Optical switch, optical switch assembly and optical switch integrated component

Abstract

The invention provides an optical switch, an optical switch assembly and an optical switch integrated component, and belongs to the technical field of optical communication. The optical switch provided by the invention comprises an input waveguide, a multi-mode waveguide and a plurality of output waveguides which are connected in sequence, the optical switch further comprises a plurality of strip-shaped electrodes located on one side of the multi-mode waveguide, and the plurality of strip-shaped electrodes can modulate an optical field propagation path in the multi-mode waveguide. The optical switch adopts a planar waveguide structure, and an optical field propagation path in the multimode waveguide can be modulated through the electrodes, so that the structure of the optical switch is effectively simplified, and the number of output ports is convenient to expand. Moreover, the optical switch adjusts the refractive index distribution of the multi-mode waveguide through the electrode, so that modulation of a light field propagation path is realized, the working range of the input wavelength of the optical switch is not limited, and wide-wavelength working can be realized.

Description

Technical Field

[0001] 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

[0002] Optical switches are core components used to achieve optical path conversion in optical wavelength division networks and access networks. They are often used in scenarios such as protection switching, network performance monitoring, and routing switching in optical networks.

[0003] Commonly used optical switches in related technologies generally include: cascade switches based on Mach-Zehnder interferometer (MZI) structure, cascade switches based on multimode interferometer (MMI) structure, and cascade switches based on microring resonator (MRR), etc. However, the structures of the above optical switches are relatively complex, and the ports are difficult to expand. Summary of the invention

[0004] 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 structure of the optical switch is relatively complex and the port is difficult to expand.

[0005] In a first aspect, an optical switch is provided, the optical switch comprising: 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 a second direction, and the plurality of strip electrodes are used to modulate the propagation path of the light field in the multimode waveguide. The second direction is perpendicular to the first direction.

[0006] The optical switch provided by the present application adopts a planar waveguide structure and can modulate the light field propagation path in a multimode waveguide through electrodes. The structure of the optical switch is simple, and the number of output ports is easy to expand. In addition, since the optical switch modulates the light field propagation path by adjusting the refractive index distribution of the multimode waveguide through electrodes, the working range of the input wavelength is not limited, and wide wavelength operation can be achieved.

[0007] Optionally, the input waveguide may include a first taper waveguide, wherein a wider end of the first taper waveguide is connected to one end of the multimode waveguide. The taper waveguide may also be referred to as a taper structure or a conical waveguide. The use of a taper waveguide can ensure that the transmission mode of light at the narrower end of the taper waveguide is a single-mode mode to reduce transmission loss and facilitate docking with a single-mode optical fiber. Furthermore, the light at the wider end of the taper waveguide is a multi-mode mode, which facilitates docking with a multi-mode waveguide.

[0008] Optionally, the input waveguide may further include: a first straight waveguide connected to an end of the first wedge-shaped waveguide away 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 away from the first wedge-shaped waveguide, that is, the input waveguide may include a plurality of wedge-shaped waveguides, and two adjacent wedge-shaped waveguides are connected by a straight waveguide.

[0009] 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.

[0010] Optionally, the at least one output waveguide may further include: a second straight waveguide connected to an end of the second wedge-shaped waveguide away 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 away from the second wedge-shaped waveguide, that is, the output waveguide may also include a plurality of wedge-shaped waveguides.

[0011] Optionally, the length of the multimode waveguide along the first direction may be 0.5P, where P is the length of a sine wave cycle of light propagating along a sine trajectory. Thus, it is possible to ensure that the optical signal can be effectively transmitted to the target output port without increasing the transmission loss of the optical signal, that is, to ensure reliable modulation of the optical propagation path.

[0012] Optionally, the width W of the multimode waveguide along the second direction may satisfy: 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.

[0013] It is understandable 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, it is possible to ensure that the output waveguides and the strip electrodes have sufficient arrangement space.

[0014] 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.

[0015] Optionally, the plurality of strip electrodes may be parallel to the first direction, and the plurality of strip electrodes may have the same length. Thus, the design complexity of the optical switch may be effectively reduced, and the design efficiency may be improved.

