-14 | 2013-03-27 | 重庆文理学院 | Micro-nano structure for enhancing nano slit transmission efficiency |
| CN106443850A (en) * | 2016-09-20 | 2017-02-22 | 上海理工大学 | One-dimensional superstructure terahertz CDMA (code division multiple access) system time domain encoder and decoder |
| CN106450625B (en) * | 2016-10-10 | 2019-07-26 | 东南大学 | A kind of artificial surface phasmon wave regulation device of Programmable Design |
| CN108199782B (en) * | 2018-02-27 | 2021-01-05 | 桂林电子科技大学 | Transmission type terahertz wave encoder and encoding system based on plasma device |
-
2018
- 2018-10-30 CN CN201811277032.0A patent/CN109473125B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN109473125A (en) | 2019-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20050237602A1 (en) | Light amplification element, light amplification apparatus and light amplification system | |
| Martinez et al. | Experimental and theoretical analysis of the self-focusing of light by a photonic crystal lens | |
| US7492804B2 (en) | Near-field light emitting device and data recording/reproduction apparatus | |
| US8238025B2 (en) | Diffractive polarizing mirror device | |
| JP2006350232A (en) | Optical material, optical element using the same, and method for manufacturing the element | |
| US8357980B2 (en) | Plasmonic high-speed devices for enhancing the performance of microelectronic devices | |
| CN114153029B (en) | Grating structure based on continuous domain constraint state | |
| CN109473125B (en) | Surface plasmon coding unit and surface plasmon coding chip | |
| Vytovtov et al. | Optical switching cell based on metamaterials and ferrite films | |
| JP6521289B2 (en) | Retardation plate in which asymmetric openings are periodically arranged in metal film | |
| Croënne et al. | Bloch impedance in negative index photonic crystals | |
| US20140321805A1 (en) | Ultra-flat plasmonic optical horn antenna | |
| D’Aguanno et al. | Second-harmonic generation at angular incidence in a negative-positive index photonic band-gap structure | |
| Wang et al. | Enhancement of the efficiency based on a sandwiched grating for separating polarized beams | |
| WO2023134248A1 (en) | Multifunctional efficient beam splitter based on metastructure grating | |
| Romanova et al. | Effect of dimensionality on the spectra of hybrid plasmonic-photonic crystals | |
| US20210271148A1 (en) | High-Efficiency End-Fire 3D Optical Phased Array Based On Multi-Layer Platform | |
| Sugaya et al. | Gain enhancement of optical leaky wave antenna excited by parabolic reflector with photonic crystal | |
| Bo et al. | Multilayered high-directional waveguide grating antenna based on interleaved etching for optical phased arrays | |
| CN115267970B (en) | Photon spin directional coupler | |
| Kwong | High system performance with plasmonic waveguides and functional devices | |
| JP2001174659A (en) | Mode separating method and mode separator | |
| Dubey et al. | Photonic bandgap analysis in 1D porous silicon photonic crystals using transfer matrix method | |
| JP4530254B2 (en) | Plasmon mode optical waveguide | |
| Ponizovskaya et al. | Metallic negative index nanostructures at optical frequencies: losses and effect of gain medium |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200804 |