Photon integrated chip and soil interface dynamic monitoring device and method

Abstract

The invention relates to the field of water and soil conservation online monitoring, in particular to a photonic integrated chip and a soil interface dynamic monitoring device and method. Comprising a substrate, and a beam splitting and combining device, a micro-ring resonator and a grating coupler which are arranged on the substrate, the beam splitting and combining device is connected with the micro-ring resonators, the micro-ring resonators are connected with the grating coupler, the perimeter of each micro-ring resonator is different, and the micro-ring resonators are sequentially arranged at intervals in sequence. According to the invention, real-time monitoring of the soil interface is realized through an accurate optical method so as to determine the height position change of the soil and air interface and further monitor water and soil loss, the method has high sensitivity, non-contact property and sustainability, the efficiency of water and soil loss monitoring can be effectively improved, and reliable technical support is provided for the fields of agriculture, environmental protection and the like.

Description

Technical Field

[0001] The present invention relates to the field of online monitoring of soil and water conservation, and in particular to a photon integrated chip, a soil interface dynamic monitoring device and a method. Background Art

[0002] Soil and water loss not only seriously affects the productivity of land, but also leads to the degradation of ecosystems, damages water quality, and exacerbates natural disasters such as floods and mudslides. Monitoring and research on soil and water loss is an important task for sustainable soil management and protection of the ecological environment.

[0003] Traditional soil and water loss monitoring methods mainly include ground surveys, physical sampling, and model simulation. These methods usually rely on field observations and long-term data accumulation. Although they can provide certain data support, they have obvious defects. For example, on-site monitoring often requires professionals, which is costly and inefficient; the data obtained through physical sampling usually reflects the status at a specific moment, and it is difficult to capture the dynamic changes of soil and water loss. In addition, conventional model simulation methods are usually based on historical data and cannot accurately reflect the current soil conditions and environmental changes, thus affecting the reliability of monitoring results.

[0004] With the advancement of science and technology, optical sensing technology and remote sensing technology are gradually applied to soil erosion monitoring. These technologies can provide data support over a large range, but there are still limitations in specific applications. Existing optical sensor equipment is often expensive, difficult to maintain, and poorly adaptable to different soil types, resulting in unsatisfactory actual monitoring results.

[0005] The rapid development of micro-nano photonics has provided a new opportunity for the research and development of new soil and water loss monitoring equipment. Microring resonators, due to their superior optical properties, can show good prospects in miniaturization and high-sensitivity detection. However, the existing technology lacks effective research on integrating microring resonators into soil and water loss monitoring systems, resulting in this potential not being fully utilized.

[0006] Therefore, there is an urgent need for an innovative soil and water loss monitoring device and method that can combine the advantages of photonic integration technology and microring resonators to achieve real-time and high-precision monitoring of soil and water loss. Summary of the invention

[0007] In response to the problems mentioned in the prior art, the present invention proposes a photonic integrated chip, a soil interface dynamic monitoring device and a method. The device can utilize the optical properties of a microring resonator to achieve high-precision monitoring of soil erosion, providing effective technical support for soil and water conservation and ecological environment management.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: The present invention discloses a photonic integrated chip, comprising a substrate and a beam splitter / combiner, a microring resonator and a grating coupler arranged on the substrate; the beam splitter / combiner is connected to the microring resonator, and the microring resonator is connected to the grating coupler, wherein there are multiple microring resonators, each of which has a different circumference, and the multiple microring resonators are arranged in sequence and spaced apart.

[0009] As a further improvement of the present invention, each microring resonator is arranged in sequence from small to large circumference, or each microring resonator is arranged in sequence from large to small circumference.

[0010] As a further improvement of the present invention, the circumference of the microring resonator corresponds to the resonant wavelength of the microring resonator itself, and the relationship is as follows:

[0011] Where: L is the circumference of the microring resonator; m is the resonance order, which is a non-negative integer; λ is the wavelength of the incident light; is the effective refractive index of the microring resonator.

[0012] As a further improvement of the present invention, the light emitted by the microring resonator is emitted along a vertical direction of the grating coupler.

[0013] As a further improvement of the present invention, the grating period of the grating coupler is calculated as shown in the following formula:

[0014] Where: k is the diffraction order, which is a non-negative integer; λ is the wavelength of the incident light, n is the waveguide refractive index; d is the grating period.

