Integrated optical switch based on In2Se3 and control method thereof

Abstract

The invention discloses an integrated optical switch based on In2Se3 and a control method thereof, and solves the problems that the existing optical switch is large in size and high in power consumption and needs constant power to maintain tuning, the optical switch provided by the invention comprises a main waveguide and a heterogeneous integrated waveguide, and due to the near-infrared transparency and low-entropy phase change characteristics of an In2Se3 thin film, the optical switch can be used for controlling the tuning of the optical switch. The on-chip optical switch device based on the material has the potentials of low on-chip insertion loss, low power consumption and high switching speed, switching of an OFF state and an ON state of an optical switch is achieved by means of the nonvolatile phase change characteristic between alpha-In2Se3 and beta-In2Se3, and then the micro-ring type optical switch device without continuous power supply is achieved. The optical switch is small in size, low in power consumption and excellent in channel balance.

Description

Technical Field

[0001] The invention relates to an optical switch and a control method thereof, and in particular to an integrated optical switch based on In2Se3 and a control method thereof. Background Art

[0002] With the rapid development of optical communication technology, the demand for high-speed, large-capacity and low-power optoelectronic devices is increasing. Silicon-based optoelectronic technology occupies a core position in large-scale integrated chips with its significant advantages such as high speed, low power consumption, high integration and good compatibility. With the rapid development of silicon-based photonic devices, optical delay lines, modulators, micro-ring filters, grating couplers, optical switches and other devices have appeared in optical communication systems.

[0003] Optical switches play an important role in on-chip optical communication systems and have important applications in optical signal transmission, interconnection and processing. In order to better handle the increasing communication traffic, optical switches with high efficiency, low loss and high speed have become an important research requirement in optical communication systems.

[0004] Optical switches (OS) in current photonic integrated circuits mainly achieve weak modulation of the refractive index through free carrier dispersion effect or thermo-optic effect, but this results in large footprint and high power consumption. Therefore, there is an urgent need for an optical switch that can maintain the switching state without consuming additional power and exhibits excellent performance in terms of response speed, device size, and power consumption. Summary of the invention

[0005] In order to solve the technical problems of large size, high power consumption and the need for constant power to maintain tuning of existing optical switches, the present invention provides an integrated optical switch based on In2Se3 and a control method thereof.

[0006] The inventive concept of the present invention:

[0007] Compared with electrical interconnection, optical interconnection has the advantages of large bandwidth, low latency, no interference and high parallelism. It is an important technical means to break through the bottleneck of traditional electrical interconnection. On-chip optical interconnection is an interconnection technology that connects optoelectronic devices with multiple functions through optical waveguides. Silicon-based optoelectronic technology is an optoelectronic integration technology that is compatible with mature microelectronic technology. This technology can combine the ultra-large-scale logic and ultra-high precision manufacturing characteristics of CMOS technology with the advantages of ultra-high speed and ultra-low power consumption of photonic technology. It is an innovative technology that can solve the contradiction between technological evolution and cost.

[0008] Phase change materials are materials that can undergo reversible phase transitions very quickly and show huge differences in optical / electrical properties through changes in atomic arrangement during phase transition. Phase change materials have some unique advantages:

[0009] (1) Phase transition between amorphous and crystalline states, with considerable tunability of resistivity and optical constants in a wide spectral range;

[0010] (2) The switching state can be maintained for several years without the need for additional power;

[0011] (3) Phase change speed is faster than nanoseconds, with ultra-fast switching speed;

[0012] (4) It has good scalability and durability.

[0013] Therefore, the introduction of phase change materials is naturally combined with integrated photonics to develop integrated optoelectronic devices.

[0014] The phase change material In2Se3 has multiple single crystal states and can undergo reversible phase changes between single crystal states without the need for a melting process and has low structural entropy. The low absorption loss and phase change structural entropy characteristics of this material can bring breakthroughs in high-speed, stable and low-power optical switch technology. By using the non-volatile phase change characteristics between α-In2Se3 and β-In2Se3, by changing the phase state of In2Se3, fast switching of optical signals can be achieved, thereby meeting the needs of optical communication systems for efficient and low-loss optical switches.

