A polarization-independent nonvolatile on-chip optical switch

Abstract

The present invention provides a polarization-independent non-volatile on-chip optical switch, comprising a silicon dioxide substrate, and also comprising a silicon-based multimode waveguide in a strip-shaped convex structure arranged in the middle of the upper surface of the silicon dioxide substrate, a linear slit is opened on the upper surface of the silicon-based multimode waveguide, and the slit is filled with Sb2S3 material; one end of the silicon-based multimode waveguide is integrally formed with a first input waveguide and a second input waveguide for inputting signals, and the other end is integrally formed with a first output waveguide and a second output waveguide for outputting signals. The present application can perform routing switching on polarization-independent optical signals, is convenient for miniaturization and integration, and has excellent performance.

Description

Technical Field

[0001] The present invention relates to the technical field of optical switches, and in particular to a polarization-independent non-volatile on-chip optical switch. Background Art

[0002] With the rapid development of optical communication and photonics technology, the demand for high-performance optical switches is also increasing. Integrated optical switches play a vital role in optical communication systems and are mainly used to control the path switching and routing of optical signals. Traditional optical switches have obvious shortcomings in practical applications, especially the inability to effectively switch optical signals that are independent of polarization. In order to overcome these limitations, optical switch solutions based on silicon photonics technology have emerged in recent years. Silicon photonics technology uses the excellent optical properties of silicon materials to achieve high-density integration and low-cost manufacturing through microelectronic processes. However, silicon photonic devices rely on carrier injection, thermo-optical effect or electro-optical effect to control the refractive index of the waveguide, but these methods have a small adjustment range, resulting in large device size and high power consumption. On the other hand, silicon photonic devices are generally polarization-sensitive due to their own structure. This is because the transmission characteristics of TE mode and TM mode are different, and the refractive index is different, resulting in many silicon photonic devices being polarization-sensitive. However, in practical applications, it is necessary to accurately control the polarization state of light, requiring optical switches to be able to process optical signals of any polarization state without affecting their performance. In order to realize polarization-independent optical switching, most of them adopt thermal-optical or electro-optical methods. However, such methods will result in a relatively large size due to the above reasons, affecting the integration. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a polarization-independent non-volatile on-chip optical switch to achieve routing switching of polarization-independent optical signals, facilitate miniaturization and integration, and have superior performance.

[0004] The present invention provides a polarization-independent non-volatile on-chip optical switch, comprising a silicon dioxide substrate, and also comprising a silicon-based multimode waveguide in a strip-shaped convex structure arranged in the middle of the upper surface of the silicon dioxide substrate, wherein the upper surface of the silicon-based multimode waveguide is provided with a linear slit extending along its length direction, and the slit is filled with Sb2S3 material; one end of the silicon-based multimode waveguide is integrally formed with a first input waveguide and a second input waveguide for inputting signals, and the other end is integrally formed with a first output waveguide and a second output waveguide for outputting signals.

[0005] Compared with the prior art, the present invention has the following advantages: the Sb2S3 material can stably exist in a crystalline or amorphous state at room temperature, and the transformation of the crystalline or amorphous state can be achieved by introducing a TE mode or a TM mode, and the Sb2S3 material has a significant refractive index difference in the crystalline or amorphous state, and maintaining this refractive index change does not require continuous energy supply, that is, it is non-volatile and has excellent performance; when the Sb2S3 material is amorphous, the input TE mode or TM mode will be output from the first output waveguide; when the Sb2 When the S3 material is crystalline, the input TE mode or TM mode will be output from the second output waveguide, and the coupling length between different polarization mode fields can be regulated by converting the crystalline or amorphous state of the filled Sb2S3 material, that is, by the phase change of the Sb2S3 material, thereby realizing the routing switching of polarization-independent optical signals; and the Sb2S3 material of the present application is a low-loss material. By filling it in the slit, it is equivalent to directly allowing the Sb2S3 material to act directly on the waveguide mode field, and the structure is compact, and the size can be reduced to facilitate miniaturization and integration.

