On-chip optical element and integrated optical element

Abstract

The utility model provides an on-chip optical element and an integrated optical element. The on-chip optical element comprises a substrate, an input coupling waveguide located on the substrate, an output coupling waveguide located on the substrate and a modulation structure. The modulation structure comprises a phase change material layer located on the substrate, the phase change material layer is a continuous film layer and comprises a plurality of units, and the refractive indexes of at least two units are different; and the input coupling waveguide and the output coupling waveguide are respectively positioned at the side parts of the modulation structure, so that light rays emitted to the modulation structure through the input coupling waveguide are propagated along a direction parallel to the surface of the phase change material layer. The integrated optical element includes the on-chip optical element.

Description

Technical Field

[0001] The present application relates to the technical field of optical signal processing, and in particular to an on-chip optical element and an integrated optical element. Background Art

[0002] With the rapid development of big data, cloud computing, and artificial intelligence, the complexity of artificial intelligence algorithm models has increased dramatically. The traditional architecture with electronic chips as the computing carrier can no longer meet the requirements of the algorithm model for computing power and energy efficiency. Since the propagation of light in the medium has the natural advantages of high speed, high parallelism, high bandwidth, and low power consumption, computing based on the limited propagation of light in the medium has received great attention at home and abroad in recent years.

[0003] Once current optical computing devices are manufactured, their performance is fixed and cannot be reconfigured, which limits their applications. Utility Model Content

[0004] The embodiments of the present application provide an on-chip optical element and an integrated optical element.

[0005] According to a first aspect of an embodiment of the present application, there is provided an on-chip optical element, the on-chip optical element comprising:

[0006] substrate;

[0007] an input coupling waveguide located on the substrate;

[0008] an output coupling waveguide located on the substrate;

[0009] A modulation structure; the modulation structure includes a phase change material layer located on the substrate, the phase change material layer is a continuous film layer, and includes a plurality of units, at least two of the units have different refractive indices; the input coupling waveguide and the output coupling waveguide are respectively located at the side of the modulation structure, so that the light incident to the modulation structure through the input coupling waveguide propagates along a direction parallel to the surface of the phase change material layer.

[0010] In one embodiment, the states of the plurality of cells include a crystalline state, an amorphous state, and an intermediate state between the crystalline state and the amorphous state, and the refractive index of the cells in the intermediate state is between the refractive index of the cells in the crystalline state and the refractive index of the cells in the amorphous state.

[0011] In one embodiment, the phase change material layer is in direct contact with the substrate.

[0012] In one embodiment, the thickness of the phase change material layer is in the range of 200 nm to 400 nm.

[0013] In one embodiment, the modulation structure further includes a waveguide structure layer located between the substrate and the phase change material layer, and the waveguide structure layer is in direct contact with the phase change material layer.

[0014] In one embodiment, the thickness of the phase change material layer is in the range of 10 nm to 50 nm.

[0015] In one embodiment, the plurality of units are arranged in multiple rows and columns.

[0016] In one embodiment, the phase change material layer includes at least one of Ge2Sb2Te5 and Sb2Se3.

[0017] In one embodiment, the modulation structure further includes a protection layer located on a side of the phase change material layer away from the substrate.

[0018] According to a second aspect of an embodiment of the present application, there is provided an integrated optical element, wherein the integrated optical element comprises the above-mentioned on-chip optical element.

[0019] The main technical effects achieved by the embodiments of the present application are:

[0020] In the on-chip optical element and integrated optical element provided by the embodiments of the present application, the phase change material layer in the modulation structure of the on-chip optical element is a continuous film layer, and the state of the phase change material can be switched between multiple states, so the states of multiple units of the phase change material layer can be controlled to realize multiple different functions of the on-chip optical element, that is, reconstruction can be achieved without changing the structure of the on-chip optical element, and the application scenarios are wider; because the input coupling waveguide and the output coupling waveguide are respectively located on the side of the modulation structure, the light incident to the modulation junction through the input coupling waveguide propagates in a direction parallel to the surface of the phase change material layer, and the on-chip optical element can be applied to diffraction neural networks, on-chip scattering optical devices, on-chip diffraction optical devices, on-chip refractive optical devices, etc., with higher application flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a three-dimensional structure of an on-chip optical element provided by an exemplary embodiment of the present application;

