CN113655644A - Electro-optical modulator - Google Patents
Electro-optical modulator Download PDFInfo
- Publication number
- CN113655644A CN113655644A CN202110796025.7A CN202110796025A CN113655644A CN 113655644 A CN113655644 A CN 113655644A CN 202110796025 A CN202110796025 A CN 202110796025A CN 113655644 A CN113655644 A CN 113655644A
- Authority
- CN
- China
- Prior art keywords
- electro
- electrode
- slit
- optical
- graphene layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 99
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 91
- 229910021389 graphene Inorganic materials 0.000 claims abstract description 91
- 239000000758 substrate Substances 0.000 claims abstract description 37
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 11
- 229910052710 silicon Inorganic materials 0.000 claims description 11
- 239000010703 silicon Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- 235000012239 silicon dioxide Nutrition 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 claims description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims 1
- 230000003993 interaction Effects 0.000 abstract description 8
- 238000004519 manufacturing process Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 5
- 238000005530 etching Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 239000000969 carrier Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- -1 graphite alkene Chemical class 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000004043 responsiveness Effects 0.000 description 2
- 239000012212 insulator Substances 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000003245 working effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
- G02F1/0305—Constructional arrangements
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
- G02F1/0305—Constructional arrangements
- G02F1/0316—Electrodes
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
- G02F1/035—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect in an optical waveguide structure
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The invention discloses an electro-optical modulator, which relates to the technical field of photonic devices and aims to localize optical signals into a graphene layer through a slit waveguide part provided with a Bragg resonant cavity, enhance the interaction between the optical signals and the graphene layer, improve the electro-optical modulation responsivity of the electro-optical modulator during working and improve the working performance of the electro-optical modulator. The electro-optic modulator includes: the device comprises a substrate, an optical waveguide structure, a graphene layer, a first electrode and a second electrode. An optical waveguide structure is formed on a substrate. The optical waveguide structure includes a slit waveguide portion provided with a bragg resonator. The graphene layer covers at least the slit waveguide portion. The slit waveguide part is used for locally positioning an optical signal into the graphene layer. The first electrode and the second electrode are formed over the substrate. The first electrode is electrically connected to the optical waveguide structure. The second electrode is electrically connected to the graphene layer.
Description
Technical Field
The invention relates to the technical field of photonic devices, in particular to an electro-optical modulator.
Background
The graphene-based electro-optic modulator is capable of modulating the amplitude of an optical signal. In addition, the graphene material has excellent optical characteristics, so that the electro-optical modulator based on the graphene has the advantages of high modulation rate, low power consumption, small volume, easiness in integration and the like, and the graphene electro-optical modulator is widely applied to the field of optical communication.
However, the electro-optic modulation responsivity of the conventional graphene electro-optic modulator is low during normal operation, so that the working performance of the graphene electro-optic modulator is poor.
Disclosure of Invention
The invention aims to provide an electro-optical modulator, which is used for locally positioning an optical signal into a graphene layer through a slit waveguide part provided with a Bragg resonant cavity, enhancing the interaction between the optical signal and the graphene layer, improving the electro-optical modulation responsivity of the electro-optical modulator during working and improving the working performance of the electro-optical modulator.
In order to achieve the above object, the present invention provides an electro-optical modulator comprising: the device comprises a substrate, an optical waveguide structure, a graphene layer, a first electrode and a second electrode.
An optical waveguide structure is formed on a substrate. The optical waveguide structure includes a slit waveguide portion provided with a bragg resonator. The graphene layer covers at least the slit waveguide portion. The slit waveguide part is used for locally positioning an optical signal into the graphene layer. The first electrode and the second electrode are formed over the substrate. The first electrode is electrically connected to the optical waveguide structure. The second electrode is electrically connected to the graphene layer.