[0015] In order to achieve the above purpose and complete the above invention concept, the present invention adopts the following technical solutions:

[0016] An integrated optical switch based on In2Se3, which is special in that it comprises a substrate layer, a waveguide layer arranged on the substrate layer, and an outer cladding layer wrapped around the waveguide layer;

[0017] The waveguide layer includes a trunk waveguide, a heterogeneous integrated waveguide and a micro-ring which are arranged side by side in sequence;

[0018] The trunk waveguide comprises an input waveguide, a first coupling waveguide and an output waveguide which are sequentially connected along the length direction;

[0019] The heterogeneous integrated waveguide includes a second coupling waveguide arranged on the substrate layer and an In2Se3 film arranged on the second coupling waveguide; the second coupling waveguide and the In2Se3 film are both arranged close to the first coupling waveguide;

[0020] The micro-ring comprises a first straight waveguide, a first curved waveguide, a second straight waveguide and a second curved waveguide (234) which are sequentially connected end to end; the first straight waveguide is arranged close to the second coupling waveguide;

[0021] The width W1 of the trunk waveguide, the width W2 of the second coupling waveguide and the width W3 of the first straight waveguide satisfy: W1≠W2 and W 1＝ W3;

[0022] The first coupled waveguide, the heterogeneous integrated waveguide and the first straight waveguide can achieve phase matching based on the state transformation of the In2Se3 thin film, so that the three form a directional coupler;

[0023] The cladding layer is used to protect the waveguide layer.

[0024] Furthermore, the trunk waveguide, the second coupling waveguide and the micro-ring are all made of silicon, silicon nitride, aluminum nitride or thin-film lithium niobate material.

[0025] Furthermore, the substrate layer is made of SOI (Silicon-on-insulator);

[0026] The envelope is air.

[0027] Further, when the first coupled waveguide, the second coupled waveguide and the micro-ring are made of silicon, the lengths of the first coupled waveguide, the second coupled waveguide, the first straight waveguide and the In2Se3 film are all Lc, and the range of Lc is 9 μm-50 μm.

[0028] Furthermore, the thickness of the In2Se3 film is H≤100nm, and its width is Smaller than the second coupling waveguide width W2.

[0029] Furthermore, when the trunk waveguide and the microring are made of silicon, the widths W3 of the first straight waveguide, the first curved waveguide, the second straight waveguide and the second curved waveguide and the width W1 of the trunk waveguide are in the range of 450 nm-650 nm.

[0030] Furthermore, when the trunk waveguide, the second coupling waveguide and the microring are made of silicon, the gap between the trunk waveguide and the second coupling waveguide, and the gap between the second coupling waveguide and the first straight waveguide are both g, and the range of g is 25nm-150nm.

[0031] Furthermore, when the trunk waveguide, the second coupling waveguide and the micro-ring are made of silicon, the thickness of the trunk waveguide, the second coupling waveguide and the micro-ring is h=220 nm.

[0032] A control method of the above-mentioned integrated optical switch based on In2Se3 is special in that:

[0033] When the light switch is turned on:

[0034] When the In2Se3 film is stimulated, the state of the In2Se3 film is converted from the α state to the β state, then the first coupling waveguide, the heterogeneous integrated waveguide and the first straight waveguide do not meet the phase matching condition, and the signal light received by the input waveguide is directly output from the output waveguide after passing through the first coupling waveguide, and the optical switch is turned on;

[0035] When the light switch is turned off:

[0036] The In2Se3 film is stimulated and its state is converted from β state to α state, so that the first coupled waveguide, the heterogeneous integrated waveguide and the first straight waveguide meet the phase matching conditions. The signal light received by the input waveguide is gradually coupled to the heterogeneous integrated waveguide when passing through the first coupled waveguide, and then coupled into the microring. At the resonant wavelength of the microring, the power of the signal light is lost, the power of the signal light output by the output waveguide drops sharply, and the optical switch is turned off.

[0037] Furthermore, the method of stimulating the In2Se3 film is thermal stimulation, light stimulation or electrical stimulation.

[0038] Beneficial effects of the present invention:

[0039] 1. An integrated optical switch based on In2Se3 provided by the present invention includes a trunk waveguide and a heterogeneous integrated waveguide. Thanks to the near-infrared transparency and low entropy phase change characteristics of the In2Se3 film, the on-chip optical switch device based on this material has the potential of low on-chip insertion loss, low power consumption and high switching speed. With the help of the non-volatile phase change characteristics between α-In2Se3 and β-In2Se3, the switching of the optical switch OFF and ON states is realized, thereby realizing a micro-ring optical switch device that does not require continuous power supply. The optical switch is small in size, low in power consumption and has excellent channel balance.

[0040] 2. The In2Se3 film used in the present invention has the property of non-volatility derived from the phase change material. Even after the external stimulus stops, the In2Se3 film can still maintain its current state, so the state of the optical switch can also remain unchanged without the need for continuous external stimulus to maintain.