[0015] A soil interface dynamic monitoring device, comprising the above-mentioned photon integrated chip, a tunable laser, a detection probe, an optical signal detector and a signal processing module; The photon integrated chip is embedded in the detection probe, the tunable laser is coupled to the waveguide end face of the photon integrated chip, one end of the optical signal detector is connected to the signal processing module, and the other end is connected to the output port of the photon integrated chip.

[0016] As a further improvement of the present invention, the tuning wavelength of the tunable laser covers the resonance wavelengths of all microring resonators.

[0017] As a further improvement of the present invention, the optical signal detector is a photodiode.

[0018] As a further improvement of the present invention, the bottom port of the detection probe is a waterproof sealing structure, wherein one end of the detection probe is inserted into the soil and the other end is set in the air.

[0019] A soil monitoring method comprises the following steps: S1, the tunable laser generates laser light of a specific wavelength and inputs the laser light into the photonic integrated chip through a beam splitter and combiner; S2, the laser enters the main waveguide, is selectively coupled by the microring resonator, and is emitted outward from the exit ports of the microring resonators at different heights through the grating coupler in sequence. The emitted laser is reflected by the soil back to the photonic integrated chip; S3. The reflected laser is introduced into the optical signal detector by the beam splitter and combiner. The optical signal detector transmits the reflected laser to the signal processing module for analysis and processing, determines the critical position of the soil-air interface, and monitors the dynamic changes of the soil position.

[0020] Compared with the prior art, the present invention has achieved the following technical effects: The micro-ring resonators in the present invention are arranged in order of circumference size. This structural design enables the device to capture extremely small changes in optical signals, which can reflect potential soil loss and provide early warning for timely measures. Compared with traditional soil monitoring methods, this device adopts a non-contact monitoring method, which greatly reduces direct intervention on the soil. It not only helps to protect the ecological environment and avoid damage to the soil structure, but also ensures the accuracy of the monitoring results. At the same time, non-contact monitoring also reduces the labor cost in the monitoring process, making the monitoring work more efficient. The present invention adopts a combination of tunable laser and signal processing module, which can capture and analyze the changes of soil environment in real time, ensuring that the device can respond quickly and provide timely and accurate monitoring data; The photonic integrated chip of the present invention can achieve large-scale, high-precision repeatable production through photolithography technology, which not only significantly improves production efficiency, but also greatly reduces the cost of the monitoring device. Compared with traditional soil monitoring equipment, this technology achieves effective cost control while ensuring monitoring accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the photon integrated chip of the present invention; Figure 2 It is a schematic diagram of the transmission principle of the microring resonator of the present invention; Figure 3 This is the output principle diagram of the grating coupler of the present invention; Figure 4 It is a schematic structural diagram of the soil interface dynamic monitoring device of the present invention.

[0022] Figure numerals: 1. microring resonator; 2. grating coupler; 3. beam splitter / combiner; 4. optical signal detector; 5. tunable laser; 6. signal processing module. DETAILED DESCRIPTION

[0023] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0028] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0029] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0030] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0031] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] like Figure 1 As shown, a photonic integrated chip of the present invention comprises a substrate and a beam splitter / combiner 3, a microring resonator 1 and a grating coupler 2 arranged on the substrate; the beam splitter / combiner 3 is connected to the microring resonator 1, and the microring resonator 1 is connected to the grating coupler 2, wherein there are multiple microring resonators 1, each of which has a different circumference, and the multiple microring resonators 1 are arranged in sequence and spaced apart.

[0034] The photon integrated chip topology of this embodiment integrates multiple micro-ring resonators 1 with different wavelengths, and the tunable laser 5 and the optical signal detector 4 are mounted on the chip to form a soil interface dynamic monitoring device, which is constructed as follows: Figure 1 shown.

[0035] The tunable laser 5 emits laser light and couples it into the photonic integrated chip, and then enters the microring resonator 1 through the beam splitter and combiner 3. The tunable laser 5 is continuously tuned to change the wavelength of the incident light. When the wavelength meets the resonance condition of the microring resonator 1, the laser light is transmitted from the microring resonator 1, and the output light is emitted to the free space through the coupling grating.

[0036] The output port of the photon integrated chip of this embodiment is partially buried under the ground surface. When the laser is incident on the air, the laser is transmitted. When the laser encounters the soil, part of the laser is reflected. The reflected light returns to the microring resonator 1 through the grating coupler 2, and is coupled back to the main waveguide to enter the optical signal detector 4. The position of the laser output port can be adjusted by changing the wavelength of the incident light. The intensity of the reflected light at the port can be obtained by synchronous detection of the light intensity, thereby obtaining the presence or absence of soil at the port. Then, the interface between the soil and the air can be obtained by continuous adjustment of the wavelength. When soil erosion occurs, the interface position changes, and the critical position of the reflected light also changes. Soil erosion monitoring is achieved by detecting the reflected light.

