Waveguide memory based on optical storage medium, manufacturing method thereof and storage equipment

Abstract

The invention relates to the technical field of silicon-based photonic integration, and provides a waveguide memory based on an optical storage medium, a manufacturing method of the waveguide memory and a memory device, and the manufacturing method of the waveguide memory based on the optical storage medium comprises the following steps: simulating a runway type micro-ring resonator; determining an optimal coupling gap and an optimal coupling length between the runway micro-ring resonant cavity and the bus waveguide, manufacturing a core layer, forming the runway micro-ring resonant cavity and the bus waveguide on the core layer according to the optimal coupling gap and the optimal coupling length, and depositing an optical storage medium on the bus waveguide by magnetron sputtering to obtain the optical storage medium. The optical storage medium can change the phase change state of the stress position under the action of external excitation so as to realize information storage through different phase states of the optical storage medium. The invention also provides a waveguide memory and a memory device obtained based on the manufacturing method. The waveguide memory prepared by the preparation method is non-toxic, friendly to human body and environment, low in manufacturing cost, simple in structure and easy to manufacture on a large scale.

Description

Technical Field

[0001] The present invention relates to the field of silicon-based photonic integration technology, and in particular to a waveguide memory based on an optical storage medium, a manufacturing method thereof, and a storage device. Background Art

[0002] As Moore's Law approaches its limit, the performance improvement of traditional electronic systems in terms of computing speed and power consumption is limited because the existing von Neumann architecture leads to the obstruction of information flow between memory and computing units. To overcome this challenge, people are looking for new solutions, among which photonic memory computing is seen as a promising alternative due to its broadband, high-speed transmission and high energy efficiency. However, current photonic computing devices have problems with volatility and high power consumption, which is not conducive to large-scale integration.

[0003] Phase change materials are temperature-responsive materials whose internal structure changes with temperature. By controlling the temperature, phase change materials can transform between crystalline and amorphous states at a very fast speed, so they are widely used in fields such as dynamic display and reconfigurable photonic devices. Sulfur-based phase change materials with Ge, Se and Te as the main elements have attracted much attention due to their non-volatility and polymorphism. Therefore, how to combine PCM with integrated waveguides to realize reconfigurable photonic devices such as optical memory is of great significance to solving the performance limitations of traditional electronic systems in terms of computing speed and power consumption. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a waveguide memory based on an optical storage medium and a manufacturing method and a storage device thereof that overcome the above problems or at least partially solve the above problems.

[0005] One aspect of the present invention provides a method for manufacturing a waveguide memory based on an optical storage medium, the method comprising:

[0006] Simulate the racetrack microring resonator: simulate the coupling gap and coupling length between the racetrack microring resonator and the bus waveguide to obtain the optimal coupling gap and the optimal coupling length, the racetrack microring resonator includes a core layer and a racetrack microring structure arranged on the core layer, the racetrack microring structure includes a racetrack microring resonator, a bus waveguide and an optical storage medium arranged on the bus waveguide and located in the coupling region between the bus waveguide and the racetrack microring resonator;

[0007] Making the core layer: preparing a substrate, and placing the substrate in an acetone solution and an isopropanol solution in turn for ultrasonic cleaning to remove impurities on the substrate to obtain the core layer;

[0008] Forming a waveguide structure: Based on the optimal coupling gap and the optimal coupling length obtained by simulation, the racetrack micro-ring resonator and the bus waveguide are exposed on the core layer by electron beam exposure technology;

[0009] Depositing optical storage medium: preparing optical storage medium target material, and depositing optical storage medium on the bus waveguide after exposing the waveguide structure by magnetron sputtering, with a deposition thickness of 1 to 100 nm. The optical storage medium changes the phase change state of the stress position under external excitation, so as to store information through different phases of the optical storage medium.

[0010] Furthermore, the method further comprises:

[0011] Depositing dielectric film: using atomic layer deposition technology to deposit a cladding dielectric film on the surface of the optical storage medium, the deposition thickness is 10 to 30 nm.

[0012] Furthermore, the sputtering conditions of magnetron sputtering in the step of depositing the optical storage medium are:

[0013] The power range is 50-120W, the rotation speed is 10-20r / min, and the sputtering time is 1-10min.

