Detection method and system of optical microcavity sensor

Abstract

The present application relates to the field of optical microcavity sensor demodulation technology, and specifically to a detection method and system for an optical microcavity sensor. Among them, the detection method of the optical microcavity sensor is applied to an optical microcavity sensor based on the optical mode localization effect, and the detection method of the optical microcavity sensor includes: obtaining the output spectrum of the optical microcavity sensor based on the optical mode localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; measuring the first resonant amplitude corresponding to the symmetric peak and the second resonant amplitude corresponding to the antisymmetric peak in the output spectrum; based on the first resonant amplitude and the second resonant amplitude, demodulating to obtain the target detection physical quantity of the optical microcavity sensor based on the optical mode localization effect. Based on the resonant amplitudes of the symmetric peak and the antisymmetric peak, the target detection physical quantity is demodulated to achieve accurate measurement of the target detection physical quantity and reduce the influence of changes in physical quantities in the environment.

Description

Technical Field

[0001] The present application relates to the technical field of optical microcavity sensor demodulation, and in particular to a detection method and system for an optical microcavity sensor. Background Art

[0002] Since the 21st century, research on optical microcavities in fields including nonlinear generation and low-threshold lasers has received widespread attention. Their ultra-high quality factor and extremely small mode volume have shown great development potential in label-free sensing. When the effective refractive index of the optical waveguide changes with the target material, the resonant wavelength of the optical microcavity drifts. Therefore, the change in the resonant wavelength in the optical microcavity is usually used to perform highly sensitive measurements of the physical quantity to be measured.

[0003] However, the fundamental difficulty of this type of sensor based on the change of resonant wavelength is how to amplify the change of its output spectrum under a small change of effective refractive index. People design complex structures to achieve different coupling requirements between the two resonant modes, so that the change of the output spectrum is amplified, thereby improving the sensing sensitivity. Compared with conventional devices based on Lorentzian resonance, the performance of this type of sensor has been significantly improved. However, in the face of extreme situations, such as single particle detection, temperature perturbation, refractive index perturbation and other small changes, it still faces problems such as insufficient sensitivity and susceptibility to external disturbances.

[0004] Therefore, it is urgent to propose a new detection method for the physical quantity to be measured by optical microcavity sensors. Summary of the invention

[0005] The embodiments of the present application provide a detection method and system for an optical microcavity sensor, which demodulates the resonant amplitude of a symmetric peak and an antisymmetric peak to obtain a target detection physical quantity, thereby achieving accurate measurement of the target detection physical quantity and reducing the impact of changes in physical quantities in the environment.

[0006] In some embodiments, a detection method for an optical microcavity sensor is provided. The detection method for the optical microcavity sensor is applied to an optical microcavity sensor based on a light modal localization effect. The detection method for the optical microcavity sensor includes: obtaining an output spectrum of the optical microcavity sensor based on a light modal localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; measuring a first resonant amplitude corresponding to the symmetric peak and a second resonant amplitude corresponding to the antisymmetric peak in the output spectrum; and demodulating based on the first resonant amplitude and the second resonant amplitude to obtain a target detection physical quantity of the optical microcavity sensor based on the light modal localization effect.

[0007] The detection method of the optical microcavity sensor provided in the embodiment of the present application is adopted, and the target detection physical quantity is demodulated based on the resonant amplitude of the symmetric peak and the antisymmetric peak in the output spectrum of the optical microcavity sensor. Since the resonant amplitude in the output spectrum is greatly affected by the target detection physical quantity and has a large variation range, it is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor change as a whole, the resonant amplitude in the output spectrum will not change. Therefore, when the ambient temperature of the entire sensor changes, it will not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0008] Optionally, measuring a first resonant amplitude corresponding to a symmetric peak and a second resonant amplitude corresponding to an antisymmetric peak in the output spectrum includes: determining a first wavelength corresponding to the symmetric peak and a second wavelength corresponding to the antisymmetric peak in the output spectrum; and determining a first resonant amplitude corresponding to the first wavelength and a second resonant amplitude corresponding to the second wavelength.

