CN115857091A - MMI polarization beam splitter of lithium niobate thin film - Google Patents
MMI polarization beam splitter of lithium niobate thin film Download PDFInfo
- Publication number
- CN115857091A CN115857091A CN202211631711.XA CN202211631711A CN115857091A CN 115857091 A CN115857091 A CN 115857091A CN 202211631711 A CN202211631711 A CN 202211631711A CN 115857091 A CN115857091 A CN 115857091A
- Authority
- CN
- China
- Prior art keywords
- waveguide
- mmi
- layer
- proton exchange
- lithium niobate
- 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
Images
Landscapes
- Optical Integrated Circuits (AREA)
Abstract
The application provides a lithium niobate thin film MMI polarization beam splitter, includes: a waveguide layer, a waveguide protection layer and a silicon substrate; the waveguide layer includes: the proton exchange waveguide, the MMI and the transition waveguide are integrated on the same lithium niobate thin film chip; the transition waveguide is a double-layer conical structure, meets the adiabatic transmission condition and is used for coupling the proton exchange waveguide with the MMI; the MMI comprises: the device comprises an input waveguide unit, a multimode interference area and an output waveguide unit; the input and output waveguides connected with the multimode interference region all adopt a conical structure, so that adiabatic transmission conditions are met; the invention solves the problem of high-efficiency coupling between the proton exchange optical waveguide and the MMI and realizes the function of polarizing and splitting beams.
Description
Technical Field
The application relates to the field of photoelectric technology, in particular to a lithium niobate thin film MMI polarization beam splitter
Background
The lithium niobate thin film optical waveguide has high electro-optic coefficient, acousto-optic coefficient and good nonlinear effect of the traditional lithium niobate waveguide, and can realize a highly integrated optical circuit, thereby becoming the most promising photoelectronic device platform. Among many optical functions, beam splitting and beam combining and polarization are the two most fundamental functions of an integrated optoelectronic platform. In order to realize the beam splitting and combining functions, a multi-mode interference coupler (MMI) based on a lithium niobate ridge waveguide is generally adopted, and has the advantages of wavelength insensitivity, small device structure, large process tolerance, small loss and the like. The polarization function of the light beam can be realized through the design of a specific structure, and TE and TM light in the waveguide is separated. However, the simultaneous implementation of the beam splitting and polarization functions only by the MMI structure leads to a complicated design and the influence of the functions on each other, resulting in a reduction in a single index. For example, the polarization extinction ratio of polarization realized by the existing MMI can only reach about 20-25dB, and the polarization noise is very high, which seriously affects the performance of the device, thereby affecting the quality of the optical path of the whole optical integrated module.
The lithium niobate optical waveguide prepared by the traditional proton exchange process only supports the transmission of a TE or TM mode naturally, and can realize a very high polarization extinction ratio index which can reach 30-50dB generally. In addition, the optical waveguide prepared by proton exchange is generally a diffusion type optical waveguide, and forms a small refractive index difference with the lithium niobate base, so that the mode size of an optical field is large when the optical field is transmitted in the waveguide. The mode field is large and easy to couple with an external optical fiber, but large-scale integration of the optical device is difficult to realize. Compared with a proton exchange waveguide, the ridge waveguide can effectively reduce the bending loss, improve the integration level of an optical device, reduce the size of an optical mode and effectively reduce the half-wave voltage of the lithium niobate electro-optical modulator. Therefore, the proposal of the patent is that the proton exchange waveguide and the ridge waveguide are simultaneously realized on the same platform, and the respective advantages of the proton exchange waveguide and the ridge waveguide can be exerted, thereby improving the optical path transmission efficiency and the functional index of the lithium niobate chip.
However, efficient coupling between the proton exchange waveguide and the lithium niobate thin-film ridge waveguide is difficult due to the difference in waveguide size. The mode field area of the lithium niobate thin film ridge waveguide is usually not more than 1um 2 The mode field area of the proton exchange waveguide is 3-4 times the mode field area of the ridge waveguide. When the optical coupling is directly coupled in a butt joint mode, very large coupling loss is generated, and the key problem of ensuring the transmission quality of the optical beam is the adoption of which mode to realize efficient coupling between the two modes. At present, the methodThe research on the mode spot conversion is only limited between the optical fiber and the waveguide, and the efficient transmission of the light beam between the on-chip proton exchange waveguide and the ridge waveguide is a problem to be solved urgently.
