A temperature-refractive-index dual-parameter sensor based on a one-dimensional photonic crystal racetrack microring

Abstract

The present invention provides a temperature-refractive-index dual-parameter sensor for a one-dimensional photonic crystal racetrack microring. The sensor comprises a bus waveguide and a one-dimensional photonic crystal racetrack microring. The bus waveguide is linearly arranged on one side of the one-dimensional photonic crystal racetrack microring and is coupled to the one-dimensional photonic crystal racetrack microring. The one-dimensional photonic crystal racetrack microring comprises a racetrack structure, and a photonic bandgap is formed between the racetrack structure and the bus waveguide. The sensor utilizes the slow light effect to generate resonance peaks with different free spectral ranges at the edge of the photonic bandgap of the one-dimensional photonic crystal racetrack microring. Because the effects of temperature and the effect of the substance being measured on the effective refractive index are reflected on different resonance peaks, the temperature and refractive index information of the substance being measured can be calculated by recording the relative changes in the positions of these resonance peaks, thereby improving detection efficiency and accuracy.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, in particular to a temperature and refractive index dual-parameter sensor of a one-dimensional photonic crystal racetrack microring. Background Art

[0002] In recent years, many silicon-based integrated devices have been used to design refractive index sensors, such as microdisk resonators, microring resonators, and photonic crystals. Microring resonators based on SOI platforms have attracted widespread attention due to their low insertion loss, high stability, simple design, and ease of fabrication. A microring resonator is a type of whispering gallery microcavity (WGM) structure. In this type of structure, light that meets the resonant conditions will reflect back and forth within the whispering gallery microcavity, generating a resonance enhancement effect that can achieve high light field intensity and Q values, making it ideal for use as sensors and filters.

[0003] However, the free spectral range (FSR) of traditional microring resonators is uniform, which means that the effects of temperature and the refractive index of the material to be measured are superimposed. In such devices, only the superimposed transmission spectrum can be obtained, and the temperature and refractive index information of the material to be measured cannot be detected. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that traditional microring resonators cannot detect the temperature and refractive index information of the substance to be measured. The present invention provides a temperature and refractive index dual parameter sensor of a one-dimensional photonic crystal racetrack microring.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] The first aspect of the embodiment of the present application provides a one-dimensional photonic crystal racetrack microring temperature and refractive index dual parameter sensor, comprising: a bus waveguide and a one-dimensional photonic crystal racetrack microring, wherein:

[0007] The bus waveguide is linearly arranged on one side of the one-dimensional photonic crystal racetrack microring, and the bus waveguide is coupled to the one-dimensional photonic crystal racetrack microring;

[0008] The one-dimensional photonic crystal racetrack microring includes a racetrack structure, and a photonic bandgap is formed between the racetrack structure and the bus waveguide.

[0009] Optionally, the bus waveguide and the one-dimensional photonic crystal racetrack microring are both made of SOI.

[0010] Optionally, the bus waveguide has a waveguide width of 380 nm and a waveguide height of 220 nm.

[0011] Optionally, the one-dimensional photonic crystal racetrack microring further includes a ring waveguide, which is used to connect two sections of racetrack structures to form the one-dimensional photonic crystal racetrack microring; the ring waveguide has a radius of 6260 nm and a width of 400 nm.

[0012] Optionally, the runway has a length of 7580 nm and a width of 400 nm.

[0013] Optionally, the one-dimensional photonic crystal racetrack microring further includes a photonic crystal microcavity, and the lattice constant of the photonic crystal microcavity is 380 nm.

[0014] Optionally, the coupling spacing between the bus waveguide and the one-dimensional photonic crystal racetrack microring is 300 nm.

[0015] A second aspect of the present application provides a temperature-refractive index dual-parameter detection method using the sensor described in the first aspect, comprising:

[0016] Obtaining a transmission spectrum of the photon bandgap edge;

[0017] determining at least one set of resonance wavelength information and resonance intensity information based on the transmission spectrum;

[0018] The temperature and refractive index of the substance to be measured are determined based on the resonance wavelength information and the resonance intensity information.

