Optical switch, optical switch assembly, and optical switch integrated part

Abstract

The present application relates to the technical field of optical communications, and provides an optical switch, an optical switch assembly, and an optical switch integrated part. The optical switch provided in the present application comprises an input waveguide, a multimode waveguide, and a plurality of output waveguides which are connected in sequence, and the optical switch further comprises a plurality of strip electrodes located on one side of the multimode waveguide, wherein the plurality of strip electrodes can modulate a light field propagation path in the multimode waveguide. According to the optical switch, a planar waveguide structure is used and the light field propagation path in the multimode waveguide can be modulated by means of the electrodes, so that the structure of the optical switch is effectively simplified, and it is convenient to increase the number of output ports. Moreover, according to the optical switch, the refractive index distribution of the multimode waveguide is adjusted by means of the electrodes, so as to modulate the light field propagation path, so that the working range of the input wavelength of the optical switch is not limited, thereby enabling broad-wavelength working.

Description

Optical switches, optical switch assemblies and optical switch integrated components

[0001] This application claims priority to Chinese patent application No. 202311085049.7, filed on August 25, 2023, entitled “Optical switch, optical switch assembly and optical switch integrated component,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of optical communication technology, and in particular to an optical switch, an optical switch assembly, and an optical switch integrated component. Background Art

[0003] Optical switches are core components used to implement optical path conversion in optical wavelength division multiplexing (WDM) networks and access networks. They are commonly used in scenarios such as protection switching, network performance monitoring, and routing switching in optical networks.

[0004] Common optical switches in related technologies generally include cascade switches based on Mach-Zehnder interferometers (MZIs), cascade switches based on multimode interferometers (MMIs), and cascade switches based on microring resonators (MRRs). However, these optical switches are relatively complex in structure and difficult to expand in terms of port number.

[0005] Summary of the Invention

[0006] The present application provides an optical switch, an optical switch assembly, and an optical switch integrated component, which can solve the technical problems in the related art that the optical switch has a relatively complex structure and the port is difficult to expand.

[0007] In a first aspect, an optical switch is provided, comprising: an input waveguide, a multimode waveguide, multiple output waveguides, and multiple strip electrodes. The input waveguide, the multimode waveguide, and the multiple output waveguides are arranged along a first direction, with the input waveguide connected to one end of the multimode waveguide, and the multiple output waveguides connected to the other end of the multimode waveguide. The multiple strip electrodes are located on one side of the multimode waveguide and spaced apart along a second direction, and are configured to modulate the propagation path of an optical field in the multimode waveguide. The second direction is perpendicular to the first direction.

[0008] The optical switch provided in this application utilizes a planar waveguide structure and is capable of modulating the optical field propagation path within a multimode waveguide through electrodes. This optical switch has a simple structure and easily expands the number of output ports. Furthermore, because the optical switch modulates the optical field propagation path by adjusting the refractive index profile of the multimode waveguide through electrodes, its operating range of input wavelengths is not limited, enabling wide-wavelength operation.

[0009] Optionally, the input waveguide may include a first wedge-shaped (taper) waveguide, the wider end of which is connected to one end of the multimode waveguide. A wedge-shaped waveguide may also be referred to as a taper structure or a tapered waveguide. Using a wedge-shaped waveguide ensures that light at the narrower end of the wedge-shaped waveguide is transmitted in a single-mode mode, reducing transmission loss and facilitating connection to a single-mode fiber. Furthermore, light at the wider end of the wedge-shaped waveguide is in a multimode mode, facilitating connection to a multimode waveguide.

[0010] Optionally, the input waveguide may further include a first straight waveguide connected to an end of the first wedge-shaped waveguide remote from the multimode waveguide. Of course, the input waveguide may further include another wedge-shaped waveguide connected to an end of the first straight waveguide remote from the first wedge-shaped waveguide. That is, the input waveguide may include multiple wedge-shaped waveguides, with two adjacent wedge-shaped waveguides connected by a straight waveguide.

[0011] Optionally, at least one of the plurality of output waveguides may include a second wedge-shaped waveguide, a wider end of the second wedge-shaped waveguide being connected to the other end of the multimode waveguide. For example, each of the plurality of output waveguides may include a second wedge-shaped waveguide.

[0012] Optionally, the at least one output waveguide may further include a second straight waveguide connected to an end of the second wedge-shaped waveguide remote from the multimode waveguide. Of course, the output waveguide may further include another wedge-shaped waveguide connected to an end of the second straight waveguide remote from the second wedge-shaped waveguide, i.e., the output waveguide may include multiple wedge-shaped waveguides.

[0013] Optionally, the length of the multimode waveguide along the first direction may be 0.5P, where P is the length of one sine wave cycle of light propagating along a sinusoidal trajectory. This ensures that the optical signal can be effectively transmitted to the target output port while avoiding increasing the transmission loss of the optical signal, thus ensuring reliable modulation of the optical propagation path.

[0014] Optionally, a width W of the multimode waveguide along the second direction may satisfy: W>N×d+(N-1)×G, where N is the number of the plurality of output waveguides, d is the width of an end of the output waveguide close to the multimode waveguide along the second direction, and G is the spacing between two adjacent output waveguides.

[0015] It is understood that the spacing may refer to the spacing between two adjacent output waveguides close to one end of the multimode waveguide along the second direction. By designing the width W of the multimode waveguide to meet the above conditions, sufficient arrangement space for the output waveguides and the strip electrodes can be ensured.