[0014] Furthermore, before depositing the optical storage medium, the method further comprises:

[0015] Passing cooling water into the magnetron sputtering environment;

[0016] The reaction chamber where the magnetron sputtering technology is performed is evacuated, and then a protective gas is introduced so that the final gas pressure in the reaction chamber is in the range of 0.5 to 2 Pa.

[0017] Furthermore, the optical storage medium is a phase change material compound composed of Sb and Se elements, or a GST material or N-GST material composed of Ge, Sb and Se elements.

[0018] Furthermore, the substrate is SOI, a glass sheet, a quartz sheet or a silicon sheet.

[0019] Furthermore, the cladding dielectric film is Al 2 O 3 .

[0020] Furthermore, the length of the core layer is 1.5 mm and the width is 1.5 mm; the width of the bus waveguide is 450 nm, the height is 220 nm, and the length is 200 μm; the radius of the racetrack microring resonator is 5 μm, and the coupling length is 3 μm;

[0021] The optical storage medium has a length of 400 nm, a width of 450 nm, and a height of 1-100 nm.

[0022] Another aspect of the present invention provides a waveguide memory based on an optical storage medium, comprising a cladding layer, a recording layer and a core layer, wherein the recording layer is implemented by a racetrack microring structure, and the racetrack microring structure comprises a racetrack microring resonant cavity, a bus waveguide and an optical storage medium disposed on the bus waveguide and located in a coupling region between the bus waveguide and the racetrack microring resonant cavity;

[0023] The racetrack micro-ring resonator is a strip-shaped ring structure, and the long axis direction of the strip-shaped ring structure is coupled with the bus waveguide side;

[0024] The bus waveguide includes an input area waveguide and an output area waveguide, the optical storage medium is located between the input area waveguide and the output area waveguide, the output end of the input area waveguide is connected to the input end of the optical storage medium, and the output end of the optical storage medium is connected to the input end of the output area waveguide;

[0025] The external excitation signal is input as an optical signal from the input area waveguide of the bus waveguide through the optical fiber. A part of the light continues to be transmitted along the direction of the bus waveguide and enters the output area waveguide of the bus waveguide through the optical storage medium. The other part of the light is coupled into the racetrack microring resonant cavity and coupled back to the output area waveguide of the bus waveguide after cyclic transmission in the racetrack microring resonant cavity. The two parts of light interfere with each other after meeting in the output area waveguide of the bus waveguide, and output a modulated optical signal.

[0026] The working principle of the waveguide memory based on optical storage medium is as follows: the optical storage medium of the bus waveguide is irradiated with an external excitation signal. The intensity and duration of the external excitation signal cause local heating of the optical storage medium, causing the optical storage medium to change from a crystalline state to an amorphous state, or vice versa. The change in the state of the optical storage medium causes the optical properties of the material to change, thereby encoding data; the data reading process includes: sending a detection light beam to irradiate the optical storage medium of the bus waveguide. Due to the different optical properties of the optical storage medium, the detection light beam will produce different reflection or transmission characteristics in different states. The light signal scattered or transmitted from the output area waveguide of the bus waveguide is received by the light detector, and the light signal is converted into an electrical signal, and the stored data is restored through the decoding process. Specifically, the optical storage medium (such as Sb 2 Se 3Materials, GST materials or N-GST materials) are able to transform between different phases (such as crystalline and amorphous states) that have different optical properties, such as refractive index and absorption rate. This material is used in optical waveguide structures to achieve data storage. A phase change material layer is embedded in the optical waveguide, and these waveguide structures usually consist of a light-guiding core (such as silicon) and a layer covered with a phase change material. The optical waveguide guides the light signal through the phase change material layer. A laser beam (usually a pulsed laser) is used to irradiate the phase change material layer in the optical waveguide. The intensity and duration of the laser cause local heating of the phase change material. The phase change material is transformed from a crystalline state to an amorphous state, or vice versa, by laser heating. This state change causes a change in the optical properties of the material, thereby encoding data. The data reading process includes: detection beam: emitting a lower intensity light beam (usually a continuous wave laser) to illuminate the phase change material layer in the optical waveguide; light signal change: due to the different optical properties of the phase change material (such as refractive index and absorption rate), the detection beam will produce different reflection or transmission characteristics in different states; detection and decoding: receiving the light signal scattered or transmitted from the waveguide through the light detector, converting the light signal into an electrical signal, and recovering the stored data through the decoding process.