[0009] In this embodiment, the first wavelength and the second wavelength are determined in the output spectrum, and then the first resonance amplitude and the second resonance amplitude are determined, so as to facilitate the determination of the target detection physical quantity.

[0010] Optionally, based on the first resonant amplitude and the second resonant amplitude, the target detection physical quantity of the optical microcavity sensor is demodulated, including: based on the first resonant amplitude and the second resonant amplitude, according to a preset formula, a demodulation parameter is calculated; in a preset mapping curve, the target detection physical quantity corresponding to the demodulation parameter is queried; the preset mapping curve includes the target detection physical quantity corresponding to each demodulation parameter.

[0011] In this embodiment, a demodulation parameter is calculated based on the first resonance amplitude and the second resonance amplitude, and then the target detection physical quantity is determined according to the demodulation parameter, thereby achieving measurement of the target detection physical quantity.

[0012] Optionally, the preset formula includes:

[0013] ;

[0014] in, is the first resonance amplitude, is the second resonance amplitude, is the demodulation parameter.

[0015] In this embodiment, the demodulation parameters are calculated by a preset formula, and the target detection physical quantity is determined according to the demodulation parameters, thereby achieving the measurement of the target detection physical quantity.

[0016] In some embodiments, a detection system of an optical microcavity sensor is provided, comprising: an optical microcavity sensor based on optical modal localization effect and a demodulation device; the optical microcavity sensor based on optical modal localization effect is configured to measure a target detection physical quantity and output an output spectrum; the demodulation device is communicatively connected to the optical microcavity sensor based on optical modal localization effect, and the demodulation device is configured to obtain an output spectrum output by the optical microcavity sensor based on optical modal localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; the first resonant amplitude corresponding to the symmetric peak and the second resonant amplitude corresponding to the antisymmetric peak in the output spectrum are measured; based on the first resonant amplitude and the second resonant amplitude, the target detection physical quantity of the optical microcavity sensor based on optical modal localization effect is obtained by demodulation.

[0017] The detection system using the optical microcavity sensor provided in the embodiment of the present application can obtain the target detection physical quantity based on the resonant amplitude demodulation in the output spectrum, and the resonant amplitude in the output spectrum is greatly affected by the target detection physical quantity, has a large change range, and is easy to observe and measure. In addition, when the environmental parameters of the optical microcavity sensor based on the optical mode localization effect change as a whole, the resonant amplitude in the output spectrum will not change. Therefore, when the ambient temperature of the entire sensor changes, it will not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0018] Optionally, an optical microcavity sensor based on the optical mode localization effect includes: a bus waveguide, a first resonant cavity and a second resonant cavity; the first resonant cavity is coupled to the bus waveguide, and the second resonant cavity is coupled to the first resonant cavity; the second resonant cavity is configured to measure a target detection physical quantity.

[0019] In this embodiment, the second resonant cavity is provided to measure the target detection physical quantity, that is, the second resonant cavity is used to sense the change of the target detection physical quantity, so that when the target detection physical quantity changes, the output spectrum of the optical microcavity sensor based on the optical mode localization effect is affected, so that the target detection physical quantity can be obtained based on the output spectrum demodulation, and the target detection physical quantity can be accurately measured.

[0020] Optionally, the first resonant cavity and the second resonant cavity are the same resonant cavity.

[0021] In this embodiment, the same and coupled first resonant cavity and second resonant cavity are used to achieve optical mode localization, thereby achieving measurement of the target detection physical quantity based on one of the first resonant cavity and the second resonant cavity.

[0022] Optionally, the coupling strength between the bus waveguide and the first resonant cavity is a first coupling strength; the coupling strength between the first resonant cavity and the second resonant cavity is a second coupling strength; and the first coupling strength is equal to the second coupling strength.