[0016] Optionally, the length of each of the plurality of strip electrodes along the first direction may be greater than or equal to the length of the multimode waveguide along the first direction. For example, the length of each strip electrode may be slightly greater than the length of the multimode waveguide to ensure effective modulation of the refractive index at both ends of the multimode waveguide.

[0017] Optionally, the plurality of strip electrodes may all be parallel to the first direction, and the plurality of strip electrodes may have the same length, thereby effectively reducing the design complexity of the optical switch and improving the design efficiency.

[0018] Optionally, each of the multiple output waveguides may correspond to two strip electrodes; and the light field propagation path between the input waveguide and each output waveguide is modulated by the two strip electrodes corresponding to the output waveguide.

[0019] Based on the above design, if it is necessary to transmit the optical signal from the input waveguide to any output waveguide, the refractive index distribution of the multimode waveguide can be changed through the two strip electrodes corresponding to any output waveguide, thereby transmitting the optical signal to any output waveguide.

[0020] Optionally, the multiple strip electrodes may include at least one common electrode, which corresponds to at least two output waveguides. That is, at least two output waveguides may share the same strip electrode. This effectively reduces the number of strip electrodes required in the optical switch, thereby reducing the structural complexity and cost of the optical switch.

[0021] Optionally, the two strip electrodes corresponding to each output waveguide can be symmetrically arranged on either side of a first axis; the distance between the first axis and a second axis is less than a threshold, and the second axis is the central axis between the input waveguide and the output waveguide. For example, the first axis and the second axis can overlap as much as possible, thereby ensuring that the two strip electrodes can effectively modulate the light propagation path between the input waveguide and the corresponding output waveguide.

[0022] Optionally, the two strip electrodes corresponding to each output waveguide may be arranged along the second direction on both sides of the input waveguide and the output waveguide, thereby effectively modulating the light field propagation path between the input waveguide and the output waveguide.

[0023] Optionally, the optical switch may further include a first cladding and a second cladding. The input waveguide, the multimode waveguide, and the multiple output waveguides are all located between the first cladding and the second cladding, and the multiple strip electrodes are located on a side of the second cladding away from the multimode waveguide. The refractive index of the input waveguide, the multimode waveguide, and the multiple output waveguides are all greater than the refractive index of the first cladding and greater than the refractive index of the second cladding.

[0024] The input waveguide, multimode waveguide, and multiple output waveguides can be formed from the same material, have the same thickness, and be located in the same layer. Alternatively, the input waveguide, multimode waveguide, and multiple output waveguides can constitute an optical waveguide layer (also referred to as an intermediate core layer). The first cladding layer is formed on the substrate and can be referred to as the lower cladding layer. Accordingly, the second cladding layer can be referred to as the upper cladding layer. The optical waveguide layer can be made of a polymer with a refractive index of n = 1.47, and the upper and lower cladding layers can be made of a polymer with a refractive index of n = 1.45. Furthermore, the lower cladding layer can be thicker than the upper cladding layer, and the upper cladding layer can be thicker than the optical waveguide layer.

[0025] In a second aspect, an optical switch assembly is provided. The optical switch assembly may include: a plurality of cascaded optical switches as provided in the first aspect. The specifications of the different optical switches may be the same or different, i.e., the number of output waveguides included in the different optical switches may be the same or different.

[0026] By cascading multiple optical switches, the number of output waveguides included in the optical switch assembly can be effectively increased, thereby achieving a multiple expansion of the number of output ports.

[0027] In a third aspect, an optical switch integrated component is provided, comprising: at least one optical processing device; and the optical switch provided in the first aspect. The at least one optical processing device is connected to at least one output waveguide of the optical switch. It is understood that the optical switch integrated component may include multiple optical processing devices, and different optical processing devices may be connected to different output waveguides.

[0028] Optionally, the at least one optical processing device may include at least one of a multiplexer, a variable optical attenuator (VOA), and a splitter.

[0029] In summary, this application provides an optical switch, an optical switch assembly, and an integrated optical switch component. This optical switch utilizes a planar waveguide structure and is capable of modulating the optical field propagation path in a multimode waveguide via electrodes. This optical switch has a simple structure and the number of output ports can be easily expanded. Furthermore, because this optical switch modulates the optical field propagation path by adjusting the refractive index profile of the multimode waveguide via electrodes, its operating range of input wavelengths is not limited, enabling wide-wavelength operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic structural diagram of an optical switch provided in an embodiment of the present application;

[0031] FIG2 is a cross-sectional view of the optical switch shown in FIG1 along a first direction x;

[0032] FIG3 is a cross-sectional view of the optical switch shown in FIG1 along a second direction y;

[0033] FIG4 is a schematic diagram of the refractive index distribution of a multimode waveguide in the second direction provided by an embodiment of the present application;

[0034] FIG5 is a schematic diagram of light field distribution in a multimode waveguide provided in an embodiment of the present application;

[0035] FIG6 is a schematic structural diagram of another optical switch provided in an embodiment of the present application;

[0036] FIG7 is a schematic diagram of a light beam propagating along a sinusoidal trajectory provided by an embodiment of the present application;

[0037] FIG8 is a schematic diagram of the arrangement of strip electrodes provided in an embodiment of the present application;

[0038] FIG9 is a schematic structural diagram of an optical switch assembly provided in an embodiment of the present application;

[0039] FIG10 is a schematic structural diagram of an optical switch integrated component provided in an embodiment of the present application;

