Multi-band router

Abstract

The present disclosure provides a multi-band router, comprising: N multi-mode waveguides for transmitting multi-mode optical signals to be routed or routed multi-mode optical signals, where N > 2; N mode multiplexers, each mode multiplexer being connected to one multi-mode waveguide for inputting multi-mode optical signals to be decomposed or outputting multi-mode optical signals after multiplexing is completed; a routing area, each corresponding to one mode multiplexer including a plurality of single-mode waveguides for changing the path of the optical signals demultiplexed by the mode multiplexer and transmitting them to a target channel; and a plurality of waveguide overlapping areas, including two multi-band double-layer waveguide conversion areas for avoiding overlap, or including waveguide crossings designed reversely within a single-layer waveguide for realizing waveguide path crossings in multiple bands.

Description

Technical Field

[0001] The present disclosure relates to the field of optical communication technologies, and in particular, to a multi-band router. Background Art

[0002] Optical communication technology plays an important role in modern communication, and an optical switching network is an important node signal routing and processing network in optical fiber communication. Common silicon-based optical switching networks on a chip are generally electro-optic switching and passive optical switching according to their working modes. The electro-optic switching device adopts an active routing method. The maintenance of the optical link requires the states of all optical switch units passed by the link to remain unchanged. In this static situation, the maintenance of the system requires a certain amount of power consumption and certain means to maintain the stability of the system.

[0003] In the working mode of passive optical switching, the entire router is static during operation, which means that the passive structure of the router has the advantages of no power consumption and system stability. Most of the existing technical solutions use unit devices that can identify the wavelength characteristics of optical signals to route by wavelength. For example, a microring resonator, but it is limited by temperature sensitivity and free spectral range, and at the same time requires multiple lasers with different wavelengths and additional wavelength converters, which is difficult to implement.

[0004] In addition, the existing technical solutions also have problems of small optical bandwidth and single band, and cannot meet the multi-band and ultra-wideband requirements of the on-chip optical router. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] Based on the above problems, the present disclosure provides a multi-band router to alleviate the above technical problems in the prior art.

[0007] (2) Technical Solutions

[0008] The present disclosure provides a multi-band router, comprising: N multi-mode waveguides (100) for transmitting multi-mode optical signals to be routed or routed multi-mode optical signals, where N>2; N mode multiplexers (200), each mode multiplexer being connected to one multi-mode waveguide for inputting multi-mode optical signals to be decomposed or outputting multi-mode optical signals after multiplexing; N-2 coupling regions for coupling high-order modes in the multi-mode waveguide to a single-mode waveguide or coupling the fundamental mode in the single-mode waveguide to a high-order mode in the multi-mode waveguide; N-1 single-mode waveguides correspondingly connected to each mode multiplexer (200) for outputting the optical signals demultiplexed by the coupling region to a routing region (300) for routing, or inputting the routed optical signals into the coupling region for mode multiplexing; a routing region (300), each corresponding to one mode multiplexer, comprising a plurality of single-mode waveguides for changing the path of the optical signals demultiplexed by the mode multiplexer and transmitting them to a target channel; and a plurality of waveguide overlapping regions (400), including two multi-band double-layer waveguide conversion regions for avoiding overlap, or including waveguide crossings reversely designed within a single-layer waveguide for realizing multi-band waveguide path crossings.

[0009] According to an embodiment of the present disclosure, the N multi-mode waveguides carry signals bidirectionally and have the same waveguide cross-section, and the number N is the same as the number of ports of the router.

[0010] According to an embodiment of the present disclosure, each mode multiplexer is connected to N-1 single-mode waveguides, and the waveguide cross-section of each single-mode waveguide meets the requirements of the fundamental mode for routing with the remaining router ports in the routing region (300), and the N mode multiplexers are exactly the same.

[0011] According to an embodiment of the present disclosure, each mode multiplexer includes N-2 coupling regions. The coupling region includes a multi-mode bus waveguide and a single-mode waveguide, and the widths of the two waveguides in the coupling region remain unchanged or change gradually, for coupling conversion between the high-order mode of the bus waveguide and the fundamental mode of the single-mode waveguide, and the conversion direction depends on the propagation direction of the optical signal.

[0012] According to an embodiment of the present disclosure, the routing region 300 includes a plurality of single-mode waveguides, and the number is Any single-mode waveguide is connected to two ports of the router by connecting the corresponding two mode multiplexers.

[0013] According to an embodiment of the present disclosure, the double-layer waveguide conversion region is composed of double-layer waveguides with changing widths, and the minimum waveguide width is determined by process limitations, while for the waveguide crossing reversely designed within the single-layer waveguide, the minimum feature size is determined by process limitations.