Compared with the prior art, the electro-optical modulator provided by the invention has the advantages that the optical waveguide structure is formed on the substrate and comprises the slit waveguide part provided with the Bragg resonant cavity. Based on this, in the operation process of the electro-optical modulator, the slit waveguide part is used for transmitting the optical signal, and the slit waveguide part can be used for locally positioning the optical signal in the Bragg resonant cavity into the slit groove of the slit waveguide part. Meanwhile, the graphene layer at least covers the slit waveguide part, so that the slit waveguide part can be used for locally transmitting optical signals into the graphene layer. Based on this, in practical application, after corresponding voltages are loaded on the graphene layer and the optical waveguide structure through the first electrode and the second electrode, the imaginary part of the effective refractive index of the graphene layer changes, so that the absorption coefficient of the graphene layer on optical signals is changed, and the modulation of the amplitude of the optical signals is realized. Meanwhile, the Bragg resonant cavity arranged at the slit waveguide part can enable the optical signal to be reflected back and forth in the graphene layer in the range of the Bragg resonant cavity, so that the interaction between the optical signal and the graphene layer is enhanced, the electro-optic modulation responsiveness of the electro-optic modulator during working can be improved, and the working performance of the electro-optic modulator is improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic perspective view of an electro-optic modulator according to an embodiment of the present invention;
FIG. 2 is a schematic top view of a structure of a slot waveguide portion according to an embodiment of the present invention.
Reference numerals:
1 is a substrate, and the surface of the substrate,
2 is an optical waveguide structure, 21 is a slit waveguide portion, 211 is a strip waveguide,
212 is a slit groove, 213 is a bragg cavity, 214 is a tuning groove,
the reference numeral 22 is a connecting part,
3 is a graphene layer, and the graphene layer,
the number 4 is the number one of the electrodes,
the number 5 is the number of the second electrode,
and 6 is a light-transmitting medium layer.
Detailed Description
Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is illustrative only and is not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure.
Various structural schematics according to embodiments of the present disclosure are shown in the figures. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers, and relative sizes and positional relationships therebetween shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, as actually required.
In the context of the present disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present. In addition, if a layer/element is "on" another layer/element in one orientation, then that layer/element may be "under" the other layer/element when the orientation is reversed. In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
An electro-optic modulator is a modulator made using the electro-optic effect of some electro-optic crystals. Specifically, when a voltage is applied to the electro-optical crystal during the operation of the electro-optical modulator, optical parameters such as the refractive index of the electro-optical crystal will change, which results in the change of the characteristics of the light wave passing through the electro-optical crystal, and thus the modulation of the phase, amplitude, intensity and polarization state of the optical signal is realized.
The graphene-based electro-optic modulator can modulate the amplitude of an optical signal. In addition, the graphene material has excellent optical characteristics, so that the electro-optical modulator based on the graphene has the advantages of high modulation rate, low power consumption, small volume, easiness in integration and the like, and the graphene electro-optical modulator is widely applied to the field of optical communication. Among them, the existing graphene electro-optic modulator generally includes: the waveguide structure comprises a substrate, a silicon waveguide formed on the substrate, and a layer of graphene covered above the silicon waveguide. The working principle of the optical fiber transmission device is that a positive pole and a negative pole of voltage are loaded on the graphene waveguide and the silicon waveguide respectively, and the Fermi level of the graphene is changed along with the change of the external voltage, so that the imaginary part of the effective refractive index of the graphene is changed, the absorption coefficient of the graphene to light is changed, and the amplitude of a transmission optical signal is modulated.
However, in the working process of the existing graphene electro-optical modulator, the interaction between the transmitted optical signal and the graphene is weak, so that the electro-optical modulation responsivity of the graphene electro-optical modulator is low, and the working performance of the graphene electro-optical modulator is poor.
In order to solve the above technical problem, an embodiment of the present invention provides an electro-optical modulator. In the electro-optical modulator, the optical waveguide structure includes a slit waveguide section provided with a Bragg resonator. And, at least on the slit waveguide portion, a graphene layer is covered. Based on this, when the electro-optical modulator during operation, the Bragg resonant cavity that sets up in slit waveguide portion department can make optical signal make a round trip to reflect in the graphite alkene layer that is located Bragg resonant cavity within range to strengthened the interact between optical signal and the graphite alkene layer, and then can improve the electro-optical modulation responsivity of electro-optical modulator during operation, promote the working property of electro-optical modulator.