Disclosure of Invention
The problem solved by the application is that the efficient coupling between the proton exchange optical waveguide and the MMI realizes a high-standard polarization function, has high-efficient beam splitting capacity and is beneficial to the large-scale application of the integrated lithium niobate thin film waveguide device.
Through a large amount of verification works such as simulation calculation and the like, the following structural scheme is finally obtained:
as shown in fig. 1, a lithium niobate thin film MMI polarizing beam splitter includes:
a silicon substrate 101, waveguide protective layers 102, 104, a waveguide layer 103;
as shown in fig. 2, the waveguide layer 103 includes a proton exchange waveguide 1031, an MMI, transition waveguides 1032, 1033;
the waveguide layer 103 is integrated on the same lithium niobate thin film chip;
the waveguide protection layer comprises a lower cladding layer 102 and an upper cladding layer 104 of a waveguide layer;
preferably, the waveguide protection layers 102, 104 are silicon oxide layers.
Preferably, the proton exchange waveguide 1031 is prepared by a gas phase proton exchange process.
Preferably, the MMI is a 1 × 2MMI, the imaging principle of which is based on the self-imaging effect of the multimode waveguide;
as shown in fig. 4, the MMI includes an input waveguide unit i, a multimode interference region ii, and an output waveguide unit iii; the input waveguide unit I includes a first input tapered waveguide 1034; the output waveguide unit iii includes a first output tapered waveguide 1036, a first output single mode waveguide 1037, a second output tapered waveguide 1038, and a second output single mode waveguide 1039; the input waveguide unit I, the multimode interference area II and the output waveguide unit III are sequentially connected;
the first input waveguide 1034 is a tapered ridge waveguide, and a linear tapered structure meets adiabatic transmission conditions, so that loss caused by mode conversion between a narrow waveguide and a wide waveguide can be reduced, a self-imaging mode phase difference can be reduced, and image quality is improved;
preferably, the first input waveguide 1034 is centrosymmetric in input;
the first and second output waveguides 1036, 1038 of the MMI are tapered ridge waveguides, and the two output waveguides are distributed at symmetrical positions in the MMI multimode waveguide area.
Preferably, the length of said MMI multimode interference region 1035
σ =0 for TE light, σ =1,w for TM light M Width of multimode interference region, n r Is the refractive index of the core layer, n s Is the cladding refractive index.
Preferably, the width of the single-mode waveguide is smaller than the maximum waveguide width meeting the single-mode condition, the length of the tapered waveguide is 40-70um, the width of the multimode interference region is 5-7um, the length is 15-20um, and the distance between the two output waveguides is 0.8-1.2um.
Preferably, the MMI waveguide structure is a ridge waveguide, and the etching rate is between 0.4 and 0.6.
Preferably, the MMI is prepared by gas-phase proton exchange simultaneously with said proton exchange waveguide 1031;
preferably, the MMI is fabricated using electron beam lithography (RIE) and inductively coupled plasma etching (ICP);
for an input light field, the phase difference between the two output light fields of the 1 × 2MMI is 0, i.e. the two output light fields are in phase.
Preferably, the lithium niobate film between the proton exchange waveguide 1031 and the MMI is etched away using inductively coupled plasma etching (ICP) prior to fabrication of the transition waveguides 1032, 1033 described above.
Preferably, the transition waveguides 1032 and 1033 are made of silicon oxynitride, and the refractive index is adjusted between the refractive indexes of the silicon oxide layer and the waveguide layer;
preferably, the transition waveguides 1032, 1033 are designed as a double-layer tapered structure; the wide end of the lower layer tapered waveguide 1033 is butted with the proton exchange waveguide 1031, the thicknesses of the two waveguides are consistent, the widths of the two waveguides are wider than the width of the proton exchange waveguide 1031, the tip part covers the first input tapered waveguide 1034 of the MMI, and the tip width is smaller than 2.5um; the width of the wide end of the upper tapered waveguide 1032 is the same as that of the wide end of the lower tapered waveguide 1033, the waveguide tip ends at the first input tapered waveguide 1034 of the MMI, and the tip width is less than 300nm; the upper tapered waveguide 1032 overlies the proton exchange waveguide 1031 on the left side.
Preferably, the design of the tapered structures of transition waveguides 1032, 1033 satisfies adiabatic transmission conditions.