[0016] 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.

[0017] 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.

[0018] Optionally, the plurality of strip electrodes may include at least one common electrode, and the common electrode corresponds to at least two output waveguides, that is, at least two output waveguides may share the same strip electrode. Thus, the number of strip electrodes required to be configured in the optical switch can be effectively reduced, thereby reducing the structural complexity and cost of the optical switch.

[0019] Optionally, the two strip electrodes corresponding to each output waveguide may be symmetrically arranged on both sides of a first axis; the distance between the first axis and the second axis is less than a threshold, and the second axis is the center axis between the input waveguide and the output waveguide. For example, the first axis and the second axis may overlap as much as possible, thereby ensuring that the two strip electrodes can achieve effective modulation of the light propagation path between the input waveguide and the corresponding output waveguide.

[0020] Optionally, the two strip electrodes corresponding to each output waveguide may be arranged on both sides of the input waveguide and the output waveguide along the second direction, thereby achieving effective modulation of the light field propagation path between the input waveguide and the output waveguide.

[0021] Optionally, the optical switch may further include: a first cladding and a second cladding. 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.

[0022] Among them, the materials of the input waveguide, multimode waveguide and multiple output waveguides can be located in the same layer, have the same thickness, and are formed of the same material. Or it can be understood that the input waveguide, multimode waveguide and multiple output waveguides can constitute an optical waveguide layer (also called an intermediate core layer). The first cladding is formed on the substrate, which can be called the lower cladding, and correspondingly, the second cladding can be called the upper cladding. The material of the optical waveguide layer can be a polymer with a refractive index of n=1.47, and the upper and lower claddings can be a polymer with a refractive index of n=1.45. In addition, the thickness of the lower cladding can be greater than that of the upper cladding, and the thickness of the upper cladding can be greater than that of the optical waveguide layer.

[0023] In a second aspect, an optical switch assembly is provided, which may include: a plurality of cascaded optical switches as provided in the first aspect, wherein the specifications of different optical switches may be the same or different, that is, the number of output waveguides included in different optical switches may be the same or different.

[0024] By cascading multiple optical switches, the number of output waveguides included in the optical switch component can be effectively increased, thereby achieving a multiple expansion of the number of output ports.

[0025] In a third aspect, an optical switch integrated component is provided, the optical switch integrated component 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 understandable that the optical switch integrated component may include multiple optical processing devices, and different optical processing devices may be connected to different output waveguides.

[0026] Optionally, the at least one optical processing device may include at least one of a multiplexer, a variable optical attenuator (VOA) and a splitter.

[0027] In summary, the present application provides an optical switch, an optical switch assembly, and an optical switch integrated component. The optical switch adopts a planar waveguide structure and can modulate the light field propagation path in a multimode waveguide through electrodes. The structure of the optical switch is simple, and the number of output ports is easy to expand. In addition, since the optical switch modulates the light field propagation path by adjusting the refractive index distribution of the multimode waveguide through electrodes, the working range of the input wavelength is not limited, and wide wavelength operation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the structure of an optical switch provided in an embodiment of the present application;

[0029] Figure 2 yes Figure 1A cross-sectional view of the optical switch shown along a first direction x;

[0030] Figure 3 yes Figure 1 A cross-sectional view of the optical switch shown along the second direction y;

[0031] Figure 4 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;

[0032] Figure 5 is a schematic diagram of light field distribution in a multimode waveguide provided in an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of the structure of another optical switch provided in an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of a light beam propagating along a sinusoidal trajectory provided by an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of the arrangement position of a strip electrode provided in an embodiment of the present application;

[0036] Fig. 9 is a structural schematic diagram of an optical switch assembly provided in an embodiment of the present application;

[0037] Fig.10 is a schematic diagram of the structure of an optical switch integrated component provided in an embodiment of the present application;

[0038] Fig.11 is a structural schematic diagram of an optical distribution network provided in an embodiment of the present application;

[0039] Fig.12 It is a structural diagram of an optical transmission network provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] 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.