[0041] 3. In the present invention, the substrate layer is made of SOI, so that the substrate layer can be used as a mounting base while ensuring stable and efficient transmission of light in the waveguide layer.

[0042] 4. In the present invention, the cladding is air, which can ensure stable and efficient transmission of light in the waveguide layer on the one hand, and because air is a stable medium, it is not easy to chemically react with the waveguide layer material, so it can protect the waveguide layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a top view of an embodiment of an integrated optical switch based on In2Se3 of the present invention;

[0044] Figure 2 yes Figure 1 AA section view.

[0045] Figure Number:

[0046] 1-substrate layer, 2-waveguide layer, 21-trunk waveguide, 211-input waveguide, 212-first coupled waveguide, 213-output waveguide, 22-heterogeneous integrated waveguide, 221-second coupled waveguide, 222-In2Se3 thin film, 23-microring, 231-first straight waveguide, 232-first curved waveguide, 233-second straight waveguide, 234-second curved waveguide, 3-cladding. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Embodiment 1

[0049] This embodiment provides an integrated optical switch based on In2Se3, combined with Figure 1 and Figure 2 As shown, the waveguide layer 2 includes a substrate layer 1 , a waveguide layer 2 disposed on the substrate layer 1 , and a cladding layer 3 wrapped around the waveguide layer 2 .

[0050] The substrate layer 1 is made of SOI and is used as a mounting base. At the same time, the difference in refractive index between the substrate layer 1 and the waveguide layer 2 helps to form an optical waveguide effect, so that light can propagate in the waveguide layer 2 in a total reflection manner, thereby reducing light loss.

[0051] The waveguide layer 2 includes a trunk waveguide 21, a heterogeneous integrated waveguide 22 and a microring 23 which are arranged side by side in sequence; the trunk waveguide 21 includes an input waveguide 211, a first coupling waveguide 212 and an output waveguide 213 which are connected in sequence along the length direction; the heterogeneous integrated waveguide 22 includes a second coupling waveguide 221 arranged on the substrate layer 1 and an In2Se3 film 222 arranged on the second coupling waveguide 221; the second coupling waveguide 221 and the In2Se3 film 222 are both arranged close to the first coupling waveguide 212; the microring 23 includes a first straight waveguide 231, a first curved waveguide 232, a second straight waveguide 233 and a second curved waveguide 234 which are connected end to end in sequence; the first straight waveguide 231 is arranged close to the second coupling waveguide 221; the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 are all made of materials such as silicon, silicon nitride, aluminum nitride or thin film lithium niobate.

[0052] The value ranges of the above device parameters are as follows:

[0053] When the first coupling waveguide 212, the second coupling waveguide 221 and the first straight waveguide 231 are made of silicon, the lengths of the first coupling waveguide 212, the second coupling waveguide 221, the first straight waveguide 231 and the In2Se3 film 222 are all Lc, and the range of Lc is 9μm-50μm. The thickness H of the In2Se3 film 222 is ≤100nm, and its width The first straight waveguide 231 has a width W3 smaller than the width W2 of the second coupled waveguide 221. When the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 are made of silicon, the width W3 of the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 is in the range of 450nm-650nm. When the trunk waveguide 21, the second coupled waveguide 221 and the first straight waveguide 231 are made of silicon, the gap between the trunk waveguide 21 and the second coupled waveguide 221, and the gap between the second coupled waveguide 221 and the first straight waveguide 231 are both g, and the range of g is 25nm-150nm. When the trunk waveguide 21 is made of silicon, the width W1 of the trunk waveguide 21 is in the range of 450nm-650nm.

[0054] The cladding 3 surrounding the waveguide layer 2 is air.

[0055] The trunk waveguide 21 and the second coupling waveguide 221 have different widths W1 and W2, that is, W1≠W2; the width W3 of the micro-ring 23 is consistent with W1, that is, W 1＝ W3: width of the In2Se3 film 222 It is set to be 100 nm smaller than the width W2 of the hetero-integrated waveguide 22 .

[0056] In this embodiment, the width W2 of the second coupling waveguide 221 is selected to be 415 nm, the thickness H of the In2Se3 film 222 is 60 nm when it is in the α state, and the thickness H of the In2Se3 film 222 is 51 nm when it is converted to the β state. The width W1 of the trunk waveguide 21 is 450 nm, and the thickness h of the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 is 220 nm.