[0019] Optionally, determining the temperature and refractive index of the substance to be measured based on the resonance wavelength information and the resonance intensity information includes:

[0020] Using the resonant wavelength sample data and the resonant intensity sample data to train a preset neural network to obtain a target neural network;

[0021] The resonance wavelength information and the resonance intensity information are input into the target neural network to determine the temperature and refractive index of the substance to be measured.

[0022] A third aspect of the embodiments of the present application provides a temperature-refractive-index dual-parameter device for a one-dimensional photonic crystal racetrack microring, comprising the temperature-refractive-index dual-parameter sensor for the one-dimensional photonic crystal racetrack microring described in the first aspect.

[0023] Compared with the existing technology, the technical solution provided by this application has the following beneficial effects:

[0024] The present invention provides a temperature-refractive-index dual-parameter sensor for a one-dimensional photonic crystal racetrack microring. The sensor comprises a bus waveguide and a one-dimensional photonic crystal racetrack microring. The bus waveguide is linearly arranged on one side of the one-dimensional photonic crystal racetrack microring and is coupled to the one-dimensional photonic crystal racetrack microring. The one-dimensional photonic crystal racetrack microring comprises a racetrack structure, and a photonic bandgap is formed between the racetrack structure and the bus waveguide. The sensor utilizes the slow light effect to generate resonance peaks with different free spectral ranges at the edge of the photonic bandgap of the one-dimensional photonic crystal racetrack microring. Because the effects of temperature and the effect of the substance being measured on the effective refractive index are reflected on different resonance peaks, the temperature and refractive index information of the substance being measured can be calculated by recording the relative changes in the positions of these resonance peaks, thereby improving detection efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a one-dimensional photonic crystal racetrack microring temperature and refractive index dual parameter sensor provided in the embodiment of the present application Figure 1 ;

[0026] Figure 2 The transmission spectrum with a wavelength from 1500nm to 1600nm obtained by simulation in the embodiment of the present application;

[0027] Figure 3 The transmission spectrum with wavelengths from 1550 nm to 1575 nm obtained by simulation in the embodiment of the present application;

[0028] Figure 4 The transmission spectrum of the one-dimensional photonic crystal racetrack micro-ring band gap edge provided in the embodiment of the present application;

[0029] Figure 5 A comparison chart of the peak extinction ratio and FSR of the one-dimensional photonic crystal racetrack microring resonance provided in an embodiment of the present application;

[0030] Figure 6 The corresponding transmission spectrum obtained by modifying the ambient refractive index provided in the embodiment of the present application;

[0031] Figure 7 A detection diagram showing the effect of changes in ambient temperature on the transmission spectrum provided in an embodiment of the present application;

[0032] Figure 8 A schematic flow chart of a temperature-refractive index dual-parameter detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present application. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0034] The terms used herein are only for describing specific embodiments and are not intended to limit this application. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0035] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0036] The accompanying drawings show some block diagrams and / or flow charts. It should be understood that some blocks in the block diagrams and / or flow charts, or combinations thereof, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when these instructions are executed by the processor, they can create a device for implementing the functions / operations described in the block diagrams and / or flow charts.

[0037] To facilitate understanding of the technical solution of the present invention, the basic structures and working principles of a dipole antenna and a monopole antenna are explained here before describing the embodiments of the present invention.

[0038] Photonic bandgap refers to the frequency range formed in photonic crystals due to the special periodic structure that blocks photons of specific wavelengths or bands. Within this frequency range, photons cannot propagate in the photonic crystal.

[0039] Resonance peak, resonance peak refers to the maximum value that the vibration amplitude (or oscillation amplitude) of an object or circuit will reach when the vibration frequency of the object or circuit is the same as the frequency of the external force (or the frequency of the input signal).

[0040] In some embodiments, see Figure 1 , Figure 1A schematic diagram of the structure of a one-dimensional photonic crystal racetrack microring temperature and refractive index dual parameter sensor provided in an embodiment of the present application; The one-dimensional photonic crystal racetrack microring temperature and refractive index dual parameter sensor provided in an embodiment of the present application includes: a bus waveguide 110 and a one-dimensional photonic crystal racetrack microring 120, wherein,

[0041] The bus waveguide 110 is linearly arranged on one side of the one-dimensional photonic crystal racetrack microring 120, and the bus waveguide 110 is coupled to the one-dimensional photonic crystal racetrack microring 120;

[0042] The one-dimensional photonic crystal racetrack microring 120 includes a racetrack structure 121 , and a photonic bandgap is formed between the racetrack structure 121 and the bus waveguide 110 .