[0023] In this embodiment, based on the first coupling strength being equal to the second coupling strength, the resonance amplitudes of the symmetric peak and the antisymmetric peak in the output spectrum are the same, and in the case where the overall physical quantity of the target detection changes in the overall environment of the optical microcavity sensor, the resonance amplitudes of the symmetric peak and the antisymmetric peak change synchronously. Therefore, there will be no relative change between the resonance amplitudes of the symmetric peak and the antisymmetric peak, thereby not affecting the measurement of the physical quantity of the target detection, and improving the stability of the system.

[0024] Optionally, the first coupling strength and the second coupling strength are both 0.5.

[0025] In this embodiment, based on limiting the first coupling strength to be equal to the second coupling strength to be 0.5, a symmetrical optical microcavity system is formed to achieve uniform distribution of energy in the resonant cavity. Any local disturbance will break the symmetry of the system, resulting in uneven energy distribution in the system, thereby achieving optical mode localization, so as to facilitate the measurement of the target detection physical quantity based on one of the first resonant cavity and the second resonant cavity.

[0026] Optionally, the optical microcavity sensor based on the optical mode localization effect further includes: an SOI substrate, and the bus waveguide, the first resonant cavity and the second resonant cavity are arranged on the SOI substrate.

[0027] In this embodiment, the reliability of the optical microcavity sensor based on the optical mode localization effect is improved by using an SOI substrate, thereby improving the reliability of the detection system of the optical microcavity sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 It is a schematic diagram of the structure of an optical microring resonator in the related art;

[0030] Figure 2 A spectrum waveform diagram generated by an optical microring resonator in the related art;

[0031] Figure 3 A structural block diagram of a detection system of an optical microcavity sensor provided in an embodiment of the present application;

[0032] Figure 4 A flow chart of a detection method of an optical microcavity sensor provided in an embodiment of the present application;

[0033] Figure 5A schematic diagram of the spectrum of an optical microcavity sensor based on the optical mode localization effect provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of an output spectrum provided by an embodiment of the present application;

[0035] Figure 7 A schematic diagram of changes in the first resonance amplitude and the second resonance amplitude when the target detection physical quantity provided in the embodiment of the present application is temperature;

[0036] Figure 8 The ambient temperature provided in the embodiment of the present application is a schematic diagram of the change of the spectrum at different temperatures;

[0037] Fig. 9 A preset mapping curve between demodulation parameters and temperature when the target detection physical quantity provided in the embodiment of the present application is temperature;

[0038] Fig.10 A graph showing the change in resonance amplitude and resonance wavelength as a function of temperature provided in an embodiment of the present application;

[0039] Fig.11 A schematic diagram of the structure of an optical microcavity sensor based on the optical modal localization effect provided in an embodiment of the present application;

[0040] Fig.12 Output spectrum diagram corresponding to different coupling strengths provided in the embodiment of the present application;

[0041] Fig.13 A schematic diagram of the structure of a detection system of an optical microcavity sensor provided in an embodiment of the present application.

[0042] Reference numerals:

[0043] 1. Optical microcavity sensor based on light mode localization effect; 11. Bus waveguide; 12. First resonant cavity; 13. Second resonant cavity; 2. Demodulation device; 21. Computer; 22. Mobile phone; 3. Laser; 4. Photodetector. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, other embodiments obtained by ordinary technicians in this field without making creative work all belong to the protection scope of the present application.

[0045] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0046] In addition, in the present application, directional terms such as "upper", "lower", "inner" and "outer" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components in the drawings.

[0047] Figure 1 Schematic diagram of the structure of an optical microring resonator in the related art.

[0048] Figure 1 (a) is a schematic diagram of the original optical microring resonator. Figure 1 (b) is a schematic diagram of the structure of an optical micro-ring resonator integrated with a Bragg grating used in the related art.

[0049] Figure 2 This is a spectrum waveform diagram generated by an optical microring resonator in the related art.