[0057] After the phase matching condition is achieved by setting the structural parameters, in order to optimize the device performance, the coupling length Lc and the coupling gap g of the coupling region need to be scanned to select an optimal value. In this embodiment, the coupling length of the coupling region ranges from 9 to 50 μm, and the coupling gap ranges from 25 to 150 nm, and an optimal value is selected within the range.

[0058] When the In2Se3 film 222 is in the α state, the phase matching between the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 is achieved by designing the waveguide structure, so that the three can form a directional coupler. Subsequently, by optimizing the length Lc and spacing g of the coupling region between the heterogeneous integrated waveguide 22 and the first coupling waveguide 212 and the first straight waveguide 231, the signal light can be coupled from the input waveguide 211 into the heterogeneous integrated waveguide 22, and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, and the signal light power output by the output waveguide 213 drops sharply, and the optical switch enters the OFF state.

[0059] When a photoinduced phase change method (such as a laser pulse) is used to stimulate the top of the In2Se3 film 222, the In2Se3 film 222 absorbs photon energy, thereby inducing the material to achieve a transition from the α state to the β state. In the β-In2Se3 state, the refractive index of the In2Se3 film 222 will change significantly. This transition causes the phase matching in the originally stable directional coupler to be destroyed, and no coupling will occur between the first coupling waveguide 212 and the heterogeneous integrated waveguide 22, and it will not be coupled into the microring 23. Therefore, the signal light in the first coupling waveguide 212 can continue to be transmitted and output from the output port of the output waveguide 213. Since no coupling occurs at this time, the optical loss is relatively low, and the optical switch enters the ON state.

[0060] When the In2Se3 film 222 is in the α state, the phase matching condition is met, most of the signal light energy stays in the microring 23, and a small amount of signal light is output from the Output port of the output waveguide 213 (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL). When the In2Se3 film 222 changes to the β state, the phase matching condition cannot be met, the signal light cannot be coupled, the optical loss is relatively low, and most of the signal light energy is output from the Output port (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL).

[0061] The optical switch can switch the optical path by switching the state of the phase change material, and the device has excellent performance by optimizing the structural parameters. In addition, the optical switch has the property of non-volatility derived from the phase change material. Even after the external stimulus stops, the In2Se3 film 222 can still maintain its current state, so the state of the optical switch can also remain unchanged without continuous external stimulus to maintain.

[0062] The control method of the above-mentioned integrated optical switch based on In2Se3 is as follows:

[0063] When the optical switch is turned on: the In2Se3 film 222 is stimulated by a laser pulse, and the state of the In2Se3 film 222 is converted from the α state to the β state. Then the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 do not meet the phase matching condition, and the signal light received by the input waveguide 211 is directly output from the output waveguide 213 after passing through the first coupling waveguide 212, and the optical switch is turned on.

[0064] When the optical switch is closed: the In2Se3 film 222 is stimulated by a laser pulse, and the state of the In2Se3 film 222 is converted from the β state to the α state, so that the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 meet the phase matching conditions. When the signal light received by the input waveguide 211 passes through the first coupling waveguide 212, it is gradually coupled to the heterogeneous integrated waveguide 22, and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, the power of the signal light output by the output waveguide 213 drops sharply, and the optical switch is closed.

[0065] Embodiment 2:

[0066] This embodiment provides an integrated optical switch based on In2Se3, combined with Figure 1 and Figure 2 As shown, the waveguide layer 2 includes a substrate layer 1 , a waveguide layer 2 disposed on the substrate layer 1 , and a cladding layer 3 wrapped around the waveguide layer 2 .

[0067] The substrate layer 1 is made of SOI and is used as a mounting base. At the same time, the difference in refractive index between the substrate layer 1 and the waveguide layer 2 helps to form an optical waveguide effect, so that light can propagate in the waveguide layer 2 in a total reflection manner, thereby reducing light loss.

[0068] The waveguide layer 2 includes a trunk waveguide 21, a heterogeneous integrated waveguide 22 and a microring 23 which are arranged side by side in sequence; the trunk waveguide 21 includes an input waveguide 211, a first coupling waveguide 212 and an output waveguide 213 which are connected in sequence along the length direction; the heterogeneous integrated waveguide 22 includes a second coupling waveguide 221 arranged on the substrate layer 1 and an In2Se3 film 222 arranged on the second coupling waveguide 221; the second coupling waveguide 221 and the In2Se3 film 222 are both arranged close to the first coupling waveguide 212; the microring 23 includes a first straight waveguide 231, a first curved waveguide 232, a second straight waveguide 233 and a second curved waveguide 234 which are connected end to end in sequence; the first straight waveguide 231 is arranged close to the second coupling waveguide 221; the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 are all made of materials such as silicon, silicon nitride, aluminum nitride or thin film lithium niobate.