[0014] According to an embodiment of the present disclosure, in the waveguide overlapping region 400, by optimizing the path, the minimum number of overlapping units is

[0015] According to the embodiments of the present disclosure, once the mode multiplexer 200, the routing area 300, and their connection manners are determined, the I / O mapping relationship of the optical signal loads the optical signal onto the corresponding mode channel, and the router passively routes the optical signal to the corresponding receiving end according to the routing table.

[0016] According to the embodiments of the present disclosure, the number of ports N can be expanded.

[0017] (III) Advantageous Effects

[0018] As can be seen from the above technical solutions, the multi-band router of the present disclosure has at least one or a part of the following advantageous effects:

[0019] (1) Simplify the topological structure to the greatest extent;

[0020] (2) Have the advantages of multi-band, non-blocking, no power consumption, stable system, and small area;

[0021] (3) There is no free spectral region and it has low loss throughout the multi-band. The multi-band router can be compatible with the wavelength division multiplexing technology on a very large bandwidth;

[0022] (4) The unit has good temperature stability and strong process tolerance ability. In addition, the multi-band router can expand the number of ports to meet the routing requirements of multi-ports and various networks. Description of the Drawings

[0023] Figure 1 Schematically shows a schematic diagram of a multi-band router according to an embodiment of the present disclosure;

[0024] Figure 2 Schematically shows a schematic diagram of a mode multiplexer in a multi-band router according to an embodiment of the present disclosure;

[0025] Figure 3a Schematically shows a schematic diagram of a waveguide overlap region in a multi-band router according to an embodiment of the present disclosure;

[0026] Figure 3b Schematically shows a schematic diagram of a waveguide overlap region in a multi-band router according to another embodiment of the present disclosure. Detailed Embodiments

[0027] The present disclosure provides a multi-band router, comprising: N input / output multimode waveguides for transmitting multimode optical signals and determining whether they are currently acting as input or output waveguides according to the data flow direction; N mode multiplexers, each including a bus waveguide, N-2 coupling regions, and N-1 single-mode waveguides, for decomposing the multimode optical signal input by the bus waveguide into single-mode signals of N-1 single-mode waveguides, or multiplexing N-1 single-mode optical signals into a multimode optical signal of the bus waveguide; a plurality of waveguide bends for changing the propagation path of the single-mode waveguide; and a plurality of overlapping regions for achieving inevitable crossings of the single-mode waveguides and meeting the multi-band requirements. The router structure utilizes the mode selection function of the mode demultiplexer and performs routing using different mode identifiers. This structure precisely designs the mode multiplexer and the double-layer waveguide region, rendering the router multi-band, low temperature-sensitive, low-loss, and low-crosstalk.

[0028] To make the objectives, technical solutions, and advantages of the present disclosure clearer and more understandable, the following further elaborates on the present disclosure in detail with reference to specific embodiments and the accompanying drawings.

[0029] In an embodiment of the present disclosure, a multi-band router is provided. As shown in Figure 1 、 Figure 2 、 Figure 3a 、 Figure 3b 、the multi-band router comprises:

[0030] N multimode waveguides 100 for transmitting the multimode optical signals to be routed or the routed multimode optical signals, where N is greater than 2, for example, N is 3, 4, 5, 6, 7, or 8;

[0031] N mode multiplexers 200, each mode multiplexer (such as 201, 202, 203, 20N) being connected to one multimode waveguide for inputting the multimode optical signal to be decomposed or outputting the multiplexed multimode optical signal; N-2 coupling regions for coupling the high-order modes in the multimode waveguide to the single-mode waveguide or coupling the fundamental mode in the single-mode waveguide to the high-order mode in the multimode waveguide; and N-1 single-mode waveguides correspondingly connected to each mode multiplexer 200 for outputting the optical signal demultiplexed by the coupling region to the routing region 300 for routing, or inputting the routed optical signal into the coupling region for mode multiplexing;

[0032] The routing region 300, each corresponding to one mode multiplexer, comprises a plurality of single-mode waveguides for changing the path of the optical signal demultiplexed by the mode multiplexer and transmitting it to the target channel; and

[0033] A plurality of waveguide overlapping regions 400, including two multi-band double-layer waveguide conversion regions for avoiding overlap, or including waveguide crossings designed reversely within a single-layer waveguide for achieving waveguide path crossings in multiple bands.

[0034] According to an embodiment of the present disclosure, N multimode waveguides bidirectionally carry signals and have the same waveguide cross-section, where the number N is the same as the number of ports of the router.

[0035] According to an embodiment of the present disclosure, each mode multiplexer is connected to N - 1 single-mode waveguides. The waveguide cross-section of each single-mode waveguide meets the fundamental mode requirements and is used for routing with the remaining router ports in the routing area 300. The N mode multiplexers are exactly the same.

