Total internal reflection light switch based on phase change material and use method thereof

Abstract

The invention belongs to the technical field of integrated photonic devices, and discloses a total internal reflection light switch based on a phase change material and a use method thereof.The phase change material area is subjected to first pretreatment, the phase change material in the phase change material area is completely converted into an amorphous state from a crystalline state, and the phase change material in the phase change material area is subjected to second pretreatment; the difference value between the refractive index of the phase change material and the refractive index of the waveguide is greater than 0.6, and at the moment, the total internal reflection light switch is in a cross state; second pretreatment is carried out on the phase-change material area, the phase-change material in the phase-change material area is completely converted into a crystalline state from an amorphous state, the difference value between the refractive index of the phase-change material and the refractive index of the waveguide is 0-0.2, at the moment, the straight-through function of the total internal reflection optical switch is achieved, the power consumption of the optical switch is remarkably reduced, and the optical switch has a wide application prospect. Performance indexes of the optical switch are optimized, multi-mode optical signal transmission is achieved, and application of the optical switch in the fields of high-speed optical communication, optical interconnection and optical calculation is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated photonic devices, and in particular, relates to a total internal reflection optical switch based on phase change materials and a method for using the same. Background Art

[0002] With the rapid advancement of information technology, optical communication and optical interconnection technology play an increasingly important role in modern information processing and transmission. Traditional electronic devices are gradually unable to meet the growing demand for data transmission in terms of speed, energy consumption and bandwidth. Optical switch technology, with its high speed, low latency and broadband characteristics, provides a key means to solve such problems. Among the many optical switch technologies, total internal reflection (TIR) ​​optical switch, as a device that uses total internal reflection of light at the interface of the medium to realize optical signal control, has attracted widespread attention due to its simple structure, low loss and easy integration. At present, the scheme of injecting carriers (electrons or holes) into the waveguide to control the refractive index of the waveguide is a common method to realize total internal reflection optical switching. This scheme utilizes the characteristic that the refractive index of silicon materials changes significantly when the carrier concentration changes. However, the insertion loss of this scheme is large, carrier injection will increase optical absorption, and the thermal effect generated by the injected current may reduce the performance of the device, which makes the traditional TIR optical switch still have bottlenecks in terms of extinction ratio, insertion loss and response speed.

[0003] In recent years, the introduction of phase change materials has provided a new path to improve the performance of optical switches. Phase change materials can be rapidly and reversibly transformed between amorphous and crystalline states under thermal or electric field stimulation, and show significant differences in refractive index and optical properties in different phases. This property makes phase change materials an ideal candidate for high-performance optical switches, especially in terms of high refractive index contrast, non-volatility and high-speed response. Phase change materials have lower optical loss and broadband transparency, and can achieve lower insertion loss. In addition, the refractive index change of phase change materials between the crystalline and amorphous states is as high as 0.6, which far exceeds the refractive index change caused by traditional carrier injection, thereby effectively controlling the propagation direction and intensity of light in optical modulation and providing a higher extinction ratio.

[0004] In the existing optical switches based on phase change materials, different structural designs have their own advantages and limitations. The prior art discloses a 1×2 directional coupler optical switch with a slot structure (Optics Express, 2020, 28(25): 37265-37275.) It utilizes the high absorption loss of GST phase change material in the amorphous state, and the embedded design enhances the interaction between the phase change material and the light field, thereby realizing the optical switching function. However, this structure has large insertion loss and high crosstalk, which significantly limits its practical application in future efficient optical signal processing. Although the Mach-Zehnder interferometer optical switch (Optics Letters, 2021, 46(17): 4224-4227.) shows a certain flexibility in performance regulation, due to its inherent large size problem, it is difficult to meet the needs of highly integrated optical networks, thereby limiting its application prospects in large-scale optical communication systems. In contrast, microring resonator optical switches (Advanced Optical Materials, 2021, 9(9): 2002049.) have attracted widespread attention due to their small insertion loss and high extinction ratio. However, the bandwidth of this structure is relatively small, which makes it difficult to meet the requirements of modern optical communication systems for high capacity and large bandwidth. Therefore, the existing optical switches based on phase change materials still need to be further optimized in terms of key performance indicators such as bandwidth, insertion loss, extinction ratio and integration to adapt to the application scenarios of high-performance optical signal processing. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a total internal reflection optical switch based on phase change material and a method of using the same, which aims to solve the technical problems of the prior art, such as small extinction ratio, large insertion loss, large crosstalk, small bandwidth, large size, volatility, and few optical signal modes.

