Optical memristor

Abstract

The invention discloses an optical memristor, and relates to the field of photon integrated circuits and optical computing, and the optical memristor comprises a waveguide layer, a ferroelectric film layer, an electrode structure and a substrate. The ferroelectric film layer is located on the upper surface of the substrate; the waveguide layer and the electrode structure are located on the upper surface of the ferroelectric film layer; the waveguide layer is used for propagating an incident light signal and performing amplitude modulation on the incident light signal; the electrode structure is used for applying an electric field to the ferroelectric film layer; and the ferroelectric film layer is used for carrying out phase modulation on optical signals transmitted in the waveguide layer under the action of the electric field. The ferroelectric material is used as the optical switch of the optical memristor, efficient modulation of the optical phase is achieved through the non-volatility and the high electro-optical effect of the ferroelectric material, and meanwhile the optical memristor has the advantages of being low in energy consumption and rapid in response.

Description

Technical Field

[0001] The present application relates to the fields of photonic integrated circuits and optical computing, and in particular to an optical memristor. Background Art

[0002] In the semiconductor industry, after nearly 50 years of development, the processing technology has gradually improved from 180nm to the current 5nm, and even the 3nm process is being explored, which has enabled the rapid development of integrated circuit technology and significantly improved the performance of electrical computing systems. However, with the development of science and technology, the bottlenecks encountered by traditional electronic chips have become increasingly obvious: the continuous reduction in transistor size has made the power consumption and heat dissipation problems of traditional electronic chips increasingly prominent; in addition, the computing speed of traditional electronic chips has always been unable to meet the needs of AI technology with complex tasks and huge computing volume. The limitations of traditional electronic chips have restricted the application and development of traditional electrical computing systems in high-speed, low-energy consumption and large-scale communications.

[0003] In response to the above challenges, optical memristors are used as an optimization solution due to their high performance characteristics, especially in the field of optical processing chips based on neuromorphic computing networks. Optical memristors have the advantages of fast computing speed, strong anti-interference ability, strong parallel processing ability, and almost no energy loss, so they will not generate heat when running for a long time. However, the current optical switches of optical memristors rely on modulation materials of thermo-optical or electro-optical effects, which are volatile and energy-intensive, thus limiting the efficiency and development of optical neuromorphic computing networks. Summary of the invention

[0004] The purpose of this application is to provide an optical memristor, using ferroelectric materials as the optical switch of the optical memristor, and utilizing its non-volatility and high electro-optical effect to achieve efficient modulation of light phase and amplitude, thereby reducing the energy consumption of the optical memristor and improving the response speed.

[0005] To achieve the above objectives, the present application provides an optical memristor, comprising:

[0006] A waveguide layer, a ferroelectric thin film layer, an electrode structure and a substrate; the ferroelectric thin film layer is located on the upper surface of the substrate; the waveguide layer and the electrode structure are both located on the upper surface of the ferroelectric thin film layer;

[0007] The waveguide layer is used to propagate an incident light signal and perform amplitude modulation on the incident light signal;

[0008] The electrode structure is used to apply an electric field to the ferroelectric thin film layer;

[0009] The ferroelectric thin film layer is used to perform phase modulation on the optical signal propagating in the waveguide layer under the action of the electric field.

[0010] Optionally, the waveguide layer includes a beam splitting waveguide, a first channel waveguide, a second channel waveguide and a beam combining waveguide;

[0011] The input end of the first channel waveguide and the input end of the second channel waveguide are both connected to the beam splitting waveguide; the output end of the first channel waveguide and the output end of the second channel waveguide are both connected to the beam combining waveguide;

[0012] The beam splitting waveguide is used to split the incident optical signal into a first optical signal and a second optical signal; the first optical signal and the second optical signal are coherent lights;

[0013] The first channel waveguide and the second channel waveguide are used to propagate the first optical signal and the second optical signal respectively;

[0014] The ferroelectric thin film layer is used to perform phase modulation on the first optical signal under the action of the electric field to obtain a first modulated optical signal;

[0015] The first modulated optical signal and the second optical signal interfere with each other in the beam combining waveguide to amplitude modulate the incident optical signal.

[0016] Optionally, the electrode structure includes a first electrode structure and a second electrode structure, and the first electrode structure and the second electrode structure are respectively located on two sides of the first channel waveguide.

[0017] Optionally, the ferroelectric thin film layer is also used to perform multi-level phase modulation on the first optical signal under the action of electric fields of different intensities.

[0018] Optionally, the waveguide layer is a ridge waveguide structure.

[0019] Optionally, the material of the waveguide layer is a semiconductor material or a ferroelectric material.

[0020] Optionally, the substrate is made of semiconductor material.

[0021] Optionally, the ferroelectric thin film layer and the substrate are connected by a bonding or adhesion process.