[0006] In a possible implementation manner, the slit is disposed in the middle of the upper surface of the silicon-based multimode waveguide, and two ends of the slit in the length direction are respectively disposed close to two ends of the silicon-based multimode waveguide in the length direction;

[0007] And the length of the silicon-based multimode waveguide satisfies the following formula:

[0008] = ;

[0009] in, represents the length of the silica-based multimode waveguide, It indicates the length of the TE mode passing through the first and last sections of the silicon-based multimode waveguide when the Sb2S3 material is in an amorphous state. It represents the TE mode coupling length when the Sb2S3 material is amorphous, It indicates the length of the TM mode passing through the first and last sections of the silicon-based multimode waveguide when the Sb2S3 material is in an amorphous state. represents the TM mode coupling length when the Sb2S3 material is in an amorphous state, p and q are numbers with opposite parity, m and n are even numbers, It indicates the length of the TE mode passing through the first and last sections of the silicon-based multimode waveguide when the Sb2S3 material is in a crystalline state. It represents the TE mode coupling length when the Sb2S3 material is in the crystalline state, It indicates the length of the TM mode passing through the first and last sections of the silicon-based multimode waveguide when the Sb2S3 material is in a crystalline state. It represents the TM mode coupling length when the Sb2S3 material is in a crystalline state.

[0010] Compared with the prior art, the above technical solution can facilitate manufacturing and molding, and can also effectively seal the Sb2S3 material. When the optical signal is input or output, an unstable transmission distance may be generated in the first transition region and the second transition region, resulting in crosstalk between the input and output signals. Therefore, each parameter needs to satisfy the above formula to eliminate crosstalk, so as to realize the function of routing switching of polarization-independent optical signals.

[0011] In a possible implementation, it further includes a silicon dioxide film layer, which covers the exposed outer surfaces of the silicon-based multimode waveguide, the first input waveguide, the second input waveguide, the first output waveguide, the second output waveguide, and the upper surface of the silicon dioxide substrate.

[0012] Compared with the prior art, the above technical solution can protect the silicon dioxide substrate, and there is a difference between the refractive index of silicon dioxide and silicon materials. This difference has an important influence on the waveguide performance of the optical switch, so that the optical performance of the optical switch can be optimized by adjusting the thickness and refractive index of the silicon dioxide layer.

[0013] In a possible implementation manner, the thickness of the silicon dioxide thin film layer is 2 μm.

[0014] Compared with the prior art, the above technical solution can optimize the optical performance of the optical switch without making the size too large.

[0015] In a possible implementation, the first input waveguide, the second input waveguide, the first output waveguide and the second output waveguide are all strip-shaped protruding structures and are all arranged in an S-shaped bend; the input ends of the first input waveguide and the second input waveguide are arranged at intervals, and the output ends of the first output waveguide and the second output waveguide are arranged at intervals.

[0016] Compared with the prior art, the S-shaped design using the above technical solution is relatively 90°, and can obtain a larger curvature radius in a small size, thereby reducing the insertion loss of the entire optical switch and improving the performance. The input ends of the first input waveguide and the second input waveguide are spaced apart, and the output ends of the first output waveguide and the second output waveguide are spaced apart, so that the TE mode and the TM mode can be easily connected and are not easily interfered with each other.

[0017] In a possible implementation, input ends of the first input waveguide and the second input waveguide are both located at the edge of the silicon dioxide substrate; output ends of the first output waveguide and the second output waveguide are both located at the edge of the silicon dioxide substrate.

[0018] Compared with the prior art, the above technical solution can facilitate input and output of signals and connection with external access media.

[0019] In a possible implementation, the thickness of the silicon-based multimode waveguide, the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide are all 300 nm.