[0041] As the core device of optical wavelength division networks and access networks, the technical capabilities of optical switches directly determine the performance of optical communication networks. The demand evolution trend of optical switches is low insertion loss, low cost, high density and large ports, and high-speed switching. The evolution path of optical switch solutions is: mechanical, microelectro mechanical systems (MEMS) and on-chip waveguide solutions. At present, there are several mainstream solutions for on-chip waveguide solutions, namely waveguide optical switches: cascade switches based on MZI structure, cascade switches based on MMI structure, and cascade switches based on microring resonators. However, these solutions have problems such as difficult port expansion, complex regulation, and limited working wavelength range.

[0042] Among them, MZI is one of the basic devices in planar waveguide devices. It consists of two directional couplers (i.e., 3dB couplers) and a phase shift arm. The phase on the phase shift arm is changed by thermal light or other modulation methods to regulate the light wave. A 1×N optical switch based on an MZI structure is generally composed of a multi-stage cascade of MZIs. For example, a 1×4 optical switch is composed of a 2-stage cascade 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 MZI levels 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 K-stage cascade.

[0043] The above-mentioned optical switch based on MZI structure has the following disadvantages: 1. Port expansion depends on the number of cascades, and the port is difficult to expand. 2. The control is complex. The optical switch based on MZI structure needs to adjust the phase of the two phase shift arms on each level of MZI structure. The N-port output needs to adjust 2^K-1 MZI structures, the total number of electrodes is 2^(K+1)-2, and each port output needs to adjust 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 working 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. That is, 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 and difficult preparation of the optical switch.

[0044] 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, form self-images at specific positions and reproduce periodically 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 regulation after cascading. In addition, the regulation 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.

[0045] The embodiment of the present application provides an optical switch, which can realize multi-port output (the number of output ports is ≥ 2) through a relatively simple structure. In addition, the optical switch is easy to control, the port scale is easy to expand, and wide wavelength operation can be realized. Figure 1 is a schematic diagram of the structure of the optical switch provided in the embodiment of the present application, Figure 2 yes Figure 1 A cross-sectional view of the optical switch along a first direction x, Figure 3 yes Figure 1 The cross-sectional view of the optical switch along the second direction y is shown. Figures 1 to 3 As shown, the optical switch provided by the 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 .

[0046] refer to Figure 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 .

[0047] refer to Figure 2 and Figure 3 The plurality of strip electrodes 40 are located on one side of the multimode waveguide 20 and are arranged at intervals along the 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.

[0048] 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 in the multimode waveguide region, or runs through the multimode waveguide region.

[0049] The working principle of the optical switch provided in the embodiment of the present application is the refractive index gradient waveguide imaging theory. After the multiple strip electrodes 40 inject current or apply voltage, the refractive index distribution of the multimode waveguide 20 can be changed, so that the multimode waveguide 20 realizes a refractive index gradient distribution in the second direction y (i.e., perpendicular to the optical axis direction). Based on this, the trajectory of the optical signal in the multimode waveguide 20 can be changed, so that it enters a specific output waveguide 30.

[0050] It is understandable 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 electrode 40, and the electro-optic effect can be achieved by applying a voltage to the strip electrode 40.

[0051] After the plurality of strip electrodes 40 are injected with current or loaded with voltage, the refractive index distribution of the multimode waveguide 20 in the second direction y may be as follows: Figure 4 As shown, the corresponding light field distribution in the multimode waveguide 20 can be as follows: Figure 5 shown. Figure 4 The horizontal axis in is the dimension 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); Figure 4 The vertical axis in is the refractive index n of the multimode waveguide 20. Figure 5 The horizontal axis in is the dimension of the multimode waveguide 20 along the first direction x, that is, the length of the multimode waveguide 20, and its unit is um; Figure 5 The vertical axis in is the width of the multimode waveguide 20, and its unit is um. Figure 5 It can be seen that under the modulation of the plurality of strip electrodes 40 , the multimode waveguide 20 can transmit the optical signal input from the input waveguide 10 to the first output waveguide 30 .