[0022] Figure 2 is a top view of an on-chip optical element provided by an exemplary embodiment of the present application;

[0023] Figure 3 is a partial structural cross-sectional view of an on-chip optical element provided by an exemplary embodiment of the present application;

[0024] Figure 4 is a partial structural cross-sectional view of an on-chip optical element provided by another exemplary embodiment of the present application;

[0025] Figure 5 is a top view of an on-chip optical element provided by another exemplary embodiment of the present application;

[0026] Figures 6 to 9 Schematic diagrams of different on-chip optical elements provided in embodiments of the present application;

[0027] Fig.10 is a graph showing the relationship between the refractive index and extinction coefficient of Sb2Se3 in different states and the wavelength of light provided by an exemplary embodiment of the present application;

[0028] Fig.11 It is a flow chart of a method for preparing an on-chip optical element provided by an exemplary embodiment of the present application. Specific embodiments

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0030] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0031] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0032] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0033] The present application embodiment provides an on-chip optical element. Figure 1 and Figure 2As shown, the on-chip optical element includes a substrate 10 , an input coupling waveguide 20 , a modulation structure 30 , and an output coupling waveguide 40 located on the substrate 10 .

[0034] like Figure 3 and Figure 4 As shown, the modulation structure 30 includes a phase change material layer 31 located on the substrate 10, the phase change material layer 31 is a continuous film layer, the phase change material layer 31 includes a plurality of units 311, and at least two of the units 311 have different refractive indices. The phase change material layer is a continuous film layer, which means that the phase change material layer is a whole film layer without patterning. Figure 1 and Figure 2 The input coupling waveguide 20 and the output coupling waveguide 40 are respectively located at the sides of the modulation structure 30 , so that the light incident on the modulation structure 30 through the input coupling waveguide 20 propagates in a direction parallel to the surface of the phase change material layer 31 .

[0035] In the on-chip optical element provided by the embodiment of the present application, the phase change material layer in the modulation structure of the on-chip optical element is a continuous film layer, and the state of the phase change material can be switched between multiple states, so the states of multiple units of the phase change material layer can be controlled to realize multiple different functions of the on-chip optical element, that is, reconstruction can be achieved without changing the structure of the on-chip optical element, and the application scenarios are wider; because the input coupling waveguide and the output coupling waveguide are respectively located on the side of the modulation structure, the light incident to the modulation junction through the input coupling waveguide propagates in a direction parallel to the surface of the phase change material layer, and the on-chip optical element can be applied to diffraction neural networks, on-chip scattering optical devices, on-chip diffraction optical devices, on-chip refractive optical devices, etc., and the application flexibility is higher.

[0036] In one embodiment, the states of the multiple units 311 of the phase change material layer 31 include a crystalline state, an amorphous state, and an intermediate state between the crystalline state and the amorphous state, and the refractive index of the intermediate state unit is between the refractive index of the crystalline state unit and the refractive index of the amorphous state unit. The transmittance of the unit 311 in the phase change material layer 31 is different when it is in different states, and the change of phase shift generated when light passes through the unit 311 is different, so that the on-chip optical element can realize light modulation; by setting the states of the multiple units of the phase change material layer to include a crystalline state, an amorphous state, and an intermediate state, the on-chip optical element can make the light modulation more precise.

[0037] Furthermore, the states of the plurality of units 311 include a plurality of intermediate states, and the refractive indexes of the units 311 in different intermediate states are different, so that the modulation of light by the on-chip optical element can be further improved.

