CN113805398A - Silicon nitride broadband optical switch - Google Patents
Silicon nitride broadband optical switch Download PDFInfo
- Publication number
- CN113805398A CN113805398A CN202111071403.1A CN202111071403A CN113805398A CN 113805398 A CN113805398 A CN 113805398A CN 202111071403 A CN202111071403 A CN 202111071403A CN 113805398 A CN113805398 A CN 113805398A
- Authority
- CN
- China
- Prior art keywords
- waveguide
- silicon nitride
- asymmetric
- optical switch
- coupler
- 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 title claims abstract description 48
- 229910052581 Si3N4 Inorganic materials 0.000 title claims abstract description 44
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 230000008878 coupling Effects 0.000 claims abstract description 7
- 238000010168 coupling process Methods 0.000 claims abstract description 7
- 238000005859 coupling reaction Methods 0.000 claims abstract description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- 230000008033 biological extinction Effects 0.000 abstract description 11
- 238000010586 diagram Methods 0.000 description 7
- 230000010363 phase shift Effects 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 238000013528 artificial neural network Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009022 nonlinear effect Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 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
- G02F1/21—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 by interference
- G02F1/225—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 by interference in an optical waveguide structure
-
- 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
- G02F1/0147—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 thermo-optic effects
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The invention relates to a silicon nitride broadband optical switch which comprises a first 3dB asymmetric adiabatic coupler, a second 3dB asymmetric adiabatic coupler, an interference arm waveguide, a reference arm waveguide and a thermal phase shifter, wherein the first 3dB asymmetric adiabatic coupler is connected with the second 3dB asymmetric adiabatic coupler; the first 3dB asymmetric adiabatic coupler and the second 3dB asymmetric adiabatic coupler have the same structure and respectively comprise a first waveguide part, a coupling region part and a second waveguide part which are sequentially connected, wherein the first end of the second waveguide part of the first 3dB asymmetric adiabatic coupler is connected with the second end of the second waveguide part of the second 3dB asymmetric adiabatic coupler through an interference arm waveguide, and the second end of the second waveguide part of the first 3dB asymmetric adiabatic coupler is connected with the first end of the second waveguide part of the second 3dB asymmetric adiabatic coupler through a reference arm waveguide; the interference arm waveguide and the reference arm waveguide are silicon nitride waveguides with equal length, and a thermal phase shifter is arranged on the interference arm waveguide. The invention solves the problem that the silicon nitride waveguide can not integrate active devices such as a variable optical attenuator and the like to make up the light-on extinction ratio.
Description
Technical Field
The invention relates to the technical field of integrated optoelectronic devices, in particular to a silicon nitride broadband optical switch.
Background
The optical switch is used as a basic unit of optical communication and widely applied to the fields of optical delay lines, laser radars, optical neural networks and the like. Mach-zehnder interferometer (MZI) optical switches are widely used in integrated photonic systems due to their large process tolerance and compact structure. However, the coupling effect of the optical power coupler in the existing MZI optical switch is affected by the wavelength change, and it is difficult to maintain the 3dB optical splitting effect in a wider operating bandwidth, so that it is important to research a broadband optical switch for an integrated photonic system with a larger optical bandwidth requirement.
Multimode interference couplers (MMI) and Directional Couplers (DC) are commonly used 3dB couplers in MZIs, but they cause unexpected reflection to the light source, and the directional couplers have strong wavelength dependence due to the dispersion of the waveguide, which ultimately leads to the non-ideal use of MZIs. In the silicon waveguide, an integrated Variable Optical Attenuator (VOA) can be adopted to make up the extinction ratio and suppress crosstalk, but due to the particularity of the silicon nitride waveguide, the VOA cannot be integrated, so that the extinction ratio in the working bandwidth of the silicon nitride optical switch directly determines whether the silicon nitride optical switch can be applied to a silicon nitride optical subsystem or not.
The loss of the silicon nitride waveguide has obvious advantages compared with the silicon waveguide, so that the silicon nitride broadband optical switch is more and more important when the silicon nitride broadband optical switch is applied to more and more extensive silicon nitride delay lines and silicon nitride phased array radar systems. Compared with the silicon nitride, the silicon nitride can bear higher optical power without obvious nonlinear effect, and the waveguide loss is lower, but the silicon nitride is suitable for passive devices, and the silicon nitride optical switch cannot be integrated with a variable optical attenuator to make up the extinction ratio.
Disclosure of Invention
The invention provides a silicon nitride broadband optical switch, which solves the problem that silicon nitride materials cannot integrate an adjustable optical attenuator to make up the extinction ratio.