Preferably, the transition waveguides 1032, 1033 are formed by Plasma Enhanced Chemical Vapor Deposition (PECVD) with the following reaction equation: n is a radical of 2 +NH 3 +N 2 O+SiH 4 →SiON x +(N 2 +H 2 ) By controlling N 2 O and SiH 4 The refractive index of the silicon oxynitride is regulated and controlled by the proportion, the silicon oxynitride is prepared by electron beam lithography (RIE) and inductively coupled plasma etching (ICP), and the double-layer conical structure is prepared by adopting a two-step lithography process. FIG. 6 is a schematic representation of various cross-sections of the invention after its preparation.
The transmission of the optical field in the waveguide is simulated by simulation, and as shown in fig. 7, the basic process of the optical field transmission is as follows: light is input from a gas-phase proton exchange waveguide 1031, output light is linearly polarized light (TE or TM), the light beam firstly passes through transition waveguides 1032 and 1033, the coupling efficiency of the coupling surface of the proton exchange waveguide 1031 and the transition waveguides 1032 and 1033 is enabled to be highest through the design of the structure size of the transition waveguides and the regulation and control of refractive index, the light beam is coupled into the transition waveguides through the proton exchange waveguide 1031, the light field is gradually compressed to the lower tapered waveguide 1033 along with the gradual narrowing of the width of the upper tapered waveguide 1032, the mode field conversion in the vertical direction is completed, then the light beam is coupled to a first input tapered ridge waveguide 1034 with larger refractive index, adiabatic transmission conditions are met in the tapered waveguides and coupled to a multi-mode interference region 1035, multi-mode interference occurs based on the self-imaging effect, the light beam is divided into two beams at the tail end of the multi-mode interference region 1035 and coupled to two corresponding tapered output waveguides 1036 and 1038, and finally output through two single- mode waveguides 1037 and 1039. Thus, the process of converting the large mode field light spot output by the proton exchange waveguide 1031 into two small mode field light spots is completed, and the function of light polarization beam splitting is realized.
The invention has the advantages and positive effects that:
the high-efficiency coupling of the proton exchange waveguide and the MMI can be realized, the stable and high-efficiency transmission of light beams is realized, and the high-standard polarization beam splitting function is realized; the traditional method that a split type spot size converter is required to be arranged on a proton exchange waveguide is abandoned, so that a spot size conversion structure and a waveguide structure are integrated on the same lithium niobate chip, miniaturization of devices is achieved, the integration level is higher, and the device is more suitable for batch production.
Description of the drawings:
FIG. 1 shows a schematic cross-sectional view of an embodiment of the present invention;
FIG. 2 shows a two-dimensional top-view schematic of an embodiment of the present invention;
FIG. 3 shows a three-dimensional perspective view of a transition waveguide in connection with an MMI in an embodiment of the invention;
FIG. 4 shows a two-dimensional top view schematic diagram of an MMI in an embodiment of the invention;
FIG. 5 shows a complete process flow diagram for the preparation of an embodiment of the present invention;
FIG. 6 shows a schematic structural view of various cross-sections after preparation of an embodiment of the present invention;
FIG. 7 shows a schematic diagram of the transmission of an optical field in a waveguide according to an embodiment of the invention;
FIG. 8 shows a pattern of different cross-sectional beam output modes in an embodiment of the present invention.
Detailed Description
For a better understanding of the present invention, the present invention will be further described below with reference to the embodiments of the present invention and the accompanying drawings.
Fig. 1 shows a schematic cross-sectional view of an embodiment of the present invention, and as shown in fig. 1, a lithium niobate thin film MMI polarizing beam splitter includes: si substrate 101, siO 2 A lower cladding 102,A waveguide layer 103, siO on the lower cladding layer 2 An upper cladding layer 104. Fig. 2 shows a two-dimensional top view schematic diagram of an embodiment of the present invention, the waveguide layers comprising a proton exchange waveguide 1031, an upper transition waveguide 1032, a lower transition waveguide 1033, and an MMI. Fig. 3 shows a three-dimensional perspective view of a transition waveguide and an MMI in an embodiment of the invention, and fig. 4 shows a two-dimensional top view schematic diagram of the MMI in the embodiment of the invention, wherein the MMI comprises an input waveguide unit i, a multi-mode interference region ii and an output waveguide unit iii. The input waveguide unit i includes: a first input tapered ridge waveguide 1034; the output waveguide unit ii includes: a first output tapered ridge waveguide 1036, a first output single mode ridge waveguide 1037, a second output tapered ridge waveguide 1038, a second output single mode ridge waveguide 1039; the input waveguide unit I, the multimode interference area II and the output waveguide unit III are connected in sequence.