[0038] In one embodiment, the substrate 10 is a SOI (Silicon On Insulator) substrate, and may also be a lithium sawn oxide substrate, or a silicon dioxide substrate. Figure 1 In the illustrated embodiment, the substrate 10 is an SOI substrate, including two silicon film layers 11 and a silicon dioxide film layer 12 located between the two silicon film layers 11 .

[0039] In one embodiment, Figure 2 and Figure 5 As shown, the orthographic projection of the modulation structure 30 on the substrate 10 is rectangular, the modulation structure 30 includes four side surfaces, and the input coupling waveguide 20 and the output coupling waveguide 40 are located outside different side surfaces of the modulation structure 30 . Figure 2 In the illustrated embodiment, the input coupling waveguide 20 and the output coupling waveguide 40 are located outside two opposite sides of the modulation structure 30 . Figure 5 In the illustrated embodiment, the input coupling waveguide 20 and the output coupling waveguide 40 are located outside two adjacent side surfaces of the modulation structure 30 .

[0040] In one embodiment, Figure 3 As shown, the phase change material layer 31 is in direct contact with the substrate 10. After the light incident through the input coupling waveguide 20 propagates to the modulation structure 30, the modulation structure 30 directly modulates the light. In this embodiment, the structure of the modulation structure 30 is relatively simple.

[0041] Furthermore, the thickness of the phase change material layer 31 is in the range of 200nm to 400nm. This configuration can make the phase change material layer 31 have a better light modulation effect. In some embodiments, the thickness of the phase change material layer 31 can be 200nm, 250nm, 300nm, 350nm, 400nm, etc.

[0042] In another embodiment, Figure 4 As shown, the modulation structure 30 further includes a waveguide structure layer 32 located between the substrate 10 and the phase change material layer 31, and the waveguide structure layer 32 is in direct contact with the phase change material layer 31. In this configuration, after the light incident through the input coupling waveguide 20 propagates to the waveguide structure layer 32, the phase change material layer 31 modulates the evanescent wave, so that the amplitude and phase of the light change. In some embodiments, the waveguide structure layer 32 can be a planar waveguide structure or other types of waveguide structures.

[0043] Furthermore, the thickness of the phase change material layer 31 is in the range of 10 nm to 50 nm. This configuration can make the phase change material layer 31 have a better light modulation effect. In some embodiments, the thickness of the phase change material layer 31 can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.

[0044] In one embodiment, Figure 2 and Figure 5 As shown, the multiple units of the phase change material layer 31 are arranged in multiple rows and columns. This arrangement can make the distribution of the refractive index of the phase change material layer 31 more diversified, thereby improving the wide application of the on-chip optical element.

[0045] In one embodiment, the orthographic projections of the units 311 in the phase change material layer 31 on the substrate 10 are all the same in shape and area. For example, the orthographic projections of the units 311 on the substrate 10 are all rectangular, circular, or other shapes. Figure 2 and Figure 5 In the illustrated embodiment, the orthographic projection of each unit 311 on the substrate 10 is in the shape of a rectangle.

[0046] In one embodiment, Figure 5 As shown, there is a gap between two adjacent units 311 in the same row in the on-chip optical element, and there is a gap between two adjacent units 311 in the same column. In other embodiments, there is no gap between two adjacent units 311 in the same row in the on-chip optical element, and there is no gap between two adjacent units 311 in the same column.

[0047] In the embodiment of the present application, when there is no gap between two adjacent units in the same row and there is no gap between two adjacent units in the same column in the on-chip optical element, different on-chip optical elements can be formed by adjusting the states of multiple units in the phase change material layer 31. Figures 6 to 9 Schematic diagram of different on-chip optical elements obtained for tuning the state of multiple units of a phase-change material layer. The black lines in the figure represent waveguide arms.

[0048] In one embodiment, the material of the phase change material layer includes at least one of Ge2Sb2Te5 and Sb2Se3. The working band of the on-chip optical element is generally 1050nm or 1550nm, and the extinction coefficients of Ge2Sb2Te5 and Sb2Se3 in this working band are very small, which helps to reduce the loss of light during propagation; and in this working band, the refractive index difference of Ge2Sb2Te5 and Sb2Se3 in different states is large, and light modulation can be effectively realized.