[0006] According to a first aspect of the present invention, a total internal reflection optical switch based on a phase change material is provided, which comprises, from bottom to top, a base and a substrate, and further comprises a waveguide and a phase change material region arranged on the substrate, wherein the waveguide comprises a first input waveguide, a second input waveguide, a first output waveguide, and a second output waveguide, wherein the first input waveguide and the second input waveguide are in contact with the phase change material region and are arranged based on a mirror symmetry of the phase change material region, the first output waveguide and the second output waveguide are in contact with the phase change material region and are arranged based on a mirror symmetry of the phase change material region, the first input waveguide, the second input waveguide ... Both output waveguides are not perpendicular to the phase change material region; the first input waveguide and the first output waveguide are parallel to each other and are respectively located on both sides of the phase change material region, and the second input waveguide and the first output waveguide are parallel to each other and are respectively located on both sides of the phase change material region; the surface of the first input waveguide in contact with the phase change material region overlaps with the surface of the first output waveguide in contact with the phase change material region; the surface of the second input waveguide in contact with the phase change material region overlaps with the surface of the first output waveguide in contact with the phase change material region, and the height of the phase change material region is greater than or equal to the height of the waveguide.

[0007] According to another aspect of the present invention, a total internal reflection optical switch based on a phase change material is provided, which comprises, from bottom to top, a base and a substrate, and also comprises a waveguide and a phase change material area arranged on the substrate, the waveguide comprising a first input waveguide, a first output waveguide, and a second output waveguide, the first input waveguide, the first output waveguide, and the second output waveguide are in contact with the phase change material area and are not perpendicular to the phase change material area; the first input waveguide and the first output waveguide are parallel to each other and are respectively located on both sides of the phase change material area; the first input waveguide and the first output waveguide are located on the same side of the phase change material area, and the first input waveguide and the first output waveguide are not parallel to each other, and the surface of the first input waveguide in contact with the phase change material area overlaps with the surface of the first output waveguide in contact with the phase change material area; the height of the phase change material area is greater than or equal to the height of the waveguide.

[0008] Preferably, a thin film layer is provided between the substrate and the phase change material area, a groove is provided inside the thin film layer, the groove runs from the top of the thin film layer to the bottom of the thin film layer, and the phase change material in the phase change material area extends downward into the groove.

[0009] Preferably, the material of the base is silicon, and the material of the substrate is silicon dioxide; the material of the thin film layer is selected from single crystal silicon, silicon nitride, lithium niobate or lithium tantalate; the material of the waveguide is selected from single crystal silicon, silicon nitride, lithium niobate or lithium tantalate.

[0010] Preferably, the material of the phase change material region is selected from Ge 2 Sb2 Te 5 ,Ge 2 Sb 2 SNT 5 , VO 2 , Sb 2 Se 3 or Sb 2 S 3 .

[0011] Preferably, the angle θ between the first output waveguide and the second output waveguide is 1 Comply with the formula; Among them, n 1 is the effective refractive index of the waveguide, n 2 is the effective refractive index of the phase change material in the phase change material region (8) when it is in a completely amorphous state.

[0012] Preferably, the surfaces of the waveguide and the phase change material region that are not covered are covered with an upper cladding layer, and the material of the upper cladding layer is selected from silicon dioxide, aluminum oxide or indium tin oxide.

[0013] According to another aspect of the present invention, a method for using a total internal reflection optical switch based on a phase change material is provided. The total internal reflection optical switch has the following two methods of use: (1) performing a first pre-treatment on the phase change material region, so that the phase change material in the phase change material region is completely transformed from a crystalline state to an amorphous state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is greater than 0.6. At this time, a signal light is input from the first input waveguide and the signal light is output from the second output waveguide, or a signal light is input from the second input waveguide and the signal light is output from the first output waveguide, or a signal light is input from the first input waveguide and the second input waveguide and the signal light is output from the second output waveguide and the first output waveguide respectively;

[0014] Or (2) performing a second pre-treatment on the phase change material area, the phase change material in the phase change material area is completely transformed from an amorphous state to a crystalline state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is 0-0.2, and signal light is input from the first input waveguide and output from the first output waveguide, or signal light is input from the second input waveguide and output from the second output waveguide; or signal light is input from the first input waveguide and the second input waveguide, and the signal light is output from the first output waveguide and the second output waveguide respectively.