[0050] Figure 2 (a) is the spectrum waveform generated by the original optical microring resonator. Figure 2 (b) is a spectrum waveform diagram generated by the optical micro-ring resonator integrated Bragg grating used in the related art.

[0051] In order to facilitate the understanding of the technical solution of the application, the background technology involved in this application is first explained below.

[0052] Since the 21st century, research on optical microcavities in the fields of nonlinear generation and low-threshold lasers has attracted extensive attention. Its ultra-high quality factor and extremely small mode volume have shown great development potential in label-free sensing. When the effective refractive index of the optical waveguide changes with the target material, the resonant wavelength of the optical microcavity drifts. Therefore, the change in the resonant wavelength in the optical microcavity is usually used to perform highly sensitive measurements of the physical quantity to be measured. Specifically, one implementation method is as follows: Figure 1 (a) and Figure 2 As shown in (a), use Figure 1 The spectrum of the optical microcavity shown in (a) will drift due to the change of the physical quantity to be measured. Therefore, the spectrum of the optical microcavity (such as Figure 2 The physical quantity to be measured can be obtained by the drift of the resonant wavelength in (a).

[0053] Another way to implement this is Figure 1 (b) and Figure 2 As shown in (b), the resonance peak splitting produced by the integrated Bragg grating of the optical microring resonator is used, and the local refractive index of the resonator changes by changing the protein concentration on the upper surface of the resonator, so that the resonant wavelengths of the two resonance peaks change accordingly (such as Figure 2 As shown in (b) in the figure), the sensitivity of the entire system was finally measured to be 0.0542nm / RIU.

[0054] Since the current sensors based on optical microcavities all use the change in the resonant wavelength to measure the physical quantity to be measured, such sensors have extremely high requirements for the amplified output of the change in the spectrum. The greater the amplification factor of the change, the easier and more accurate it is to observe the change. The fundamental difficulty of such sensors lies in how to amplify the change in their output spectrum under a small change in the effective refractive index. People design complex structures to achieve different coupling requirements between the two resonant modes, so that the change in the output spectrum is amplified, thereby improving the sensing sensitivity. Compared with conventional devices based on Lorentzian resonance, the performance of such sensors has been significantly improved. However, in the face of extreme situations, such as single particle detection, temperature perturbation, refractive index perturbation and other small changes, they still face problems such as insufficient sensitivity and susceptibility to external disturbances. In addition, if the ambient temperature of the entire sensor changes, it will also cause the wavelength of the sensor to shift, resulting in measurement errors.

[0055] Figure 3 This is a structural block diagram of the detection system of the optical microcavity sensor provided in an embodiment of the present application.

[0056] In order to solve the above problems, combined Figure 3 As shown, the embodiment of the present application provides a detection system of an optical microcavity sensor, including: an optical microcavity sensor 1 based on the optical mode localization effect and a demodulation device 2. The optical microcavity sensor 1 based on the optical mode localization effect is configured to measure the target detection physical quantity and output the output spectrum. The demodulation device 2 is connected to the optical microcavity sensor 1 based on the optical mode localization effect ( Figure 3 The demodulation device 2 is schematically connected using dotted lines in the figure), and is configured to obtain an output spectrum of the optical microcavity sensor 1 based on the optical mode localization effect, and to demodulate the target detection physical quantity of the optical microcavity sensor 1 based on the optical mode localization effect according to the resonant amplitude in the output spectrum.

[0057] The detection system using the optical microcavity sensor provided in the embodiment of the present application can obtain the target detection physical quantity based on the resonant amplitude demodulation in the output spectrum, and the resonant amplitude in the output spectrum is greatly affected by the target detection physical quantity, has a large variation range, and is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor change as a whole, the resonant amplitude in the output spectrum will not change. Therefore, when the ambient temperature of the entire sensor changes, it will not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0058] Alternatively, if Figure 3 As shown, the demodulation device 2 includes but is not limited to one or more of a computer 21, a mobile phone 22, a tablet computer (not shown in the figure) and a mobile wearable device (not shown in the figure). It is sufficient that the demodulation device can realize the functions described above.