[0043] In this embodiment, an optical signal passing through the substance to be measured is input from one side of the bus waveguide 110. The optical signal that meets the resonance condition is coupled into the one-dimensional photonic crystal racetrack microring. When it is transmitted to the coupling region where the distance between the bus waveguide 110 and the one-dimensional photonic crystal racetrack microring 120 is relatively short, the light that meets the coupling condition will produce near-field coupling, enter the one-dimensional photonic crystal racetrack microring 120 for transmission, and after transmitting one circle in the one-dimensional photonic crystal racetrack microring 120, it reaches the coupling region again and produces constructive interference with the light in the bus waveguide 110. The light that meets the resonance condition produces a resonance enhancement effect and continues to transmit in the one-dimensional photonic crystal racetrack microring 120, while the light that does not meet the resonance condition will pass directly through the bus waveguide 110 and be output from the through port.

[0044] The one-dimensional photonic crystal racetrack microring 120 is a centrosymmetric structure made of silicon. The bus waveguide 110 is also made of silicon. A one-dimensional photonic crystal air hole is etched into the one-dimensional photonic crystal racetrack microring 120. Due to the slow light effect, resonance peaks with varying free spectral ranges (FSRs) are generated at the edge of the photonic bandgap of the one-dimensional photonic crystal racetrack microring. In a one-dimensional photonic crystal racetrack microring with a non-uniform FSR, the temperature and refractive index of the material being measured will overlap, but due to the non-uniform FSR of the resonance peaks, the effects of both can be observed separately.

[0045] In some embodiments, the bus waveguide and the one-dimensional photonic crystal racetrack microring are both made of SOI.

[0046] In some embodiments, the bus waveguide has a waveguide width of 380 nm and a waveguide height of 220 nm.

[0047] In some embodiments, the one-dimensional photonic crystal racetrack microring further includes a ring waveguide, which is used to connect two sections of racetrack structures to form the one-dimensional photonic crystal racetrack microring; the ring waveguide has a radius of 6260 nm and a width of 400 nm.

[0048] In some embodiments, the racetrack has a length of 7580 nm and a width of 400 nm.

[0049] In some embodiments, the one-dimensional photonic crystal racetrack microring further includes a photonic crystal microcavity, and the lattice constant of the photonic crystal microcavity is 380 nm. Here, the number of photonic crystal microcavities can be adjusted according to actual needs and is not limited thereto.

[0050] In some embodiments, the coupling spacing between the bus waveguide and the one-dimensional photonic crystal racetrack microring is 300 nm.

[0051] In an example, see Figure 2 and Figure 3 ; Figure 2 The transmission spectrum of the embodiment of the present application with a wavelength from 1500nm to 1600nm obtained by simulation is provided. Figure 3 The transmission spectrum of wavelengths from 1550nm to 1575nm obtained through simulation in the embodiment of the present application. The resonance peaks with different free spectral ranges are generated at the edge of the photonic bandgap of the one-dimensional photonic crystal racetrack microring. Due to the slow light effect, the interaction between the light and the substance to be measured here is strong, and the extinction ratio of the resonance peak is high, that is, the resonance peak at the edge of the bandgap has an uneven FSR, and the FSR of the resonance peak away from the bandgap becomes equal. The resonance peaks at 1550~1575nm were magnified and analyzed to intuitively show the uneven distribution of the resonance peaks and free spectral range here.