The technical scheme adopted by the invention for solving the technical problems is as follows: the silicon nitride broadband optical switch comprises a first 3dB asymmetric adiabatic coupler, a second 3dB asymmetric adiabatic coupler, an interference arm waveguide, a reference arm waveguide and a thermal phase shifter; the first 3dB asymmetric adiabatic coupler and the second 3dB asymmetric adiabatic coupler have the same structure and respectively comprise a first waveguide part, a coupling region part and a second waveguide part which are sequentially connected, wherein the first waveguide part is of an asymmetric structure; a first end of the second waveguide section of the first 3dB adiabatic asymmetric coupler is connected to a second end of the second waveguide section of the second 3dB adiabatic asymmetric coupler by the interference arm waveguide, and a second end of the second waveguide section of the first 3dB adiabatic asymmetric coupler is connected to a first end of the second waveguide section of the second 3dB adiabatic asymmetric coupler by the reference arm waveguide; the interference arm waveguide and the reference arm waveguide are silicon nitride waveguides with equal length, and the thermal phase shifter is arranged on the interference arm waveguide.
The thickness of the interference arm waveguide, the reference arm waveguide and the second waveguide part is 0.8um, and the width is 1 um.
The waveguide width at the first end of the first waveguide section is not equal to the waveguide width at the second end.
The ratio of the waveguide width at the first end to the waveguide width at the second end of the first waveguide section is 1: 2.
The waveguide width of the first end of the first waveguide portion is 0.5um, and the waveguide width of the second end is 1 um.
The length of the interference arm waveguide and the reference arm waveguide is 750 um.
The thermal phase shifter adopts the aluminium electrode to heat, the width of aluminium electrode is 1.4um, and thickness is 0.4 um.
The thermal phase shifter is located 1.7um above the interference arm waveguide, and the total length of the thermal phase shifter is 750 um.
Advantageous effects
Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects: the silicon nitride waveguide is adopted, and compared with the silicon waveguide, the silicon nitride waveguide has lower loss and has greater advantages in a delay line and a laser radar. The invention adopts the 3dB asymmetric adiabatic coupler to ensure that the wavelength sensitivity is low, the silicon nitride waveguide can not be electrically adjusted, so that an adjustable optical attenuator can not be integrated to make up the extinction ratio, and the working bandwidth of the silicon nitride optical switch is limited. The invention adopts an asymmetric structure to reduce the length of the coupling part of the adiabatic coupler, and can reduce the volume of the whole optical device.
Drawings
FIG. 1 is a schematic structural diagram of an embodiment of the present invention;
FIG. 2 is a schematic diagram of a 3dB asymmetric adiabatic coupler according to an embodiment of the present invention;
FIG. 3 is a field strength transmission diagram for a 3dB asymmetric adiabatic coupler in an embodiment of the present invention;
FIG. 4 is a wavelength scan of a 3dB asymmetric adiabatic coupler in an embodiment of the present invention;
FIG. 5 is a schematic cross-sectional view of a thermal phase shifter according to an embodiment of the present invention;
FIG. 6 is a graph of field strength distribution when a thermal phase shifter is heated to Pi phase shift in an embodiment of the present invention;
FIG. 7 is a graph of the optical field intensity propagation for an embodiment of the present invention with a phase shift of 0;
FIG. 8 is a graph of extinction ratio versus wavelength for an embodiment of the present invention.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
Embodiments of the present invention relate to a silicon nitride broadband optical switch, as shown in fig. 1, comprising a first 3dB asymmetric adiabatic coupler 1, a second 3dB asymmetric adiabatic coupler 2, an interference arm waveguide 3, a reference arm waveguide 4, and a thermal phase shifter 5.
As shown in fig. 2, the first 3dB asymmetric adiabatic coupler 1 and the second 3dB asymmetric adiabatic coupler 2 have the same structure, and each includes a first waveguide portion a, a coupling region portion B, and a second waveguide portion C, which are connected in sequence, where the first waveguide portion a has an asymmetric structure. In this embodiment, the ratio of the waveguide width W1 at the first end of the first waveguide portion a to the waveguide width W2 at the second end is 1:2, for example, the waveguide width W1 at the first end of the first waveguide portion a is 0.5um, and the waveguide width W2 at the second end is 1um, in this embodiment, the widths at the two ends of the first waveguide portion a are designed to be different, so that mode mismatch is generated, and the wavelength sensitivity is reduced, fig. 3 is a field intensity transmission diagram of a 3dB asymmetric adiabatic coupler in the embodiment of the present invention, and fig. 4 is a wavelength scanning diagram of a 3dB asymmetric adiabatic coupler in the embodiment of the present invention. As can be seen from fig. 4, the sensitivity to wavelength is significantly reduced and the operating bandwidth is significantly increased due to the mode mismatch generated by the asymmetric design.