[0040] FIG11 is a schematic diagram of the structure of an optical distribution network provided in an embodiment of the present application;

[0041] FIG12 is a schematic diagram of the structure of an optical transmission network provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The optical switch, optical switch assembly, and optical switch integrated component provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] As core components of optical wavelength division multiplexing (WDM) networks and access networks, the technical capabilities of optical switches directly determine the performance of optical communication networks. The evolving demand for optical switches is for low insertion loss, low cost, high-density, large ports, and high-speed switching. The evolution of optical switch solutions follows three paths: mechanical, microelectromechanical systems (MEMS), and on-chip waveguide solutions. Currently, there are several mainstream on-chip waveguide solutions, namely waveguide optical switches: cascade switches based on MZI structures, cascade switches based on MMI structures, and cascade switches based on microring resonators. However, these solutions all suffer from issues such as difficulty in port expansion, complex control, and limited operating wavelength range.

[0044] Among them, MZI is one of the basic devices in planar waveguide devices. It consists of two directional couplers (i.e., 3dB couplers) and phase-shifting arms. The phase on the phase-shifting arm is changed by thermo-optical or other modulation methods to regulate the light wave. A 1×N optical switch based on an MZI structure is generally composed of a cascade of multiple stages of MZI. For example, a 1×4 optical switch is composed of a cascade of two stages of MZI structures. Among them, a 1×N optical switch refers to an optical switch with one input port and N output ports, where N is an integer greater than 1. It can be understood that the larger N is, the more stages of MZI need to be cascaded. In summary, for an optical switch based on an MZI structure, N (N=2^K) port outputs require 2^K-1 MZI structures to be obtained through a cascade of K stages.

[0045] The above-mentioned optical switch based on the MZI structure has the following disadvantages: 1. Port expansion depends on the number of cascades, and the ports are difficult to expand. 2. The control is complex. The optical switch based on the MZI structure needs to adjust the phase of the two phase shift arms on each level of the MZI structure. The N-port output requires adjustment of 2^K-1 MZI structures, with a total number of electrodes of 2^(K+1)-2. Each port output requires adjustment of 2K electrodes. 3. The control technology is based on single-mode waveguide phase modulation (0 to π). The relationship between the phase change θ and the refractive index change δ is: θ = 2×π×L×δ / λ, where L is the single-mode waveguide control length and λ is the operating wavelength. From the above formula, it can be concluded that the phase change θ is directly related to the wavelength λ, resulting in differences in phase changes at different wavelengths, and the actual wavelength working range is limited. In other words, the wavelength range of the optical signal input to the optical switch is limited. 4. The 3dB coupler has strict process tolerance requirements, and the balanced phase shift arm is difficult to manufacture, resulting in low manufacturing process tolerance of the optical switch and difficult preparation.

[0046] MMI is also one of the basic devices in planar waveguide devices. The MMI waveguide structure supports multiple modes simultaneously. Multiple modes interfere inside the waveguide space, forming self-images at specific positions and periodically reproducing to achieve lossless output. A 1×N optical switch based on an MMI structure (also called an MMI coupler) is generally composed of a 1×N MMI and an N×N MMI cascaded through a modulation arm. For example, a 1×3 optical switch consists of two cascaded MMI couplers and a thermal phase shifter. However, the optical switch based on the MMI structure has the disadvantages of large insertion loss and complex control after cascading. In addition, the control technology of the optical switch is also based on phase modulation, and the relationship between the phase change θ and the refractive index change δ is: θ = 2×π×L×δ / λ. Since the phase change θ is directly related to the wavelength λ, the working range of the input wavelength is also limited.

[0047] An embodiment of the present application provides an optical switch that can achieve multi-port output (the number of output ports ≥ 2) through a relatively simple structure. In addition, the optical switch is simple to control, the port scale is easy to expand, and wide wavelength operation can be achieved. Figure 1 is a structural schematic diagram of the optical switch provided in an embodiment of the present application, Figure 2 is a cross-sectional view of the optical switch shown in Figure 1 along the first direction x, and Figure 3 is a cross-sectional view of the optical switch shown in Figure 1 along the second direction y. As shown in Figures 1 to 3, the optical switch provided in an embodiment of the present application includes: an input waveguide 10, a multimode waveguide 20, a plurality of output waveguides 30, and a plurality of strip electrodes 40.

[0048] 1 , the input waveguide 10 , the multimode waveguide 20 and the plurality of output waveguides 30 are arranged along a first direction x, and the input waveguide 10 is connected to one end of the multimode waveguide 20 , and the plurality of output waveguides 30 are connected to the other end of the multimode waveguide 20 .

[0049] 2 and 3 , the plurality of strip electrodes 40 are located on one side of the multimode waveguide 20 and are spaced apart along a second direction y. The plurality of strip electrodes 40 are used to modulate the light field propagation path in the multimode waveguide 20. The second direction y is perpendicular to the first direction x.

[0050] In the embodiment of the present application, the first direction x may be a direction parallel to the optical axis, and the first direction x may be referred to as a length direction, and the second direction y may be referred to as a width direction. The region where the multimode waveguide 20 is located may be referred to as a multimode waveguide region, and the electrode array composed of the plurality of strip electrodes 40 is located within the multimode waveguide region or extends through the multimode waveguide region.