[0052] In an example, see Figure 4 and Figure 5 ; Figure 4 The transmission spectrum of the one-dimensional photonic crystal racetrack micro-ring band gap edge provided in the embodiment of the present application; Figure 5 A comparison chart of the extinction ratio and FSR of the resonance peaks of the one-dimensional photonic crystal racetrack microring provided in the embodiment of this application. Each resonance peak is marked, and the free spectral range between each marked resonance peak is calculated and compared with the FSR of the normal distribution resonance peak outside the band gap. Figure 4 From the transmission spectrum, it can be seen that there are more FSR uneven resonance peaks at the edge of the band gap of the one-dimensional photonic crystal racetrack microring, which is basically consistent with the expected spectrum line. In the area far away from the band gap edge, the FSR area of ​​the resonance peak is equal, and the resonance peak here is the normal resonance peak.

[0053] In an example, see Figure 6 ; Figure 6The corresponding transmission spectrum obtained by modifying the ambient refractive index is provided in the embodiment of the present application. The transmission spectra under different refractive indices are analyzed. Due to the drastic change of the resonance peak FSR at the edge of the band gap, the resonance peak intensity and resonance wavelength corresponding to different resonance wavelengths will also change drastically, and some resonance peaks may even disappear. At this time, it is extremely difficult to calculate the temperature and refractive index information of the substance to be measured by calculating the different resonance peak intensities and wavelength changes. The more obvious resonance peaks are selected to calculate their refractive index sensitivity. The main performance indicators of the refractive index sensor include detection limit (DL) and sensitivity (S). Sensitivity refers to the ratio between the sensor output variable and the change in the signal to be measured. The greater the change in the sensor output signal caused by a unit change in the signal to be measured, the higher the sensitivity of the sensor, and the more accurately it can detect tiny signal changes. The calculation formula for sensitivity is as follows:

[0054] ;

[0055] Where ∆λ is the shift of the resonant wavelength, and ∆n is the change in the refractive index of the object being measured.

[0056] The detection limit refers to the smallest refractive index change that a sensor can detect, usually expressed as DL and measured in RIU (refractive index unit). The lower the detection limit, the lower the detectable concentration of the analyte and the better the sensing performance. The detection limit of a sensor is related to its structure, measurement device performance, and noise signal strength. If the noise signal is ignored, the detection limit of the sensor can be expressed as follows:

[0057] ;

[0058] According to the above formula, the wavelength shift is calculated by selecting the more obvious resonance peaks of the transmission spectra with refractive index n=1.3330 and n=1.3355. Then, the refractive index sensor performance of the one-dimensional photonic crystal racetrack microring is calculated to be approximately 316nm / RIU.

[0059] In an example, see Figure 7 ; Figure 7 This example shows the effect of ambient temperature changes on the transmission spectrum. The ambient refractive index was controlled at 1.333 to simulate a common deionized water test environment. The transmission spectra of a one-dimensional photonic crystal racetrack microring were measured as the temperature varied from 290K to 300K. The transmission spectra were then superimposed to provide a visual analysis of the effect of temperature on the FSR. The temperature sensing performance of this structure was measured by selecting the most prominent resonant peak in the transmission spectrum. The results indicate a temperature sensitivity of 78 pm / K for this structure.

[0060] This embodiment utilizes the slow light effect to generate resonance peaks with varying free spectral ranges at the edge of the photonic bandgap of a one-dimensional photonic crystal racetrack microring. Because the effects of temperature and the substance under test on the effective refractive index are reflected in different resonance peaks, the temperature and refractive index information of the substance under test can be calculated by recording the relative changes in the positions of these resonance peaks, thereby improving detection efficiency and accuracy.

[0061] In some embodiments, see Figure 8 , Figure 8 A schematic flow chart of a temperature-refractive index dual-parameter detection method provided in an embodiment of the present application; the temperature-refractive index dual-parameter detection method provided in an embodiment of the present application includes:

[0062] S810, obtaining a transmission spectrum of the photon bandgap edge;

[0063] S820, determining at least one set of resonance wavelength information and resonance intensity information based on the transmission spectrum;

[0064] S830: Determine the temperature and refractive index of the substance to be measured based on the resonance wavelength information and the resonance intensity information.

[0065] In this embodiment, the temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring in the above embodiment is used to obtain the transmission spectrum of the photonic bandgap edge, and then the temperature and refractive index of the substance to be measured are determined based on the resonant wavelength information and resonant intensity information in the transmission spectrum.