[0049] Preferably, the phase change material layer is made of Sb2Se3. Fig.10 The graph is a graph showing the relationship between the refractive index and extinction coefficient of Sb2Se3 in different states and the wavelength of light, wherein curve a represents the relationship between the refractive index and wavelength of crystalline Sb2Se3, curve b represents the relationship between the extinction coefficient and wavelength of crystalline Sb2Se3, curve c represents the relationship between the refractive index and wavelength of amorphous Sb2Se3, and curve d represents the relationship between the extinction coefficient and wavelength of amorphous Sb2Se3. Fig.10 It can be seen that when the wavelength of light is 1050nm, the refractive index of crystalline Sb2Se3 is 4.5, and the refractive index of amorphous Sb2Se3 is 3.3; when the wavelength of light is 1550nm, the refractive index of crystalline Sb2Se3 is 4, and the refractive index of amorphous Sb2Se3 is 3.2; when the wavelength of light is 1050nm and 1550nm, the extinction coefficients of crystalline Sb2Se3 and amorphous Sb2Se3 are close to zero. That is, when the wavelength of light is 1050nm and 1550nm, the refractive index difference between crystalline Sb2Se3 and amorphous Sb2Se3 is large and the extinction coefficients are very small.

[0050] In one embodiment, the modulation structure further comprises a protective layer located on a side of the phase change material layer away from the substrate, and the orthographic projection of the protective layer on the substrate covers the orthographic projection of the phase change material layer on the substrate. The protective layer can protect the phase change material layer from being oxidized. In some embodiments, the material of the protective layer is indium zinc oxide or indium tin oxide, so that the transmittance of the protective layer to laser is high, and the laser loss can be reduced when the laser is used to irradiate the phase change material layer.

[0051] The present application also provides a method for preparing an on-chip optical element. Fig.11 As shown, the preparation method includes the following steps 110 and 120.

[0052] In step 110, an intermediate structure is provided, wherein the intermediate structure includes a substrate, an input coupling waveguide, an output coupling waveguide and a modulation structure located on the substrate, wherein the modulation structure includes a phase change material layer, wherein the input coupling waveguide and the output coupling waveguide are respectively located at sides of the modulation structure; the phase change material layer is a continuous film layer including a plurality of units, and an initial state of the phase change material layer is an amorphous state.

[0053] In one embodiment, when the modulation structure includes a waveguide structure layer, the preparation process of the intermediate structure is as follows:

[0054] First, a waveguide structure layer, an input coupling waveguide and an output coupling waveguide are formed on a substrate.

[0055] After this step, the obtained structure may be cleaned. In some embodiments, acetone, anhydrous ethanol, and deionized water may be used for cleaning in sequence.

[0056] Subsequently, a photoresist layer is formed. The photoresist layer is provided with an opening. The opening is a region where a phase change material layer is to be formed. The opening exposes the waveguide structure layer.

[0057] In one embodiment, the step of forming a photoresist layer may include the following process: first forming a photoresist film layer on the entire surface, the orthographic projection of the photoresist film layer on the substrate can cover the substrate; then the photoresist film layer is sequentially exposed, developed and fixed to obtain the photoresist layer. The material of the photoresist may be a negative photoresist. The photoresist film layer may be formed by a spin coating process, for example, a photoresist spin coater may be used to first spin coat at a spin coating speed of 700 rad / s for 9 seconds, and then spin coat at a spin coating speed of 3000 rad / s for 40 seconds to obtain the photoresist film layer. After the photoresist film is obtained by the spin coating process, it may be dried, the drying temperature may be 120°C, and the drying time may be 90 seconds. When exposing the photoresist film, a contact ultraviolet lithography machine may be used, and the exposure dose may be 300 J / cm2. After the exposure is completed, the obtained structure may be dried, the drying temperature may be 120°C, and the drying time may be 90 seconds. In the developing step, RD6 developer can be used, and the developing time can be 50 seconds. In the fixing step, deionized water can be used for fixing, and the fixing time can be 60 seconds.