[0037] In this embodiment, the microring resonator 1 is a microring structure, and the microring resonator 1 is made of a high refractive index material, preferably silicon or silicon nitride, and is manufactured by photolithography and etching technology to ensure that a suitable microring shape and size are formed; Figure 1 As shown, in the embodiment, five microring resonators 1 are preferably provided, and each microring resonator 1 is arranged in sequence and spaced apart. From left to right in the figure, the circumference of each microring resonator 1 increases successively. The circumference of the microring resonator 1 is related to the resonant wavelength of the microring resonator 1 itself. The specific relationship is shown in the following formula:

[0038] Where: L is the circumference of the microring resonator; m is the resonance order, which is a non-negative integer; λ is the wavelength of the incident light; is the effective refractive index of the microring resonator.

[0039] Therefore, according to the above relationship, the selection of the resonance wavelength is achieved by adjusting the circumference of the microring resonator 1 .

[0040] In this embodiment, the circumference of each microring resonator 1 increases from left to right, but it is not limited to this. The circumference of each microring resonator 1 may also be set to decrease from left to right. In this way, when the wavelength of the incident light meets the resonance condition of the microring resonator 1, the light will be enhanced in the microring resonator 1, and the light of the wavelength will be transmitted from the microring resonator 1, such as Figure 2 As shown; a series of resonant microrings of different lengths are topologically integrated on the photonic integrated chip of the embodiment, corresponding to different resonant wavelengths. When the wavelength of the tuned laser is changed, the laser can be controlled to be transmitted from different microrings and transmission ports, so that the photonic integrated chip has the ability of multi-wavelength selection and can realize optical wavelength selection and control.

[0041] The main function of the grating coupler 2 in this embodiment is to effectively couple the optical signal in the waveguide into spatial light and recouple the optical signal reflected from the soil interface back into the waveguide. In the device of the present invention, the design and performance of the grating coupler 2 directly affect the overall sensitivity and accuracy of the device.

[0042] The grating coupler 2 uses the principle of diffraction and interference of light to convert the optical signal transmitted in the waveguide into spatial light and emit it at an appropriate angle; the grating coupler 2 is usually composed of a series of periodic grooves or protrusions. The geometric characteristics of these structures determine the coupling efficiency and emission direction of the light. In order to improve the coupling efficiency, the embodiment adopts an adiabatic double cone design to expand the coupling area. The optical signal at a given incident angle can be diffracted by the periodic structure of the grating and then emitted outward, such as Figure 3 When the diffraction condition is met, the light wave will be emitted in a specific angle direction. When the following formula is met, the light will be emitted vertically from the waveguide, or the vertical reflected light can be coupled back to the chip.

[0043]

[0044] Where: k is the diffraction order, which is a non-negative integer; λ is the wavelength of the incident light, n is the waveguide refractive index; d is the grating period.

[0045] The period of the grating coupler 2 is designed by the above formula to ensure efficient light coupling and diffraction, and to ensure that light can be effectively converted into spatial light.

[0046] The tunable laser 5 in the present invention is the light source of the device, which excites different microring resonators 1 by adjusting the output wavelength; in the embodiment, the tunable laser 5 can operate within a specific wavelength range, such as 1550 nm ± 40 nm. The wavelength of light in this range is suitable for most photodetectors and optical fiber transmission. The output of the laser is connected to the main waveguide of the photonic integrated chip through the beam splitter and combiner 3 to ensure stable laser input. The tunable laser 5 is specifically arranged at the incident port of the photonic integrated chip and is coupled to the main waveguide using an end-face coupling process. During specific use, the temperature and current of the tunable laser 5 are adjusted so that the laser wavelength can flexibly respond to the resonance conditions of different microring resonators 1.

[0047] The optical signal detector 4 in the embodiment is responsible for capturing the reflected signal from the photon integrated chip. The detector uses a photodiode or an avalanche photodiode (APD) to improve the detection sensitivity and reaction speed. Among them, APD is more suitable for weak signal detection. The output of the detector is connected to the signal processing module 6 through a cable, which can process and analyze the signal and compare the reflected signal with a preset threshold to determine the position of the water-soil interface.