[0022] Optionally, the optical memristor further comprises a cladding layer;

[0023] The cladding layer is coated on the upper surface of the waveguide layer, and covers the waveguide layer, the ferroelectric thin film layer and the electrode structure.

[0024] Optionally, the material of the cladding is SiO2.

[0025] According to the specific embodiments provided in this application, this application has the following technical effects:

[0026] The present application provides an optical memristor, which uses ferroelectric materials as the optical switch of the optical memristor, and utilizes its non-volatility and high electro-optical effect to achieve efficient modulation of light phase and amplitude, while reducing the energy consumption of the optical memristor and improving the response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of the structure of an optical memristor in one embodiment of the present application;

[0029] Figure 2 This is a schematic diagram of a waveguide layer structure of an optical memristor in one embodiment of the present application;

[0030] Figure 3 This is a schematic diagram of the electrode structure position of an optical memristor in one embodiment of the present application;

[0031] Figure 4 This is a schematic diagram of a multi-level phase modulation result of an optical signal of an optical memristor in one embodiment of the present application.

[0032] Reference numerals: 101 - waveguide layer, 102 - ferroelectric thin film layer, 103 - electrode structure, 104 - substrate, 201 - beam splitting waveguide, 202 - first channel waveguide, 203 - second channel waveguide, 204 - beam combining waveguide, 301 - first electrode structure, 302 - second electrode structure. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] This application proposes an optical memristor, which uses ferroelectric materials as optical switches of the optical memristor, and uses its non-volatility and high electro-optical effect to achieve efficient modulation of optical phase and amplitude, while reducing the energy consumption of the optical memristor and improving the response speed. By changing the intensity of the electric field applied to the ferroelectric material, the optical refractive index of the ferroelectric material can be changed, and the optical signal can be multi-level phase modulated, and further multi-level amplitude modulation of the incident optical signal can be achieved.

[0035] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] In an exemplary embodiment, Figure 1 As shown, an optical memristor is provided, which includes: a waveguide layer 101, a ferroelectric thin film layer 102, an electrode structure 103 and a substrate 104. The ferroelectric thin film layer 102 is located on the upper surface of the substrate 104; the waveguide layer 101 and the electrode structure 103 are both located on the upper surface of the ferroelectric thin film layer 102. The waveguide layer 101 is used to propagate an incident light signal and to perform amplitude modulation on the incident light signal; the electrode structure 103 is used to apply an electric field to the ferroelectric thin film layer 102; and the ferroelectric thin film layer 102 is used to perform phase modulation on the light signal propagating in the waveguide layer 101 under the action of the electric field.

[0037] The material of the waveguide layer 101 is a semiconductor material or a ferroelectric material. In an exemplary embodiment, the material of the waveguide layer 101 is Si or lead magnesium niobate titanium (PMN-PT). The waveguide material is formed into a ridge waveguide structure by micro-nano processing (such as etching, etc.). In an exemplary embodiment, the height of the ridge waveguide structure is 160nm and the width is 800nm.

[0038] In an exemplary embodiment, the material of the ferroelectric thin film layer 102 is lead magnesium lead titanium niobate (PMN-PT) with a thickness of 200 nm. The ferroelectric thin film layer 102 is planarized by chemical mechanical polishing and reactive ion etching processes.

[0039] The substrate 104 is made of semiconductor material and is connected to the ferroelectric thin film layer 102 through a bonding or adhesion process. In an exemplary embodiment, the substrate material is SOI and has a height of 220 nm.

[0040] In an exemplary embodiment, Figure 2 As shown, the waveguide layer 101 includes a beam splitting waveguide 201, a first channel waveguide 202, a second channel waveguide 203, and a beam combining waveguide 204. The input ends of the first channel waveguide 202 and the second channel waveguide 203 are both connected to the beam splitting waveguide 201; the output ends of the first channel waveguide 202 and the second channel waveguide 203 are both connected to the beam combining waveguide 204. The waveguide layer 101 has an interference function and can realize non-volatile amplitude modulation of the incident optical signal.

[0041] The beam splitting waveguide 201 has a splitting effect, which can split a single incident light signal into two coherent light signals and output them. In an exemplary embodiment, the splitting ratio of the beam splitting waveguide 201 is 50:50. The incident light signal is input into the optical memristor through a waveguide coupling method, and the waveguide coupling method includes end face coupling and grating coupling. The beam splitting waveguide 201 splits the incident light signal into a first light signal and a second light signal. The first light signal and the second light signal are coherent lights, which propagate in the first channel waveguide 202 and the second channel waveguide 203, respectively. The ferroelectric thin film layer 102 phase modulates the first light signal under the action of the electric field to obtain a first modulated light signal. The first modulated light signal and the second light signal interfere in the beam combining waveguide 204 to achieve amplitude modulation of the incident light signal.