[0069] The value ranges of the above device parameters are as follows:

[0070] When the first coupling waveguide 212, the second coupling waveguide 221 and the first straight waveguide 231 are made of silicon, the lengths of the first coupling waveguide 212, the second coupling waveguide 221, the first straight waveguide 231 and the In2Se3 film 222 are all Lc, and the range of Lc is 9μm-50μm. The thickness H of the In2Se3 film 222 is ≤100nm, and its width is smaller than the width W2 of the second coupled waveguide 221. When the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 are made of silicon, the width W3 of the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 is in the range of 450nm-650nm. When the trunk waveguide 21, the second coupled waveguide 221 and the first straight waveguide 231 are made of silicon, the gap between the trunk waveguide 21 and the second coupled waveguide 221, and the gap between the second coupled waveguide 221 and the first straight waveguide 231 are both g, and the range of g is 25nm-150nm. When the trunk waveguide 21 is made of silicon, the width W1 of the trunk waveguide 21 is in the range of 450nm-650nm. The cladding 3 wrapped outside the waveguide layer 2 is air.

[0071] The trunk waveguide 21 and the second coupling waveguide 221 have different widths W1 and W2, that is, W1≠W2; the width W3 of the micro-ring 23 is consistent with W1, that is, W1=W3; the width of the In2Se3 film 222 It is set to be 100 nm smaller than the width W2 of the hetero-integrated waveguide 22 .

[0072] In this embodiment, the width W2 of the second coupling waveguide 221 is selected to be 415 nm, the thickness H of the In2Se3 film 222 is 60 nm when it is in the α state, and the thickness H of the In2Se3 film 222 is 51 nm when it is converted to the β state. The width W1 of the trunk waveguide 21 is 450 nm, and the thickness h of the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 is 220 nm.

[0073] After the phase matching condition is achieved by setting the structural parameters, in order to optimize the device performance, the coupling length Lc and the coupling gap g of the coupling region need to be scanned to select an optimal value. In this embodiment, the coupling length of the coupling region ranges from 9 to 50 μm, and the coupling gap ranges from 25 to 150 nm, and an optimal value is selected within the range.

[0074] When the In2Se3 film 222 is in the α state, the phase matching between the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 is achieved by designing the waveguide structure, so that the three can form a directional coupler. Subsequently, by optimizing the length Lc and spacing g of the coupling region between the heterogeneous integrated waveguide 22 and the first coupling waveguide 212 and the first straight waveguide 231, the signal light can be coupled from the input waveguide 211 into the heterogeneous integrated waveguide 22, and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, and the signal light power output by the output waveguide 213 drops sharply, and the optical switch enters the OFF state.

[0075] When the thermally induced phase change method (such as heating with a temperature control platform) is used, the designed device is placed on the temperature control platform, and the heating temperature and heating time of the temperature platform are controlled to make the In2Se3 film 222 reach the phase change temperature, thereby inducing the material to achieve the transition from the α state to the β state. In the β-In2Se3 state, the refractive index of the In2Se3 film 222 will change significantly. This transition causes the phase matching in the originally stable directional coupler to be destroyed, and no coupling is generated between the first coupling waveguide 212 and the heterogeneous integrated waveguide 22, and it will not be coupled into the microring 23. Therefore, the signal light in the first coupling waveguide 212 can continue to be transmitted and output from the output port of the output waveguide 213. Since no coupling occurs at this time, the optical loss is relatively low, and the optical switch enters the ON state.

[0076] When the In2Se3 film 222 is in the α state, the phase matching condition is met, most of the signal light energy stays in the microring 23, and a small amount of signal light is output from the Output port of the output waveguide 213 (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL). When the In2Se3 film 222 changes to the β state, the phase matching condition cannot be met, the signal light cannot be coupled, the optical loss is relatively low, and most of the signal light energy is output from the Output port (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL).

[0077] The optical switch can switch the optical path by switching the state of the phase change material, and the device has excellent performance by optimizing the structural parameters. In addition, the optical switch has the property of non-volatility derived from the phase change material. Even after the external stimulus stops, the In2Se3 film 222 can still maintain its current state, so the state of the optical switch can also remain unchanged without continuous external stimulus to maintain.