[0051] The optical switch provided in this embodiment operates on the principle of refractive index gradient waveguide imaging. By injecting current or applying voltage to the multiple strip electrodes 40, the refractive index profile of the multimode waveguide 20 is altered, resulting in a gradient refractive index profile in the second direction y (i.e., perpendicular to the optical axis). This alters the trajectory of the optical signal in the multimode waveguide 20, directing it into a specific output waveguide 30.

[0052] It is understood that the refractive index distribution of the multimode waveguide 20 can be changed by using the thermo-optic effect. In addition, the refractive index distribution of the multimode waveguide 20 can also be changed by using the electro-optic effect or carrier injection. The thermo-optic effect and carrier injection can be achieved by injecting current into the strip electrodes 40, and the electro-optic effect can be achieved by applying a voltage to the strip electrodes 40.

[0053] After the multiple strip electrodes 40 inject current or apply voltage, the refractive index distribution of the multimode waveguide 20 in the second direction y can be as shown in Figure 4, and the corresponding optical field distribution in the multimode waveguide 20 can be as shown in Figure 5. The horizontal axis in Figure 4 is the size of the multimode waveguide 20 along the second direction y, that is, the width of the multimode waveguide 20, and its unit is micrometer (um); the vertical axis in Figure 4 is the refractive index n of the multimode waveguide 20. The horizontal axis in Figure 5 is the size of the multimode waveguide 20 along the first direction x, that is, the length of the multimode waveguide 20, and its unit is um; the vertical axis in Figure 5 is the width of the multimode waveguide 20, and its unit is um. Referring to Figure 5, it can be seen that under the modulation of the multiple strip electrodes 40, the multimode waveguide 20 is able to transmit the optical signal input from the input waveguide 10 to the first output waveguide 30.

[0054] In summary, the embodiments of the present application provide an optical switch that adopts a planar waveguide structure and is capable of modulating the light field propagation path in a multimode waveguide through electrodes.

[0055] The optical switch has a simple structure and the number of output ports can be easily expanded. Furthermore, because the optical switch modulates the light field propagation path by adjusting the refractive index distribution of the multimode waveguide through electrodes, its operating range of input wavelengths is not limited, enabling wide-wavelength operation.

[0056] Figure 6 is a schematic diagram of the structure of another optical switch provided by an embodiment of the present application. As shown in Figure 6, the input waveguide 10 may include a first wedge-shaped waveguide 101, the wider end of which is connected to one end of the multimode waveguide 20. The width of the wedge-shaped waveguide may refer to the dimension along the second direction y.

[0057] For example, the width of the first wedge-shaped waveguide 101 can gradually change from 3.5 μm to 10 μm, that is, the width of the first wedge-shaped waveguide 101 at the end close to the multimode waveguide 20 can be 10 μm, and the width of the end away from the multimode waveguide 20 can be 3.5 μm. The dimension (i.e., length) of the first wedge-shaped waveguide 101 along the first direction x can be 200 μm.

[0058] 6 , the input waveguide 10 may further include a first straight waveguide 102 connected to an end of the first wedge-shaped waveguide 101 away from the multimode waveguide 20. The straight waveguide may be a strip waveguide with a constant width.

[0059] The dimension (ie, width) of the first straight waveguide 102 along the second direction y may be equal to the width of the end of the first wedge-shaped waveguide 101 away from the multimode waveguide 20. For example, the width of the first straight waveguide 102 may be 3.5 μm.

[0060] 6 , at least one of the plurality of output waveguides 30 may include a second wedge-shaped waveguide 301, wherein a wider end of the second wedge-shaped waveguide 301 is connected to the other end of the multimode waveguide 20. For example, in the optical switch shown in FIG6 , each output waveguide 30 may include a second wedge-shaped waveguide 301.

[0061] For example, the width of the second wedge-shaped waveguide 301 can gradually change from 10 μm to 3.5 μm, that is, the width of the second wedge-shaped waveguide 301 at the end close to the multimode waveguide 20 can be 10 μm, and the width of the end away from the multimode waveguide 20 can be 3.5 μm. The dimension of the second wedge-shaped waveguide 301 along the first direction x can also be 200 μm.

[0062] In the embodiments of the present application, wedge-shaped waveguides are used in the input and output waveguides. This ensures that light at the narrower end of the wedge-shaped waveguide is transmitted in a single-mode mode, reducing transmission loss and facilitating connection with single-mode optical fibers. Furthermore, light at the wider end of the wedge-shaped waveguide is transmitted in a multimode mode, facilitating connection with multimode waveguides.

[0063] Continuing with FIG6 , the at least one output waveguide 30 may further include a second straight waveguide 302 connected to the end of the second wedge-shaped waveguide 301 remote from the multimode waveguide 20. The dimension (i.e., width) of the second straight waveguide 302 along the second direction y may be equal to the width of the end of the second wedge-shaped waveguide 301 remote from the multimode waveguide 20. For example, the width of the second straight waveguide 302 may be 3.5 μm.

[0064] It is understood that the size of the narrower end of the wedge-shaped waveguide is not necessarily limited to 3.5 μm and can be adjusted based on the material properties, as long as the transmission mode is single-mode. Similarly, the size of the wider end of the wedge-shaped waveguide is not necessarily limited to 10 μm and can be adjusted based on actual effects. For example, the size of the wider end of the wedge-shaped waveguide can be 8 μm, 9 μm, 11 μm, or other values. The embodiments of the present application do not impose any restrictions on the size of the wedge-shaped waveguide.