[0036] According to an embodiment of the present disclosure, each mode multiplexer includes N - 2 coupling regions. The coupling region includes a multimode bus waveguide and a single-mode waveguide. In the coupling region, the widths of the two waveguides remain unchanged or change gradually, which is used for the coupling conversion between the high-order mode of the bus waveguide and the fundamental mode of the single-mode waveguide. The conversion direction depends on the optical signal propagation direction.

[0037] According to an embodiment of the present disclosure, the routing area 300 includes multiple single-mode waveguides, and the number is Any single-mode waveguide connects two ports of the router by connecting the corresponding two mode multiplexers.

[0038] According to an embodiment of the present disclosure, the double-layer waveguide conversion region is composed of double-layer waveguides with varying widths. The minimum waveguide width is determined by process limitations, while the waveguide crossings reverse-designed within the single-layer waveguide, and the minimum feature size is determined by process limitations.

[0039] According to an embodiment of the present disclosure, in the waveguide overlap region 400, such as 401 and 402, by optimizing the path, the minimum number of overlapping units is

[0040] According to an embodiment of the present disclosure, once the mode multiplexer 200, the routing area 300, and their connection methods are determined, the I / O mapping relationship of the optical signal loads the optical signal into the corresponding mode channel, and the router passively routes the optical signal to the corresponding receiving end according to the routing table.

[0041] According to an embodiment of the present disclosure, the number of ports N can be expanded.

[0042] Define the ports of the router as where i represents the port number (i = 1, 2,.., N), and j represents the mode number (j = 0, 1,.., N - 2). Taking as an example, the (N - 1) modes represented by the number j communicate with the remaining (N - 1) ports through a waveguide respectively. For example, the communication pairs and can be used as the upstream port and the downstream port (i.e., the input and output ports) with each other. When bidirectional signal transmission is required, two wavelength channels λ1 and λ2 can be used for distinction.

[0043] The shape and size of multimode waveguides and single-mode waveguides are related not only to the number of modes and the operating wavelength range, but also to the material platform. For example, they can be waveguides made of silicon materials, waveguides formed by ion implantation or etching of lithium niobate materials, waveguides made of silicon nitride materials, and waveguides made of silicon oxide materials, or a combination thereof.

[0044] Taking the waveguides of N multiplexers 200 as an example of SOI waveguides, the shape can be a ridge waveguide or a strip waveguide. The strip waveguide is a fully etched waveguide with a simple structure, while the ridge waveguide has a partially etched flat layer, with greater coupling ability and can reduce the length of the coupling region. The coupling region adopts an asymmetric directional coupler structure and works based on the coupling principle of evanescent waves, that is: since the dielectric material confines the optical field through the real part of the refractive index, an evanescent wave with an intensity gradually decaying as the distance from the waveguide core increases will appear outside the waveguide core region. When two waveguides are close enough, coupling will occur between the evanescent waves, enabling light to be coupled between the two waveguides. Due to the different coupling coefficients of different wavelengths, there are different minimum coupling lengths at the central wavelengths of multiple bands (such as C and O). By reasonably designing the band width and the coupling region, a strong evanescent wave coupling size that satisfies two wavelengths can be obtained. Further, by performing a gradual change design on the coupling region, a C+O dual-band mode multiplexer can be exemplarily obtained.

[0045] Figure 3a and Figure 3b Two implementation methods of the waveguide overlapping region 400 are given. Figure 3a The shown double-layer structure is not limited to the form of Si-SiN-Si and depends on the main working material layer and process capabilities.

[0046] The multi-band router provided by the present invention realizes multi-band optical signal routing. There are N ports in this router, defined as P1-P N , and each port can carry both upstream and downstream signals simultaneously to simplify the topology to the greatest extent (communication between the input and output of the same port does not need to pass through the router, which is a type of communication connection performed locally inside the port). The round-trip communication between any two ports P i and P j is mapped one-to-one with the two mode identifiers of the two ports to use as few mode numbers as possible.

[0047] So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that the implementation methods not illustrated or described in the accompanying drawings or the text of the specification are all forms known to those of ordinary skill in the art and have not been described in detail. In addition, the above definitions of each element and method are not limited to the specific structures, shapes or methods mentioned in the embodiments, and those of ordinary skill in the art can simply change or replace them.

[0048] Based on the above description, those skilled in the art should have a clear understanding of the multi-band router of the present disclosure.

[0049] In summary, the present disclosure provides a multi-band router, which has the advantages of multi-band, non-blocking, no power consumption, stable system, and small floor area. Since there is no free spectral range and it has low loss throughout the multi-band, the multi-band router can be compatible with wavelength division multiplexing technology over a very large bandwidth. The unit temperature stability of this architecture is good, and the process tolerance ability is strong. In addition, the multi-band router can expand the number of ports to meet the routing requirements of multi-ports and various networks.