[0020] Compared with the prior art, the above technical solution enables the silicon-based multimode waveguide, the first input waveguide, the second input waveguide, the first output waveguide and the second output waveguide to effectively transmit signals while not being too large in size and having a clear transmission structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the present invention;

[0022] Figure 2 This is a schematic diagram of the first transition area and the second transition area of ​​the present invention;

[0023] Figure 3 Schematic diagram of parameters under TE mode when the Sb2S3 material is amorphous in one embodiment of the present invention;

[0024] Figure 4 Schematic diagram of parameters under TM mode when the Sb2S3 material is amorphous in one embodiment of the present invention;

[0025] Figure 5 Schematic diagram of parameters under TE mode when the Sb2S3 material is in a crystalline state in one embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of parameters under TM mode when the Sb2S3 material is in a crystalline state in one embodiment of the present invention;

[0027] Figure 7 It is a refractive index diagram of different phases at the cross section of the Sb2S3 material of the present invention;

[0028] Figure 8 Schematic diagram of the number of modes in an embodiment of the present invention;

[0029] Fig. 9 is the length of the transition zone under different modes of the present invention;

[0030] Fig.10 It is a diagram of the square transmission situation of the present invention under two modes;

[0031] Fig.11 is a bandwidth performance diagram of the present invention;

[0032] Description of reference numerals:

[0033] 1-silicon dioxide substrate, 11-silicon-based multimode waveguide, 12-silicon dioxide thin film layer, 111-slit, 112-first input waveguide, 113-second input waveguide, 114-first output waveguide, 115-second output waveguide, 116-first transition region, 117-second transition region. DETAILED DESCRIPTION

[0034] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0035] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0036] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. For simplified description below, the TM mode optical signal is referred to as TM mode, and the TE mode optical signal is referred to as TE mode.

[0038] As attached Figure 1 As shown, an embodiment of the present application discloses a polarization-independent non-volatile on-chip optical switch, comprising a silicon dioxide substrate 1, and also comprising a silicon-based multimode waveguide 11 in a strip-shaped protruding structure arranged in the middle of the upper surface of the silicon dioxide substrate 1, a linear slit 111 extending along its length direction is opened on the upper surface of the silicon-based multimode waveguide 11, and the slit 111 is filled with Sb2S3 material; one end of the silicon-based multimode waveguide 11 is integrally formed with a first input waveguide 112 and a second input waveguide 113 for inputting signals, and the other end is integrally formed with a first output waveguide 114 and a second output waveguide 115 for outputting signals.

[0039] In this embodiment, the silicon-based multimode waveguide 11, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114 and the second output waveguide 115 are all silicon waveguides; the silicon dioxide substrate 1 is a rectangular parallelepiped structure, and the silicon-based multimode waveguide 11 is extended along the length direction of the silicon dioxide substrate 1 and is a linear structure; the depth of the slit 111 can be opened to the upper surface of the silicon dioxide substrate 1, so that the bottom of the slit 111 is connected to the upper surface of the silicon dioxide substrate 1, or it can be opened to a certain depth without being connected to the upper surface of the silicon dioxide substrate 1, in order to fill the Sb2S3 material. The Sb2S3 material can stably exist in a crystalline or amorphous state at room temperature. The conversion of the crystalline or amorphous state can be achieved by introducing a TE mode or a TM mode. The Sb2S3 material has a significant refractive index difference in the crystalline or amorphous state, and maintaining this refractive index change does not require continuous energy supply, that is, it is non-volatile and has excellent performance. When the Sb2S3 material is amorphous, the input TE mode or TM mode will be output from the first output waveguide; when the Sb2S3 material is crystalline, the input TE mode or TM mode will be output from the second output waveguide, and the coupling length between different polarization mode fields can be regulated by converting the crystalline or amorphous state of the filled Sb2S3 material, that is, by the phase change of the Sb2S3 material, thereby realizing the routing switching of polarization-independent optical signals. The Sb2S3 material of the present application is a low-loss material filler. By filling it in the slit 111, it is equivalent to directly interacting the Sb2S3 material with the waveguide mode field. The structure is compact and the size can be reduced to facilitate miniaturization and integration.

[0040] At a wavelength of 1550nm, the refractive index of Sb2S3 material in the amorphous and crystalline states is 2.712 and 3.308 respectively, and it has extremely low extinction coefficients in both states. Figure 7 As shown, Sb2S3 material can control the coupling behavior of TE mode and TM mode by adjusting the propagation constants in silicon-based multimode waveguide11.