The first end C1 of the second waveguide section C of the first 3dB asymmetric adiabatic coupler 1 is connected to the second end C2 of the second waveguide section C of the second 3dB asymmetric adiabatic coupler 2 through the interference arm waveguide 3, and the second end C2 of the second waveguide section C of the first 3dB asymmetric adiabatic coupler 1 is connected to the first end C1 of the second waveguide section C of the second 3dB asymmetric adiabatic coupler 2 through the reference arm waveguide 4; the interference arm waveguide 3 and the reference arm waveguide 4 are silicon nitride waveguides with equal length, and the thermal phase shifter 5 is arranged on the interference arm waveguide 3. It can be found that the silicon nitride broadband optical switch of the present embodiment has asymmetric adiabatic couplers on the left and right sides, the phase modulation is performed in the middle by a thermal phase shifter, the adiabatic couplers on both sides can cancel out the phase difference caused by asymmetry by antisymmetric connection, and the coupling part length of the adiabatic coupler is reduced by adopting an asymmetric structure.
In the present embodiment, the thickness of the interference arm waveguide 3, the reference arm waveguide 4, the second waveguide portion C is 0.8um, the width is 1um, and the length of the interference arm waveguide 3 and the reference arm waveguide 4 is 750 um.
As shown in fig. 5, the thermal phase shifter 5 in the present embodiment is heated using an aluminum electrode having a width of 1.4um and a thickness of 0.4 um. The aluminium electrode is located 1.7um department above the arm waveguide of interfering (being carborundum waveguide), the total length that hot phase shifter 5 was the same with interfering arm waveguide 3, is 750 um. FIG. 6 is a diagram showing the distribution of the field strength when the thermal phase shifter is heated to Pi phase shift, and the phase difference between the two arms is realized by heating to generate the optical path switching, in this embodiment, the Pi phase shift power is 0.135W.
Fig. 7 is a diagram of the propagation of the optical field intensity at a phase shift of 0 according to an embodiment of the present invention. FIG. 8 is a graph of extinction ratio versus wavelength for an embodiment of the present invention. It can be seen that the extinction ratio of the silicon nitride broadband optical switch of the present embodiment is greater than 20dB in a large bandwidth range of 130nm or more in the c-band, and the extinction ratio of the silicon nitride broadband optical switch of the present embodiment exceeds 40dB in the vicinity of 1550nm, by the design of the present embodiment.
As can be easily found, the silicon nitride waveguide adopted by the invention has lower loss compared with the silicon waveguide and has greater advantages in delay lines and laser radars. The invention adopts the 3dB asymmetric adiabatic coupler to ensure that the wavelength sensitivity is low, the silicon nitride waveguide can not be electrically adjusted, so that an adjustable optical attenuator can not be integrated to make up the extinction ratio, and the working bandwidth of the silicon nitride optical switch is limited. The invention adopts an asymmetric structure to reduce the length of the coupling part of the adiabatic coupler, and can reduce the volume of the whole optical device.
Claims (8)
1. A silicon nitride broadband optical switch is characterized by comprising a first 3dB asymmetric adiabatic coupler, a second 3dB asymmetric adiabatic coupler, an interference arm waveguide, a reference arm waveguide and a thermal phase shifter; the first 3dB asymmetric adiabatic coupler and the second 3dB asymmetric adiabatic coupler have the same structure and respectively comprise a first waveguide part, a coupling region part and a second waveguide part which are sequentially connected, wherein the first waveguide part is of an asymmetric structure; a first end of the second waveguide section of the first 3dB adiabatic asymmetric coupler is connected to a second end of the second waveguide section of the second 3dB adiabatic asymmetric coupler by the interference arm waveguide, and a second end of the second waveguide section of the first 3dB adiabatic asymmetric coupler is connected to a first end of the second waveguide section of the second 3dB adiabatic asymmetric coupler by the reference arm waveguide; the interference arm waveguide and the reference arm waveguide are silicon nitride waveguides with equal length, and the thermal phase shifter is arranged on the interference arm waveguide.
2. The silicon nitride broadband optical switch of claim 1, wherein the interference arm waveguide, the reference arm waveguide, and the second waveguide section are each 0.8um thick and 1um wide.
3. The silicon nitride broadband optical switch of claim 1, wherein a waveguide width at a first end of the first waveguide section is not equal to a waveguide width at a second end.
4. The silicon nitride broadband optical switch of claim 3, wherein a ratio of a waveguide width at a first end to a waveguide width at a second end of the first waveguide section is 1: 2.
5. The silicon nitride broadband optical switch of claim 3, wherein the first end of the first waveguide section has a waveguide width of 0.5um and the second end has a waveguide width of 1 um.