[0058] Subsequently, a phase change material layer is formed, and the phase change material layer covers the opening of the photoresist layer.

[0059] In this embodiment, a magnetron sputtering device can be used to form a phase change material layer. The vacuum degree of the coating chamber of the magnetron sputtering device can be 3×10 -4 Pa, the pressure of the coating chamber is 0.8 Pa, the argon flow rate can be 30 sccm, the RF power can be 30 w, the sputtering time is 100 s, the sputtering rate is 3 angstroms / s, and the thickness of the final phase change material layer is 30 nm.

[0060] Subsequently, the photoresist layer is removed.

[0061] The photoresist layer can be removed by a microwave plasma stripper. The parameters of the microwave plasma stripper can be set as follows: power 300w, argon flow 280sccm, oxygen flow 20sccm, time 30s. After removing the photoresist layer, the obtained structure can be cleaned. The cleaning process can be as follows: first, the obtained structure is placed in a culture dish filled with acetone reagent, and the culture dish is placed in an ultrasonic cleaning machine for cleaning. The parameters of the ultrasonic cleaning machine can be set as follows: power 30w, time 180s; after the ultrasonic cleaning is completed, use anhydrous ethanol and deionized water to clean again.

[0062] In another embodiment, when the modulation structure only includes a phase change material layer, the preparation process of the intermediate structure is as follows:

[0063] First, an input coupling waveguide and an output coupling waveguide are formed on a substrate.

[0064] After this step, the obtained structure may be cleaned. In some embodiments, acetone, anhydrous ethanol, and deionized water may be used for cleaning in sequence.

[0065] Subsequently, a photoresist layer is formed, wherein the photoresist layer is provided with an opening, and the opening is a region where a phase change material layer is to be formed.

[0066] The specific details of the step of forming the photoresist layer refer to the above embodiment and will not be described in detail again.

[0067] Subsequently, a phase change material layer is formed, and the phase change material layer covers the opening of the photoresist layer.

[0068] The specific details of the step of forming the phase change material layer refer to the above embodiment and will not be described in detail again.

[0069] Subsequently, the photoresist layer is removed.

[0070] The specific details of the step of removing the photoresist layer refer to the above embodiment and will not be described in detail again.

[0071] In step 120, a laser pulse is used to irradiate at least one of the units, so that the state of the unit changes.

[0072] In one embodiment, the step of irradiating at least one of the units with a laser pulse includes the following process: irradiating at least one of the units with a first laser pulse so that the state of the unit irradiated by the first laser pulse changes to a crystalline state; irradiating at least one of the units with a second laser pulse so that the state of the unit irradiated by the first laser pulse changes to an intermediate state, wherein the refractive index of the intermediate state unit is between the refractive index of the crystalline unit and the refractive index of the amorphous unit; the first laser pulse and the second laser pulse have different energies.

[0073] By controlling the number of laser pulses irradiated to the unit, the energy of the laser pulse can be precisely controlled, thereby precisely adjusting the state of the unit. Before using laser pulses to irradiate the unit of the phase change material layer, the required refractive index distribution of the phase change material layer can be determined according to the data to be processed, and then the number of laser pulses irradiated to each unit can be determined according to the required refractive index distribution of the phase change material layer. Using laser pulses to change the state of the unit does not rely on lithography and etching processes, which can greatly improve the flexibility of on-chip optical element reconstruction, while reducing process errors and phase noise caused by lithography and etching; compared with the solution of using electrical pulses to change the state of the unit, complex electrode wiring is not required, which can simplify the structure.

[0074] In one embodiment, the step of using a second laser pulse to irradiate at least one of the units so that the state of the unit irradiated by the first laser pulse changes to an intermediate state includes the following process: using a plurality of second laser pulses with different energies to irradiate different units respectively to obtain a plurality of units in different intermediate states.