[0065] Alternatively, the output waveguide 30 may be a wedge-shaped waveguide connected to a straight waveguide as shown in FIG6 , or a wedge-shaped waveguide connected to a straight waveguide, followed by a wedge-shaped waveguide. Similarly, the input waveguide 10 may be a wedge-shaped waveguide connected to a straight waveguide, followed by a wedge-shaped waveguide. The present embodiment does not limit the structure of the input and output waveguides, as long as mode matching is achieved as much as possible and loss is reduced.

[0066] In this embodiment of the present application, since the optical switch operates based on the theory of refractive index gradient waveguide imaging, the length of the multimode waveguide 20 can be determined based on the imaging position of the light. Optionally, the length of the multimode waveguide 20 along the first direction x can be 0.5P, where P represents the pitch and 1P is the length of one sine wave cycle of the light beam propagating along the sinusoidal trajectory. That is, as shown in Figure 7, the length of the multimode waveguide 20 can be the length of 0.5 sine wave cycles of the light beam propagating along the trajectory, thereby ensuring that the optical signal can be effectively transmitted along the trajectory to the target output waveguide, i.e., the target output port.

[0067] Of course, the length of the multimode waveguide 20 can also be 1.5P or 2.5P, etc. However, designing the length of the multimode waveguide 20 to be 0.5P not only avoids increasing the size, cost, and manufacturing complexity of the optical switch, but also effectively reduces the loss of optical signals during transmission.

[0068] For example, assuming the optical switch is a 1×8 optical switch, the length of the multimode waveguide 20 (i.e., the dimension along the first direction x) can be 950 μm to 1050 μm, for example, 1000 μm. Alternatively, if the optical switch is a 1×20 optical switch, the length of the multimode waveguide 20 can be 1250 μm to 1350 μm, for example, 1300 μm or 1340 μm.

[0069] Optionally, the width W of the multimode waveguide 20 (i.e., the dimension along the second direction y) may satisfy: W>N×d+(N−1)×G, where N is the number of the plurality of output waveguides 30, d is the width of the output waveguide 30 at one end adjacent to the multimode waveguide 20 along the second direction y, and G is the spacing between two adjacent output waveguides 30.

[0070] It is understood that the spacing G between the output waveguides 30 may refer to the spacing near one end of the multimode waveguide 20, and the spacing G may refer to the distance along the second direction y. For example, the spacing G may refer to the spacing at the wider end of the second wedge-shaped waveguide 301.

[0071] It is also understood that the spacing G between two adjacent output waveguides 30 can be flexibly adjusted based on optical insertion loss and crosstalk specifications. For example, if the optical switch is a 1×8 optical switch, the spacing G can be 1 μm or 2 μm. Alternatively, if the optical switch is a 1×20 optical switch, the spacing G can be 0 μm, 1 μm, or even larger.

[0072] For example, for a 1×8 optical switch and a 1×20 optical switch, the width W of the multimode waveguide 20 can be 240 μm. Of course, the width of the multimode waveguide 20 can also be flexibly adjusted according to the requirements of the application scenario.

[0073] The above description is based on the example of multiple output waveguides 30 arranged at equal intervals G. Of course, the multiple output waveguides 30 can also be arranged at unequal intervals. For example, the multiple output waveguides 30 can be divided into two groups with the central axis of the input waveguide 10 as the dividing line. The multiple output waveguides 30 located on one side of the central axis can be arranged at equal intervals according to a first interval, the multiple output waveguides 30 located on the other side of the central axis can be arranged at equal intervals according to a second interval, and the spacing between the two output waveguides 30 located on both sides of the central axis can be a third interval. The first interval and the second interval can be equal, and the third interval can be greater than the first interval.

[0074] In the embodiment of the present application, the length of each strip electrode 40 in the plurality of strip electrodes 40 along the first direction x may be greater than or equal to the length of the multimode waveguide 20 along the first direction x.

[0075] It is understood that the strip electrodes 40 can be made of a metal material, such as gold (Au). Furthermore, the length of the strip electrodes 40 can be adjusted based on the thermal conductivity of the metal material. For example, the length of each strip electrode 40 can be slightly greater than the length of the multimode waveguide 20. This ensures that the strip electrodes 40 can effectively modulate the refractive index at both ends of the multimode waveguide 20.

[0076] For example, assuming the optical switch is a 1×8 optical switch, the length of the multimode waveguide 20 can be 1000 μm, and the length of each strip electrode 40 can be greater than or equal to 1000 μm, for example, 1100 μm. Alternatively, if the length of the multimode waveguide 20 is 1300 μm, the length of each strip electrode 40 can be greater than or equal to 1300 μm.

[0077] 1 , the plurality of strip electrodes 40 may be parallel to the first direction x, and the lengths of the plurality of strip electrodes 40 may be equal. By arranging the plurality of strip electrodes 40 in parallel and having equal lengths, the design complexity of the optical switch can be effectively reduced and the design efficiency can be improved.

[0078] In the embodiment of the present application, each of the multiple output waveguides 30 may correspond to two strip electrodes 40. Furthermore, the optical field propagation path between the input waveguide 10 and each output waveguide 30 is modulated by the two strip electrodes 40 corresponding to the output waveguide 30. In other words, if it is desired to transmit an optical signal from the input waveguide 10 to any output waveguide 30, the refractive index profile of the multimode waveguide 20 may be altered by the two strip electrodes 40 corresponding to any output waveguide 30, thereby enabling the optical signal to be transmitted to that output waveguide 30.

[0079] Since each output waveguide 30 corresponds to an output port, it can also be understood that each output port of the optical switch can be modulated by two strip electrodes 40 .

