Optical waveguide device and optical switch system

Abstract

An optical waveguide device and an optical switch system comprise a first input optical fiber, a second input optical fiber, a first optical fiber coupling structure, a first waveguide structure, a first-stage multimode interference coupler structure, a Mach-Zehnder structure, a second-stage multimode interference coupler structure, a second waveguide structure and a second optical fiber coupling structure which are connected in sequence. A first control electrode and a second control electrode are arranged at the corresponding positions of the Mach-Zehnder structure. The utility model provides an optical waveguide device which depends on a silicon substrate platform, utilizes a polymer as a waveguide material, adopts a Mach-Zehnder structure and a multimode interference coupler, realizes a 2 * 2 optical switch function, can well realize random switching of an optical path between two output ports, has potential economic and application values, and has a wide application prospect. The method can be widely applied to the field of optical communication. Moreover, the optical switch array system can be formed through various topological forms according to different application scenes.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical waveguides, and in particular relates to an optical waveguide device and an optical switch system. Background Art

[0002] The demand for communication system capacity has prompted the development of all-optical switching networks. As the core equipment of all-optical switching networks, optical switches play an important role in optical routing and optical interconnection, and are widely used as routing selectors, wavelength selectors, and optical cross-connection devices in optical communication systems. Existing optical switches are difficult to achieve topological cascading, have a narrow application range, and are costly, bulky, and have large losses. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides an optical waveguide device and an optical switch system.

[0004] The purpose of the utility model is to be achieved by adopting the following technical solutions. According to an optical waveguide device proposed by the utility model, it includes a first input optical fiber and a second input optical fiber, the first input optical fiber and the second input optical fiber are aligned with the first waveguide structure through a first optical fiber coupling structure, the other end of the first waveguide structure is connected to a first-level multimode interference coupler structure, the first-level multimode interference coupler structure is connected to a Mach-Zehnder structure, the other end of the Mach-Zehnder structure is connected to a second-level multimode interference coupler structure, the other end of the second-level multimode interference coupler structure is connected to a second waveguide structure, the second waveguide structure is aligned with the first output optical fiber and the second output optical fiber through a second optical fiber coupling structure, and the first control electrode and the second control electrode are arranged at corresponding positions of the Mach-Zehnder structure.

[0005] Furthermore, it includes a polymer waveguide optical switch unit chip using a silicon substrate, wherein the silicon substrate is coated with a lower cladding, a core layer, and an upper cladding in sequence, the core layer includes a multimode interference coupler structure core layer, a conventional waveguide structure core layer, and a Mach-Zehnder structure core layer, a first control electrode and a second control electrode are arranged on the surface of the upper cladding at a corresponding position of the Mach-Zehnder structure core layer, the Mach-Zehnder structure includes a Mach-Zehnder structure core layer, the first-level multimode interference coupler structure and the second-level multimode interference coupler structure both include a multimode interference coupler structure core layer, and the first waveguide structure and the second waveguide structure both include a conventional waveguide structure core layer.

[0006] Furthermore, the first optical fiber coupling structure and the second optical fiber coupling structure are fixed on the polymer waveguide optical switch unit chip by optical glue.

[0007] Furthermore, the material coated on the lower cladding layer, the core layer and the upper cladding layer is a polymer waveguide glue with different refractive indices.

[0008] Furthermore, the Mach-Zehnder structure adopts a structure with an arc. The Mach-Zehnder structure is divided into two modulation arms, which divide the optical path into two parts. The optical path is transmitted on the two modulation arms respectively. Both modulation arms are arc-shaped, and in the transmission direction of the optical path, the spacing between the two modulation arms first increases and then decreases.

[0009] An optical switch system comprises a plurality of optical waveguide devices connected by waveguide channels, wherein the plurality of optical waveguide devices are connected to form an optical switch array structure, wherein a cross junction is formed at the cross-overlapping position of the waveguide channels, and an arc transition structure is arranged from the input end and the output end of the cross junction to the center position of the cross junction.

[0010] Furthermore, the optical switch array structure adopts a Bene structure. The N×N optical switch system of the Bene structure is divided into 2Log2N-1 levels, and the number of optical waveguide devices in each level is The total number of optical waveguide devices is indivual.

[0011] Furthermore, the optical switch array structure adopts a Cross-bar structure, and the number of optical waveguide devices in the N×N optical switch system of the Cross-bar structure is N. 2 , the number of optical switch units passing through the optical transmission path of the Cross-bar structure is in the range of 1 to 2N-1.

