Two-waveband fused three-dimensional photon integrated coupling device

Abstract

The invention relates to a two-waveband fused three-dimensional photonic integrated coupler, which comprises a first waveguide layer, a second waveguide layer, a silicon dioxide upper cladding, a silicon dioxide lower cladding and a silicon substrate, and is characterized in that the second waveguide layer comprises a silicon nitride coupling waveguide, a silicon nitride connecting waveguide and a silicon nitride bent double-S-shaped waveguide; wherein the second waveguide layer is arranged above the first waveguide layer, and a silicon dioxide lower cladding and a silicon dioxide upper cladding are sequentially arranged on the silicon substrate. According to the scheme, the problems that an existing integrated optical loop is low in multi-wavelength coupling efficiency, complex in optical path design and low in integration level are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon-based optoelectronic devices, and relates to an interlayer and multiplexer with dual-band characteristics, and in particular to a dual-band fused three-dimensional photon integrated coupling device. Background Art

[0002] In the field of integrated photonics, multi-wavelength transmission and processing of optical signals is one of the key technologies to improve communication bandwidth and system performance. Existing technologies usually use single waveguides or multimode waveguides to transmit optical signals, but these designs have low coupling and conversion efficiency between different wavelengths and have large optical loss problems. Especially in multi-layer integrated photonic chips, the coupling of optical signals between different waveguide layers is more complicated, and it is necessary to solve the problems of spatial coupling and directional coupling.

[0003] Photonic interlayer couplers and multiplexers are commonly used optical coupling structures, which are widely used for optical signal transmission between different waveguide layers or adjacent waveguides. However, existing coupler designs are usually only optimized for optical signals of a single wavelength and cannot efficiently couple optical signals of multiple wavelengths at the same time, thus limiting their application in multi-band integrated systems. Especially in wavelength division multiplexing (WDM) systems, optical signals of different wavelengths usually need to be processed through independent optical paths, which not only increases the complexity of the system but also reduces the processing efficiency. Therefore, there is an urgent need for an integrated photonic device that can simultaneously process O-band (1260-1360nm) and C-band (1530-1565nm) optical signals to reduce coupling losses, improve integration, and simplify the overall optical path design. Summary of the invention

[0004] The present invention is aimed at the technical problems existing in the prior art and provides a three-dimensional photonic integrated coupling device with dual-band fusion. The purpose of the present invention is to provide an interlayer and multiplexing device with dual-band characteristics, which solves the problems of low multi-wavelength coupling efficiency, complex optical path design and low integration of existing integrated optical circuits.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a dual-band fused three-dimensional photonic integrated coupling device, comprising a first waveguide layer, a second waveguide layer, a silicon dioxide upper cladding layer, a silicon dioxide lower cladding layer and a silicon substrate, wherein the second waveguide layer comprises a silicon nitride coupling waveguide, a silicon nitride connecting waveguide and a silicon nitride bent double S-type waveguide, wherein the second waveguide layer is arranged above the first waveguide layer, and a silicon dioxide lower cladding layer and a silicon dioxide upper cladding layer are sequentially arranged on the silicon substrate.

[0006] As an improvement of the present invention, the front end of the first waveguide layer is a silicon straight waveguide, and the rear end is closely connected to a silicon tapered waveguide; the material of the first waveguide layer is silicon, the thickness is 0.22μm, the straight waveguide width is 0.5μm, the silicon tapered waveguide width changes linearly, the front end of the silicon tapered waveguide is the same as the straight waveguide width, the rear end width is 0.2μm, and the silicon tapered waveguide length is 16.6μm; the front end of the silicon nitride connecting waveguide is a silicon nitride tapered waveguide, and the rear end is closely connected to a silicon nitride straight waveguide; the silicon nitride connecting waveguide is 0.25μm away from the first waveguide layer in the z direction, the material is silicon nitride, the thickness is 0.4μm, the tapered waveguide width changes linearly, the front end width of the silicon nitride tapered waveguide is 0.2μm, the rear end width of the silicon nitride tapered waveguide is 1μm, the straight waveguide width is the same as the rear end width of the tapered waveguide, and the length of the silicon nitride tapered waveguide is 16.3μm.

[0007] As an improvement of the present invention, the silicon nitride coupled waveguide is a tapered waveguide with a left end width of 1 μm, a right end width of 1.05 μm, and a length of 145 μm; wherein the width of the silicon nitride curved double S-type waveguide is 1 μm, the front end of the silicon nitride curved double S-type waveguide is a silicon nitride straight waveguide, and the rear end is closely connected to the silicon nitride curved waveguide, the silicon nitride curved waveguide has an area of ​​15 μm×7 μm, and the rear end of the curved waveguide is closely connected to a second silicon nitride straight waveguide.