[0080] For example, a 1×8 optical switch may include eight output waveguides 30 and sixteen strip electrodes 40. Assuming that the eight output waveguides 30 arranged along the second direction y are P1 to P8 from top to bottom, and the sixteen strip electrodes 40 arranged along the second direction y are E1 to E16 from top to bottom, the correspondence between the output waveguides 30 and the strip electrodes 40 can be found in Table 1. As shown in Table 1, the two strip electrodes corresponding to the i-th output waveguide Pi may be Ei and E(i+8), where i is a positive integer not greater than 8. For example, the two strip electrodes corresponding to the second output waveguide P2 may be E2 and E10.

[0081] Table 1

[0082] In order to ensure the modulation effect on the light field propagation path, the two strip electrodes 40 corresponding to each output waveguide 30 can be symmetrically arranged on both sides of the first axis, and the distance between the first axis and the second axis can be less than the threshold value, and the second axis is the central axis between the input waveguide 10 and the output waveguide 30. Since the distance between the first axis and the second axis is less than the threshold value, it can be ensured that the distance between the two axes is close. For example, the two axes can overlap as much as possible. Accordingly, the positional relationship between the strip electrodes 40 and the input waveguide 10 and the output waveguide 30 can be understood as follows: the central axis between the input waveguide 10 and each output waveguide 30 can overlap as much as possible with the central axis of the two strip electrodes 40 corresponding to the output waveguide 30.

[0083] For example, as shown in Figure 8, a 1×8 optical switch may include eight output waveguides 30 and fourteen strip electrodes 40. Assume that the eight output waveguides 30 arranged along the second direction y are P1 to P8 from top to bottom, and the fourteen strip electrodes 40 arranged along the second direction y are E1 to E14 from top to bottom. The two strip electrodes 40 corresponding to output waveguide P1 are E1 and E8. These two strip electrodes E1 and E8 may be symmetrically arranged on either side of a first axis, which may coincide with the central axis (i.e., the second axis) between the input waveguide 10 and the output waveguide P1.

[0084] Optionally, the two strip electrodes 40 corresponding to each output waveguide 30 may be arranged along the second direction y on both sides of the input waveguide 10 and the output waveguide 30. That is, along the second direction y, the two strip electrodes 40 corresponding to each output waveguide 30 are located outside the input waveguide 10 and the output waveguide 30. This allows for effective modulation of the optical field propagation path between the input waveguide 10 and the output waveguide 30.

[0085] For example, with continued reference to FIG. 8 , the two strip electrodes E1 and E8 corresponding to the output waveguide P1 may be arranged on both sides of the input waveguide 10 and the output waveguide P1 along the second direction y.

[0086] It is understood that the position of the strip electrodes 40 may not completely meet the above conditions. Accordingly, the light field propagation path can be adjusted by adjusting the magnitude of the injected current or applied voltage. In other words, the ultimate effect is to modulate the mode field distribution and effective refractive index of multiple modes by injecting current or applying voltage into the strip electrodes 40, thereby modulating the light field propagation path.

[0087] In the embodiment of the present application, the plurality of strip electrodes 40 may include at least one common electrode, and the common electrode corresponds to at least two output waveguides 30, that is, the common electrode may be shared by at least two output waveguides 30. Since at least two output waveguides 30 may share the same strip electrode 40, the number of strip electrodes 40 required in the optical switch can be effectively reduced, thereby effectively reducing the structural complexity and cost of the optical switch.

[0088] For example, as shown in FIG8 , a 1×8 optical switch can use 14 strip electrodes 40. Alternatively, if the optical switch is a 1×20 optical switch, 30 strip electrodes 40 can be used. It is understood that the position and number of the strip electrodes 40 can be adjusted based on the position and number of the output waveguides 30. For example, a 1×8 optical switch can use 12 or fewer strip electrodes 40, and a 1×20 optical switch can also use a smaller number of strip electrodes 40.

[0089] For the 1×8 optical switch shown in Figure 8, the correspondence between output waveguides 30 and strip electrodes 40 can be found in Table 2. As can be seen from Table 2, output waveguide P3 corresponds to strip electrodes E3 and E10, and output waveguide P4 corresponds to strip electrodes E4 and E10, meaning that output waveguides P3 and P4 share strip electrode E10. Furthermore, output waveguide P5 corresponds to strip electrodes E5 and E11, and output waveguide P6 corresponds to strip electrodes E5 and E12, meaning that output waveguides P5 and P6 share strip electrode E5. Because strip electrodes E5 and E10 are shared, this 1×8 optical switch only requires 14 strip electrodes to control the eight output waveguides (i.e., the eight output ports).

[0090] Table 2

[0091] It is also understandable that the output waveguides 30 in the optical switch may not share the strip electrodes 40 , that is, different output waveguides 30 may correspond to different strip electrodes 40 . Accordingly, a 1×N optical switch may include 2N strip electrodes 40 .

[0092] Optionally, as shown in Figures 2 and 3 , the optical switch provided in the embodiments of the present application may further include a first cladding layer 50 and a second cladding layer 60. The input waveguide 10, the multimode waveguide 20, and the plurality of output waveguides 30 are all located between the first cladding layer 50 and the second cladding layer 60, and the plurality of strip electrodes 40 are located on a side of the second cladding layer 60 away from the multimode waveguide 20.