[0012] Furthermore, the optical switch array structure adopts an N-Stage Planar Architecture structure. The N×N optical switch system of the N-Stage Planar Architecture structure is divided into N stages connected in series, and the number of optical waveguide devices of adjacent stages is different. When N is an even number, half of the stages use optical waveguide devices, and the other half of the level uses Optical waveguide devices are needed to create an N×N optical switch system An optical waveguide device.

[0013] Furthermore, the optical switch array structure adopts a Switch-and-select structure or a Dilated Banyan structure, and the number of optical waveguide devices in any N×N optical switch system composed of the two structures is 2N.(N-1), and the number of optical waveguide devices on the optical transmission path is 2Log2N.

[0014] Compared with the prior art, the utility model is beneficial in that:

[0015] The utility model proposes an optical waveguide device that relies on a silicon substrate platform, uses polymer as a waveguide material, adopts a Mach-Zehnder structure, and a multimode interference coupler to realize a 2×2 optical switch function, which can well realize arbitrary switching of the optical path at two output ports, has potential economic and application value, and can be widely used in the field of optical communications. In addition, the utility model can form an optical switch array system through a variety of topological forms according to different application scenarios.

[0016] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the optical waveguide device in the embodiment of the utility model;

[0018] Figure 2a It is a partial schematic diagram of an optical waveguide device in an embodiment of the utility model;

[0019] Figure 2b for Figure 2a Schematic diagram of the cross section at A in the middle;

[0020] Figure 2c for Figure 2a Schematic diagram of the cross section at B;

[0021] Figure 2d for Figure 2a Schematic diagram of the cross section at C in the middle;

[0022] Figure 3a A schematic diagram of the light path simulation result of the optical waveguide device in the embodiment of the utility model;

[0023] Figure 3b It is another schematic diagram of light path simulation results of the optical waveguide device in the embodiment of the utility model;

[0024] Figure 4a This is a schematic diagram of the structure of the optical switch system of the Bene structure;

[0025] Figure 4b The schematic diagram of the optical switch system structure of the Cross-bar structure;

[0026] Figure 4c The schematic diagram of the optical switch system structure of N-Stage Planar Architecture;

[0027] Figure 4dThe schematic diagram of the optical switch system structure of the Switch-and-select structure;

[0028] Figure 4e This is a schematic diagram of the structure of the optical switch system of the Dilated Banyan structure;

[0029] Figure 5 Schematic diagram of the structure of the cross junction in the optical switch system.

[0030] [Reference Signs]

[0031] 1-1, first input optical fiber, 1-2, second input optical fiber, 2, polymer waveguide optical switch unit chip, 3-1, first output optical fiber, 3-2, second output optical fiber, 4-1, first optical fiber coupling structure, 4-2, second optical fiber coupling structure, 5-1, first waveguide structure, 5-2, second waveguide structure, 6-1, first-level multimode interference coupler structure, 6-2, second-level multimode interference coupler structure, 7-Mach-Zehnder structure, 8-1, first control electrode, 8-2, second control electrode, 9, multimode interference coupler structure core layer, 10, conventional waveguide structure core layer, 11, Mach-Zehnder structure core layer, 12, upper cladding, 13, lower cladding, 14, silicon substrate. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] An embodiment of an optical waveguide device of the utility model is as follows Figures 1 to 3b As shown, hereinafter referred to as the device. The device is based on a silicon substrate platform, uses polymer as a waveguide material, and adopts a Mach-Zehnder combined with a multimode interference coupler structure to realize a 2×2 optical switch function, which can well realize arbitrary switching of the optical path at two output ports, and the device can be used as an optical switch unit for topological cascading to realize the form of an optical switch array system, which can be widely used in the field of optical communications.

[0034] The device includes two input optical fibers (respectively a first input optical fiber 1-1 and a second input optical fiber 1-2), a polymer waveguide optical switch unit chip 2, and two output optical fibers (respectively a first output optical fiber 3-1 and a second output optical fiber 3-2). The polymer waveguide optical switch unit chip 2 includes two optical fiber coupling structures (respectively a first optical fiber coupling structure 4-1 and a second optical fiber coupling structure 4-2), a conventional waveguide structure (respectively a first waveguide structure 5-1 and a second waveguide structure 5-2), two multimode interference coupler structures (respectively a first-level multimode interference coupler structure 6-1 and a second-level multimode interference coupler structure 6-2), a Mach-Zehnder structure 7 and two control electrodes (respectively a first control electrode 8-1 and a second control electrode 8-2).