[0042] In an exemplary embodiment, Figure 3 As shown, the electrode structure 103 includes a first electrode structure 301 and a second electrode structure 302 , and the first electrode structure 301 and the second electrode structure 302 are respectively located on two sides of the first channel waveguide 202 .

[0043] The first electrode structure 301 and the second electrode structure 302 are deposited on the upper surface of the ferroelectric thin film layer 102. In an exemplary embodiment, the distance between the first electrode structure 301 and the second electrode structure 302 is 5 um. The electrode structure 103 adopts an Au / Ti structure to improve the adsorption and stability of the electrode material.

[0044] The ferroelectric thin film layer 102 is also used to perform multi-level phase modulation on the first optical signal under the action of electric fields of different intensities. The external electric field can change the polarization state of the ferroelectric material, and the change in the polarization state will cause the optical refractive index of the ferroelectric material to change, thereby realizing the phase modulation of the optical signal without static power consumption. Due to the non-volatile nature of the ferroelectric material, when the electric field is removed, the phase modulation result obtained by the optical signal still exists. In combination with the application of electric fields of different intensities, multi-level phase modulation of the optical signal can be realized. In an exemplary embodiment, Figure 4 As shown, it can be seen that changing the strength of the external electric field can achieve multi-level phase modulation of the optical signal; changing the direction of the external electric field can achieve writing and erasing of the optical signal data.

[0045] In an exemplary embodiment, the optical memristor further includes a cladding layer, which is coated on the upper surface of the waveguide layer 101 and encloses the waveguide layer 101, the ferroelectric thin film layer 102 and the electrode structure 103. The cladding material is SiO2. In an exemplary embodiment, the cladding thickness is 2 um.

[0046] The present application also provides an application scenario, which applies the above-mentioned optical memristor. Specifically: The optical memristor provided in this embodiment can be applied in information processing scenarios. The information processing scenario includes an information acquisition link, a data processing link and a result output link; the information acquisition link acquires the original information data to be processed, and the data processing link processes the original data, including storage, calculation, etc., and finally obtains the analysis result, which is output by the output link. The optical memristor provided in this embodiment is applied to the data processing link. Specifically in the data processing process, the optoelectronic combination technology can be used to control the seamless conversion of optoelectronic signals to realize the storage and calculation of photon data.

[0047] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. An optical memristor, characterized in that: The optical memristor comprises: a waveguide layer, a ferroelectric thin film layer, an electrode structure and a substrate; the ferroelectric thin film layer is located on the upper surface of the substrate; the waveguide layer and the electrode structure are both located on the upper surface of the ferroelectric thin film layer; The waveguide layer is used to propagate an incident light signal and perform amplitude modulation on the incident light signal; The electrode structure is used to apply an electric field to the ferroelectric thin film layer; The ferroelectric thin film layer is used to perform phase modulation on the optical signal propagating in the waveguide layer under the action of the electric field.

2. The optical memristor according to claim 1, characterized in that The waveguide layer includes a beam splitting waveguide, a first channel waveguide, a second channel waveguide and a beam combining waveguide; The input end of the first channel waveguide and the input end of the second channel waveguide are both connected to the beam splitting waveguide; the output end of the first channel waveguide and the output end of the second channel waveguide are both connected to the beam combining waveguide; The beam splitting waveguide is used to split the incident optical signal into a first optical signal and a second optical signal; the first optical signal and the second optical signal are coherent lights; The first channel waveguide and the second channel waveguide are used to propagate the first optical signal and the second optical signal respectively; The ferroelectric thin film layer is used to perform phase modulation on the first optical signal under the action of the electric field to obtain a first modulated optical signal; The first modulated optical signal and the second optical signal interfere with each other in the beam combining waveguide to amplitude modulate the incident optical signal.

3. The optical memristor according to claim 2, characterized in that: The electrode structure includes a first electrode structure and a second electrode structure, and the first electrode structure and the second electrode structure are respectively located on two sides of the first channel waveguide.

4. The optical memristor according to claim 2, characterized in that: The ferroelectric thin film layer is also used to perform multi-level phase modulation on the first optical signal under the action of electric fields of different intensities.

5. The optical memristor according to claim 1, characterized in that: The waveguide layer is a ridge waveguide structure.

6. The optical memristor according to claim 1, characterized in that: The material of the waveguide layer is a semiconductor material or a ferroelectric material.

7. The optical memristor according to claim 1, characterized in that: The material of the substrate is semiconductor material.

8. The optical memristor according to claim 1, characterized in that: The ferroelectric thin film layer and the substrate are connected by a bonding or adhesion process.

9. The optical memristor according to claim 1, characterized in that: The optical memristor further includes a cladding layer; The cladding layer is coated on the upper surface of the waveguide layer, and covers the waveguide layer, the ferroelectric thin film layer and the electrode structure.

10. The optical memristor according to claim 9, characterized in that: The material of the cladding layer is SiO2.

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