[0027] Another aspect of the present invention provides a storage device, comprising an external excitation module and an array-integrated waveguide memory based on an optical storage medium as described above.

[0028] The waveguide memory based on optical storage medium provided by the embodiment of the present invention and its manufacturing method and storage device, by simulating the racetrack microring resonator, confirming the optimal coupling gap and the optimal coupling length between the racetrack microring resonant cavity and the bus waveguide, and then manufacturing the core layer, forming the racetrack microring resonant cavity and the bus waveguide on the core layer according to the optimal coupling gap and the optimal coupling length obtained by simulation, and depositing the optical storage medium on the bus waveguide by magnetron sputtering, the optical storage medium will change the phase change state of the stress position under the external excitation, so as to realize the storage of information through the different phases of the optical storage medium. The memory is non-toxic, friendly to the human body and the environment, low in manufacturing cost, simple in structure, easy to manufacture on a large scale, and can effectively solve the performance limitation problem of traditional electronic systems in terms of computing speed and power consumption.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0031] Figure 1 A flow chart of a method for manufacturing a waveguide memory based on an optical storage medium provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the structure of a waveguide memory based on an optical storage medium provided by an embodiment of the present invention;

[0033] Figure 3 A refractive index curve diagram of the optical storage medium 2 proposed in an embodiment of the present invention when it is in an amorphous state;

[0034] Figure 4 A refractive index curve diagram of the optical storage medium 2 provided in the embodiment of the present invention when it is in a crystalline state;

[0035] Figure 5 A transmittance curve diagram of a waveguide memory based on an optical storage medium provided in an embodiment of the present invention when the optical storage medium is in a crystalline state and an amorphous state respectively, when inputting and outputting from a bus waveguide port. DETAILED DESCRIPTION

[0036] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0037] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0038] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined.

[0039] Figure 1 The flowchart of the method for manufacturing the waveguide memory based on the optical storage medium proposed by the present invention is shown. Figure 1 A method for manufacturing a waveguide memory based on an optical storage medium provided by an embodiment of the present invention comprises the following steps:

[0040] S11, simulate the racetrack microring resonator: simulate the coupling gap and coupling length between the racetrack microring resonator and the bus waveguide to obtain the optimal coupling gap and the optimal coupling length, the racetrack microring resonator includes a core layer and a racetrack microring structure arranged on the core layer, the racetrack microring structure includes a racetrack microring resonator, a bus waveguide and an optical storage medium arranged on the bus waveguide and located in the coupling area between the bus waveguide and the racetrack microring resonator. In this embodiment, the racetrack microring resonator includes a core layer and a racetrack microring structure, the racetrack microring resonator, the bus waveguide and the optical storage medium of the racetrack microring structure are all arranged on the core layer. The present invention simulates the coupling gap and coupling length between the racetrack microring resonator and the bus waveguide, first sets a coupling gap, changes the coupling length, and optimizes the transmission spectrum. After determining the optimal coupling length, fix the coupling length, change the coupling gap, and obtain the best transmission spectrum. At this time, the optimal coupling gap and the optimal coupling length are obtained. The bus waveguide includes an input area waveguide and an output area waveguide, the optical storage medium is located between the input area waveguide and the output area waveguide, the output end of the input area waveguide is connected to the input end of the optical storage medium, and the output end of the optical storage medium is connected to the input end of the output area waveguide.

[0041] The racetrack microring resonant cavity in this embodiment is a long strip ring structure, and the long axis direction of the long strip ring structure is coupled with the bus waveguide side. Specifically, the racetrack microring (also called "racetrack type" microring) has a long strip loop similar to a racetrack, and a common form is to change a circular microring into a long strip ring structure. The purpose of this design is to improve the propagation characteristics and coupling efficiency of light in the ring. The long axis direction of the racetrack microring is longer and the width is narrower. It usually presents a rectangular or similar shape loop, which makes the propagation path of light in the ring longer and enhances the interaction between light and the material in the ring. The racetrack microring optimizes the propagation and resonance performance of light in the ring by adjusting the geometric shape of the long strip loop. Compared with ordinary microrings, the structural design of the racetrack microring improves the transmission and coupling efficiency of light. The racetrack microring uses a longer optical path to enhance the interaction between light and microring materials, thereby improving the resonance efficiency and sensitivity. Light is reflected more times in the long strip loop, thereby improving the transmission and resonance performance of light.