[0066] In some embodiments, S830, determining the temperature and refractive index of the substance to be measured based on the resonance wavelength information and the resonance intensity information, includes:

[0067] Using the resonant wavelength sample data and the resonant intensity sample data to train the preset neural network to obtain the target neural network;

[0068] The resonance wavelength information and the resonance intensity information are input into the target neural network to determine the temperature and refractive index of the substance to be measured.

[0069] In this embodiment, the parameters of the preset neural network can be adjusted using a loss function, and the process is iterated until the loss parameter of the preset neural network reaches a preset threshold, indicating that the processing accuracy of the preset neural network meets the requirements, thereby obtaining a target neural network. By inputting the transmission spectrum into the target neural network, the temperature and refractive index of the substance being tested can be directly read, greatly improving detection efficiency.

[0070] In some embodiments, the present application provides a temperature-refractive-index dual-parameter device for a one-dimensional photonic crystal racetrack microring, including the above-mentioned temperature-refractive-index dual-parameter sensor for the one-dimensional photonic crystal racetrack microring.

[0071] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of the present application may be combined or coupled in a variety of ways, even if such combinations or couplings are not explicitly described in the present application. In particular, without departing from the spirit and teachings of the present application, the features described in the various embodiments and / or claims of the present application may be combined or coupled in a variety of ways. All of these combinations and / or couplings fall within the scope of the present application. Therefore, the scope of the present application should not be limited to the above-described embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A one-dimensional photonic crystal racetrack microring temperature and refractive index dual parameter sensor, characterized in that: include: bus waveguide and one-dimensional photonic crystal racetrack microring, where Resonance peaks with different free spectral ranges are generated at the edge of the photonic band gap of the one-dimensional photonic crystal racetrack microring. Since the influence of temperature on the effective refractive index and the influence of the measured material on the effective refractive index will be reflected on different resonance peaks, the temperature and refractive index information of the measured material can be calculated by recording the relative changes in the positions of each resonance peak. The bus waveguide is linearly arranged on one side of the one-dimensional photonic crystal racetrack microring, and the bus waveguide is coupled to the one-dimensional photonic crystal racetrack microring; The one-dimensional photonic crystal racetrack microring includes a racetrack structure, and a photonic bandgap is formed between the racetrack structure and the bus waveguide.

2. The temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 1, characterized in that: The bus waveguide and the one-dimensional photonic crystal racetrack microring are both made of SOI.

3. The temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 1, characterized in that: The bus waveguide has a waveguide width of 380 nm and a waveguide height of 220 nm.

4. The temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 3, characterized in that: The one-dimensional photonic crystal racetrack microring further includes a ring waveguide, which is used to connect two sections of racetrack structures to form the one-dimensional photonic crystal racetrack microring; the ring waveguide has a radius of 6260 nm and a width of 400 nm.

5. The temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 4, characterized in that: The runway has a length of 7580 nm and a width of 400 nm.

6. The temperature-refractive index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 5, characterized in that: The one-dimensional photonic crystal racetrack microring further includes a photonic crystal microcavity, and the lattice constant of the photonic crystal microcavity is 380 nm.

7. The temperature-refractive-index dual-parameter sensor of the one-dimensional photonic crystal racetrack microring according to claim 6, characterized in that: The coupling spacing between the bus waveguide and the one-dimensional photonic crystal racetrack microring is 300 nm.

8. A temperature-refractive index dual-parameter detection method using the sensor according to any one of claims 1 to 7, characterized in that: include: Obtaining a transmission spectrum of the photon bandgap edge; determining at least one set of resonance wavelength information and resonance intensity information based on the transmission spectrum; Determining the temperature and refractive index of the substance to be measured based on the resonance wavelength information and the resonance intensity information includes: Using the resonant wavelength sample data and the resonant intensity sample data to train a preset neural network to obtain a target neural network; The resonance wavelength information and the resonance intensity information are input into the target neural network to determine the temperature and refractive index of the substance to be measured.

9. A temperature-refractive-index dual-parameter device for a one-dimensional photonic crystal racetrack microring, characterized in that: A temperature and refractive index dual parameter sensor comprising the one-dimensional photonic crystal racetrack microring according to any one of claims 1 to 7.

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