[0093] The first cladding layer 50 is formed on the substrate 70 and is therefore also referred to as a lower cladding layer. The second cladding layer 60 is also referred to as an upper cladding layer. Furthermore, the refractive index of the input waveguide 10, the refractive index of the multimode waveguide 20, and the refractive index of the plurality of output waveguides 30 are all greater than the refractive index of the first cladding layer 50 and greater than the refractive index of the second cladding layer 60.

[0094] Optionally, the input waveguide 10, multimode waveguide 20, and multiple output waveguides 30 can be located in the same layer, have the same thickness, and be formed from the same material. Alternatively, the input waveguide 10, multimode waveguide 20, and multiple output waveguides 30 can constitute an optical waveguide layer, also known as an intermediate core layer. Accordingly, the refractive index profile of the optical switch can be understood as follows: a high refractive index in the intermediate core layer and a low refractive index in the upper and lower cladding layers.

[0095] In an embodiment of the present application, the optical waveguide layer can be made of a polymer with a refractive index of n = 1.47, while the upper and lower cladding layers can be made of polymers with a refractive index of n = 1.45. Furthermore, the thickness of the lower cladding layer can be greater than that of the upper cladding layer, and the thickness of the upper cladding layer can be greater than that of the optical waveguide layer. For example, the thickness of the lower cladding layer can be 15 μm, the thickness of the upper cladding layer can be 6.5 μm, and the thickness of the optical waveguide layer can be 3.5 μm.

[0096] It can be understood that the thicknesses of the first cladding layer 50 , the optical waveguide layer, and the second cladding layer 60 are for illustration only. The thicknesses of the above-mentioned film layers can be adjusted according to the refractive index of the material, which is not limited in this embodiment of the present application.

[0097] In summary, embodiments of the present application provide an optical switch that utilizes a planar waveguide structure and is capable of modulating the optical field propagation path in a multimode waveguide via electrodes. This optical switch has a simple structure, and the number of output ports can be easily expanded. Furthermore, because the optical switch modulates the optical field propagation path by adjusting the refractive index distribution of the multimode waveguide via electrodes, its operating range of input wavelengths is not limited, enabling wide-wavelength operation. Furthermore, because at least two output waveguides in this optical switch can share a strip electrode, the number of strip electrodes required in the optical switch can be effectively reduced, thereby effectively reducing the structural complexity and cost of the optical switch.

[0098] The present application also provides an optical switch assembly, as shown in Figure 9 . This optical switch assembly can include multiple cascaded optical switches 100, as provided in the above embodiments. The cascaded connection of two optical switches 100 may refer to connecting the input waveguide of one optical switch 100 to the output waveguide of another optical switch. Referring to Figure 9 , the two optical switches 100 can be cascaded via a waveguide 200 . This waveguide 200 can be a curved waveguide to ensure proper arrangement of adjacent optical switches 100 .

[0099] It is understood that within the optical switch assembly, different optical switches 100 may contain different numbers of output waveguides. By cascading multiple optical switches 100, the number of output waveguides can be effectively increased, thereby exponentially expanding the number of output ports. For example, a 1×4 optical switch and a 1×16 optical switch can be cascaded in two stages to create a 1×64 optical switch. A 1×N optical switch can be cascaded in M ​​stages (M ≥ 2) to create an optical switch with N^M ports. For example, a 1×8 optical switch can be cascaded in two stages to create a 1×64 optical switch.

[0100] The present invention also provides an optical switch integrated component, as shown in FIG10 . The optical switch integrated component includes: at least one optical processing device 300 and the optical switch 100 provided in the above embodiment. The at least one optical processing device 300 is connected to at least one output waveguide of the optical switch 100.

[0101] It can be understood that the optical switch integrated component may include multiple optical processing devices 300 , wherein each optical processing device 300 may be connected to an output waveguide of the optical switch 100 , and different optical processing devices 300 may be connected to different output waveguides.

[0102] Optionally, the at least one optical processing device 300 may include at least one of a multiplexer, a VOA, and an optical splitter. The multiplexer may combine service light and test light. The VOA and optical splitter may implement functions such as adjustable optical attenuation and equal or unequal ratio optical splitting.

[0103] In one possible implementation, the optical switch, optical switch assembly, or optical switch integrated component provided in the embodiments of the present application can be applied to an access network, such as a digital-quick optical distribution network (DQ-ODN). Furthermore, the optical switch can be used for ODN project acceptance, fault diagnosis, and early warning.

[0104] As shown in Figure 11, DQ-ODN may include: a network control engine (NCE) or a network management system, access equipment deployed in the central computer room, an optical switch unit (OSU) and an optical distribution frame (ODF), and a splitter. Referring to Figure 11, an optical artificial intelligence (OAI) board and a passive optical network (PON) board are deployed in the access equipment. The OAI board may also be referred to as a phase receiving module. The DQ-ODN can realize fiber to the home (FTTH), fiber to the building (FTTB) or fiber to the curb (FTTC). A manhole may be deployed between the central computer room and the splitter. In addition, multiple levels of splitters may be deployed between the central computer room and the user, for example, a 1:4 splitter and a 1:16 splitter may be deployed. The OSU in the DQ-ODN may adopt the optical switch, optical switch assembly or optical switch integrated component provided in the embodiments of the present application.