As shown in fig. 1, an embodiment of the present invention provides an electro-optic modulator. The electro-optic modulator includes: the optical waveguide structure comprises a substrate 1, an optical waveguide structure 2, a graphene layer 3, a first electrode 4 and a second electrode 5.
As shown in fig. 1 and 2, the optical waveguide structure 2 is formed on a substrate 1. The optical waveguide structure 2 includes a slit waveguide portion 21 provided with a bragg resonator 213. The graphene layer 3 covers at least the slit waveguide portion 21. The slit waveguide section 21 serves to localize an optical signal into the graphene layer 3. A first electrode 4 and a second electrode 5 are formed over the substrate 1. The first electrode 4 is electrically connected to the optical waveguide structure 2. The second electrode 5 is electrically connected to the graphene layer 3.
Specifically, the base may be a semiconductor substrate on which no film layer is formed. For example: the base can be a silicon-based substrate such as a silicon substrate and a silicon-on-insulator substrate.
With the optical waveguide structure described above, the structure and specification of the slit waveguide portion included in the optical waveguide structure, and the specification of the bragg resonator disposed on the slit waveguide portion may be set according to the optical parameters (e.g., wavelength) of the optical signal to be modulated, the bragg reflection condition, and actual requirements. For example: as shown in fig. 2, the slit waveguide section 21 may have at least two strip waveguides 211, and slit grooves 212 between adjacent strip waveguides 211. In addition, the material of the optical waveguide structure may be set according to actual requirements, and is not specifically limited herein. For example: the material of the optical waveguide structure may be silicon.
In some cases, as shown in fig. 1, the optical waveguide structure 2 described above may further include a connection portion 22 formed on the substrate 1. The first electrode 4 is electrically connected to the slit waveguide portion 21 through a connection portion 22. The specific structure and specification of the connection portion 22 may be set according to the actual application, as long as the first electrode 4 and the slit waveguide portion 21 can be electrically connected by the connection portion 22. For example: the connection portion 22 may be located on one side of the slit waveguide portion 21 in the width direction of the slit waveguide portion 21. Also, the thickness of the connection portion 22 may be smaller than that of the slit waveguide portion 21. While the connection portion 22 may be integrally formed with the slit waveguide portion 21. In this case, the slit waveguide 21 is formed on the substrate 1 by etching in the same film layer, and the connection portion 22 is formed at the same time, so that the manufacturing efficiency of the electro-optical modulator can be improved and the manufacturing cost of the electro-optical modulator can be reduced.
For the graphene layer, the thickness of the graphene layer may be set according to an actual application scenario. For example: as shown in fig. 1, the layer thickness of the graphene layer 3 may be greater than or equal to the thickness of the slit waveguide part 21. At this time, the graphene layer 3 can fill the slit groove 212 of the slit waveguide 21, so that most of the optical signal transmitted through the slit waveguide 21 is located in the graphene layer 3, thereby further enhancing the interaction between the optical signal and the graphene layer 3. In addition, the coverage of the graphene layer on the substrate can also be set according to practical application scenarios. Specifically, the graphene layer may cover only the upper side of the slit waveguide section. Alternatively, as shown in fig. 1, the graphene layer 3 may also be coated on the surface of the substrate 1 exposed from the optical waveguide structure 2, so that the second electrode 5 is electrically connected to the graphene layer 3.
As for the first electrode and the second electrode, the shape and specification of the first electrode and the second electrode, and the specific position of the first electrode and the second electrode above the substrate may be set according to the actual application scenario, as long as the first electrode and the second electrode can be applied to the electro-optical modulator provided by the embodiment of the present invention. In addition, the material of the first electrode and the second electrode can be a conductive metal material. For example: the conductive metal material may be gold, copper, aluminum, or the like. The electro-optical modulator provided by the embodiment of the invention can be manufactured by a mature CMOS process, and the electro-optical modulator can be miniaturized while the manufacturing yield of the electro-optical modulator is improved.