[0042] S12, making a core layer: preparing a substrate, and placing the substrate in an acetone solution and an isopropanol solution for ultrasonic cleaning in turn, removing impurities on the substrate to obtain a core layer. Specifically, the present invention places the substrate in an acetone solution and an isopropanol solution for ultrasonic cleaning in turn for a preset time, and then dries the substrate.

[0043] S13. Forming a waveguide structure: Based on the optimal coupling gap and the optimal coupling length obtained by simulation, the racetrack micro-ring resonator and the bus waveguide are exposed on the core layer by electron beam exposure technology.

[0044] S14, depositing optical storage medium: prepare an optical storage medium target material, and deposit the optical storage medium on the bus waveguide after the waveguide structure is exposed by magnetron sputtering, with a deposition thickness of 1 to 100 nm. The optical storage medium can change the phase change state of the stress position under external excitation, so as to store information through different phases of the optical storage medium. Specifically, the sputtering conditions of magnetron sputtering in the step of depositing the optical storage medium are: power range of 50 to 120 W, rotation speed of 10 to 20 r / min, and sputtering time of 1 to 10 min. The final gas pressure range in the reaction chamber is 0.5 to 2 Pa. Specifically, the optical storage medium film is in an amorphous state without external excitation. External excitation such as laser, pulse or temperature can be applied to the optical storage medium film to change the phase change state of the stress position under external excitation and transform it into a crystalline state.

[0045] Furthermore, before performing the deposition of the optical storage medium, the following operations not shown in the drawings are also included:

[0046] Introduce cooling water into the magnetron sputtering environment - turn on the air compressor and the water chiller to cool down the magnetron sputtering;

[0047] The reaction chamber where the magnetron sputtering technology is performed is evacuated, and then a protective gas is introduced so that the final gas pressure in the reaction chamber is in the range of 0.5 to 2 Pa.

[0048] The method for manufacturing a waveguide memory based on an optical storage medium provided in an embodiment of the present invention simulates a racetrack-type microring resonator, simulates the coupling gap and coupling length between the racetrack waveguide and the bus waveguide, obtains an optimal solution, selects a material with strong stability as a substrate, and sequentially places the substrate in acetone and isopropanol for ultrasonic cleaning to remove impurities. The waveguide structure is exposed according to the optimal solution of the coupling gap and coupling length obtained by simulation, and then an optical storage medium target is prepared, and the optical storage medium is deposited on the exposed bus waveguide by magnetron sputtering. The present invention uses the substrate as a core layer, the optical storage medium as a recording layer, and records data in the optical storage medium to obtain a waveguide for an optical storage device. The storage device is non-toxic, friendly to the human body and the environment, has a low manufacturing cost, a simple structure, and is easy to manufacture on a large scale. The optical storage medium used in the present invention is a phase change material, which will change the phase change state of the stress position under the action of external stimulation. When storing data, the target medium phase state of the optical storage medium corresponding to the data to be stored is determined, and the optical storage medium is controlled to switch to the target medium phase state through external stimulation, so as to store information through different phase states of the optical storage medium. When the phase change material switches to different phases, the light wave mode is coupled in the coupling area of ​​the bus waveguide and the racetrack waveguide. Since the two output light beams interfere, the transmission spectrum is shifted. When reading data, the optical properties of the optical storage medium can be determined by analyzing the output light signal, and the stored data is read according to the medium phase state corresponding to the optical properties of the optical storage medium.

[0049] In a specific example, the resistivity of the optical storage medium is very low in the amorphous state, which can be used to represent the number 0; the resistivity is higher in the crystalline state, which can be represented as the number 1. This property can be used to store digital information. Specifically, the storage of information is based on the process of phase change of the material. Phase change materials use external excitation, such as laser, pulse or temperature change to change their physical state, which includes refractive index and absorptivity. For example, when the laser is irradiated on the phase change material, the material absorbs the energy of the laser and changes from the crystalline state to the amorphous state, or vice versa. This state change is reversible, which means that information can be written, read and erased. Specifically, the crystalline state and the amorphous state have different optical properties, which enables them to be mapped to different storage data. By identifying these changes in physical states, the stored data can be read. That is, the writing of information can be achieved through the phase transition of the optical storage medium material, and the information can be retrieved by reading the optical properties of the material. The erasing process is to restore the material to its initial state through a laser or pulse of a specific intensity. When writing specific data, external excitations such as laser, pulse or temperature can be controlled according to the data to be stored, and the phase transition of the material can be changed by laser, pulse or temperature changes to achieve the storage of the corresponding data.