[0052] In summary, the embodiment of the present application provides an optical switch, which adopts a planar waveguide structure and can modulate the light field propagation path in a multimode waveguide through electrodes. The structure of the optical switch is simple, and the number of output ports is easy to expand. In addition, since the optical switch modulates the light field propagation path by adjusting the refractive index distribution of the multimode waveguide through electrodes, the working range of the input wavelength is not limited, and wide wavelength operation can be achieved.

[0053] Figure 6 Schematic diagram of another optical switch provided in an embodiment of the present application. Figure 6 As shown, the input waveguide 10 may include a first wedge-shaped waveguide 101, and a wider end of the first wedge-shaped waveguide 101 is connected to one end of the multimode waveguide 20. The width of the wedge-shaped waveguide may refer to a dimension along the second direction y.

[0054] For example, the width of the first wedge-shaped waveguide 101 can be gradually changed from 3.5um to 10um, that is, the width of the first wedge-shaped waveguide 101 at one end close to the multimode waveguide 20 can be 10um, and the width of the first wedge-shaped waveguide 101 at one end away from the multimode waveguide 20 can be 3.5um. The dimension (i.e., length) of the first wedge-shaped waveguide 101 along the first direction x can be 200um.

[0055] Continue to refer Figure 6 The input waveguide 10 may further include: a first straight waveguide 102, the first straight waveguide 102 being connected to an end of the first wedge-shaped waveguide 101 away from the multimode waveguide 20. The straight waveguide may refer to a strip waveguide with a constant width.

[0056] 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 um.

[0057] Alternatively, if Figure 6 As shown, at least one of the plurality of output waveguides 30 may include a second wedge-shaped waveguide 301, and a wider end of the second wedge-shaped waveguide 301 is connected to the other end of the multimode waveguide 20. For example, Figure 6 In the optical switch shown, each output waveguide 30 may include a second wedge-shaped waveguide 301 .

[0058] For example, the width of the second wedge-shaped waveguide 301 can gradually change from 10um to 3.5um, that is, the width of the second wedge-shaped waveguide 301 close to the multimode waveguide 20 can be 10um, and the width of the second wedge-shaped waveguide 301 away from the multimode waveguide 20 can be 3.5um. The size of the second wedge-shaped waveguide 301 along the first direction x can also be 200um.

[0059] In the embodiment of the present application, a wedge-shaped waveguide is used in the input waveguide and the output waveguide, which can ensure that the transmission mode of light at the narrower end of the wedge-shaped waveguide is a single-mode mode, so as to reduce transmission loss and facilitate docking with a single-mode optical fiber. In addition, the light at the wider end of the wedge-shaped waveguide is a multi-mode mode, which is convenient for docking with a multi-mode waveguide.

[0060] Continue to refer Figure 6 , the at least one output waveguide 30 may further include: a second straight waveguide 302, the second straight waveguide 302 being connected to an end of the second wedge-shaped waveguide 301 away 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 away from the multimode waveguide 20. For example, the width of the second straight waveguide 302 may also be 3.5 um.

[0061] It is understandable that the size of the narrower end of the wedge-shaped waveguide is not necessarily limited to 3.5um, and can be adjusted according to the material properties, as long as the transmission mode can be ensured to be a single-mode mode. Similarly, the size of the wider end of the wedge-shaped waveguide is not necessarily limited to 10um, and can be adjusted according to the actual effect. For example, the size of the wider end of the wedge-shaped waveguide can be 8um, 9um, 11um or other values. The embodiment of the present application does not limit the size of the wedge-shaped waveguide.

[0062] Optionally, the output waveguide 30 may be Figure 6 As shown, a wedge-shaped waveguide is connected to a straight waveguide, or a wedge-shaped waveguide is connected to a straight waveguide, and then connected to a wedge-shaped waveguide. Similarly, the input waveguide 10 can also be a wedge-shaped waveguide connected to a straight waveguide, and then connected to a wedge-shaped waveguide. The embodiment of the present application does not limit the structure of the input waveguide and the output waveguide, as long as the mode matching is achieved as much as possible and the loss is reduced.