[0041] As attached Figure 2 , Attachment Figure 3 , Attachment Figure 4 , Attachment Figure 5 And attached Figure 6As shown, in some embodiments, the slit 111 is arranged in the middle of the upper surface of the silicon-based multimode waveguide 11, and the two ends of the slit 111 in the length direction are respectively arranged close to the two ends of the length direction of the silicon-based multimode waveguide 11, so that a first transition region 116 and a second transition region 117 are respectively formed on both sides of the slit 111 in the length direction on the silicon-based multimode waveguide 11; that is, the first transition region 116 and the second transition region 117 are both naturally formed when the slit 111 is arranged in the middle of the upper surface of the silicon-based multimode waveguide 11; in this embodiment, the lengths of the first transition region 116 and the second transition region 117 are both 0.5%~0.6% of the length of the silicon-based multimode waveguide 11, so 0.05μm is taken in this embodiment. In this way, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114 and the second output waveguide 115 can be integrally formed with the silicon-based multimode waveguide 11, and the Sb2S3 material can be effectively sealed. When the TM mode and the TE mode are input or output, an unstable transmission distance may be generated in the first transition region 116 and the second transition region 117. However, the length of the first transition region 116 and the second transition region 117 can control this unstable transmission distance within a certain range, and the crosstalk of the input and output signals caused by this unstable transmission distance can be eliminated through the formula described later.

[0042] The length of the silicon-based multimode waveguide 11 satisfies the following formula:

[0043] = ;

[0044] in, represents the length of the silicon-based multimode waveguide 11, It indicates the length of the TE mode passing through the first section and the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state, It represents the TE mode coupling length when the Sb2S3 material is amorphous, It represents the length of the TM mode passing through the first section and the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state. represents the TM mode coupling length when the Sb2S3 material is in an amorphous state, p and q are numbers with opposite parity, m and n are even numbers, It indicates the length of the TE mode passing through the first section and the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, It represents the TE mode coupling length when the Sb2S3 material is in the crystalline state, It indicates the length of the TM mode passing through the first section and the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, It represents the TM mode coupling length when the Sb2S3 material is in a crystalline state.

[0045] Specifically, as attached Figure 3 As shown, It indicates the length of the TE mode passing through the first section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state, and the first section includes the first transition region 116. It also indicates the length of the TE mode passing through the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state, and the tail section includes the second transition region 117. Since the two lengths are theoretically defined to be equal, both are used. express.

[0046] As attached Figure 4 As shown, It indicates the length of the TM mode passing through the first section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state, and the first section includes the first transition region 116. It also indicates the length of the TM mode passing through the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in an amorphous state, and the tail section includes the second transition region 117. Since the two lengths are theoretically defined to be equal, they are both expressed as express.

[0047] As attached Figure 5 As shown, It indicates the length of the TE mode passing through the first section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, and the first section includes the first transition region 116. It also indicates the length of the TE mode passing through the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, and the tail section includes the second transition region 117. Since the two lengths are theoretically defined to be equal, both are used express.

[0048] As attached Figure 6 As shown, It indicates the length of the TM mode passing through the first section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, and the first section includes the first transition region 116. It also indicates the length of the TM mode passing through the tail section of the silicon-based multimode waveguide 11 when the Sb2S3 material is in a crystalline state, and the tail section includes the second transition region 117. Since the two lengths are theoretically defined to be equal, they are both expressed as express.

[0049] In addition, the above formula is only identical in theory, but not in practice, because there will definitely be errors in actual production design. As long as it is within an acceptable error range, the above formula can be considered to be valid, as will be described later.

[0050] The theoretical coupling lengths of TE mode and TM mode can be expressed as:

[0051] ;

[0052] ;

[0053] in, represents the theoretical coupling length of TE mode, represents the theoretical coupling length of the TM mode, represents the effective refractive index of the TE mode, represents the effective refractive index of the TE first-order mode, represents the TM mode effective refractive index, represents the effective refractive index of the TM first-order mode, Indicates wavelength.