[0050] The method for manufacturing a waveguide memory based on an optical storage medium provided in an embodiment of the present invention further includes, after step S14, step S15 (not shown in the drawings):

[0051] S15, depositing dielectric film: using atomic layer deposition technology ALD to deposit a cladding dielectric film on the surface of the optical storage medium, with a deposition thickness of 10 to 30 nm. The material of the cladding dielectric film can be Al 2 O 3 In this embodiment, by depositing a cladding layer on the surface of the optical storage medium, the light limiting and protection effects on the optical storage medium can be effectively achieved.

[0052] The substrate in the embodiment of the present invention may be SOI, a glass sheet, a quartz sheet, a silicon sheet or other substrates with a patterned structure.

[0053] In one embodiment of the present invention, the length of the core layer may be 1.5 mm, and the width may be 1.5 mm; the width of the bus waveguide is 450 nm, the height is 220 nm, and the length is 200 μm; the radius of the racetrack microring resonator is 5 μm, and the coupling length is 3 μm;

[0054] The optical storage medium has a length of 400 nm, a width of 450 nm, and a height of 1-100 nm.

[0055] In one embodiment of the present invention, the optical storage medium may be a phase change material compound composed of Sb and Se elements, preferably Sb 2 Se3 In this embodiment, the waveguide is composed of a bus waveguide and a racetrack-type microring, i.e., a racetrack waveguide. A coupling gap is provided between the racetrack waveguide and the bus waveguide. An optical storage medium that can undergo a reversible phase transition from an amorphous state to a crystalline state under the action of the evanescent field coupling of the waveguide is provided in the coupling region of the bus waveguide. The optical storage medium material is selected from Sb 2 Se 3 Phase change materials. Combining PCM and integrated waveguides can be used in reconfigurable photonic devices such as optical memory, optical memristor and optical synapse, and microring resonator has the characteristics of wavelength selectivity and high quality factor, which can be used as the technical basis for photon storage computing array structure. The present invention adopts Sb 2 Se 3 A reconfigurable waveguide memory is realized, which has the advantage of small refractive index change and can reduce the resonant wavelength shift of the device. 2 Se 3 The material can be used as an optical storage medium to avoid mutual interference among the microring resonator units, making it easier to expand the array size in order to establish a device structure with a low resonant wavelength shift.

[0056] In this embodiment, a binary PCM such as Sb 2 Se 3 As an optical storage medium for reconfigurable waveguide memory. Sb 2 Se 3 The imaginary part of the refractive index of the crystalline and amorphous states is close to 0 at a wavelength of 1550nm, resulting in the material absorbing very little external light signals. 2 Se 3 The real part of the refractive index of the material changes during the phase transition less than that of the widely used Ge 2 Sb 2 Te 5 (GST), which can reduce the RWS of the device. In addition, Sb 2 Se 3 Multi-level phase change can be achieved by using appropriate light or electric pulses, that is, electric pulse micro-heaters (such as PIN and ITO) can freely control a single phase change device. The electric drive technology is relatively mature and suitable for large-scale integration of photonic phase change arrays.

[0057] In another embodiment of the present invention, the optical storage medium may also be a GST material or N-GST material composed of Ge, Sb, and Se elements. In this embodiment, N-GST material, i.e., N-doped Ge 2 Sb 2 Te 5 , achieving more phase transitions, each phase corresponds to a refractive index, and realizing waveguide memory for multi-bit data storage.

[0058] The present invention provides a method for preparing a waveguide memory based on an optical storage medium. When the optical storage medium switches between different phases, the light wave mode will be coupled in the coupling region of the bus waveguide and the micro-ring cavity, and different phase change states are used to store information. The optical storage device records information by controlling the phase change of the material. The information can be stored in the material in different phases, and the information can be retrieved by reading the optical properties of these phases. For example, by stimulating the phase change of the material, data can be stored in different locations, and these data can be restored by detecting the optical properties of the material during the reading process. The present invention prepares Sb by magnetron sputtering. 2 Se 3 The thin film is initially deposited in an amorphous state with a low refractive index. External excitation can be used to trigger the film to crystallize into a crystalline state with a high refractive index. Further decrystallization requires the use of high pulse energy, thereby completing the reconstruction of the optical storage medium.