In this embodiment, the adopted base material is an x-cut lithium niobate crystal, and the lithium niobate optical waveguide prepared by proton exchange only supports the transmission in the TE mode.
The thickness of the lithium niobate film is 0.6um. The proton exchange waveguide 1031 adopts a gas-phase proton exchange method, has high refractive index variation, and has a narrower waveguide line width, does not need annealing and has less damage to a crystal structure compared with the conventional proton exchange method. In this embodiment, the width of the proton exchange waveguide 1031 is 2um, the exchange depth is 0.6um, i.e. the thickness of the lithium niobate thin film, and the refractive index contrast is 0.05.
The proton exchange waveguide 1031 is coupled to the 1 × 2MMI through transition waveguides 1032 and 1033, in this embodiment, the first input tapered waveguide 1034 is input in central symmetry, the width of the tip of the waveguide 1034 is 0.8um, the width of the wide end is 1.6um, the length is 40um, the taper rate is 20nm/um, the sizes of the first and second output tapered waveguides 1036 and 1038 are the same, but the width and the tip are opposite to each other. Connected to the first input tapered waveguide 1034 is a multimode interference region 1035 having a width W of 5um and a length L of 15.5um, where the beam is split into two beams at the end of the multimode interference region 1035 where the first double self-image is generated, coupled to the first and second output tapered waveguides 1036, 1038, and output via the single mode waveguides 1037, 1039, with a 1.2um spacing between the two output waveguides. The 1 multiplied by 2MMI is a ridge waveguide structure, the total thickness is 0.6um of the thickness of the lithium niobate thin film, and the etching depth is 0.3um. The MMI and the proton exchange waveguide 1031 simultaneously perform gas phase proton exchange, and after the proton exchange is completed, an MMI waveguide design pattern is obtained through Electron Beam Lithography (EBL) and inductively coupled plasma etching (ICP).
The transition waveguides 1032, 1033 enable efficient coupling of the proton exchange waveguide 1031 to the MMI as described above. In this embodiment, the transition waveguide is a double-layer tapered structure, is made of silicon oxynitride, has a refractive index of 1.8, and is butted with the output end face of the proton exchange waveguide 1031, the width of the wide end of the lower tapered waveguide 1033 is 2.7um, the width of the tip is 2um, and the length L is long 2 20um, a taper rate of 35nm/um, and a thickness of 0.6um, deposited on the first input tapered waveguide 1032 over a length L 3 Is 10um. The width of the wide end of the upper tapered waveguide 1032 is 2.7um the same as the wide end of the waveguide 1033, the thickness is 0.3um, the tip ends at the input of the first tapered waveguide 1034 on the right side, and the width is 200nm. In addition, the upper tapered waveguide 1032 is left overlying the proton exchange waveguide 1031.
When preparing transition waveguide, firstly etching 0.6um lithium niobate film between proton exchange waveguide and MMI by ICP technique, after etching, NH at 300 deg.C 3 ,N 2 O,SiH 4 The transition waveguide (silicon oxynitride) is prepared by deposition by a PECVD method in a mixed gas environment, and the reaction equation is N 2 +NH 3 +N 2 O+SiH 4 →SiON x +(N 2 +H 2 ) By controlling N 2 O and SiH 4 The refractive index of the silicon oxynitride is regulated and controlled by the ratio of the upper layer of the tapered waveguide and the lower layer of the tapered waveguide, the upper layer of the tapered waveguide 1032 is obtained by adopting an Electron Beam Lithography (EBL) technology and an inductively coupled plasma etching (ICP) technology, and the lower layer of the tapered waveguide 1033 is also etched by utilizing the EBL and the ICP technology. After the waveguide layer is prepared, a silicon oxide film is deposited on the surface of the lithium niobate crystal to be used as a protective layer 104, and finally, the end face of the wafer is polished by Chemical Mechanical Polishing (CMP). The complete process flow of the preparation of the embodiment of the invention is shown in fig. 5, and fig. 6 is a schematic structural diagram of different cross sections after the preparation of the embodiment of the invention is completed.