[0015] According to another aspect of the present invention, a method for using a total internal reflection optical switch based on a phase change material is provided. The total internal reflection optical switch has the following two methods of use: (1) performing a first pre-treatment on the phase change material region, so that the phase change material in the phase change material region is completely transformed from a crystalline state to an amorphous state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is greater than 0.6, and at this time, a signal light is input from the first input waveguide, and the signal light is output from the second output waveguide;

[0016] Or (2) a second pre-treatment is performed on the phase change material area, and the phase change material in the phase change material area is completely transformed from an amorphous state to a crystalline state, so that the refractive index of the phase change material and the refractive index of the waveguide differ by 0 to 0.2. At this time, signal light is input from the first input waveguide, and the signal light is output from the first output waveguide.

[0017] Preferably, the first pretreatment or the second pretreatment is selected from thermal annealing, electric pulse or laser pulse. When the first pretreatment and the second pretreatment use the same processing method, the power of the first pretreatment is greater than the power of the second pretreatment, and the time of the first pretreatment is less than the time of the second pretreatment.

[0018] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0019] 1. The present invention designs a phase change region between the input waveguide and the output waveguide, and embeds a phase change material in the phase change region, changes the phase change state of the phase change material, thereby changing the effective refractive index of the phase change material, and then changes the effective refractive index difference between the phase change material and the waveguide, and changes the transmission direction of the optical signal by regulating the effective refractive index difference between the phase change material and the waveguide, thereby realizing the selective output of the optical signal in different output waveguides. By changing the phase change material to be in a crystalline state and an amorphous state, the selective mutual conversion of the optical signal output waveguide is realized respectively. In the crystalline state, the effective refractive index difference between the phase change material and the waveguide is small, and the optical signal is in a straight-through state at this time. When the optical signal is input from the first input waveguide, the optical signal is output from the first output waveguide; in the amorphous state, the effective refractive index difference between the phase change material and the waveguide is large, and the optical signal is in a cross state at this time. When the optical signal is input from the first input waveguide, the optical signal is output from the second output waveguide, completing the selective conversion of the optical signal in the output waveguide. The total internal reflection optical switch uses phase change materials to achieve adjustable switch. The phase change material can achieve low insertion loss, large bandwidth, large extinction ratio and small crosstalk in both phase change states. It has great application prospects in high-speed optical communications, optical interconnection and optical computing.

[0020] 2. In order to satisfy the total reflection condition when the phase change material is in an amorphous state and reduce the reflection crosstalk when the phase change material is in a crystalline state, the present invention limits the angle θ between the first output waveguide and the second output waveguide. 1 Comply with the formula; Among them, n 1 is the effective refractive index of the waveguide, n 2 is the effective refractive index of the phase change material in the phase change material region (8) when it is in a completely amorphous state.

[0021] 3. The present invention applies phase change materials to total internal reflection optical switches, which can give full play to their large refractive index change and non-volatility advantages, simplify the structural design and improve the device response speed and reliability. The non-volatile properties of phase change materials enable them to maintain their state without continuous energy supply after phase transition, significantly reducing the power consumption of optical switches, optimizing the performance indicators of optical switches, realizing multi-modal optical signal transmission, and promoting their application in high-speed optical communications, optical interconnection and optical computing.

[0022] 4. The phase change region structure adopted in the present invention reduces the size of the total internal reflection optical switch and reduces the process difficulty by designing a phase change region between the input waveguide and the output waveguide and adopting a phase change region structure in which a groove is filled with a phase change material. It is simpler than the existing structure based on carrier injection, and the overall size of the device is significantly reduced. In addition, the manufacturing process is simple and the process tolerance is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a total internal reflection optical switch based on phase change material provided in Example 1.

[0024] Figure 2 This is a schematic cross-sectional view along XX of a total internal reflection optical switch based on phase change material in Example 1.

[0025] Figure 3 This is a schematic diagram of the structure of a total internal reflection optical switch based on phase change material provided in Example 2.

[0026] Figure 4 This is a schematic cross-sectional view along XX of a total internal reflection optical switch based on phase change material in Example 2.

[0027] Figure 5 A schematic structural diagram of a total internal reflection optical switch based on phase change material provided by the present invention.