In practical applications, as shown in fig. 1 and 2, the slit waveguide part 21 is used for transmitting an optical signal to be modulated, and it is capable of localizing the optical signal in the bragg resonant cavity 213 into the slit groove 212 of the slit waveguide part 21. Meanwhile, since the graphene layer 3 covers at least the slit waveguide part 21, the slit waveguide part 21 can localize the transmitted optical signal into the graphene layer 3 located inside the slit groove 212. Moreover, after the first electrode 4 and the second electrode 5 load the corresponding voltages on the graphene layer 3 and the optical waveguide structure 2, the imaginary part of the effective refractive index of the graphene layer 3 changes, so that the absorption coefficient of the graphene layer 3 to the optical signal is changed, and the modulation of the amplitude of the optical signal is realized. Meanwhile, the bragg resonant cavity 213 disposed at the slit waveguide portion 21 enables the optical signal to be reflected back and forth in the graphene layer 3 within the range of the bragg resonant cavity 213, so that the optical signal can be sufficiently modulated in the graphene layer 3 in which the absorption coefficient changes.
The connection relationship between the first electrode and the second electrode and the positive electrode and the negative electrode of the external circuit, respectively, and the magnitude of the voltage applied to the optical waveguide structure 2 and the graphene layer 3 by the first electrode and the second electrode can be determined according to the modulation requirement of the amplitude of the optical signal to be modulated.
As can be seen from the above, the electro-optical modulator according to the embodiment of the invention can locally transmit the transmitted optical signal into the graphene layer through the slit waveguide. Meanwhile, the optical signal can be reflected back and forth in the graphene layer in the range of the Bragg resonant cavity by the Bragg resonant cavity arranged at the slit waveguide part, so that the interaction between the optical signal and the graphene layer is enhanced, the electro-optic modulation responsiveness of the electro-optic modulator during working can be improved, and the working performance of the electro-optic modulator is improved.
In one example, as shown in fig. 1 and 2, a plurality of adjustment structures are opened on the slit waveguide part 21 along the extending direction of the slit waveguide part 21, and the adjustment structures are periodically distributed. Each of the adjustment structures includes a plurality of adjustment grooves 214 that penetrate the slit waveguide part 21 in the thickness direction of the slit waveguide part 21 and are provided at intervals. The bragg resonant cavity 213 is a portion where the slit groove 212 provided in the slit waveguide portion 21 is located between the adjacent tuning structures.
Specifically, the number of cycles of the adjusting structure may be set according to information such as a modulation requirement of the amplitude of the optical signal, a magnitude of the voltage applied to the first electrode and the second electrode, and an actual requirement, which is not specifically limited herein. It is contemplated that the bragg cavity, as described above, enables the optical signal to be reflected back and forth within the graphene layer within the range of the bragg cavity, thereby enabling the optical signal to be adequately modulated within the graphene layer with the altered absorption coefficient. In addition, since the bragg resonant cavity is a portion where the slit groove of the slit waveguide portion is located between the adjacent adjustment structures, the larger the number of periods of the adjustment structures is, the larger the number of bragg resonant cavities provided in the slit waveguide portion is, in the case where other factors are the same. Accordingly, the more efficient the optical signal is reflected back and forth within the bragg cavity.