[0075] In one embodiment, step 120 can be completed by the following process: controlling the light source to generate laser, using an arbitrary waveform generator to digitally modulate the laser generated by the light source into laser pulses, and the laser pulses are focused onto the surface of the phase change material layer by the objective lens. A piezoelectric displacement stage can be used to control the horizontal movement of the intermediate structure to facilitate the laser pulse to program different areas of the phase change material layer. Among them, the light source can be a 639nm laser diode, and the objective lens can be an 80x objective lens.

[0076] An embodiment of the present application further provides an integrated optical element, which includes the on-chip optical element described in any of the above embodiments.

[0077] In one embodiment, the integrated optical element is used to process a single-frame image, and the integrated optical element further includes a light source, a beam expander, a digital micromirror, a 4f optical system, and an objective lens. The laser generated by the light source passes through the beam expander and is incident on the digital micromirror, where the image information is written by the digital micromirror, and then passes through the 4f optical system and the objective lens in sequence and enters the on-chip optical element. The wavelength of the laser generated by the light source may be, for example, 1550 nm, 1050 nm, etc.

[0078] In one embodiment, the integrated optical element is used to process multimodal data, and the integrated optical element also includes a controller, a light source, a spectrometer, multiple modulators, and multiple photodiodes. The spectrometer is used to split the input light provided by the light source into multiple beams to obtain multiple sub-beams; the multiple modulators are used to modulate each sub-beam to obtain a modulated sub-beam; the on-chip optical element is used to perform optical data processing on the multiple modulated sub-beams to obtain multiple output sub-beams; each photodiode is used to detect the output sub-beams and output electrical signals; the controller is connected to the spectrometer, multiple modulators, and multiple photodiodes, respectively. The controller is used to obtain the electrical signals output by each photodiode and perform data processing, output modulated signals to each modulator, and adjust the number and power of the sub-beams of the spectrometer.

[0079] In one embodiment, the integrated optical element may be an optical computing module, that is, the integrated optical element is applied in the field of optical computing.

[0080] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0081] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the disclosure disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0082] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. An on-chip optical element, characterized in that: The on-chip optical element comprises: substrate; an input coupling waveguide located on the substrate; an output coupling waveguide located on the substrate; A modulation structure; the modulation structure includes a phase change material layer located on the substrate, the phase change material layer is a continuous film layer, and includes a plurality of units, at least two of the units have different refractive indices; the input coupling waveguide and the output coupling waveguide are respectively located at the side of the modulation structure, so that the light incident to the modulation structure through the input coupling waveguide propagates along a direction parallel to the surface of the phase change material layer.

2. The on-chip optical element according to claim 1, characterized in that: The states of the plurality of cells include a crystalline state, an amorphous state, and an intermediate state between the crystalline state and the amorphous state, and the refractive index of the cell in the intermediate state is between the refractive index of the cell in the crystalline state and the refractive index of the cell in the amorphous state.

3. The on-chip optical element according to claim 1, characterized in that: The phase change material layer is in direct contact with the substrate.

4. The on-chip optical element according to claim 3, characterized in that: The thickness of the phase change material layer ranges from 200nm to 400nm.

5. The on-chip optical element according to claim 1, characterized in that: The modulation structure further includes a waveguide structure layer located between the substrate and the phase change material layer, and the waveguide structure layer is in direct contact with the phase change material layer.

6. The on-chip optical element according to claim 5, characterized in that: The thickness of the phase change material layer is in the range of 10 nm to 50 nm.

7. The on-chip optical element according to claim 1, characterized in that: The multiple units are arranged in multiple rows and columns.

8. The on-chip optical element according to claim 1, characterized in that: The phase change material layer is made of Ge2Sb2Te5 or Sb2Se3.

9. The on-chip optical element according to claim 1, characterized in that: The modulation structure further includes a protection layer located on a side of the phase change material layer away from the substrate.

10. An integrated optical element, characterized in that: The integrated optical element comprises the on-chip optical element according to any one of claims 1 to 9.

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