[0050] It should also be noted that the above are different embodiments provided by the present disclosure. These embodiments are used to illustrate the technical content of the present disclosure, rather than to limit the scope of the claimed rights of the present disclosure. A feature of one embodiment can be applied to other embodiments through appropriate modification, replacement, combination, and separation.

[0051] It should be noted that, in this article, unless otherwise specified, an element with "a" does not mean that there is only one such element, but may have one or more such elements.

[0052] In addition, in this article, unless otherwise specified, ordinal numbers such as "first", "second", etc. are only used to distinguish multiple elements with the same name, and do not indicate the existence of a rank, level, execution order, or process order between them. A "first" element and a "second" element may appear in the same component together, or in different components separately. The existence of an element with a larger ordinal number does not necessarily mean the existence of another element with a smaller ordinal number.

[0053] In this article, unless otherwise specified, the so-called feature A "or" (or) or "and / or" (and / or) feature B means that A exists alone, B exists alone, or A and B exist simultaneously; the so-called feature A "and" (and) or "and" (and) or "and" (and) feature B means that A and B exist simultaneously; the so-called "including", "comprising", "having", "containing" means including but not limited to this.

[0054] In addition, in this article, terms such as "above", "below", "left", "right", "front", "rear", or "between" are only used to describe the relative positions between multiple elements, and can be extended in interpretation to include translation, rotation, or mirroring. In addition, in this article, unless otherwise specified, the statement "an element is on another element" or similar does not necessarily mean that the element contacts the other element.

[0055] In addition, unless otherwise specifically described or steps that must occur in sequence, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the required design. Also, based on considerations of design and reliability, the above embodiments can be used in combination with each other or with other embodiments, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0056] The specific embodiments described above further elaborate on the objectives, technical solutions, and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not used to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A multi-band router, comprising: N multi-mode waveguides (100) for transmitting multi-mode optical signals to be routed or routed multi-mode optical signals, where N > 2; N mode multiplexers (200), each mode multiplexer connected to one multi-mode waveguide, for inputting multi-mode optical signals to be decomposed or outputting multi-mode optical signals that have been multiplexed; N - 2 coupling regions for coupling high-order modes in the multi-mode waveguide to a single-mode waveguide or coupling the fundamental mode in the single-mode waveguide to a high-order mode in the multi-mode waveguide; N - 1 single-mode waveguides, correspondingly connected to each mode multiplexer (200), for outputting the optical signals demultiplexed by the coupling region to the routing region (300) for routing, or inputting the routed optical signals into the coupling region for mode multiplexing; A routing region (300), each corresponding to a mode multiplexer including a plurality of single-mode waveguides for changing the path of the optical signals demultiplexed by the mode multiplexer and transmitting them to the target channel; And A plurality of waveguide overlapping regions (400), including two multi-band double-layer waveguide conversion regions for avoiding overlap, or including waveguide crossings reverse-designed within a single-layer waveguide for realizing multi-band waveguide path crossings.

2. The multi-band router according to claim 1, wherein the N multi-mode waveguides bidirectionally carry signals, have the same waveguide cross-section, and the number N is the same as the number of ports of the router.

3. The multi-band router according to claim 1, each mode multiplexer is connected to (N - 1) single-mode waveguides, and the waveguide cross-section of each single-mode waveguide meets the fundamental mode requirement for routing with the remaining router ports in the routing region (300), and the N mode multiplexers are exactly the same.

4. The multi-band router according to claim 1, each mode multiplexer includes N - 2 coupling regions, and the coupling region includes a multi-mode bus waveguide and a single-mode waveguide. In the coupling region, the widths of the two waveguides remain unchanged or change gradually, for the coupling conversion between the high-order mode of the bus waveguide and the fundamental mode of the single-mode waveguide, and the conversion direction depends on the propagation direction of the optical signal.

5. The multi-band router according to claim 1, wherein the routing area (300) comprises a plurality of single-mode waveguides, and the number is Any one of the single-mode waveguides is connected to two ports of the router by connecting corresponding two mode multiplexers.

6. The multi-band router according to claim 1, the double-layer waveguide conversion region is composed of double-layer waveguides with varying widths, and the minimum waveguide width is determined by process limitations, while for the waveguide crossings reverse-designed within a single-layer waveguide, the minimum feature size is determined by process limitations.

7. For the multi-band router according to claim 1, in the waveguide overlapping region (400), by optimizing the path, the minimum number of overlapping units is 8. The multi-band router according to claim 1, once the mode multiplexer (200) and the routing region (300) and their connection methods are determined, the I / O mapping relationship of the optical signal loads the optical signal onto the corresponding mode channel, and the router passively routes the optical signal to the corresponding receiving end according to the routing table.

9. The multi-band router according to claim 1, the number of ports N can be expanded.

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