6. The silicon nitride broadband optical switch of claim 1, wherein the interference arm waveguide and the reference arm waveguide are 750um in length.
7. The silicon nitride broadband optical switch of claim 1, wherein the thermal phase shifter is heated using an aluminum electrode having a width of 1.4um and a thickness of 0.4 um.
8. The silicon nitride broadband optical switch of claim 1, wherein the thermal phase shifter is located 1.7um above the interference arm waveguide, and has a total length of 750 um.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111071403.1A CN113805398A (en) | 2021-09-14 | 2021-09-14 | Silicon nitride broadband optical switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111071403.1A CN113805398A (en) | 2021-09-14 | 2021-09-14 | Silicon nitride broadband optical switch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113805398A true CN113805398A (en) | 2021-12-17 |
Family
ID=78941201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111071403.1A Pending CN113805398A (en) | 2021-09-14 | 2021-09-14 | Silicon nitride broadband optical switch |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113805398A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1651950A (en) * | 2004-01-26 | 2005-08-10 | 林克斯光化网络公司 | High-tolerance broadband-optical switch in planar lightwave circuits |
| CN104849878A (en) * | 2015-06-03 | 2015-08-19 | 东南大学 | Silicon nitride waveguide calorescence switch array chip based on Mach-Zahnder structure and production method thereof |
| CN108227084A (en) * | 2018-01-16 | 2018-06-29 | 上海理工大学 | Unrelated integrated optical switch of a kind of polarization based on silicon nitride waveguides and preparation method thereof |
-
2021
- 2021-09-14 CN CN202111071403.1A patent/CN113805398A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1651950A (en) * | 2004-01-26 | 2005-08-10 | 林克斯光化网络公司 | High-tolerance broadband-optical switch in planar lightwave circuits |
| CN104849878A (en) * | 2015-06-03 | 2015-08-19 | 东南大学 | Silicon nitride waveguide calorescence switch array chip based on Mach-Zahnder structure and production method thereof |
| CN108227084A (en) * | 2018-01-16 | 2018-06-29 | 上海理工大学 | Unrelated integrated optical switch of a kind of polarization based on silicon nitride waveguides and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| JIHO JOO: ""Cost-Effective 2 × 2 Silicon Nitride Mach-Zehnder Interferometric (MZI) Thermo-Optic Switch"", 《IEEE PHOTONICS TECHNOLOGY LETTERS》, vol. 30, no. 8, 30 April 2018 (2018-04-30), pages 1, XP011682021, DOI: 10.1109/LPT.2018.2814616 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7212326B2 (en) | Optical external modulator | |
| Jinguji et al. | Two-port optical wavelength circuits composed of cascaded Mach-Zehnder interferometers with point-symmetrical configurations | |
| JP2844525B2 (en) | Polarization independent optical device | |
| Wang et al. | Silicon–lithium niobate hybrid intensity and coherent modulators using a periodic capacitively loaded traveling-wave electrode | |
| Shen et al. | High-Performance Silicon 2× 2 Thermo-Optic Switch for the 2-$\mu $ m Wavelength Band | |
| CN112764287A (en) | Half-wave two-dimensional scanning optical phased array based on flat grating antenna | |
| CN111290191B (en) | Directional coupler and optical switch based on silicon nitride platform | |
| WO2019213139A1 (en) | Active photonic networks on integrated lithium niobate platforms | |
| JP2006251429A (en) | Variable dispersion compensator | |
| US5801871A (en) | Wide band and low driving voltage optical modulator with improved connector package | |
| CN110927992B (en) | Optical switch | |
| CN117434652A (en) | Coarse wavelength division multiplexer with low crosstalk and low temperature drift | |
| US10248002B2 (en) | Optical circuit, and optical switch using same | |
| CN113805398A (en) | Silicon nitride broadband optical switch | |
| CN112034638A (en) | Polarization-independent optical phase shifter | |
| JP7131425B2 (en) | optical modulator | |
| CN116520493A (en) | TE mode and TM mode separated polarization beam splitter chip based on film lithium niobate | |
| CN103392149A (en) | Optical gate switch | |
| US20050147352A1 (en) | Waveguide optical modulator | |
| CN113189706B (en) | Integrated adjustable silicon optical delay unit and delay line | |
| CN113204132B (en) | End face coupler and preparation method thereof | |
| Zheng et al. | Investigation on push-pull polymer Mach-Zehnder interferometer electro-optic switches using improved 3-D mode propagation analysis method | |
| JPH08234149A (en) | Optical filter using electron - optical material | |
| CN112904479B (en) | Optical switch based on reverse Fano coupling micro-ring | |
| EP0667542B1 (en) | Broadband integrated optical proximity coupler |
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 |