Specifically, the number of the adjustment grooves included in each adjustment structure and the shape and specification of the adjustment grooves may be set according to actual requirements. Illustratively, each of the adjusting structures includes a plurality of adjusting grooves, and the size of the adjusting grooves and the distance between adjacent adjusting grooves in the same adjusting structure satisfy the bragg reflection condition at the corresponding wavelength of the optical signal. Specifically, the formula of the bragg reflection condition is as follows:
wherein, as shown in FIG. 2, L1To adjust the length of the slot 214. L is2The spacing of adjacent adjustment slots 214. Real (neff1) is the Real part of the effective refractive index of the slit waveguide part 21 located at the slit groove 212. Real (neff2) is the Real part of the effective refractive index of the slit waveguide part 21 located at the adjustment groove 214. m is the number of reflection orders. λ is the wavelength of the optical signal. Specifically, the specific value of Real (neff1) and the width G of the slot 2121The width of the slit waveguide portion 21, and the height of the slit waveguide portion 21. For example: when the width of the slit waveguide part 21 is 500nm and the height of the slit waveguide part 21 is 220nm, the width G of the slit groove 2121At 100nm, Real (neff1) has a value of 1.5131; when the width G of the slit groove 2121At 120nm, Real (neff1) had a value of 1.4541; when the width G of the slit groove 2121At 150, Real (neff1) has a value of 1.3930. The value of Real (neff1) can be based on the width G of the corresponding slot 2121The width of the slit waveguide portion 21 and the height of the slit waveguide portion 21 were calculated by simulation. Similarly, Real (neff2) is specified and the width G of the adjustment slot 2142The width of the slit waveguide portion 21, and the height of the slit waveguide portion 21. The specific determination manner of Real (neff2) can refer to the determination manner of Real (neff1), and is not described herein again. Based on this, in the practical application process, the wavelength corresponding to the optical signal to be modulated is a known quantity. In this case, the parameters may be determined by setting some values and calculating the remaining values in L1, L2, Real (neff1) and Real (neff2) according to actual needs.
In addition, since the bragg resonant cavity is a portion where the slit groove of the slit waveguide portion is located between the adjacent tuning structures, the bragg resonant cavity determines the distance between the adjacent tuning structures. The cavity length L of the Bragg resonant cavity can be determined according to the formula
A determination is made. Where λ is the wavelength of the optical signal. neff1 is the effective refractive index of the slit waveguide portion at the slit groove. In practical applications, the wavelength corresponding to the optical signal to be modulated is a known quantity. For the determination of the specific value of neff1, reference may be made to the above. Base ofHere, with λ and neff1 known, the cavity length L of the bragg cavity can be calculated from the above formula.
In practical applications, in the slit waveguide section 21 shown in fig. 2, the adjustment structure on the left side of the bragg cavity 213 is the first adjustment structure, and the adjustment structure on the right side of the bragg cavity 213 is the second adjustment structure. When the optical signal is transmitted to the first adjusting structure, a part of the optical signal satisfying the bragg reflection condition is reflected back, and another part of the optical signal can be transmitted into the bragg cavity 213 from the first adjusting structure and continue to be transmitted forward. After transmission to the second tuning structure, the optical signal satisfying the corresponding bragg reflection condition is reflected back into the bragg cavity 213 by the second tuning structure, and the optical signal interferes with the optical signal retransmitted through the first tuning structure. Based on this, the optical signal is reflected back and forth in the bragg resonant cavity 213, so that the optical signal is transmitted back and forth in the graphene layer 3 within the range of the bragg resonant cavity 213, the interaction between the optical signal and the graphene layer 3 can be enhanced, and the effective length of the interaction between the optical signal and the graphene layer 3 is increased.
In one example, as shown in fig. 2, each of the adjustment grooves 214 may be symmetrical about a central axis of the slit groove 212. In this case, when each of the adjustment grooves 214 is symmetrical about the central axis of the slit groove 212, the distribution of the adjustment structure within the slit waveguide section 21 is more regular, facilitating the manufacture of the electro-optical modulator provided by the embodiment of the present invention.
Of course, the adjustment groove may not be symmetrical with respect to the central axis of the slit groove. Specifically, the upper and lower distribution conditions of each adjusting groove about the central axis of the slit groove can be set according to actual requirements as long as the bragg reflection condition under the wavelength corresponding to the optical signal to be modulated can be met.