[0063] In the embodiment of the present application, since the working principle of the optical switch is the refractive index gradient waveguide imaging theory, 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 a sine wave cycle of the light beam propagating along the sine trajectory. That is, Figure 7 As shown, the length of the multimode waveguide 20 can be the length of 0.5 sine wave cycles of light propagating along the track, thereby ensuring that the optical signal can be effectively transmitted along the track to the target output waveguide, that is, the target output port.

[0064] 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 can not only avoid increasing the size, cost and manufacturing process complexity of the optical switch, but also effectively reduce the loss of optical signals during transmission.

[0065] For example, assuming that 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) may be 950um to 1050um, for example, 1000um. Alternatively, if the optical switch is a 1×20 optical switch, the length of the multimode waveguide 20 may be 1250 to 1350, for example, 1300um or 1340um.

[0066] 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, wherein N is the number of the plurality of output waveguides 30, d is the width of one end of the output waveguide 30 close to the multimode waveguide 20 along the second direction y, and G is the spacing between two adjacent output waveguides 30.

[0067] It is understood that the spacing G between the output waveguides 30 may refer to the spacing close to 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.

[0068] It can also be understood that the spacing G between two adjacent output waveguides 30 can be flexibly adjusted according to the optical insertion loss and crosstalk indicators. For example, assuming that the optical switch is a 1×8 optical switch, the spacing G can be 1um or 2um. Alternatively, if the optical switch is a 1×20 optical switch, the spacing G can be 0, or 1um or even larger.

[0069] 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 um. Of course, the width of the multimode waveguide 20 can also be flexibly adjusted according to the requirements of the application scenario.

[0070] 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 the first interval, the multiple output waveguides 30 located on the other side of the central axis can be arranged at equal intervals according to the second interval, and the interval between the two output waveguides 30 located on both sides of the central axis can be the third interval. Among them, the first interval and the second interval can be equal, and the third interval can be greater than the first interval.

[0071] In the embodiment of the present application, the length of each of 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.

[0072] It is understandable that the material of the strip electrode 40 can be a metal material, such as gold (Au). In addition, the length of the strip electrode 40 can be adjusted according to the heat conduction effect 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. Thus, it can be ensured that the strip electrode 40 can also effectively modulate the refractive index at both ends of the multimode waveguide 20.

[0073] For example, assuming that the optical switch is a 1×8 optical switch, the length of the multimode waveguide 20 may be 1000um, and the length of each strip electrode 40 may be greater than or equal to 1000um, for example, 1100um. Alternatively, if the length of the multimode waveguide 20 is 1300um, the length of each strip electrode 40 may be greater than or equal to 1300um.

[0074] Alternatively, if Figure 1 As shown, 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 the same length, the design complexity of the optical switch may be effectively reduced and the design efficiency may be improved.

[0075] 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. That is, if it is necessary to transmit the optical signal from the input waveguide 10 to any output waveguide 30, the refractive index distribution of the multimode waveguide 20 may be changed by the two strip electrodes 40 corresponding to any output waveguide 30, thereby transmitting the optical signal to any output waveguide 30.

[0076] 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 .

[0077] For example, a 1×8 optical switch may include 8 output waveguides 30 and 16 strip electrodes 40. Assuming that the 8 output waveguides 30 arranged along the second direction y are P1 to P8 in order from top to bottom, and the 16 strip electrodes 40 arranged along the second direction y are E1 to E16 in order from top to bottom, the corresponding relationship between the output waveguides 30 and the strip electrodes 40 can refer to 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.

[0078] Table 1

[0079]

[0080] 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 electrode 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.