[0054] In this embodiment, the width of the slit 111 needs to be determined by computer model simulation, because the width of the slit 111 will affect the filling width of the Sb2S3 material and directly affect the refractive index. Therefore, after the width of the slit 111 is determined, the theoretical coupling length of the TE mode and the TM mode needs to be calculated according to the above formula. and In order to determine the length L of the silicon-based multimode waveguide 11, there are four modes in this embodiment, namely, the input TM mode when the Sb2S3 material is crystalline, the input TE mode when the Sb2S3 material is crystalline, the input TM mode when the Sb2S3 material is amorphous, and the input TE mode when the Sb2S3 material is amorphous. Figure 8 As shown, the appropriate width of the silicon-based multimode waveguide 11 and the filling width of the Sb2S3 material can be determined by parametrically scanning the results of the silicon-based multimode waveguide 11 and the Sb2S3 material filling. Figure 8 The two lines in the middle are the dividing lines between the number of modes four and five when the Sb2S3 material is in the crystalline state and the amorphous state. In this embodiment, we can obtain the required structural parameters by taking the intersection of these two lines. m =600~700nm, W ss =50~300nm, W ss Indicates the filling width of Sb2S3 material, W m represents the width of the silicon-based multimode waveguide 11, and W ss Limited to 50~145nm, because W ss Too large will result in higher insertion loss.

[0055] As attached Figure 8 As shown, the appropriate filling width of the silicon-based multimode waveguide 11 and the Sb2S3 material can be determined by parametrically scanning the width of the silicon-based multimode waveguide 11 and the filling width of the Sb2S3 material. The goal is to make the number of modes that can be excited in each waveguide section four, as shown in the attached figure. Figure 8As shown in the figure, the two lines are the dividing lines between the number of modes four and five when the Sb2S3 material is in the crystalline state and the amorphous state. By taking the intersection of these two lines, we can get the required structural parameters. m =600~700nm, W ss =50~300nm, W ss Indicates the filling width of Sb2S3 material, W m represents the width of the silicon-based multimode waveguide 11, and then the sum of the mode components that can be excited by these parameters is calculated. After calculation, W ss It is limited to 50~145nm because W ss Too large will result in higher insertion loss.

[0056] As attached Fig. 9 As shown, in W m =700nm, W was measured ss =50nm and W ss =145nm, the lengths of the TE mode and TM mode passing through the first and tail sections of the silicon-based multimode waveguide 11 when the Sb2S3 material is in crystalline and amorphous states, and the lengths are approximated using a computer, and then the average of the values ​​at 50nm and 145nm is taken.

[0057] Specifically, as attached Figure 3 As shown, when the Sb2S3 material is amorphous, the TE mode is input. , , as attached Fig. 9 As shown in (a), The intersection of the solid line and the dotted line is determined by computer. , where 6 is the coefficient generated by the computer enumeration algorithm. The purpose is to minimize the L value error of the four modes, that is, p takes the value of 6.

[0058] As attached Figure 4 As shown, when the Sb2S3 material is amorphous, the TM mode is input. , , as attached Fig. 9 As shown in (b), The approximate determination is done by computer, and the intersection of the solid line and the dotted line is taken. , where 4 is the coefficient generated by the computer enumeration algorithm, the purpose is to minimize the L value error of the four modes, that is, p takes the value of 6 and n takes the value of -2.

[0059] As attached Figure 5 As shown, when the Sb2S3 material is in a crystalline state, the TE mode is input. , , as attached Fig. 9 (c) The approximate determination is done by computer, and the intersection of the solid line and the dotted line is taken. =9.711μm, where 7 is the coefficient generated by the computer enumeration algorithm. The purpose is to minimize the L value error of the four modes, that is, p takes the value of 7 and n takes the value of -2.

[0060] As attached Figure 6 As shown, when the Sb2S3 material is in a crystalline state, the TM mode is input. , , as attached Fig. 9 (d) As shown, The approximate determination is done by computer, and the intersection of the solid line and the dotted line is taken. , where 5 is the coefficient generated by the computer enumeration algorithm, the purpose is to minimize the L value error of the four modes, that is, q takes the value of 7 and m takes the value of -2.