[0035] The light beam can enter the device in two ways. According to the transmission direction of the light beam, the light beam passes through the corresponding input optical fiber (the first input optical fiber 1-1 and / or the second input optical fiber 1-2), the first optical fiber coupling structure 4-1, the first waveguide structure 5-1, the first multimode interference coupler structure 6-1, the Mach-Zehnder structure 7, the second multimode interference coupler structure 6-2, the second waveguide structure 5-2, the second optical fiber coupling structure 4-2, and then outputs through the corresponding output optical fiber (the first output optical fiber 3-1 and / or the second output optical fiber 3-2). The Mach-Zehnder structure 7 is provided with a first control electrode 8-1 and a second control electrode 8-2 corresponding to the two light beams.

[0036] The first input optical fiber 1-1 and the second input optical fiber 1-2 are aligned with the first waveguide structure 5-1 through the first optical fiber coupling structure 4-1, and the first output optical fiber 3-1 and the second output optical fiber 3-2 are aligned with the second waveguide structure 5-2 through the second optical fiber coupling structure 4-2. The optical fiber coupling structure includes a V-groove structure and a U-groove structure for fixing the optical fiber, and the optical fiber is fixed in the optical fiber coupling structure. The optical fiber coupling structure is fixed on the polymer waveguide optical switch unit chip 2 by optical glue, so as to align the optical fiber with the waveguide structure. The Mach-Zehnder structure 7 is also connected to the first-level multimode interference coupler 6-1 and the second-level multimode interference coupler 6-2 respectively through a conventional waveguide structure.

[0037] like Figure 2aThe schematic diagram of the optical waveguide device near the input end is shown. The polymer waveguide optical switch unit chip 2 uses a silicon substrate 14, and the lower cladding 13, the core layer, and the upper cladding 12 are coated on the silicon substrate 14 in sequence. The materials coated on different layers are polymer waveguide glues with different refractive indices. The coating film method can reduce the volume and reduce the cost. The core layer structure at different positions of the polymer waveguide optical switch unit chip 2 is different, wherein a multimode interference coupler core layer 9 is set at the multimode interference coupler structure position, a conventional waveguide structure core layer 10 is set at the conventional waveguide structure position, and a Mach-Zehnder structure core layer 11 is set at the Mach-Zehnder structure 7 position. The multimode interference coupler core layer 9 is a whole, and the conventional waveguide structure core layer 10 and the Mach-Zehnder structure core layer 11 are divided into two parallel parts, which are equal to the number of light beams that can be input / output by the optical waveguide device.

[0038] In a conventional waveguide structure, two conventional waveguide structure core layers 10 are provided, corresponding to the two light beams respectively. A control electrode is prepared on the upper surface of the Mach-Zehnder structure 7, and the Mach-Zehnder structure 7 is provided with two Mach-Zehnder structure core layers 11, corresponding to the two light beams and the two control electrodes (respectively, the first control electrode 8-1 and the second control electrode 8-2). The Mach-Zehnder structure 7 uses a simulated structure with a suitable curvature. The Mach-Zehnder structure 7 is divided into two modulation arms, which divides the optical path into two parts. The optical path is transmitted on the two modulation arms respectively. The two modulation arms are at a certain distance from each other and are both arc-shaped. In the transmission direction of the optical path, the spacing between the two modulation arms increases first and then decreases, thereby reducing the channel loss under the premise of ensuring that there is no mutual interference between the electrodes.

[0039] The optical signal input by the first input optical fiber 1-1 (or the second input optical fiber 1-2) is divided into two paths after passing through the first-level multimode interference coupler 6-1, and enters the two interference arms (two Mach-Zehnder structure core layers 11) of the Mach-Zehnder structure 7 respectively. The two optical signals generate a phase difference under the action of the corresponding control electrodes, thereby determining which output port of the second-level multimode interference coupler 6-2 to interfere with and output, thereby realizing the switching of the optical path between the first output optical fiber 3-1 and the second output optical fiber 3-2 and the optical switch function.

[0040] Figure 3a , Figure 3b The simulation results of an optical waveguide device that relies on a silicon substrate platform, uses polymer as a waveguide material, and adopts the structure of a Mach-Zehnder and multi-mode interference coupler to achieve a 2×2 optical switch function.

[0041] In order to realize an N×N optical switch system with a large number of ports, the utility model proposes a variety of topological structures, namely: (a) Bene structure, (b) Cross-bar structure, (c) N-Stage PlanarArchitecture structure, (d) Switch-and-select structure, and (e) Dilated Banyan structure.