[0078] The control method of the above-mentioned integrated optical switch based on In2Se3 is as follows:

[0079] When the optical switch is turned on: the state of the In2Se3 film 222 is converted from the α state to the β state through thermal stimulation of the In2Se3 film 222, then the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 do not meet the phase matching condition, and the signal light received by the input waveguide 211 is directly output from the output waveguide 213 after passing through the first coupling waveguide 212, and the optical switch is turned on.

[0080] When the optical switch is closed: by thermally stimulating the In2Se3 film 222, the state of the In2Se3 film 222 is converted from the β state to the α state, so that the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 meet the phase matching conditions. When the signal light received by the input waveguide 211 passes through the first coupling waveguide 212, it is gradually coupled to the heterogeneous integrated waveguide 22 and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, the power of the signal light output by the output waveguide 213 drops sharply, and the optical switch is closed.

[0081] Embodiment three:

[0082] This embodiment provides an integrated optical switch based on In2Se3, combined with Figure 1 and Figure 2 As shown, the waveguide layer 2 includes a substrate layer 1 , a waveguide layer 2 disposed on the substrate layer 1 , a heat conducting layer 4 located above the waveguide layer, and a cladding layer 3 wrapped around the waveguide layer 2 and the heat conducting layer 4 .

[0083] The substrate layer 1 is made of SOI and is used as a mounting base. At the same time, the difference in refractive index between the substrate layer and the waveguide layer 2 helps to form an optical waveguide effect, so that light can propagate in the waveguide layer 2 in a total reflection manner, thereby reducing light loss.

[0084] The waveguide layer 2 includes a trunk waveguide 21, a heterogeneous integrated waveguide 22 and a microring 23 which are arranged side by side in sequence; the trunk waveguide 21 includes an input waveguide 211, a first coupling waveguide 212 and an output waveguide 213 which are connected in sequence along the length direction; the heterogeneous integrated waveguide 22 includes a second coupling waveguide 221 arranged on the substrate layer 1 and an In2Se3 film 222 arranged on the second coupling waveguide 221; the second coupling waveguide 221 and the In2Se3 film 222 are both arranged close to the first coupling waveguide 212; the microring 23 includes a first straight waveguide 231, a first curved waveguide 232, a second straight waveguide 233 and a second curved waveguide 234 which are connected end to end in sequence; the first straight waveguide 231 is arranged close to the second coupling waveguide 221; the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 are all made of materials such as silicon, silicon nitride, aluminum nitride or thin film lithium niobate.

[0085] The value ranges of the above device parameters are as follows:

[0086] When the first coupling waveguide 212, the second coupling waveguide 221 and the first straight waveguide 231 are made of silicon, the lengths of the first coupling waveguide 212, the second coupling waveguide 221, the first straight waveguide 231 and the In2Se3 film 222 are all Lc, and the range of Lc is 9μm-50μm. The thickness H of the In2Se3 film 222 is ≤100nm, and its width The first straight waveguide 231 has a width W3 smaller than the width W2 of the second coupled waveguide 221. When the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 are made of silicon, the width W3 of the first straight waveguide 231, the first curved waveguide 232, the second straight waveguide 233 and the second curved waveguide 234 is in the range of 450nm-650nm. When the trunk waveguide 21, the second coupled waveguide 221 and the first straight waveguide 231 are made of silicon, the gap between the trunk waveguide 21 and the second coupled waveguide 221, and the gap between the second coupled waveguide 221 and the first straight waveguide 231 are both g, and the range of g is 25nm-150nm. When the trunk waveguide 21 is made of silicon, the width W1 of the trunk waveguide 21 is in the range of 450nm-650nm.

[0087] The cladding 3 surrounding the waveguide layer 2 is air.

[0088] The trunk waveguide 21 and the second coupling waveguide 221 have different widths W1 and W2, that is, W1≠W2; the width W3 of the micro-ring 23 is consistent with W1, that is, W 1＝ W3: width of the In2Se3 film 222 It is set to be 100 nm smaller than the width W2 of the hetero-integrated waveguide 22 .

[0089] In this embodiment, the width W2 of the second coupling waveguide 221 is selected to be 415 nm, the thickness H of the In2Se3 film 222 is 60 nm when it is in the α state, and the thickness H of the In2Se3 film 222 is 51 nm when it is converted to the β state. The width W1 of the trunk waveguide 21 is 450 nm, and the thickness h of the trunk waveguide 21, the second coupling waveguide 221 and the microring 23 is 220 nm.