In one example, as shown in fig. 2, the adjustment groove 214 may be a rectangular adjustment groove 214 having an arc-shaped chamfer.
It should be appreciated that in the fabrication of electro-optic modulators, more sophisticated CMOS processes are typically employed to improve the fabrication yield of the electro-optic modulator. Based on this, in the process of actually manufacturing the electro-optical modulator provided in the embodiment of the present invention, after the adjustment groove 214 is obtained by etching on the slit waveguide portion 21 by using photolithography and etching processes under the condition that the adjustment groove 214 designed theoretically is the rectangular adjustment groove 214, due to the existence of manufacturing errors, the actually obtained adjustment groove 214 is the rectangular adjustment groove 214 with the arc-shaped chamfer, so that a deviation exists between the theoretically designed structure and the actually manufactured structure, and further, the size of the adjustment groove 214 cannot completely satisfy the bragg reflection condition at the wavelength corresponding to the optical signal, so that the working performance of the electro-optical modulator is poor. Under the condition that the adjusting groove 214 designed theoretically is a rectangular adjusting groove 214 with an arc-shaped chamfer, the appearance of the adjusting groove 214 obtained after photoetching and etching is basically consistent with that of the adjusting groove 214 designed theoretically, so that the adjusting groove 214 obtained under the condition of theoretical design or after actual manufacturing meets the Bragg reflection condition under the corresponding wavelength of an optical signal, the manufacturing precision of the electro-optical modulator can be prevented from being influenced due to the existence of manufacturing errors, and the working performance of the electro-optical modulator is improved.
In one example, the electro-optic modulator may further include a layer of light-transmissive medium 6, as shown in FIG. 1. The light-transmitting medium layer 6 is formed at least between the slit waveguide portion 21 and the graphene layer 3.
It is understood that, as shown in fig. 1, the light-transmitting property described above has a light-transmitting characteristic, and therefore, even if the light-transmitting medium layer 6 is provided between the slit waveguide section 21 and the graphene layer 3, transmission of an optical signal within the graphene layer 3 is not affected. Moreover, the light-transmitting medium layer 6 is a non-conductive insulating layer, so that the insulating medium layer can separate the graphene layer 3 from the slit waveguide 21, and potential carriers in the graphene layer 3 are prevented from being injected into the slit waveguide 21 after voltages are applied to the graphene layer 3 and the slit waveguide 21 through the first electrode 4 and the second electrode 5, that is, the first electrode 4 and the second electrode 5 are prevented from being short-circuited, so that the working reliability of the electro-optic modulator can be improved. Specifically, the material and the thickness of the transparent medium layer 6 may be set according to actual requirements, and are not specifically limited herein. For example: the material of the transparent dielectric layer 6 may be aluminum oxide, silicon dioxide, silicon nitride, or the like. The thickness of the light-transmitting medium layer 6 may be 5nm to 20 nm.
In addition, the forming position of the light-transmitting medium layer can be set according to the coverage range of the graphene layer and the practical application scene, as long as the graphene layer and the slit waveguide part can be separated. For example: in the case where the graphene layer covers only the slit waveguide portion, the light-transmitting medium layer may be formed only between the slit waveguide portion and the graphene layer. Another example is: as shown in fig. 1, the light-transmitting medium layer 6 may cover the substrate 1 and the optical waveguide structure 2. The graphene layer 3 is formed on a portion of the light-transmitting medium layer 6 covering the slit waveguide portion 21 and the substrate 1. At this time, the light-transmitting medium layer 6 can separate not only the graphene layer 3 from the slit waveguide portion 21 but also the substrate 1 from the graphene layer 3. Based on this, when the substrate 1 is a silicon substrate and the slit waveguide portion 21 is formed on the surface of the silicon substrate, the existence of the light-transmitting medium layer 6 can also prevent potential carriers in the graphene layer 3 from being injected into the optical waveguide structure 2 through the silicon substrate, thereby further improving the operational reliability of the electro-optic modulator.