[0048] The signal processing module 6 of this embodiment is the core of data analysis in the system, and is responsible for processing the data output by the optical signal detector 4. Its main functions include: real-time acquisition of optical signal data output by the detector, and the use of an analog-to-digital converter (ADC) to convert analog signals into digital signals for subsequent processing; the use of algorithms to extract features from the acquired data, analyze changes in reflected light signals, and identify the location of the soil-air interface through a set data model, such as a filtering algorithm and a threshold judgment method.

[0049] When the device is used, the photon integrated chip is assembled with the detection probe, and it is ensured that the lower port of the detection probe is inserted into the soil and the upper port is exposed to the air.

[0050] The laser transmitted from the microring resonator 1 enters the free space through the grating coupler 2. The laser will advance in the air and reflect back after contacting the soil interface. The reflected light signal is coupled back to the microring resonator 1 again and returns along the main waveguide, and is finally captured by the optical signal detector 4. The optical signal detector 4 converts the acquired optical signal into an electrical signal and sends it to the signal processing module 6 to record the reflected light intensity data in real time.

[0051] The signal processing module 6 analyzes the reflected signal data obtained through the edge computing algorithm and analyzes the interface height between the soil and the air. When the reflected light intensity is lower than the set threshold, the system automatically determines that there is soil loss. According to the calculation results of the signal processing module 6, the real-time monitoring information is fed back to the user. If the interface change is detected to exceed the set range, the system will issue an alarm to prompt the user to take necessary measures.

[0052] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0053] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A photonic integrated chip, characterized in that: It includes a substrate and a beam splitter / combiner, a micro-ring resonator and a grating coupler arranged on the substrate; the beam splitter / combiner is connected to the micro-ring resonator, and the micro-ring resonator is connected to the grating coupler, wherein there are multiple micro-ring resonators, each of which has a different circumference, and multiple micro-ring resonators are arranged in sequence and spaced apart.

2. A photonic integrated chip according to claim 1, characterized in that: Each micro-ring resonator is arranged in sequence from small to large circumference, or each micro-ring resonator is arranged in sequence from large to small circumference.

3. A photonic integrated chip according to claim 2, characterized in that: The circumference of the microring resonator corresponds to the resonant wavelength of the microring resonator's own response, and the relationship is as follows: Where: L is the circumference of the microring resonator; m is the resonance order, which is a non-negative integer; λ is the wavelength of the incident light; is the effective refractive index of the microring resonator.

4. The photonic integrated chip according to claim 1, characterized in that: The light emitted from the microring resonator is emitted along a vertical direction of the grating coupler.

5. A photonic integrated chip according to claim 4, characterized in that: The grating period of the grating coupler is calculated as follows: Where: k is the diffraction order, which is a non-negative integer; λ is the wavelength of the incident light, n is the waveguide refractive index; d is the grating period.

6. A soil interface dynamic monitoring device, characterized in that: It comprises the photon integrated chip as claimed in claim 1, a tunable laser, a detection probe, an optical signal detector and a signal processing module; The photon integrated chip is embedded in the detection probe, the tunable laser is coupled to the waveguide end face of the photon integrated chip, one end of the optical signal detector is connected to the signal processing module, and the other end is connected to the output port of the photon integrated chip.

7. A soil interface dynamic monitoring device according to claim 6, characterized in that: The tuning wavelength of the tunable laser covers the resonance wavelengths of all microring resonators.

8. A soil interface dynamic monitoring device according to claim 6, characterized in that: The optical signal detector is a photodiode.

9. A soil interface dynamic monitoring device according to claim 6, characterized in that: The bottom port of the detection probe is a waterproof sealing structure, wherein one end of the detection probe is inserted into the soil, and the other end is set in the air.

10. A soil monitoring method, characterized in that: The following steps are involved: S1, the tunable laser generates laser light of a specific wavelength and inputs the laser light into the photonic integrated chip through a beam splitter and combiner; S2, the laser enters the main waveguide, is selectively coupled by the microring resonator, and is emitted outward from the exit ports of the microring resonators at different heights through the grating coupler in sequence. The emitted laser is reflected by the soil back to the photonic integrated chip; S3. The reflected laser is introduced into the optical signal detector by the beam splitter and combiner. The optical signal detector transmits the reflected laser to the signal processing module for analysis and processing, determines the critical position of the soil-air interface, and monitors the dynamic changes of the soil position.

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