[0008] As an improvement of the present invention, the maximum value of the spacing between the second silicon nitride straight waveguide and the silicon nitride coupling waveguide is 0.075 μm, and the minimum value is 0.05 μm.

[0009] As an improvement of the present invention, the first waveguide layer is prepared by using a standard photolithography patterning and silicon material etching process, and the second waveguide layer is prepared by using a standard photolithography patterning and silicon nitride material etching process.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] The dual-band interlayer and multiplexing device of the present invention realizes efficient coupling and synthesized output of optical signals of different wavelengths by inputting C-band optical signals and O-band optical signals into the interlayer coupler and the multiplexer respectively. This design can significantly improve the coupling efficiency of the multi-wavelength integrated optical circuit system.

[0012] The dual-band interlayer and multiplexing device of the present invention simplifies the complex optical path structure in the traditional wavelength division multiplexing (WDM) system by realizing the synthesis and splitting of optical signals of different bands in different waveguide layers, thereby reducing the device occupation area and improving the integration.

[0013] The dual-band interlayer and multiplexing device of the present invention effectively reduces the coupling loss between different waveguide layers by adopting a combined structure of an interlayer coupler and a multiplexer, while ensuring low-loss transmission of O-band and C-band optical signals in the output waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a top view of an interlayer and multiplexing device having dual-band characteristics of the present invention;

[0015] Figure 2 It is a general view of the interlayer and multiplexing device with dual-band characteristics of the present invention;

[0016] Figure 3 It is a general view of the interlayer device having interlayer coupling characteristics of the present invention;

[0017] Figure 4 is a top view of a multiplexing device with O-band and C-band multiplexing according to the present invention;

[0018] Figure 5 It is the overall coupling efficiency between the layers and the multiplexing device with dual-band multiplexing characteristics of the present invention.

[0019] In the figure, 1. silicon straight waveguide, 2. silicon tapered waveguide, 3. silicon nitride tapered waveguide, 4. silicon nitride straight waveguide, 5. silicon nitride straight waveguide, 6. silicon nitride bent waveguide, 7. second silicon nitride straight waveguide, 8. silicon nitride coupled waveguide, 9. silicon first waveguide layer, 10. silicon nitride connecting waveguide, 11. silicon nitride bent double S-type waveguide, 12. silicon dioxide upper cladding, 13. silicon dioxide lower cladding, 14. silicon substrate. DETAILED DESCRIPTION

[0020] In order to deepen the understanding of the present invention, the present embodiment is described in detail below with reference to the accompanying drawings.

[0021] Example: See Figure 1-Figure 5 A dual-band fused three-dimensional photonic integrated coupling device comprises a first waveguide layer 9, a second waveguide layer, a silicon dioxide upper cladding layer 12, a silicon dioxide lower cladding layer 13 and a silicon substrate 14, wherein the second waveguide layer comprises a silicon nitride coupling waveguide 8, a silicon nitride connecting waveguide 10 and a silicon nitride bent double S-type waveguide 11, wherein the second waveguide layer is arranged above the first waveguide layer, and the silicon dioxide lower cladding layer 13 and the silicon dioxide upper cladding layer 12 are sequentially arranged on the silicon substrate 14.

[0022] The front end of the first waveguide layer 9 is a silicon straight waveguide (1), and the rear end is closely connected to a silicon tapered waveguide 2; the material of the first waveguide layer is silicon, the thickness is 0.22μm, the straight waveguide width is 0.5μm, the width of the silicon tapered waveguide changes linearly, the front end of the silicon tapered waveguide is the same as the straight waveguide width, the rear end width is 0.2μm, and the length of the silicon tapered waveguide is 16.6μm; the front end of the silicon nitride connecting waveguide 10 is a silicon nitride tapered waveguide 3, and the rear end is closely connected to a silicon nitride straight waveguide 4; the silicon nitride connecting waveguide 10 is 0.25μm away from the first waveguide layer 9 in the z direction, the material is silicon nitride, the thickness is 0.4μm, and the tapered waveguide width changes linearly The front end width of the silicon nitride tapered waveguide is 0.2μm, the rear end width of the silicon nitride tapered waveguide is 1μm, the straight waveguide width is the same as the rear end width of the tapered waveguide, the length of the silicon nitride tapered waveguide is 16.3μm, and the silicon nitride coupled waveguide 8 is a tapered waveguide with a left end width of 1μm, a right end width of 1.05μm, and a length of 145μm; wherein the width of the silicon nitride curved double S-type waveguide 11 is 1μm, the front end of the silicon nitride curved double S-type waveguide 11 is the silicon nitride straight waveguide 5, and the rear end is closely connected to the silicon nitride curved waveguide 6, the footprint of the silicon nitride curved waveguide 6 is 15μm×7μm, and the rear end of the curved waveguide is closely connected to the second silicon nitride straight waveguide 7. The curved waveguide and the straight waveguide at the other end are symmetrically distributed with respect to 5 and 6. The maximum value of the spacing between the second silicon nitride straight waveguide 7 and the silicon nitride coupling waveguide 8 is 0.075 μm, and the minimum value is 0.05 μm. The first waveguide layer is prepared by standard photolithography patterning and silicon material etching processes, and the second waveguide layer is prepared by standard photolithography patterning and silicon nitride material etching processes.