In the above description, the technical details of patterning, etching, and the like of each layer are not described in detail. It will be appreciated by those skilled in the art that layers, regions, etc. of the desired shape may be formed by various technical means. In addition, in order to form the same structure, those skilled in the art can also design a method which is not exactly the same as the method described above. In addition, although the embodiments are described separately above, this does not mean that the measures in the embodiments cannot be used in advantageous combination.
The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present disclosure, and such alternatives and modifications are intended to be within the scope of the present disclosure.
Claims (10)
1. An electro-optic modulator, comprising: a substrate, a first electrode and a second electrode,
an optical waveguide structure formed on the substrate; the optical waveguide structure comprises a slit waveguide part provided with a Bragg resonant cavity;
a graphene layer covering at least the slit waveguide section; the slit waveguide part is used for locally positioning an optical signal into the graphene layer;
and a first electrode and a second electrode formed over the substrate; the first electrode is electrically connected with the optical waveguide structure; the second electrode is electrically connected to the graphene layer.
2. The electro-optic modulator of claim 1, wherein a plurality of adjusting structures are formed on the slot waveguide portion along the extending direction of the slot waveguide portion, and the adjusting structures are periodically distributed; each adjusting structure comprises a plurality of adjusting grooves which penetrate through the slit waveguide part along the thickness direction of the slit waveguide part and are arranged at intervals;
the Bragg resonant cavity is a part of the slit groove of the slit waveguide part between the adjacent adjusting structures.
3. The electro-optic modulator of claim 2, wherein the plurality of tuning grooves included in each of the tuning structures have a size and a spacing between adjacent tuning grooves in the same tuning structure that satisfy a bragg reflection condition at a corresponding wavelength of the optical signal; and/or the presence of a gas in the gas,
each of the adjustment grooves is symmetrical about a central axis of the slit groove.
4. The electro-optic modulator of claim 2, wherein the adjustment slot is a rectangular adjustment slot having an arcuate chamfer.
5. The electro-optic modulator of claim 1, further comprising a light transmissive dielectric layer; the light-transmitting medium layer is at least formed between the slit waveguide part and the graphene layer.
6. The electro-optic modulator of claim 5, wherein the light-transmissive medium layer is made of alumina, silicon dioxide or silicon nitride; and/or the presence of a gas in the gas,
the thickness of the light-transmitting medium layer is 5 nm-20 nm.
7. The electro-optic modulator of claim 5, wherein the light-transmissive medium layer overlies the substrate and the optical waveguide structure; the graphene layer is formed on a portion of the light-transmitting medium layer covering the slit waveguide portion and the substrate.
8. The electro-optic modulator of claim 1, wherein the optical waveguide structure further comprises a connection portion formed on the substrate; the first electrode is electrically connected to the slit waveguide portion through the connection portion.
9. The electro-optic modulator of claim 1, wherein the first electrode and the second electrode are each gold, copper, or aluminum.