[0061] It can be found that there are slight errors in the final L in the four modes. According to the above, due to various unavoidable factors in actual production design, there will definitely be errors. Technical personnel in this field can flexibly adjust the acceptance range of the error based on the performance of the tested optical switch so that the performance of the optical switch is not affected within the error range. Therefore, in this embodiment, one of the intermediate values ​​9.67μm is taken as the length L of the silicon-based multimode waveguide 11.

[0062] As attached Fig.10 As shown, the light field propagation of TE mode and TM mode of Sb2S3 material in amorphous and crystalline states is shown. It can be seen that by switching the phase state of Sb2S3 material, polarization-independent functions can be achieved with high performance. Fig.11 The figure shows the bandwidth performance of the optical switch provided by this embodiment in the 1540nm-1560nm band. The crosstalk of the optical switch is less than -10dB, and the insertion loss is less than 0.35dB. At a wavelength of 1550nm, the crosstalk of the TE mode / TM mode in the amorphous and crystalline states is -25.3 dB / -26.8 dB and -21.9 dB / -27.4 dB, respectively, and the insertion loss is 0.09 dB / 0.02 dB and 0.04 dB / 0.08 dB.

[0063] In some embodiments, a silicon dioxide film layer 12 is further included, and the silicon dioxide film layer 12 is coated on the exposed outer surfaces of the silicon-based multimode waveguide 11, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115, as well as the upper surface of the silicon dioxide substrate 1. That is, after the silicon dioxide substrate 1, the silicon-based multimode waveguide 11, the Sb2S3 material, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115 are all manufactured, the silicon dioxide film layer 12 is formed on the upper surface, and can be formed by using the existing oxidation method or chemical vapor deposition method. The silicon dioxide film layer 12 can protect the silicon dioxide substrate 1, and there is a difference between the refractive index of silicon dioxide and silicon material, which has an important influence on the waveguide performance of the optical switch, so that by adjusting the thickness and refractive index of the silicon dioxide layer 13, it is convenient to optimize the optical performance of the optical switch.

[0064] In some embodiments, the thickness of the silicon dioxide film layer 12 is 2 μm, which can optimize the optical performance of the optical switch without making the size too large.

[0065] In some embodiments, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115 are all strip-shaped convex structures and are all arranged in an S-shaped bend; the input ends of the first input waveguide 112 and the second input waveguide 113 are arranged at intervals, and the output ends of the first output waveguide 114 and the second output waveguide 115 are arranged at intervals. The spacing distance between the input ends of the first input waveguide 112 and the second input waveguide 113 is 4 μm, and the spacing distance between the output ends of the first output waveguide 114 and the second output waveguide 115 is 4 μm. Compared with the 90° design, the above-mentioned S-shape can obtain a larger radius of curvature in a small size, thereby reducing the insertion loss of the entire optical switch and improving the performance. The input ends of the first input waveguide 112 and the second input waveguide 113 are arranged at intervals, and the output ends of the first output waveguide 114 and the second output waveguide 115 are arranged at intervals, so that the TE mode and the TM mode can be easily connected and are not easily interfered with each other.

[0066] In some embodiments, the first input waveguide 112 and the second input waveguide 113 are symmetrically arranged, and the output end of the first input waveguide 112 and the output end of the second input waveguide 113 gradually approach each other; the first input waveguide 112 and the first output waveguide 114 are symmetrically arranged, and the first output waveguide 114 and the second output waveguide 115 are symmetrically arranged. This allows the entire optical switch to be symmetrical as a whole, which is convenient for manufacturing and connection with an external access medium.

[0067] In some embodiments, the input ends of the first input waveguide 112 and the second input waveguide 113 are both located at the edge of one end in the length direction of the silicon dioxide substrate 1; the output ends of the first output waveguide 114 and the second output waveguide 115 are both located at the edge of the other end in the length direction of the silicon dioxide substrate 1. This is beneficial for inputting and outputting signals and for connecting with external access media.