[0090] After the phase matching condition is achieved by setting the structural parameters, in order to optimize the device performance, the coupling length Lc and the coupling gap g of the coupling region need to be scanned to select an optimal value. In this embodiment, the coupling length of the coupling region ranges from 9 to 50 μm, and the coupling gap ranges from 25 to 150 nm, and an optimal value is selected within the range.

[0091] When the In2Se3 film 222 is in the α state, the phase matching between the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 is achieved by designing the waveguide structure, so that the three can form a directional coupler. Subsequently, by optimizing the length Lc and spacing g of the coupling region between the heterogeneous integrated waveguide 22 and the first coupling waveguide 212 and the first straight waveguide 231, the signal light can be coupled from the input waveguide 211 into the heterogeneous integrated waveguide 22, and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, and the signal light power output by the output waveguide 213 drops sharply, and the optical switch enters the OFF state.

[0092] The thermal conductive layer is connected to the electrode layer, and the electrode layer is used to supply power to the thermal conductive layer to heat the thermal conductive layer, thereby causing the thermal conductive layer to heat the phase change material in the waveguide layer and change the state of the phase change material. The thermal conductive layer is connected to the electrode, and a controlled pulse voltage is applied to the electrode to generate Joule heat to ensure that the phase change condition is met.

[0093] Corresponding to the method of photoinduced phase change, the method of electroinduced phase change replaces the light pulse with an electric pulse. The electric pulse heats the material through the Joule heating effect, thereby inducing the material to achieve a transition from the α state to the β state. In the β-In2Se3 state, the refractive index of the In2Se3 film 222 will change significantly. This transition causes the phase matching in the originally stable directional coupler to be destroyed, and no coupling will occur between the first coupling waveguide 212 and the heterogeneous integrated waveguide 22, and it will not be coupled into the microring 23. Therefore, the signal light in the first coupling waveguide 212 can continue to be transmitted and output from the output port of the output waveguide 213. Since no coupling occurs at this time, the optical loss is relatively low, and the optical switch enters the ON state.

[0094] When the In2Se3 film 222 is in the α state, the phase matching condition is met, most of the signal light energy stays in the microring 23, and a small amount of signal light is output from the Output port of the output waveguide 213 (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL). When the In2Se3 film 222 changes to the β state, the phase matching condition cannot be met, the signal light cannot be coupled, the optical loss is relatively low, and most of the signal light energy is output from the Output port (at this time, the power ratio of the Output port output to the Input port is the insertion loss IL).

[0095] The optical switch can switch the optical path by switching the state of the phase change material, and the device has excellent performance by optimizing the structural parameters. In addition, the optical switch has the property of non-volatility derived from the phase change material. Even after the external stimulus stops, the In2Se3 film 222 can still maintain its current state, so the state of the optical switch can also remain unchanged without continuous external stimulus to maintain.

[0096] The control method of the above-mentioned integrated optical switch based on In2Se3 is as follows:

[0097] When the optical switch is turned on: the In2Se3 film 222 is stimulated by an electric pulse, and the state of the In2Se3 film 222 is converted from the α state to the β state. Then the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 do not meet the phase matching condition, and the signal light received by the input waveguide 211 is directly output from the output waveguide 213 after passing through the first coupling waveguide 212, and the optical switch is turned on.

[0098] When the optical switch is closed: the In2Se3 film 222 is stimulated by an electric pulse, and the state of the In2Se3 film 222 is converted from the β state to the α state, so that the first coupling waveguide 212, the heterogeneous integrated waveguide 22 and the first straight waveguide 231 meet the phase matching conditions. When the signal light received by the input waveguide 211 passes through the first coupling waveguide 212, it is gradually coupled to the heterogeneous integrated waveguide 22, and then coupled into the microring 23; at the resonant wavelength of the microring 23, the power of the signal light is lost, the power of the signal light output by the output waveguide 213 drops sharply, and the optical switch is closed.

[0099] The three external stimulation methods used in the above three examples are also applicable when the material of the waveguide layer 21 changes, such as the material of the waveguide layer 21 changes to silicon nitride, aluminum nitride, thin-film lithium niobate, etc. The specific structural parameters are adjusted according to the change of the waveguide material and the required performance.