[0028] Figure 6 This is a schematic cross-sectional diagram along XX of a total internal reflection optical switch based on a phase change material provided by the present invention.

[0029] Figure 7A schematic structural diagram of a total internal reflection optical switch based on phase change material provided by the present invention.

[0030] Figure 8 This is a schematic cross-sectional diagram along XX of a total internal reflection optical switch based on a phase change material provided by the present invention.

[0031] Fig. 9 (a) shows the phase change material in the amorphous state. 0 The transmittance spectrum of the output port after the input of the mode light; (b) is the TE of the phase change material in the amorphous state 0 Field distribution diagram of the waveguide after mode light input; (c) is the TE of the phase change material in the crystalline state 0 The transmittance spectrum of the output port after the input of the mode light; (d) is the TE of the phase change material in the crystalline state 0 Field distribution diagram of the waveguide after mode light is input.

[0032] Fig.10 (a) shows the phase change material in the amorphous state. 1 The transmittance spectrum of the output port after the input of the mode light; (b) is the TE of the phase change material in the amorphous state 1 Field distribution diagram of the waveguide after mode light input; (c) is the TE of the phase change material in the crystalline state 1 The transmittance spectrum of the output port after the input of the mode light; (d) is the TE of the phase change material in the crystalline state 1 Field distribution diagram of the waveguide after mode light is input.

[0033] Fig.11 (a) shows the phase change material in the amorphous state. 2 The transmittance spectrum of the output port after the input of the mode light; (b) is the TE of the phase change material in the amorphous state 2 Field distribution diagram of the waveguide after mode light input; (c) is the TE of the phase change material in the crystalline state 2 The transmittance spectrum of the output port after the input of the mode light; (d) is the TE of the phase change material in the crystalline state 2 Field distribution diagram of the waveguide after mode light is input.

[0034] Fig.12 The figure is a schematic diagram of the phase change process of the phase change material in a total internal reflection optical switch based on the phase change material of the present invention.

[0035] In all the drawings, the same figure numbers are used to represent the same elements or structures, wherein: 1. first input waveguide; 2. second input waveguide; 3. first output waveguide; 4. second output waveguide; 5. base; 6. substrate; 7. thin film layer; 8. phase change material region; 9. upper cladding. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Example 1

[0038] A total internal reflection optical switch based on phase change material, the structure of which is as follows Figure 1-2 As shown, it includes: from bottom to top, a base 5, a substrate 6 and a thin film layer 7, and also includes a first input waveguide 1, a second input waveguide 2, a phase change region 8, a first output waveguide 3 and a second output waveguide 4 arranged on the thin film layer 7.

[0039] The first input waveguide 1 and the second input waveguide 2 are in contact with the phase change material area 8 and are arranged in a mirror-symmetrical manner based on the phase change material area 8; the first output waveguide 3 and the second output waveguide 4 are in contact with the phase change material area 8 and are arranged in a mirror-symmetrical manner based on the phase change material area 8; the first input waveguide 1, the second input waveguide 2, the first output waveguide 3 and the second output waveguide 4 are not perpendicular to the phase change material area 8; the first input waveguide 1 and the first output waveguide 3 are parallel to each other and are respectively located on both sides of the phase change material area 8; the second input waveguide 2 and the first output waveguide 4 are parallel to each other and are located on both sides of the phase change material area 8; The first input waveguide 1 and the second output waveguide 3 are respectively located on both sides of the phase change material area 8; the surface of the first input waveguide 1 in contact with the phase change material area 8 overlaps with the surface of the first output waveguide 4 in contact with the phase change material area 8; the surface of the second input waveguide 2 in contact with the first output waveguide 3 overlaps with the surface of the first output waveguide 3 in contact with the phase change material area 8, and the top of the phase change material area 8 is higher than the top of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4, or is flush with the top of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4.

[0040] The material of the waveguide is silicon-based, and the phase change material is Sb 2 S 3 , a silicon wafer with a standard thickness of 725 μm is selected as the substrate 5, the substrate 6 is 2 μm thick silicon dioxide, the width of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4 are all 5 μm, and a ridge waveguide structure with an etching depth h of 100 nm is adopted, and the branch angle θ 1 The phase change region has a depth of 220 nm, a length of 80 μm, and a width of 1.5 μm. The waveguide etching depth h is less than the sum of the thickness of the single crystal silicon thin film layer 7 and the waveguide (H).