The process can be used for completing the processA preparation method of a lithium niobate thin film MMI polarizing beam splitter. The transmission of the optical field in the waveguide in this embodiment is simulated by simulation, as shown in fig. 7, the optical beam is coupled into transition waveguides (silicon oxynitride) 1032, 1033 from the proton exchange waveguide 1031, the optical field is gradually compressed to the lower tapered waveguide 1033 as the width of the upper tapered waveguide 1032 gradually becomes narrower, so as to complete mode field conversion in the vertical direction, then coupled to the first input tapered ridge waveguide 1034 with larger refractive index, coupled to the multi-mode interference region 1035 in the tapered waveguide satisfying adiabatic transmission condition, so as to generate multi-mode interference based on self-image effect, at the position where the first double self-image is generated, the optical beam is divided into two beams at the end of the multi-mode interference region 1035, and coupled to the corresponding two tapered output waveguides 1036, 1038, and finally output through the two single- mode waveguides 1037, 1039, so as to complete the transmission of the optical field with an area of 1.5um 2 To 0.7um 2 Fig. 8 shows the output speckle patterns of the light beams with different cross sections in this embodiment. The phase difference between the two output light fields of the 1 × 2MMI is 0, that is, the two output light fields are in phase and both are in the TE mode. The energy of an output field is reserved by about 98%, and the splitting ratio is 1:1, the light power of two output light fields can be equally divided, and the extinction ratio reaches about 40 dB.
The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should be covered by the present patent.
Claims (8)
1. A lithium niobate thin film MMI polarizing beam splitter comprising:
silicon substrate, waveguide protective layer, waveguide layer;
the waveguide layer comprises a proton exchange waveguide, an MMI and a transition waveguide;
the waveguide layer is integrated on the same lithium niobate thin film chip.
2. The lithium niobate thin film MMI polarizing beam splitter of claim 1, wherein:
the waveguide protection layer comprises a lower cladding layer and an upper cladding layer of the waveguide layer;
the waveguide protection layer is a silicon oxide layer.
3. The lithium niobate thin film MMI polarizing beam splitter of claim 1, wherein:
the proton exchange waveguide is prepared by a gas phase proton exchange process.
4. The lithium niobate thin film MMI polarizing beam splitter of claim 1, wherein:
the MMI is 1 × 2MMI, and the imaging principle of the MMI is based on the self-imaging effect of the multi-mode waveguide;
the multimode interference waveguide comprises an input waveguide unit, a multimode interference region and an output waveguide unit;
the input waveguide unit comprises a first input tapered waveguide and a centrosymmetric input;
the output waveguide unit comprises a first output tapered waveguide, a first output single mode waveguide, a second output tapered waveguide and a second output single mode waveguide;
the input waveguide unit, the multimode interference area and the output waveguide unit are connected in sequence;
the design of the conical structure meets the adiabatic transmission condition.
5. The MMI of claim 4, wherein:
MMI and the proton exchange waveguide of claim 3 are prepared by gas phase proton exchange simultaneously;
the preparation is finished by using electron beam lithography (RIE) and inductively coupled plasma etching (ICP);
the waveguide structure is a ridge waveguide.
6. The lithium niobate thin film MMI polarizing beam splitter of claim 1, wherein:
before the transition waveguide is prepared, the lithium niobate thin film between the proton exchange waveguide and the MMI is etched by adopting an inductively coupled plasma etching technology (ICP).
7. The lithium niobate thin film MMI polarizing beam splitter of claim 1, wherein:
the transition waveguide material adopts silicon oxynitride, and the refractive index is regulated between the refractive indexes of the silicon oxide layer and the waveguide layer;
the waveguide is designed into a double-layer conical structure;
the wide end of the lower conical waveguide is butted with the proton exchange waveguide, the two waveguides have the same thickness and the width is wider than the width of the proton exchange waveguide, and the tip part covers the first input conical waveguide of the MMI;
the width of the wide end of the upper layer tapered waveguide is consistent with that of the wide end of the lower layer tapered waveguide, and the waveguide tip is cut off at the first input tapered waveguide of the MMI;
the left side of the upper layer of conical waveguide covers the proton exchange waveguide;
the design of the conical structure meets the adiabatic transmission condition.