[0081] For example, Figure 8 As shown, the 1×8 optical switch may include 8 output waveguides 30 and 14 strip electrodes 40. Assume that the 8 output waveguides 30 arranged along the second direction y are P1 to P8 in order from top to bottom, and the 14 strip electrodes 40 arranged along the second direction y are E1 to E14 in order from top to bottom. Among them, the two strip electrodes 40 corresponding to the output waveguide P1 are E1 and E8, and the two strip electrodes E1 and E8 can be symmetrically arranged on both sides of the first axis, and the first axis can coincide with the central axis (i.e., the second axis) between the input waveguide 10 and the output waveguide P1.

[0082] 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. Thus, effective modulation of the light field propagation path between the input waveguide 10 and the output waveguide 30 can be achieved.

[0083] For example, continue to refer to Figure 8 The two strip electrodes E1 and E8 corresponding to the output waveguide P1 can be arranged on both sides of the input waveguide 10 and the output waveguide P1 along the second direction y.

[0084] It is understandable that the position of the strip electrode 40 may not completely meet the above conditions, and accordingly, the light field propagation path can be adjusted by adjusting the injection current or the applied voltage. That is, the final effect is to modulate the light field propagation path by injecting current or applying voltage into the strip electrode 40 to adjust the mode field distribution and effective refractive index of multiple modes.

[0085] 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 to be configured in the optical switch may be effectively reduced, thereby effectively reducing the structural complexity and cost of the optical switch.

[0086] For example, Figure 8As shown, a 1×8 optical switch may use 14 strip electrodes 40. Alternatively, if the optical switch is a 1×20 optical switch, 30 strip electrodes 40 may be used. It is understood that the position and number of the strip electrodes 40 may be adjusted according to the position and number of the output waveguides 30, for example, a 1×8 optical switch may use 12 or less strip electrodes 40, and a 1×20 optical switch may also use a lesser number of strip electrodes 40.

[0087] for Figure 8 For the 1×8 optical switch shown, the corresponding relationship between the output waveguide 30 and the strip electrode 40 can be referred to Table 2. As can be seen from Table 2, the output waveguide P3 corresponds to the strip electrodes E3 and E10, and the output waveguide P4 corresponds to the strip electrodes E4 and E10, that is, the output waveguides P3 and P4 share the strip electrode E10. In addition, the output waveguide P5 corresponds to the strip electrodes E5 and E11, and the output waveguide P6 corresponds to the strip electrodes E5 and E12, that is, the output waveguides P5 and P6 share the strip electrode E5. Since the strip electrodes E5 and E10 are common electrodes, the 1×8 optical switch only needs to use 14 strip electrodes to achieve the regulation of 8 output waveguides (i.e., 8 output ports).

[0088] Table 2

[0089]

[0090] 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 .

[0091] Alternatively, if Figure 2 and Figure 3 As shown, the optical switch provided in the embodiment of the present application may further include: a first cladding 50 and a second cladding 60. The input waveguide 10, the multimode waveguide 20 and the plurality of output waveguides 30 are all located between the first cladding 50 and the second cladding 60, and the plurality of strip electrodes 40 are located on a side of the second cladding 60 away from the multimode waveguide 20.

[0092] The first cladding layer 50 is formed on the substrate 70 and is therefore also referred to as a lower cladding layer, and the second cladding layer 60 is also referred to as an upper cladding layer. In addition, 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.

[0093] Optionally, the input waveguide 10, the multimode waveguide 20 and the plurality of output waveguides 30 may be located in the same layer, have the same thickness, and be formed of the same material. Alternatively, it can be understood that the input waveguide 10, the multimode waveguide 20 and the plurality of output waveguides 30 may constitute an optical waveguide layer, which may also be referred to as an intermediate core layer. Accordingly, the refractive index distribution of the optical switch may be understood as follows: the intermediate core layer has a high refractive index, and the upper and lower cladding layers have a low refractive index.

[0094] In the embodiment of the present application, the material of the optical waveguide layer can be a polymer with a refractive index of n=1.47, and the upper cladding and the lower cladding can be polymers with a refractive index of n=1.45. In addition, the thickness of the lower cladding can be greater than the thickness of the upper cladding, and the thickness of the upper cladding can be greater than the thickness of the optical waveguide layer. For example, the thickness of the lower cladding can be 15um, the thickness of the upper cladding can be 6.5um, and the thickness of the optical waveguide layer can be 3.5um.