[0068] In some embodiments, the thickness of the silicon-based multimode waveguide 11, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115 are all 300 nm. The width formed by the silicon-based multimode waveguide 11 and the slit 111 is 700 nm, wherein the width of the slit 111 is 140 nm; the length of the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115 can be 8 μm. The silicon-based multimode waveguide 11, the first input waveguide 112, the second input waveguide 113, the first output waveguide 114, and the second output waveguide 115 can effectively transmit signals without being too large in size and having a clear structure.

[0069] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description, and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0070] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application 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. A polarization-independent non-volatile on-chip optical switch, comprising a silicon dioxide substrate (1), characterized in that: It also comprises a silicon-based multimode waveguide (11) in a strip-shaped protruding structure arranged in the middle of the upper surface of the silicon dioxide substrate (1); the upper surface of the silicon-based multimode waveguide (11) is provided with a linear slit (111) extending along its length direction, and the slit (111) is filled with Sb2S3 material; one end of the silicon-based multimode waveguide (11) is integrally formed with a first input waveguide (112) and a second input waveguide (113) for inputting signals, and the other end is integrally formed with a first output waveguide (114) and a second output waveguide (115) for outputting signals; the slit (111) is arranged in the middle of the upper surface of the silicon-based multimode waveguide (11), and the two ends of the slit (111) in the length direction are respectively arranged close to the two ends of the silicon-based multimode waveguide (11) in the length direction; And the length of the silicon-based multimode waveguide (11) satisfies the following formula: = ； in, represents the length of the silicon-based multimode waveguide (11), represents the length of the TE mode passing through the first section and the tail section of the silicon-based multimode waveguide (11) when the Sb2S3 material is in an amorphous state, represents the TE mode coupling length when the Sb2S3 material is in an amorphous state, represents the length of the TM mode passing through the first section and the tail section of the silicon-based multimode waveguide (11) when the Sb2S3 material is in an amorphous state, represents the TM mode coupling length when the Sb2S3 material is in an amorphous state, p and q are numbers with opposite parity, m and n are even numbers, represents the length of the TE mode passing through the first section and the tail section of the silicon-based multimode waveguide (11) when the Sb2S3 material is in a crystalline state, represents the TE mode coupling length when the Sb2S3 material is in a crystalline state, represents the length of the TM mode passing through the first section and the tail section of the silicon-based multimode waveguide (11) when the Sb2S3 material is in a crystalline state, It represents the TM mode coupling length when the Sb2S3 material is in a crystalline state.

2. The polarization-independent non-volatile on-chip optical switch according to claim 1, characterized in that: It also includes a silicon dioxide film layer (12), the silicon dioxide film layer (12) covering the exposed outer surfaces of the silicon-based multimode waveguide (11), the first input waveguide (112), the second input waveguide (113), the first output waveguide (114), the second output waveguide (115), and the upper surface of the silicon dioxide substrate (1).

3. The polarization-independent non-volatile on-chip optical switch according to claim 2, characterized in that: The thickness of the silicon dioxide thin film layer (12) is 2 μm.

4. The polarization-independent non-volatile on-chip optical switch according to claim 3, characterized in that: The first input waveguide (112), the second input waveguide (113), the first output waveguide (114), and the second output waveguide (115) are all strip-shaped protruding structures and are all arranged in an S-shaped bend; the input ends of the first input waveguide (112) and the second input waveguide (113) are arranged at intervals, and the output ends of the first output waveguide (114) and the second output waveguide (115) are arranged at intervals.

5. The polarization-independent non-volatile on-chip optical switch according to claim 4, characterized in that: The input ends of the first input waveguide (112) and the second input waveguide (113) are both located at the edge of the silicon dioxide substrate (1); and the output ends of the first output waveguide (114) and the second output waveguide (115) are both located at the edge of the silicon dioxide substrate (1).

6. The polarization-independent non-volatile on-chip optical switch according to claim 5, characterized in that: The silicon-based multimode waveguide (11), the first input waveguide (112), the second input waveguide (113), the first output waveguide (114), and the second output waveguide (115) all have a thickness of 300 nm.

Images