[0041] An electric pulse with high power and short time is applied to the phase change region 8, so that the phase change material is transformed from a crystalline state to an amorphous state, and the difference between the refractive index of the phase change material and the refractive index of the waveguide is 0.6, so that the transmission direction of the optical signal is input from the first input waveguide 1, and the signal light is output from the first output waveguide 4, the signal light is input from the second input waveguide 2, and the signal light is output from the second output waveguide 3. At this time, the total internal reflection optical switch is in a "cross" state; an electric pulse with low power and long time is applied to the phase change region 8, so that the phase change material is transformed from an amorphous state to a crystalline state, and the difference between the refractive index of the phase change material and the refractive index of the waveguide is 0.1, so that the transmission direction of the optical signal is input from the first input waveguide 1, and the signal light is output from the first output waveguide 3, the signal light is input from the second input waveguide 2, and the signal light is output from the second output waveguide 4. The total internal reflection optical switch is in a "straight-through" state.

[0042] The first pretreatment converts the phase change material from a crystalline state to an amorphous state, and adopts a high-power, short-time thermal annealing, electric pulse or laser pulse to locally heat it, so that the temperature of the phase change material exceeds the melting point of the material, breaking the chemical bonds in the crystalline material, and then rapidly cooling it, so that the atoms in the molten phase change material do not have time to rearrange bonds to form an amorphous state; the second pretreatment converts the phase change material from an amorphous state to a crystalline state, and the second pretreatment adopts a low-power, long-time thermal annealing, electric pulse or laser pulse to locally heat it. When the temperature of the material is between the crystallization temperature and the melting point, the phase change material will crystallize, thereby forming a crystalline state with a higher refractive index, so that the phase change material in the phase change material area is completely converted from the amorphous state to the crystalline state.

[0043] The following test is performed on the total internal reflection optical switch based on phase change material provided in the above embodiment: the structure is input into the simulation software FDTD and simulated, and it can be obtained that the TE of the total internal reflection optical switch is in the crystalline and amorphous state of the phase change material. 0 (Base model), TE 1 (first-order mode) and TE 2 Output waveguide transmission spectrum and overall field distribution diagram when (second-order) mode light is input.

[0044] like Fig. 9 As shown, Fig. 9 (a) and (b) show the TE when the phase change material is in the amorphous state. 0 Output transmittance spectrum and field distribution diagram for mode light input. In the reflective output port, TE 0The transmittance reaches -0.096dB, while the crosstalk of the through output port is only -39.51dB. Almost all optical signals are output from the reflection output port and a good light wave mode is maintained, realizing the "crossover" function of the total internal reflection optical switch.

[0045] Fig. 9 (c) and (d) show the TE when the phase change material is in the crystalline state. 0 Output transmittance spectrum and field distribution diagram for mode light input. In the through output port, TE 0 The transmittance reaches -0.107dB, while the crosstalk of the reflection output port is only -21.28dB. Almost all optical signals are output from the through output port and maintain a good light wave mode, realizing the "through" function of the total internal reflection optical switch.

[0046] like Fig.10 As shown, Fig.10 (a) and (b) show the TE when the phase change material is in the amorphous state. 1 Output transmittance spectrum and field distribution diagram for mode light input. In the reflective output port, TE 1 The transmittance reaches -0.377dB, while the crosstalk of the through output port is only -33.74dB. Almost all optical signals are output from the reflection output port and a good light wave mode is maintained, realizing the "crossover" function of the total internal reflection optical switch.

[0047] Fig.10 (c) and (d) show the TE when the phase change material is in the crystalline state. 1 Output transmittance spectrum and field distribution diagram for mode light input. In the through output port, TE 1 The transmittance reaches -0.339dB, while the crosstalk of the reflection output port is only -20.87dB. Almost all optical signals are output from the through output port and maintain a good light wave mode, realizing the "through" function of the total internal reflection optical switch.

[0048] like Fig.11 As shown, Fig.11 (a) and (b) show the TE when the phase change material is in the amorphous state. 2 Output transmittance spectrum and field distribution diagram for mode light input. In the reflective output port, TE 2 The transmittance reaches -0.814dB, while the crosstalk of the through output port is only -29.38dB. Almost all optical signals are output from the reflection output port and a good light wave mode is maintained, realizing the "crossover" function of the total internal reflection optical switch.