[0042] Figures 4a to 4e The schematic diagrams of five topological structures are given. Each rectangular box in the schematic diagram represents a 2×2 optical switch unit (an optical waveguide device), and the straight line part represents the waveguide channel. A 4×4 optical switch system is taken as an example for explanation.

[0043] The Bene structure has many features, such as reconfigurability and non-blocking, and requires the least number of optical switch units in the N×N optical switch system. Figure 4a As shown in the figure. The N×N optical switch system of Bene structure requires 2Log2N-1 stages, and the number of optical switch units in each stage is The total number of optical switch units is , N≥4, such as Figure 4a It is a 4×4 Bene structure with 3 levels, 6 optical switch units, and 2 cross junctions, which are formed by the intersection of two waveguide channels. The outstanding feature of the Bene structure is that it requires the least number of optical switch units, and the number of optical switch units on each light propagation path is the same, making the Bene structure the most suitable structure for large-port optical switches.

[0044] Cross-bar structure Figure 4b As shown in Figure 1, the structure is simple and easy to expand. However, the number of optical switch units required in the Cross-bar structure reaches N. 2 And it cannot be optimized. If the number of ports >> 1, the consistency of the optical switch unit actually processed will greatly limit the maximum number of ports that the Cross-bar structure can reach, which is also a disadvantage compared with the Bene structure. In addition, the number of optical switch units passing through the optical transmission path is not fixed, and the number of optical switch units varies between 1 and 2N-1. At the same time, the power dissipation of different paths is also different, so that the output optical power is related to the optical transmission path.

[0045] N-Stage Planar Architecture structure Figure 4c As shown, it is realized by connecting N stages in series. When using 2×2 optical switch units as sub-units, half of the stages use optical switch units, and the other half of the level uses optical switch units. When N is an even number, creating an N×N optical switch array requires The structure can realize the generalized non-blocking characteristic.

[0046] For the Switch-and-select structure and the Dilated Banyan structure, the number of optical switch units required to form an N×N optical switch system is 2N.(N-1). One advantage of these two topologies is that each optical switch unit has only a single optical path in a certain switch state. This eliminates the spatial overlap of the two optical paths, thereby reducing crosstalk. In addition, these two structures also ensure that the number of optical switch units on each optical transmission path is fixed, which is 2Log2N, which also makes the insertion loss of the optical switch independent of the optical transmission path. However, the number of optical switch units required by these two structures is the largest among the five optical switch systems, making these two structures unable to be effectively expanded. The characteristics of different optical switch topologies are shown in Table 1.

[0047]

[0048] Table 1

[0049] It can be seen that under the above five topological structures, there will be cross-overlapping between the waveguide channels to form a cross-junction. In view of this situation, the utility model proposes the following form of cross-junction to reduce the transmission loss caused by the cross-overlapping situation: the cross-junction is a deformation of two 1×1MMI structures overlapping at 90° to each other, such as Figure 5 As shown, the cross junction is a cross-shaped waveguide structure with two input ends and two output ends, and an arc transition structure is set at the center of each input end and output end to the cross junction. By making an arc transition to the cross junction, the difficulty of the preparation process is reduced while the transmission efficiency of the optical signal is improved.

[0050] The optical waveguide device of the utility model adopts the material form of silicon substrate plus polymer, which can greatly improve the film forming property of waveguide glue and reduce the overall cost of the device, and utilizes the adjustable refractive index property of polymer waveguide glue to achieve the reduction of the overall volume of the device.

[0051] The utility model improves coupling efficiency and reduces coupling loss by designing an optical fiber coupling structure on a polymer waveguide optical switch unit chip, and reduces additional loss caused by mode mismatch, end face gap, etc. by coating an optical glue with a refractive index at the connection.

[0052] The utility model adopts a multi-mode interference coupler structure to realize the distribution of light paths, improves the processability of product preparation, increases the process tolerance during the preparation process, and is conducive to reducing product production costs.

[0053] The utility model uses 2×2 polymer waveguide optical switch unit chips as modular units, and can perform on-chip or / and off-chip topological cascading according to requirements to form an optical switch array system structure, which can be applied to more complex optical path systems.