[0059] Figure 2 The schematic diagram of the structure of a waveguide memory based on an optical storage medium provided by another embodiment of the present invention. The waveguide memory based on an optical storage medium can be prepared by using the preparation method of the waveguide memory based on an optical storage medium provided by the above embodiment. Figure 2 As shown, the waveguide storage device based on the optical storage medium provided by the embodiment of the present invention includes a cladding (not shown in the figure), a recording layer and a core layer 5. The recording layer is implemented by a racetrack-type microring structure. The racetrack-type microring structure includes a racetrack microring resonant cavity 4, a bus waveguide and an optical storage medium 2 arranged on the bus waveguide and located in the coupling area between the bus waveguide and the racetrack microring resonant cavity 4.

[0060] Furthermore, the racetrack microring resonant cavity 4 is a strip-shaped ring structure, and the long axis direction of the strip-shaped ring structure is coupled to the bus waveguide side. The racetrack microring resonant cavity in this embodiment has a strip-shaped loop similar to a racetrack, and a common form is to adjust the circular microring into the required strip-shaped ring structure. The long axis direction is longer and the width is narrower, usually presenting a rectangular or similar shape loop. The racetrack microring resonant cavity uses a longer optical path to enhance the interaction between light and microring materials, thereby improving the resonance efficiency and sensitivity. Light is reflected more times in the strip loop, thereby improving the transmission and resonance performance of light.

[0061] In this embodiment, the bus waveguide includes an input area waveguide 1 and an output area waveguide 3, the optical storage medium 2 is located between the input area waveguide 1 and the output area waveguide 3, the output end of the input area waveguide 1 is connected to the input end of the optical storage medium 2, and the output end of the optical storage medium 2 is connected to the input end of the output area waveguide 3.

[0062] In a specific embodiment, the optical storage medium 2 is a deposited low-loss phase change material Sb 2 Se 3.

[0063] In the present invention, external excitation such as a laser signal (hereinafter referred to as an optical signal) is input from the input area waveguide 1 of the bus waveguide through an optical fiber, a portion of the light continues to be transmitted along the direction of the bus waveguide, and enters the output area waveguide 3 of the bus waveguide from the optical storage medium 2, and the other portion of the light is coupled into the racetrack microring resonant cavity 4, and after cyclic transmission in the racetrack microring resonant cavity 4, it is coupled back to the output area waveguide 3 of the bus waveguide; the two portions of light interfere with each other after meeting in the output area waveguide of the bus waveguide, and a modulated optical signal is output.

[0064] The working principle of the waveguide memory based on optical storage medium is as follows: the optical storage medium of the bus waveguide is irradiated with an external excitation signal. The intensity and duration of the external excitation signal cause local heating of the optical storage medium, causing the optical storage medium to change from a crystalline state to an amorphous state, or vice versa. The change in the state of the optical storage medium causes the optical properties of the material to change, thereby encoding data; the data reading process includes: sending a detection beam to irradiate the optical storage medium of the bus waveguide. Due to the different optical properties of the optical storage medium, the detection beam will produce different reflection or transmission characteristics in different states. The light signal scattered or transmitted from the output area waveguide of the bus waveguide is received by the light detector, and the light signal is converted into an electrical signal, and the stored data is restored through the decoding process. Specifically as follows: the optical storage medium (such as Sb 2 Se 3 Materials, GST materials or N-GST materials) are able to transform between different phases (such as crystalline and amorphous states) that have different optical properties, such as refractive index and absorption rate. This material is used in optical waveguide structures to achieve data storage. A phase change material layer is embedded in the optical waveguide, and these waveguide structures usually consist of a light-guiding core (such as silicon) and a layer covered with a phase change material. The optical waveguide guides the light signal through the phase change material layer. A laser beam (usually a pulsed laser) is used to irradiate the phase change material layer in the optical waveguide. The intensity and duration of the laser cause local heating of the phase change material. The phase change material is transformed from a crystalline state to an amorphous state, or vice versa, by laser heating. This state change causes a change in the optical properties of the material, thereby encoding data. The data reading process includes: detection beam: emitting a lower intensity light beam (usually a continuous wave laser) to illuminate the phase change material layer in the optical waveguide; light signal change: due to the different optical properties of the phase change material (such as refractive index and absorption rate), the detection beam will produce different reflection or transmission characteristics in different states; detection and decoding: receiving the light signal scattered or transmitted from the waveguide through the light detector, converting the light signal into an electrical signal, and recovering the stored data through the decoding process.