[0023] like Figure 1 As shown, Figure 1 It is a top view of the interlayer and multiplexing device with dual-band characteristics of the present invention, including a first waveguide layer 9, a second waveguide layer 8, 10 and 11 from bottom to top. The first waveguide layer is prepared by standard photolithography patterning and silicon material etching process. The second waveguide layer is located above the first waveguide layer, and the material is silicon nitride with a thickness of 0.4μm. The second waveguide layer is prepared by standard photolithography patterning and silicon nitride material etching process.

[0024] As a preferred embodiment, Figure 2 As shown, Figure 2 It is a full view of the interlayer and multiplexing device with dual-band characteristics of the present invention, including a first waveguide layer 9, second waveguide layers 8, 10 and 11, a silicon dioxide upper cladding layer 12, a silicon dioxide lower cladding layer 13, and a silicon substrate 14; light 1 represents light incident in the communication O band, light 2 represents light incident in the communication C band, and light 3 represents light after the communication O band and the communication C band are combined.

[0025] Figure 3FIG. 1 is a full view of the interlayer device with interlayer coupling characteristics of the present invention. Figure 3 As shown, the front end of the first waveguide layer 9 is a straight waveguide 1, and the rear end is closely connected to a tapered waveguide 2; the material of the first waveguide layer is silicon, with a thickness of 0.22μm, the straight waveguide width is 0.5μm, the tapered waveguide width changes linearly, the front end of the tapered waveguide is the same as the straight waveguide width, the rear end width is 0.2μm, and the tapered waveguide length is 16.6μm. The front end of the second waveguide layer connecting waveguide 10 is a silicon nitride tapered waveguide 3, and the rear end is closely connected to a silicon nitride straight waveguide 4; the silicon nitride connecting waveguide 10 is 0.25μm away from the first waveguide layer 9 in the z direction, and the material is silicon nitride, with a thickness of 0.4μm, the tapered waveguide width changes linearly, the front end width of the silicon nitride tapered waveguide is 0.2μm, the rear end width of the silicon nitride tapered waveguide is 1μm, the straight waveguide width is the same as the rear end width of the tapered waveguide, and the length of the silicon nitride tapered waveguide is 16.3μm.

[0026] Figure 4 It is a top view of the multiplexing device with O-band and C-band optical multiplexing of the present invention, which is composed of a silicon nitride coupling waveguide 8 and a silicon nitride curved S-type waveguide 11, wherein the coupling waveguide 8 is a tapered waveguide with a width of 1μm at the left end, a width of 1.05μm at the right end, and a length of 145μm; wherein the width of the double S-type waveguide 11 is 1μm. The front end of the double S-type waveguide 11 is a straight waveguide 5, and the rear end is closely connected to a curved waveguide 6, which has an area of ​​15μm×7μm. The rear end of the curved waveguide is closely connected to a straight waveguide 7, and the curved waveguide at the other end is symmetrically distributed with the straight waveguide 5 and 6. The maximum value of the gap between the straight waveguide 7 and the coupling waveguide 8 is 0.075μm, and the minimum value is 0.05μm.

[0027] The present invention significantly improves the optical signal transmission efficiency and integration by cascading an interlayer coupler and a multiplexer in series, and is suitable for fields such as high-speed optical communication and multi-wavelength photonic integrated circuits.

[0028] The interlayer and multiplexing device with dual-band characteristics of the present invention operates in the TE polarization mode of the communication O band and the communication C band.