[0095] It can be understood that the thicknesses of the first cladding layer 50, the optical waveguide layer and the second cladding layer 60 are only for illustration, and the thicknesses of the above-mentioned film layers can be adjusted according to the refractive index of the material, which is not limited in the embodiments of the present application.

[0096] In summary, an embodiment of the present application provides 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. The structure of the optical switch is simple, and the number of output ports is easy to expand. In addition, since the optical switch modulates the light field propagation path by adjusting the refractive index distribution of the multimode waveguide through electrodes, the working range of the input wavelength is not limited, and wide wavelength operation can be achieved. In addition, since at least two output waveguides in the optical switch can share a strip electrode, the number of strip electrodes required to be set in the optical switch can be effectively reduced, thereby effectively reducing the structural complexity and cost of the optical switch.

[0097] The present application also provides an optical switch assembly, such as Fig. 9 As shown, the optical switch assembly may include a plurality of cascaded optical switches 100 as provided in the above embodiments. The cascaded connection of two optical switches 100 may refer to the connection of an input waveguide of one optical switch 100 with an output waveguide of another optical switch. Fig. 9 , two optical switches 100 can be cascaded through a waveguide 200. The waveguide 200 can be a curved waveguide to ensure that adjacent optical switches 100 can be reasonably arranged.

[0098] It is understandable that in the optical switch assembly, the number of output waveguides included in different optical switches 100 may be different. By cascading multiple optical switches 100, the number of output waveguides can be effectively increased, thereby achieving a doubling of 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 achieve a 1×64 optical switch. A 1×N optical switch can be cascaded in M ​​(M≥2) stages to achieve an optical switch with N^M ports. For example, a 1×8 optical switch can be cascaded in two stages to achieve a 1×64 optical switch.

[0099] The present application also provides an optical switch integrated component, such as Fig.10 As shown, 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 .

[0100] It can be understood that the optical switch integrated component may include a plurality of 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.

[0101] Optionally, the at least one optical processing device 300 may include at least one of a multiplexer, a VOA and a splitter. The multiplexer may realize the function of combining service light and test light. The VOA and the splitter may realize functions such as adjustable optical attenuation, equal or unequal ratio splitting, etc.

[0102] In a 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 an access network, for example, a digital-quick optical distribute network (DQ-ODN). In addition, the optical switch can be used for ODN project acceptance, fault diagnosis and early warning, etc.

[0103] like Fig.11 As shown in FIG, DQ-ODN may include: a network control engine (NCE) or a network management system, access equipment deployed in a central computer room, an optical switch unit (OSU) and an optical distribution frame (ODF), and an optical splitter. Fig.11, an optical artificial intelligence (OAI) board and a passive optical network (PON) board are deployed in the access device. Among them, the OAI board can also be called 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 can be deployed between the central computer room and the splitter. In addition, multiple levels of splitters can be deployed between the central computer room and the user, for example, a 1:4 splitter and a 1:16 splitter can be deployed. Among them, the OSU in the DQ-ODN can adopt the optical switch, optical switch assembly or optical switch integrated component provided in the embodiment of the present application.

[0104] Optionally, the optical splitter in this implementation can be an optical splitter with a built-in fiber iris. Unlike other solutions based on optical time domain reflectometer (OTDR) technology to achieve optical path scanning and fault diagnosis, the DQ-ODN solution provided in the embodiment of the present application can be based on the "optical iris" technology, using the optical microstructure of the 1×N optical splitter in the ODN to introduce a unique differential phase change in the optical signal to achieve the intelligence of passive optical devices. This solution can automatically detect the link status and network faults of the optical cable, accurately locate the fault point, and the fault location error is within 2 meters.

[0105] 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 detection. Fig.12As shown, 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.

[0106] 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 "plurality" means two or more.

[0107] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0108] The above is only an optional implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope 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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