[0059] Optionally, combined Figure 3 As shown, the detection system of the optical microcavity sensor also includes: a laser 3 and a photodetector 4. The propagation direction of the light signal in the detection system of the optical microcavity sensor is as follows: Figure 3 As shown by arrows E and F. The light output by the laser 3 enters the optical microcavity sensor 1 based on the optical mode localization effect, propagates in the optical microcavity sensor 1 based on the optical mode localization effect, and the optical microcavity sensor 1 based on the optical mode localization effect outputs an optical signal; the photodetector 4 receives the optical signal output by the optical microcavity sensor 1 based on the optical mode localization effect, and transmits it to the demodulation device 2 for demodulation.

[0060] Figure 4 A flow chart of a detection method of an optical microcavity sensor provided in an embodiment of the present application.

[0061] Combination Figure 3 The detection system of the optical microcavity sensor shown in the embodiment of the present application also provides a detection method of the optical microcavity sensor, the execution subject of the method can be a demodulation device, and the detection method of the optical microcavity sensor is applied to an optical microcavity sensor based on the optical mode localization effect, such as Figure 4 As shown, the detection method of the optical microcavity sensor includes steps S100 to S300, which are specifically as follows:

[0062] Step S100, obtaining an output spectrum of the optical microcavity sensor; the output spectrum includes a symmetric peak and an antisymmetric peak.

[0063] Figure 5 A schematic diagram of the spectrum of an optical microcavity sensor based on the optical mode localization effect provided in an embodiment of the present application.

[0064] Combination Figure 5As shown, the output spectrum of the optical microcavity sensor based on the optical mode localization effect provided by the embodiment of the present application is different from the output spectrum of the traditional single microring resonant cavity system. The output spectrum of the present application is characterized by periodic split peaks. The reason is that when the two resonant cavities are coupled, the symmetry and degeneracy of the resonant mode are broken, and the original single resonant peak is split into two separate resonant peaks, which are respectively called symmetric peak and anti-symmetric peak, and their propagation directions are counterclockwise and clockwise respectively.

[0065] Specifically, Figure 5 The split peaks include multiple cycles. Figure 5 Between the middle wavelengths λ1 and λ2 is a period of split peaks, which include a symmetric peak M1 and an antisymmetric peak M2.

[0066] Figure 6 A schematic diagram of an output spectrum provided in an embodiment of the present application. Figure 6 The spectrum shown in Figure 5 The spectrum between wavelengths λ1 and λ2 in the spectrum shown.

[0067] It should be understood that the output spectrum used in the present application has a period of symmetric peaks and antisymmetric peaks, that is, it only contains one symmetric peak and one antisymmetric peak, such as Figure 6 shown.

[0068] Step S200 , measuring a first resonance amplitude corresponding to a symmetric peak and a second resonance amplitude corresponding to an antisymmetric peak in an output spectrum.

[0069] Optionally, combined Figure 6 As shown, measuring the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the antisymmetric peak in the output spectrum includes step S201 and step S202:

[0070] Step S201 : determining, in the output spectrum, a first wavelength λ3 corresponding to a symmetric peak and a second wavelength λ4 corresponding to an antisymmetric peak.

[0071] Step S202: determining a first resonance amplitude Φ1 corresponding to the first wavelength and a second resonance amplitude Φ2 corresponding to the second wavelength.

[0072] In this embodiment, the first wavelength and the second wavelength are determined in the output spectrum, and then the first resonance amplitude and the second resonance amplitude are determined, so as to facilitate the determination of the target detection physical quantity.

[0073] Specifically, combined Figure 6 As shown, the first resonance amplitude is the transmittance Φ1, and the second resonance amplitude is the transmittance Φ2.