[0105] Optionally, the optical splitter in this implementation can be one with a built-in optical iris. Unlike other solutions based on optical time domain reflectometer (OTDR) technology for optical path scanning and fault diagnosis, the DQ-ODN solution provided in the embodiment of the present application can be based on "optical iris" technology and utilize the optical microstructure of the 1×N optical splitter in the ODN to introduce unique differential phase changes in the optical signal, thereby realizing the intelligence of passive optical components. This solution can automatically detect the link status of the optical cable and network faults, accurately locate the fault point, and the fault location error is within 2 meters.

[0106] In another possible implementation, the optical switch, optical switch assembly or optical switch integrated component provided in the embodiment of the present application can be applied to a transmission network and can be used for performance testing. As shown in Figure 12, the transmission network may include: a multiplexer (Mux), an erbium doped fiber amplifier (EDFA), a reconfigurable optical add / drop multiplexer (ROADM) and a demultiplexer (DeMux) connected in sequence between the add wave (ADD) end and the drop wave (DROP) end. In addition, the transmission network may also include at least one optical power meter (OPM) and / or at least one OTDR. Each OPM and each OTDR can access the transmission network through an optical switch (OSW). The OSW can adopt the optical switch, optical switch assembly or optical switch integrated component provided in the embodiment of the present application.

[0107] In the embodiments of the present application, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "at least one" means one or more, and "a plurality" means two or more.

[0108] In this application, the term "and / or" simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0109] The above are merely optional embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An optical switch, characterized in that: The optical switch comprises: an input waveguide, a multimode waveguide, a plurality of output waveguides, and a plurality of strip electrodes; The input waveguide, the multimode waveguide and the plurality of output waveguides are arranged along a first direction, and the input waveguide is connected to one end of the multimode waveguide, and the plurality of output waveguides are connected to the other end of the multimode waveguide; The plurality of strip electrodes are located on one side of the multimode waveguide and are arranged at intervals along the second direction, and the plurality of strip electrodes are used to modulate the light field propagation path in the multimode waveguide; The second direction is perpendicular to the first direction.

2. The optical switch according to claim 1, characterized in that: The input waveguide includes a first wedge-shaped waveguide, a wider end of the first wedge-shaped waveguide is connected to one end of the multimode waveguide.

3. The optical switch according to claim 2, characterized in that: The input waveguide further includes: a first straight waveguide connected to an end of the first wedge-shaped waveguide away from the multimode waveguide.

4. The optical switch according to any one of claims 1 to 3, characterized in that: At least one of the plurality of output waveguides comprises a second wedge-shaped waveguide, a wider end of the second wedge-shaped waveguide being connected to the other end of the multimode waveguide.

5. The optical switch according to claim 4, characterized in that: The at least one output waveguide further includes: a second straight waveguide connected to an end of the second wedge-shaped waveguide away from the multimode waveguide.

6. The optical switch according to any one of claims 1 to 5, characterized in that: The length of the multimode waveguide along the first direction is 0.5P, where P is the length of a sinusoidal wave cycle of light propagating along a sinusoidal trajectory.

7. The optical switch according to any one of claims 1 to 6, characterized in that: The width W of the multimode waveguide along the second direction satisfies: W>N×d+(N-1)×G; Wherein, N is the number of the plurality of output waveguides, d is the width of one end of the output waveguide close to the multimode waveguide along the second direction, and G is the spacing between two adjacent output waveguides.

8. The optical switch according to any one of claims 1 to 7, characterized in that: A length of each of the plurality of strip-shaped electrodes along the first direction is greater than or equal to a length of the multi-mode waveguide along the first direction.

9. The optical switch according to any one of claims 1 to 8, characterized in that: The plurality of strip electrodes are all parallel to the first direction, and the plurality of strip electrodes have the same length along the first direction.

10. The optical switch according to any one of claims 1 to 9, characterized in that: Each of the plurality of output waveguides corresponds to two of the strip electrodes; The optical field propagation path between the input waveguide and each output waveguide is modulated by the two strip electrodes corresponding to the output waveguide.

11. The optical switch according to claim 10, characterized in that: The plurality of strip electrodes include at least one common electrode, and the common electrode corresponds to at least two of the output waveguides.

12. The optical switch according to claim 10 or 11, characterized in that: The two strip electrodes corresponding to each output waveguide are symmetrically arranged on both sides of the first axis; A distance between the first axis and a second axis is smaller than a threshold, and the second axis is a center axis between the input waveguide and the output waveguide.

13. The optical switch according to any one of claims 10 to 12, characterized in that: The two strip electrodes corresponding to each output waveguide are arranged on both sides of the input waveguide and the output waveguide along the second direction.

14. The optical switch according to any one of claims 1 to 13, characterized in that: The optical switch further comprises: a first cladding layer and a second cladding layer; The input waveguide, the multimode waveguide and the plurality of output waveguides are all located between the first cladding and the second cladding, and the plurality of strip electrodes are located on a side of the second cladding away from the multimode waveguide; The refractive index of the input waveguide, the refractive index of the multimode waveguide and the refractive index of the plurality of output waveguides are all greater than the refractive index of the first cladding and greater than the refractive index of the second cladding.

15. An optical switch assembly, characterized in that: The optical switch assembly comprises: a plurality of cascaded optical switches according to any one of claims 1 to 14.

16. An optical switch integrated component, characterized in that: The optical switch integrated component comprises: at least one optical processing device, and the optical switch according to any one of claims 1 to 14; Wherein, the at least one optical processing device is connected to at least one output waveguide of the optical switch.

17. The optical switch integrated component according to claim 16, characterized in that: The at least one optical processing device includes at least one of a multiplexer, a variable optical attenuator, and an optical splitter.

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