10. An electro-optic modulator according to any one of claims 1 to 9 wherein the base is a silicon-based substrate; and/or the material of the optical waveguide structure is silicon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110796025.7A CN113655644A (en) | 2021-07-14 | 2021-07-14 | Electro-optical modulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110796025.7A CN113655644A (en) | 2021-07-14 | 2021-07-14 | Electro-optical modulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113655644A true CN113655644A (en) | 2021-11-16 |
Family
ID=78489497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110796025.7A Pending CN113655644A (en) | 2021-07-14 | 2021-07-14 | Electro-optical modulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113655644A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101960346A (en) * | 2008-02-29 | 2011-01-26 | 株式会社藤仓 | Planar optical waveguide element, chromatic dispersion compensator, optical filter, optical resonator and methods for designing the element, chromatic dispersion compensator, optical filter and optical resonator |
| CN103245636A (en) * | 2013-05-16 | 2013-08-14 | 成都谱视科技有限公司 | Enhancement-type slit optical waveguide grating FP (Fabry Perot) cavity optical biochemistry sensing chip |
| CN108181735A (en) * | 2017-12-25 | 2018-06-19 | 武汉邮电科学研究院 | A kind of graphene electro-optical modulator and preparation method thereof |
| US20180246350A1 (en) * | 2017-02-24 | 2018-08-30 | The George Washington University | Graphene-based plasmonic slot electro-optical modulator |
| CN113039645A (en) * | 2018-09-28 | 2021-06-25 | 剑桥企业有限公司 | Photoelectric detector |
-
2021
- 2021-07-14 CN CN202110796025.7A patent/CN113655644A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101960346A (en) * | 2008-02-29 | 2011-01-26 | 株式会社藤仓 | Planar optical waveguide element, chromatic dispersion compensator, optical filter, optical resonator and methods for designing the element, chromatic dispersion compensator, optical filter and optical resonator |
| CN103245636A (en) * | 2013-05-16 | 2013-08-14 | 成都谱视科技有限公司 | Enhancement-type slit optical waveguide grating FP (Fabry Perot) cavity optical biochemistry sensing chip |
| US20180246350A1 (en) * | 2017-02-24 | 2018-08-30 | The George Washington University | Graphene-based plasmonic slot electro-optical modulator |
| CN108181735A (en) * | 2017-12-25 | 2018-06-19 | 武汉邮电科学研究院 | A kind of graphene electro-optical modulator and preparation method thereof |
| CN113039645A (en) * | 2018-09-28 | 2021-06-25 | 剑桥企业有限公司 | Photoelectric detector |
Non-Patent Citations (2)
| Title |
|---|
| XIN WANG ET AL: "Highly sensitive compact refractive index sensor based on phase-shifted sidewall Bragg gratings in slot waveguide", 《APPLIED OPTICS》, pages 1 - 2 * |
| 王少亮: "基于石墨烯与狭缝波导的相位调制器研究", 《浙江大学硕士学位论文》, pages 3 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9110348B2 (en) | Optical element and Mach-Zehnder optical waveguide element | |
| CN110780468B (en) | Optical modulator, optical modulator module, and optical transmitter module | |
| US7447387B2 (en) | Electro-optical modulator with curving resonator | |
| US8014636B2 (en) | Electrical contacts on top of waveguide structures for efficient optical modulation in silicon photonic devices | |
| US10996539B2 (en) | Electro-optic modulator | |
| JP4828018B2 (en) | Optical modulator, method for manufacturing the same, and optical semiconductor device | |
| CN111487793B (en) | Z-cut LNOI electro-optical modulator capable of improving modulation efficiency and application thereof | |
| US20130251300A1 (en) | Athermal ring optical modulator | |
| CN111665645B (en) | Electro-optical modulator | |
| US10222675B2 (en) | Thin film plasmonic optical modulator | |
| CN107238951B (en) | Low bias large bandwidth electro-optic modulator | |
| KR20110112126A (en) | Silicon based optical modulator | |
| CN107290874B (en) | Large bandwidth electro-optic modulator | |
| JP5263718B2 (en) | Semiconductor optical modulator | |
| CN114583420A (en) | Phase shifter and manufacturing method thereof, semiconductor device and optical communication system | |
| JP6409299B2 (en) | Optical modulation element and optical modulator | |
| CN113655644A (en) | Electro-optical modulator | |
| CN110045520B (en) | Electro-optic phase modulator | |
| US20220404651A1 (en) | Optical Modulator and Related Apparatus | |
| CN113359330A (en) | Sinking electrode lithium niobate thin film electro-optical modulator and preparation method thereof | |
| CN113659016A (en) | Photoelectric detector | |
| US5920419A (en) | Quantum well electro-optical modulator | |
| WO2024029011A1 (en) | Optical modulator | |
| CN110989215B (en) | Differential lithium niobate modulator | |
| US20240248332A1 (en) | Electro-optic modulator, manufacturing method thereof, and optical communication system |
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 |