[0065] Figure 3 1 shows a refractive index curve when the optical storage medium 2 proposed in the embodiment of the present invention is in an amorphous state; the solid line and the dotted line represent the refractive index n and the extinction coefficient k respectively. Figure 3 , Sb near the communication band 1550nm 2 Se 3 The refractive index is distributed around 3.285 and the extinction coefficient is 0.

[0066] Figure 4 1 shows a refractive index curve diagram of the optical storage medium 2 provided by the embodiment of the present invention when it is in a crystalline state; the solid line and the dotted line represent the refractive index n and the extinction coefficient k respectively. Figure 4 , Sb near the communication band 1550nm 2 Se 3 The refractive index is distributed around 4.05, and the extinction coefficient is 0. Compared with the amorphous state, the crystalline Sb 2 Se 3 The refractive index of Sb changes greatly, but the extinction coefficient does not increase. 2 Se 3 One of the most important characteristics of the material, making it an ideal PCM for programmable photonics.

[0067] In this embodiment, the resonant coupling between the micro-ring resonator 4 and the bus waveguide is achieved by interfering the resonant path with a coherent background path. The optical storage medium 2 is placed in the background path as a phase modulator, and by switching its phase change state, different phase delays can be introduced into the bus waveguide, so that the phase difference between the output light in the micro-ring resonator 4 and the output light in the optical storage medium 2 can be converted between 0-π.

[0068] Figure 5 The transmittance curve of the waveguide memory based on the optical storage medium provided by an embodiment of the present invention when the optical storage medium is in crystalline and amorphous states respectively, when input and output from the bus waveguide port, the short dashed line is the transmittance of the racetrack-type microring resonator when no optical storage medium is added, the long dashed line and the solid line represent the transmittance when the phase change material is in crystalline and amorphous states respectively, it can be seen that information is stored through different phases of the optical storage medium, and information is read by restoring different optical properties of the material.

[0069] In addition, another embodiment of the present invention provides a storage device, including an external excitation module and an array-integrated waveguide storage device based on an optical storage medium as described in the above embodiment. The external excitation module can be implemented by selecting an external excitation method such as laser, pulse or temperature according to the strain characteristics of the optical storage medium.

[0070] The waveguide memory based on optical storage medium provided by the embodiment of the present invention and its manufacturing method and storage device, by simulating the racetrack microring resonator, confirming the optimal coupling gap and the optimal coupling length between the racetrack microring resonant cavity and the bus waveguide, and then manufacturing the core layer, forming the racetrack microring resonant cavity and the bus waveguide on the core layer according to the optimal coupling gap and the optimal coupling length obtained by simulation, and depositing the optical storage medium on the bus waveguide by magnetron sputtering, the optical storage medium will change the phase change state of the stress position under the external excitation, so as to realize the storage of information through the different phases of the optical storage medium. The memory is non-toxic, friendly to the human body and the environment, low in manufacturing cost, simple in structure, easy to manufacture on a large scale, and can effectively solve the performance limitation problem of traditional electronic systems in terms of computing speed and power consumption.