[0054] In summary, the utility model proposes an optical waveguide device that relies on a silicon substrate platform, uses polymer as a waveguide material, adopts a Mach-Zehnder structure, and a multimode interference coupler to realize a 2×2 optical switch function. It can well realize the arbitrary switching of the optical path at two output ports, has potential economic and application value, and can be widely used in the field of optical communications. And the utility model can be used according to different application scenarios, including but not limited to Figures 4a to 4e topological form to form an optical switch array structure system.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An optical waveguide device, characterized in that: The invention comprises a first input optical fiber (1-1) and a second input optical fiber (1-2); the first input optical fiber (1-1) and the second input optical fiber (1-2) are aligned with a first waveguide structure (5-1) through a first optical fiber coupling structure (4-1); the other end of the first waveguide structure (5-1) is connected to a first-level multimode interference coupler structure (6-1); the first-level multimode interference coupler structure (6-1) is connected to a Mach-Zehnder structure (7); the other end of the Mach-Zehnder structure (7) is connected to a second-level multimode interference coupler structure (6-2); the other end of the second-level multimode interference coupler structure (6-2) is connected to a second waveguide structure (5-2); the second waveguide structure (5-2) is aligned with a first output optical fiber (3-1) and a second output optical fiber (3-2) through a second optical fiber coupling structure (4-2); and a first control electrode (8-1) and a second control electrode (8-2) are arranged at corresponding positions of the Mach-Zehnder structure (7).

2. An optical waveguide device according to claim 1, characterized in that: The invention comprises a polymer waveguide optical switch unit chip (2) using a silicon substrate (14), wherein a lower cladding layer (13), a core layer, and an upper cladding layer (12) are sequentially coated on the silicon substrate (14), wherein the core layer comprises a multimode interference coupler structure core layer (9), a conventional waveguide structure core layer (10), and a Mach-Zehnder structure core layer (11), wherein a first control electrode (8-1) and a second control electrode (8-2) are arranged on the surface of the upper cladding layer (12) at a position corresponding to the Mach-Zehnder structure core layer (11), wherein the Mach-Zehnder structure (7) comprises a Mach-Zehnder structure core layer (11), wherein the first-level multimode interference coupler structure (6-1) and the second-level multimode interference coupler structure (6-2) both comprise a multimode interference coupler structure core layer (9), and wherein the first waveguide structure (5-1) and the second waveguide structure (5-2) both comprise a conventional waveguide structure core layer (10).

3. An optical waveguide device according to claim 2, characterized in that: The first optical fiber coupling structure (4-1) and the second optical fiber coupling structure (4-2) are fixed on the polymer waveguide optical switch unit chip (2) by optical glue.

4. An optical waveguide device according to claim 2, characterized in that: The material coated on the lower cladding layer (13), the core layer and the upper cladding layer (12) is a polymer waveguide glue with different refractive indices.

5. The optical waveguide device according to claim 1, characterized in that: The Mach-Zehnder structure (7) adopts a structure with an arc. The Mach-Zehnder structure (7) is divided into two modulation arms, which divide the optical path into two parts. The optical path is transmitted on the two modulation arms respectively. Both modulation arms are arc-shaped, and in the transmission direction of the optical path, the distance between the two modulation arms increases first and then decreases.

6. An optical switch system, characterized in that: The invention comprises a plurality of optical waveguide devices connected by waveguide channels, wherein the plurality of optical waveguide devices are connected to form an optical switch array structure, a cross junction is formed at the cross-overlapping position of the waveguide channels, and an arc transition structure is arranged from the input end and the output end of the cross junction to the center position of the cross junction.

7. An optical switch system according to claim 6, characterized in that: The optical switch array structure adopts the Bene structure. The N×N optical switch system of the Bene structure is divided into 2Log2N-1 levels. The number of optical waveguide devices in each level is The total number of optical waveguide devices is indivual.

8. An optical switch system according to claim 6, characterized in that: The optical switch array structure adopts a Cross-bar structure. The number of optical waveguide devices in the N×N optical switch system of the Cross-bar structure is N. 2 , the number of optical switch units passing through the optical transmission path of the Cross-bar structure is in the range of 1 to 2N-1.

9. An optical switch system according to claim 6, characterized in that: The optical switch array structure adopts an N-Stage Planar Architecture structure. The N×N optical switch system of the N-Stage Planar Architecture structure is divided into N stages connected in series. The number of optical waveguide devices of adjacent stages is different. When N is an even number, half of the stages use optical waveguide devices, and the other half of the level uses Optical waveguide devices are needed to create an N×N optical switch system An optical waveguide device.

10. An optical switch system according to claim 6, characterized in that: The optical switch array structure adopts a Switch-and-select structure or a Dilated Banyan structure. The number of optical waveguide devices in any N×N optical switch system composed of the two structures is 2N·(N-1), and the number of optical waveguide devices on the optical transmission path is 2Log2N.

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