8. The transition waveguide of claim 7, wherein:
the transition waveguide is prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD);
the preparation is completed through electron beam lithography (RIE) and inductively coupled plasma etching (ICP);
the double-layer tapered structure is completed by a two-step photolithography process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211631711.XA CN115857091A (en) | 2022-12-19 | 2022-12-19 | MMI polarization beam splitter of lithium niobate thin film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211631711.XA CN115857091A (en) | 2022-12-19 | 2022-12-19 | MMI polarization beam splitter of lithium niobate thin film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115857091A true CN115857091A (en) | 2023-03-28 |
Family
ID=85674064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211631711.XA Pending CN115857091A (en) | 2022-12-19 | 2022-12-19 | MMI polarization beam splitter of lithium niobate thin film |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115857091A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117008249A (en) * | 2023-10-07 | 2023-11-07 | 之江实验室 | Lithium niobate wavelength division multiplexer and optical signal multiplexing method |
| CN117538985A (en) * | 2024-01-10 | 2024-02-09 | 合肥芯智华光子科技有限公司 | Film lithium niobate integrated optical engine |
| CN117590628A (en) * | 2024-01-18 | 2024-02-23 | 北京航空航天大学 | Optical device based on thin film lithium niobate waveguide, preparation method and working method |
-
2022
- 2022-12-19 CN CN202211631711.XA patent/CN115857091A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117008249A (en) * | 2023-10-07 | 2023-11-07 | 之江实验室 | Lithium niobate wavelength division multiplexer and optical signal multiplexing method |
| CN117008249B (en) * | 2023-10-07 | 2024-04-02 | 之江实验室 | Lithium niobate wavelength division multiplexer and optical signal multiplexing method |
| CN117538985A (en) * | 2024-01-10 | 2024-02-09 | 合肥芯智华光子科技有限公司 | Film lithium niobate integrated optical engine |
| CN117538985B (en) * | 2024-01-10 | 2024-05-03 | 合肥芯智华光子科技有限公司 | Film lithium niobate integrated optical engine |
| CN117590628A (en) * | 2024-01-18 | 2024-02-23 | 北京航空航天大学 | Optical device based on thin film lithium niobate waveguide, preparation method and working method |
| CN117590628B (en) * | 2024-01-18 | 2024-03-29 | 北京航空航天大学 | Optical device based on thin film lithium niobate waveguide, preparation method and working method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9377587B2 (en) | Fiber optic coupler array | |
| CN115857091A (en) | MMI polarization beam splitter of lithium niobate thin film | |
| US9195001B2 (en) | Spot size converter, optical transmitter, optical receiver, optical transceiver, and method of manufacturing spot size converter | |
| US7546007B2 (en) | Broadband optical via | |
| US7664352B1 (en) | Spot size converter | |
| EP2634613B1 (en) | Optical device, optical transmitter, optical receiver, optical transceiver, and method of manufacturing optical device | |
| CN113640913B (en) | LNOI (Low noise optical) fundamental mode spot converter directly coupled with single-mode fiber | |
| CN106959485B (en) | Directional coupling type TM polarizer and beam splitter based on sub-wavelength grating | |
| WO2022135095A1 (en) | End face coupler and manufacturing method therefor | |
| US11520175B2 (en) | Active region-less modulator and method | |
| JP4377195B2 (en) | Manufacturing method of optical module | |
| CN111522096B (en) | Method for preparing silicon waveguide and silicon oxide waveguide mode converter | |
| CN113534337A (en) | Processing method and structure of silicon photonic chip optical coupling structure | |
| CN113376743B (en) | Spot-size converter based on long-period grating | |
| CN115877506B (en) | Film lithium niobate end face coupler covering visible light wave band and preparation method thereof | |
| CN102033264A (en) | Manufacturing method of ridge-shaped optical waveguide and inverted-cone coupler assembly | |
| CN114924352B (en) | Apodized grating coupler for coupling optical fiber and mixed surface plasma waveguide | |
| CN214954215U (en) | Convex self-enhanced focusing coupling grating coupler | |
| JP4114791B2 (en) | Laminated optical waveguide | |
| CN114924348B (en) | Three-dimensional edge coupler based on silicon dioxide optical waveguide | |
| CN116643350B (en) | End-face coupler and optical chip system | |
| CN117908189A (en) | Efficient asymmetric directional coupler applied to 2.5-dimensional heterogeneous integrated optical waveguide | |
| CN115113329B (en) | Optical waveguide mode spot conversion device and manufacturing method thereof | |
| RU2712985C1 (en) | Mode converter device | |
| JP2820202B2 (en) | Manufacturing method of spot size converter |
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 |