[0071] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, any one of the claimed embodiments may be used in any combination.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a waveguide memory based on an optical storage medium, characterized in that: The method comprises: Simulate the racetrack microring resonator: simulate the coupling gap and coupling length between the racetrack microring resonator and the bus waveguide to obtain the optimal coupling gap and the optimal coupling length, the racetrack microring resonator includes a core layer and a racetrack microring structure arranged on the core layer, the racetrack microring structure includes a racetrack microring resonator, a bus waveguide and an optical storage medium arranged on the bus waveguide and located in the coupling region between the bus waveguide and the racetrack microring resonator; Making the core layer: preparing a substrate, and placing the substrate in an acetone solution and an isopropanol solution in turn for ultrasonic cleaning to remove impurities on the substrate to obtain the core layer; Forming a waveguide structure: Based on the optimal coupling gap and the optimal coupling length obtained by simulation, the racetrack micro-ring resonator and the bus waveguide are exposed on the core layer by electron beam exposure technology; Depositing optical storage medium: preparing optical storage medium target material, and depositing optical storage medium on the bus waveguide after exposing the waveguide structure by magnetron sputtering, with a deposition thickness of 1 to 100 nm. The optical storage medium changes the phase change state of the stress position under external excitation, so as to store information through different phases of the optical storage medium.

2. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The method further comprises: Depositing dielectric film: using atomic layer deposition technology to deposit a cladding dielectric film on the surface of the optical storage medium, the deposition thickness is 10 to 30 nm.

3. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The sputtering conditions of magnetron sputtering in the step of depositing the optical storage medium are: The power range is 50-120W, the rotation speed is 10-20r / min, and the sputtering time is 1-10min.

4. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: Prior to depositing the optical storage medium, it also includes: Passing cooling water into the magnetron sputtering environment; The reaction chamber in which the magnetron sputtering technology is performed is evacuated, and then a protective gas is introduced so that the final gas pressure in the reaction chamber is in the range of 0.5 to 2 Pa.

5. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The optical storage medium is a phase change material compound composed of Sb and Se elements, or a GST material or N-GST material composed of Ge, Sb and Se elements.

6. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The substrate is SOI, a glass sheet, a quartz sheet or a silicon sheet.

7. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The cladding dielectric film is Al2O3.

8. The method for manufacturing a waveguide memory based on an optical storage medium according to claim 1, characterized in that: The length of the core layer is 1.5 mm and the width is 1.5 mm; the width of the bus waveguide is 450 nm, the height is 220 nm, and the length is 200 μm; the radius of the racetrack microring resonator is 5 μm; The optical storage medium has a length of 400 nm, a width of 450 nm, and a height of 1-100 nm.

9. A waveguide memory based on an optical storage medium, characterized in that: The optical storage device comprises a cladding layer, a recording layer and a core layer, wherein the recording layer is implemented by a racetrack-type microring structure, and the racetrack-type microring structure comprises a racetrack microring resonant cavity, a bus waveguide and an optical storage medium disposed on the bus waveguide and located in a coupling region between the bus waveguide and the racetrack microring resonant cavity; The racetrack micro-ring resonator is a strip-shaped ring structure, and the long axis direction of the strip-shaped ring structure is coupled with the bus waveguide side; The bus waveguide includes an input area waveguide and an output area waveguide, the optical storage medium is located between the input area waveguide and the output area waveguide, the output end of the input area waveguide is connected to the input end of the optical storage medium, and the output end of the optical storage medium is connected to the input end of the output area waveguide; The external excitation signal is input as an optical signal from the input area waveguide of the bus waveguide through the optical fiber. A part of the light continues to be transmitted along the direction of the bus waveguide and enters the output area waveguide of the bus waveguide through the optical storage medium. The other part of the light is coupled into the racetrack microring resonant cavity and coupled back to the output area waveguide of the bus waveguide after cyclic transmission in the racetrack microring resonant cavity. The two parts of light interfere with each other after meeting in the output area waveguide of the bus waveguide, and output a modulated optical signal. The working principle of the waveguide memory based on optical storage medium is as follows: the optical storage medium of the bus waveguide is irradiated with an external excitation signal, and the intensity and duration of the external excitation signal cause local heating of the optical storage medium, so that the optical storage medium changes from a crystalline state to an amorphous state, or vice versa, the state change of the optical storage medium causes the optical properties of the material to change, thereby realizing the encoding of data; the data reading process includes: sending a detection light beam to irradiate the optical storage medium of the bus waveguide, due to the different optical properties of the optical storage medium, the detection light beam will produce different reflection or transmission characteristics in different states, and the light signal scattered or transmitted from the output area waveguide of the bus waveguide is received by the light detector, the light signal is converted into an electrical signal, and the stored data is restored through the decoding process.

10. A storage device, characterized in that: A waveguide memory based on an optical storage medium as claimed in claim 1 comprising an array integrated arrangement.

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