[0074] Exemplarily, the target detection physical quantity includes but is not limited to physical quantities such as temperature or density.

[0075] Figure 7 A schematic diagram of changes in the first resonant amplitude and the second resonant amplitude when the target detection physical quantity provided in the embodiment of the present application is temperature.

[0076] For example, under different temperature changes, the output spectra of the optical microcavity sensor correspond to curves L1, L2, L3, L4 and L5, respectively. Among them, the initial temperature is 0K corresponding to curve L1, the temperature change is 2K corresponding to curve L2, the temperature change is 4K corresponding to curve L3, the temperature change is 6K corresponding to curve L4, and the temperature change is 8K corresponding to curve L5. It can be seen that as the temperature gradually increases, the resonant amplitude of the symmetrical peak in the output spectrum gradually decreases, while the resonant amplitude of the antisymmetric peak gradually increases, that is, the first resonant amplitude ( Figure 7 The lowest point on the left side of the same curve in the figure) gradually decreases, while the second resonance amplitude ( Figure 7 The lowest point on the right side of the same curve in the figure) gradually increases. Therefore, the change of the resonance amplitude can be used to determine the relationship between the first resonance amplitude and the second resonance amplitude in different output spectra to determine the current temperature. In this way, the temperature can be detected.

[0077] It should be understood that when the target detection physical quantity is other physical quantities, the output spectrum can also refer to Figure 7 The output spectrum is shown.

[0078] Figure 8 The ambient temperature provided in the embodiment of the present application is a schematic diagram of the change of the spectrum at different temperatures.

[0079] Exemplarily, at different ambient temperatures, the output spectra of the optical microcavity sensor correspond to curves L6, L7, and L8, respectively. Among them, the initial ambient temperature is 0K, corresponding to curve L6 (solid line), the ambient temperature changes to 4K, corresponding to curve L7 (dashed line), and the ambient temperature changes to 8K, corresponding to curve L8 (dotted line). It can be seen that with the overall increase in ambient temperature, the first resonant amplitude and the second resonant amplitude in the output spectrum do not change (that is, the minimum transmittance of each curve does not change), only the wavelength has an overall shift (the curve is overall shifted left or right). Since the wavelength is not used when measuring the target detection physical quantity in this application, the detection method of this application is not affected by the overall change in ambient temperature.

[0080] It should be understood that when the overall environmental physical quantity changes, the overall wavelength in the output spectrum will shift without affecting the resonant amplitude of the output wavelength. Therefore, the present application is not affected by the overall changes of other environmental physical quantities.

[0081] Step S300: demodulating to obtain a target detection physical quantity of the optical microcavity sensor based on the first resonance amplitude and the second resonance amplitude.

[0082] Optionally, based on the first resonance amplitude and the second resonance amplitude, demodulation is performed to obtain a target detection physical quantity of the optical microcavity sensor, including step S301 and step S302, which are specifically as follows:

[0083] Step S301: Based on the first resonance amplitude and the second resonance amplitude, a demodulation parameter is calculated according to a preset formula.

[0084] Step S302: In a preset mapping curve, query the target detection physical quantity corresponding to the demodulation parameter; the preset mapping curve includes the target detection physical quantity corresponding to each demodulation parameter.

[0085] In this embodiment, a demodulation parameter is calculated based on the first resonance amplitude and the second resonance amplitude, and then the target detection physical quantity is determined according to the demodulation parameter, thereby achieving measurement of the target detection physical quantity.

[0086] Optionally, the preset formula includes:

[0087] ;

[0088] in, is the first resonance amplitude, is the second resonance amplitude, is the demodulation parameter.

[0089] In this embodiment, the demodulation parameters are calculated by a preset formula, and the target detection physical quantity is determined according to the demodulation parameters, thereby achieving the measurement of the target detection physical quantity.

[0090] Fig. 9 The preset mapping curve between the demodulation parameter and the temperature provided in the embodiment of the present application is when the target detection physical quantity is temperature.