[0049] Fig.11(c) and (d) show the TE when the phase change material is in the crystalline state. 2 Output transmittance spectrum and field distribution diagram for mode light input. In the through output port, TE 2 The transmittance reaches -0.737dB, while the crosstalk of the reflection output port is only -20.69dB. Almost all optical signals are output from the straight-through output port and maintain a good light wave mode, realizing the "straight-through" function of the total internal reflection optical switch. The above-mentioned total internal reflection optical switch uses phase change materials to realize the selection of the optical signal output port, with low insertion loss, small crosstalk, large extinction ratio, large bandwidth, and non-volatility.

[0050] Example 2

[0051] A total internal reflection optical switch based on phase change material, the structure of which is as follows Figure 3-4 As shown, from bottom to top, it is a base 5 and a substrate 6, and also includes a waveguide and a phase change material area 8 arranged on the substrate 6, the waveguide includes a first input waveguide 1, a second input waveguide 2, a first output waveguide 3, and a second output waveguide 4, the first input waveguide 1 and the second input waveguide 2 are in contact with the phase change material area 8 and are arranged based on the mirror symmetry of the phase change material area 8, the first output waveguide 3 and the second output waveguide 4 are in contact with the phase change material area 8 and are arranged based on the mirror symmetry of the phase change material area 8, the first input waveguide 1, the second input waveguide 2, the first output waveguide 3 and the second output waveguide 4 are not perpendicular to the phase change material area 8; the first input waveguide 1 and the first output waveguide 3 are parallel to each other and are respectively Located on both sides of the phase change material area 8, the second input waveguide 2 and the first output waveguide 4 are parallel to each other and are respectively located on both sides of the phase change material area 8; the surface of the first input waveguide 1 in contact with the phase change material area 8 overlaps with the surface of the first output waveguide 4 in contact with the phase change material area 8; the surface of the second input waveguide 2 in contact with the first output waveguide 3 overlaps with the surface of the first output waveguide 3 in contact with the phase change material area 8, and the top of the phase change material area 8 is higher than the top of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4, or is flush with the top of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4. The material of the waveguide is silicon-based, and the phase change material is Sb 2 S 3 , a silicon wafer with a standard thickness of 220nm is selected as the substrate 5, the substrate 6 is 2μm thick silicon dioxide, the width of the first input waveguide 1, the second input waveguide 2, the first output waveguide 3, and the second output waveguide 4 are all 5μm, and a strip waveguide structure with an etching depth of h of 220nm is adopted, and the branch angle θ 1 Select 70°. The phase change region has a depth of 220 nm, a length of 80 μm, and a width of 1.5 μm.

[0052] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A total internal reflection optical switch based on phase change material, characterized in that: The invention relates to a device for manufacturing a phase change material region (8) comprising a base (5) and a substrate (6) from bottom to top, and further comprising a waveguide and a phase change material region (8) arranged on the substrate (6); the waveguide comprises a first input waveguide (1), a second input waveguide (2), a first output waveguide (3), and a second output waveguide (4); the first input waveguide (1) and the second input waveguide (2) are in contact with the phase change material region (8) and are arranged in a mirror-symmetrical manner based on the phase change material region (8); the first output waveguide (3) and the second output waveguide (4) are in contact with the phase change material region (8) and are arranged in a mirror-symmetrical manner based on the phase change material region (8); the first input waveguide (1), the second input waveguide (2), the first output waveguide (3), and the second output waveguide (4) are not in contact with the phase change material region (8); The first input waveguide (1) and the first output waveguide (3) are parallel to each other and are respectively located on both sides of the phase change material area (8); the second input waveguide (2) and the first output waveguide (4) are parallel to each other and are respectively located on both sides of the phase change material area (8); the surface of the first input waveguide (1) in contact with the phase change material area (8) overlaps with the surface of the first output waveguide (4) in contact with the phase change material area (8); the surface of the second input waveguide (2) in contact with the phase change material area (8) overlaps with the surface of the first output waveguide (3) in contact with the phase change material area (8); the height of the phase change material area (8) is greater than or equal to the height of the waveguide.