[0029] When the interlayer and multiplexing device with dual-band characteristics of the present invention is working, the input communication C-band TE mode polarized light signal is incident through the first waveguide layer. Because the first waveguide layer and the second waveguide layer are mode-matched, the C-band light will leak into the second waveguide layer. Similarly, the input communication O-band TE mode polarized light signal is incident through the multiplexer. Because the mode and phase are matched, the O-band light will be transferred to the integrated waveguide in the second waveguide layer.

[0030] The core principle of the interlayer coupler is phase matching in the optical waveguide, and the coupling efficiency depends on the length of the coupling region.

[0031] The interlayer and multiplexing device with dual-band characteristics of the present invention adopts a double-layer waveguide design, and there is a certain distance between the multiplexer and the second waveguide layer. By adjusting the height difference between the first waveguide layer and the second waveguide layer, the distance between the second waveguide layer and the multiplexer, the width, thickness, coupling length and other structural parameters of the waveguide, the optical modes between the waveguides can be matched, the incident light can be coupled to a specific waveguide, and high-efficiency coupling of the device can be achieved.

[0032] The interlayer and multiplexing device with dual-band characteristics of the present invention is simulated by 3D-FDTD, and the simulation results are as follows: Figure 5 As shown, the C-band peak coupling efficiency is -0.45dB, the peak wavelength is 1580nm, and it has a 3-dB coupling bandwidth of 40nm. The O-band peak coupling efficiency is -0.22dB, the peak wavelength is 1325nm, and it has a 3-dB coupling bandwidth of 60nm.

[0033] It should be noted that the above embodiments are not intended to limit the protection scope of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions all fall within the protection scope of the claims of the present invention.

Claims

1. A dual-band fusion three-dimensional photon integrated coupling device, characterized in that: The invention comprises a first waveguide layer, a second waveguide layer, a silicon dioxide upper cladding layer, a silicon dioxide lower cladding layer and a silicon substrate, wherein the second waveguide layer comprises a silicon nitride coupling waveguide, a silicon nitride connecting waveguide and a silicon nitride bent double S-type waveguide, wherein the second waveguide layer is arranged above the first waveguide layer, and a silicon dioxide lower cladding layer and a silicon dioxide upper cladding layer are arranged in sequence on the silicon substrate.

2. The dual-band fusion three-dimensional photonic integrated coupling device according to claim 1, characterized in that: The front end of the first waveguide layer is a silicon straight waveguide, and the rear end is closely connected to a silicon tapered waveguide; The material of the first waveguide layer is silicon, with a thickness of 0.22μm, a straight waveguide width of 0.5μm, a silicon tapered waveguide width that changes linearly, a front end of the silicon tapered waveguide has the same width as the straight waveguide, a rear end width of 0.2μm, and a silicon tapered waveguide length of 16.6μm; the front end of the silicon nitride connecting waveguide is a silicon nitride tapered waveguide, and a silicon nitride straight waveguide is tightly connected to the rear end; the silicon nitride connecting waveguide is 0.25μm away from the first waveguide layer in the z direction, and the material is silicon nitride with a thickness of 0.4μm, a tapered waveguide width that changes linearly, a front end width of the silicon nitride tapered waveguide is 0.2μm, a rear end width of the silicon nitride tapered waveguide is 1μm, the straight waveguide width is the same as the rear end width of the tapered waveguide, and the length of the silicon nitride tapered waveguide is 16.3μm.

3. The dual-band fusion three-dimensional photonic integrated coupling device according to claim 1, characterized in that: The silicon nitride coupled waveguide is a tapered waveguide with a width of 1 μm at the left end, a width of 1.05 μm at the right end, and a length of 145 μm; the width of the silicon nitride curved double S-type waveguide is 1 μm, the front end of the silicon nitride curved double S-type waveguide is a silicon nitride straight waveguide 5, and the rear end is closely connected to the silicon nitride curved waveguide. The area of ​​the silicon nitride curved waveguide is 15 μm×7 μm, and the rear end of the curved waveguide is closely connected to the second silicon nitride straight waveguide.

4. The dual-band fusion three-dimensional photonic integrated coupling device according to claim 1, characterized in that: The maximum value of the spacing between the second silicon nitride straight waveguide and the silicon nitride coupling waveguide is 0.075 μm, and the minimum value is 0.05 μm.

5. The dual-band fusion three-dimensional photonic integrated coupling device according to claim 1, characterized in that: The first waveguide layer is prepared by using a standard photolithography patterning and silicon material etching process, and the second waveguide layer is prepared by using a standard photolithography patterning and silicon nitride material etching process.

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