[0100] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An integrated optical switch based on In2Se3, characterized in that: It comprises a substrate layer (1), a waveguide layer (2) arranged on the substrate layer (1), and an outer cladding layer (3) wrapped around the waveguide layer (2); The waveguide layer (2) comprises a trunk waveguide (21), a heterogeneous integrated waveguide (22) and a micro-ring (23) which are arranged in sequence side by side; The trunk waveguide (21) comprises an input waveguide (211), a first coupling waveguide (212), and an output waveguide (213) which are sequentially connected along the length direction; The heterogeneous integrated waveguide (22) comprises a second coupling waveguide (221) arranged on the substrate layer (1) and an In2Se3 film (222) arranged on the second coupling waveguide (221); the second coupling waveguide (221) and the In2Se3 film (222) are both arranged close to the first coupling waveguide (212); The micro-ring (23) comprises a first straight waveguide (231), a first curved waveguide (232), a second straight waveguide (233) and a second curved waveguide (234) which are sequentially connected end to end; the first straight waveguide (231) is arranged close to the second coupling waveguide (221); The width W1 of the trunk waveguide (21), the width W2 of the second coupling waveguide (221), and the width W3 of the first straight waveguide (231) satisfy: W1≠W2 and W 1＝ W3; The first coupled waveguide (212), the heterogeneous integrated waveguide (22), and the first straight waveguide (231) can achieve phase matching based on the state transformation of the In2Se3 thin film (222), so that the three form a directional coupler; The cladding layer (3) is used to protect the waveguide layer (2).

2. The integrated optical switch based on In2Se3 according to claim 1, characterized in that: The trunk waveguide (21), the second coupling waveguide (221) and the micro-ring (23) are all made of silicon, silicon nitride, aluminum nitride or thin-film lithium niobate material.

3. The integrated optical switch based on In2Se3 according to claim 2, characterized in that: The substrate layer (1) is made of SOI; The envelope (3) is air.

4. The integrated optical switch based on In2Se3 according to claim 3, characterized in that: When the first coupling waveguide (212), the second coupling waveguide (221) and the microring (23) are made of silicon, the lengths of the first coupling waveguide (212), the second coupling waveguide (221), the first straight waveguide (231) and the In2Se3 film (222) are all Lc, and the range of Lc is 9 μm-50 μm.

5. The integrated optical switch based on In2Se3 according to claim 4, characterized in that: The thickness H of the In2Se3 film (222) is ≤ 100 nm, and its width Smaller than the width W2 of the second coupling waveguide (221).

6. The integrated optical switch based on In2Se3 according to claim 5, characterized in that: When the trunk waveguide (21) and the micro-ring (23) are made of silicon, the width W3 of the first straight waveguide (231), the first curved waveguide (232), the second straight waveguide (233) and the second curved waveguide (234) and the width W1 of the trunk waveguide (21) are in the range of 450nm-650nm.

7. The integrated optical switch based on In2Se3 according to claim 6, characterized in that: When the trunk waveguide (21), the second coupling waveguide (221) and the micro-ring (23) are made of silicon, the gap between the trunk waveguide (21) and the second coupling waveguide (221), and the gap between the second coupling waveguide (221) and the first straight waveguide (231) are both g, and the range of g is 25nm-150nm.

8. The integrated optical switch based on In2Se3 according to claim 7, characterized in that: When the trunk waveguide (21), the second coupling waveguide (221) and the microring (23) are made of silicon, the thickness of the trunk waveguide (21), the second coupling waveguide (221) and the microring (23) is h=220 nm.

9. A control method for an integrated optical switch based on In2Se3 according to any one of claims 1 to 8, characterized in that: When the light switch is turned on: When the In2Se3 film (222) is stimulated and the state of the In2Se3 film (222) is converted from the α state to the β state, the first coupling waveguide (212), the heterogeneous integrated waveguide (22) and the first straight waveguide (231) do not meet the phase matching condition, the signal light received by the input waveguide (211) is directly output from the output waveguide (213) after passing through the first coupling waveguide (212), and the optical switch is turned on; When the light switch is turned off: The In2Se3 film (222) is stimulated, and the state of the In2Se3 film (222) is converted from the β state to the α state, so that the first coupling waveguide (212), the heterogeneous integrated waveguide (22) and the first straight waveguide (231) meet the phase matching condition. When the signal light received by the input waveguide (211) passes through the first coupling waveguide (212), it is gradually coupled to the heterogeneous integrated waveguide (22) and then coupled into the microring (23); at the resonant wavelength of the microring (23), the power of the signal light is lost, the power of the signal light output by the output waveguide (213) drops sharply, and the optical switch is closed.

10. The control method of the integrated optical switch based on In2Se3 according to claim 9, characterized in that: The method of stimulating the In2Se3 film (222) is thermal stimulation, light stimulation or electrical stimulation.

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