2. A total internal reflection optical switch based on phase change material, characterized in that: The invention comprises, from bottom to top, a base (5) and a substrate (6), and also comprises a waveguide and a phase change material region (8) arranged on the substrate (6); the waveguide comprises a first input waveguide (1), a first output waveguide (3) and a second output waveguide (4); the first input waveguide (1), the first output waveguide (3) and the second output waveguide (4) are all in contact with the phase change material region (8) and are not perpendicular to the phase change material region (8); the first input waveguide (1) and the first output waveguide (3) are parallel to each other and are respectively located on both sides of the phase change material region (8); the first input waveguide (1) and the first output waveguide (4) are located on the same side of the phase change material region (8), and the first input waveguide (1) and the first output waveguide (4) are not parallel to each other; the surface of the first input waveguide (1) in contact with the phase change material region (8) overlaps with the surface of the first output waveguide (4) in contact with the phase change material region (8); the height of the phase change material region (8) is greater than or equal to the height of the waveguide.

3. A total internal reflection optical switch based on phase change material as claimed in claim 1 or 2, characterized in that: A thin film layer (7) is also arranged between the substrate (6) and the phase change material area (8), and a groove is arranged inside the thin film layer (7), and the groove runs from the top of the thin film layer (7) to the bottom of the thin film layer (7), and the phase change material in the phase change material area (8) extends downward into the groove.

4. A total internal reflection optical switch based on phase change material as claimed in claim 3, characterized in that: The material of the base (5) is silicon, and the material of the substrate (6) is silicon dioxide; the material of the thin film layer (7) is selected from single crystal silicon, silicon nitride, lithium niobate or lithium tantalate; the material of the waveguide is selected from single crystal silicon, silicon nitride, lithium niobate or lithium tantalate.

5. A total internal reflection optical switch based on phase change material as claimed in claim 1 or 2, characterized in that: The material of the phase change material region (8) is selected from Ge2Sb2Te5, Ge2Sb2SnTe5, VO2, Sb2Se3 or Sb2S3.

6. A total internal reflection optical switch based on phase change material as claimed in claim 1 or 2, characterized in that: The angle θ1 between the first output waveguide and the second output waveguide conforms to the formula; Wherein, n1 is the effective refractive index of the waveguide, and n2 is the effective refractive index of the phase change material in the phase change material region (8) when in a completely amorphous state.

7. A total internal reflection optical switch based on phase change material as claimed in claim 1 or 2, characterized in that: The surfaces of the waveguide and the phase change material region (8) that are not covered are covered with an upper cladding layer (9), and the material of the upper cladding layer (9) is selected from silicon dioxide, aluminum oxide or indium tin oxide.

8. A method for using a total internal reflection optical switch based on a phase change material as claimed in any one of claims 1, 3 to 7, characterized in that: The total internal reflection optical switch has the following two usage methods: (1) performing a first pre-treatment on the phase change material region, so that the phase change material in the phase change material region is completely transformed from a crystalline state to an amorphous state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is greater than 0.

6. At this time, a signal light is input from the first input waveguide and the signal light is output from the second output waveguide; or a signal light is input from the second input waveguide and the signal light is output from the first output waveguide; or a signal light is input from the first input waveguide and the second input waveguide and the signal light is output from the second output waveguide and the first output waveguide respectively; Or (2) a second pre-treatment is performed on the phase change material area, and the phase change material in the phase change material area is completely transformed from an amorphous state to a crystalline state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is 0 to 0.

2. At this time, signal light is input from the first input waveguide and the signal light is output from the first output waveguide; or signal light is input from the second input waveguide and the signal light is output from the second output waveguide; or signal light is input from the first input waveguide and the second input waveguide, and the signal light is output from the first output waveguide and the second output waveguide respectively.

9. A method for using a total internal reflection optical switch based on a phase change material according to any one of claims 2 to 7, characterized in that: The total internal reflection optical switch has the following two usage methods: (1) performing a first pre-treatment on the phase change material region, so that the phase change material in the phase change material region is completely transformed from a crystalline state to an amorphous state, so that the difference between the refractive index of the phase change material and the refractive index of the waveguide is greater than 0.6, and at this time, signal light is input from the first input waveguide, and the signal light is output from the second output waveguide; Or (2) a second pre-treatment is performed on the phase change material area, and the phase change material in the phase change material area is completely transformed from an amorphous state to a crystalline state, so that the refractive index of the phase change material and the refractive index of the waveguide differ by 0 to 0.

2. At this time, signal light is input from the first input waveguide, and the signal light is output from the first output waveguide.

10. The method for using the total internal reflection optical switch based on phase change material according to claim 8 or 9, characterized in that: The first pre-treatment or the second pre-treatment is selected from thermal annealing, electric pulse or laser pulse.

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