[0091] For example, in combination Fig. 9 As shown, different demodulation parameters correspond to different temperature data. After the demodulation parameters are calculated according to the preset formula, the first resonance amplitude and the second resonance amplitude, Fig. 9 The corresponding temperature is found on the curve L9 to measure the temperature.

[0092] Specifically, the demodulation parameter in the present application is the change in the resonance amplitude.

[0093] Fig.10 This is a graph showing the change in resonance amplitude and resonance wavelength as a function of temperature provided in an embodiment of the present application.

[0094] For example, Fig.10In the figure, curve L9 shows the change of the resonance amplitude with temperature, and curve L 10 is the change of the resonant wavelength with temperature. Fig.10 It can be seen that the change in the resonant amplitude with temperature changes significantly increases compared to the change in the resonant wavelength, which indicates that the change in the resonant amplitude is larger and easier to observe. And by calculating the slope of curve L9, the sensing sensitivity of the system is 10.77% / K, and the corresponding curve L 10 The obtained sensing sensitivity is only 0.0043% / K. Therefore, the detection method of the optical microcavity sensor based on resonant amplitude detection provided by the embodiment of the present application is 3 orders of magnitude more sensitive than the traditional detection method based on resonant wavelength change, thus achieving high-sensitivity sensing of the optical microcavity sensor.

[0095] The detection method of the optical microcavity sensor provided in the embodiment of the present application is adopted, and the target detection physical quantity is demodulated based on the resonant amplitude of the symmetric peak and the antisymmetric peak in the output spectrum of the optical microcavity sensor. Since the resonant amplitude in the output spectrum is greatly affected by the target detection physical quantity and has a large variation range, it is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor change as a whole, the resonant amplitude in the output spectrum will not change. Therefore, when the ambient temperature of the entire sensor changes, it will not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0096] Corresponding to the detection method of the optical microcavity sensor described above, the embodiment of the present application also provides a detection system of an optical microcavity sensor, including: an optical microcavity sensor 1 based on the optical mode localization effect and a demodulation device 2. The optical microcavity sensor 1 based on the optical mode localization effect is configured to measure the target detection physical quantity and output the output spectrum; the demodulation device 2 is connected to the optical microcavity sensor 1 based on the optical mode localization effect in communication, and the demodulation device 2 is configured to obtain the output spectrum output by the optical microcavity sensor 1 based on the optical mode localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the antisymmetric peak in the output spectrum are measured; based on the first resonance amplitude and the second resonance amplitude, the target detection physical quantity of the optical microcavity sensor 1 based on the optical mode localization effect is demodulated.

[0097] The detection system using the optical microcavity sensor provided in the embodiment of the present application can obtain the target detection physical quantity based on the resonant amplitude demodulation in the output spectrum, and the resonant amplitude in the output spectrum is greatly affected by the target detection physical quantity, has a large variation range, and is easy to observe and measure. In addition, when the environmental parameters of the optical microcavity sensor 1 based on the optical mode localization effect change as a whole, the resonant amplitude in the output spectrum will not change. Therefore, when the ambient temperature of the entire sensor changes, it will not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0098] Fig.11 A schematic diagram of the structure of an optical microcavity sensor based on the optical modal localization effect provided in an embodiment of the present application.

[0099] Optionally, combined Fig.11 As shown, the optical microcavity sensor 1 based on the optical mode localization effect includes: a bus waveguide 11, a first resonant cavity 12 and a second resonant cavity 13. The first resonant cavity 12 is coupled to the bus waveguide 11, and the second resonant cavity 13 is coupled to the first resonant cavity 12. The second resonant cavity 13 is configured to measure the target detection physical quantity.

[0100] In this embodiment, the second resonant cavity 13 is provided to measure the target detection physical quantity, that is, the second resonant cavity 13 is used to sense the change of the target detection physical quantity, so that when the target detection physical quantity changes, the output spectrum of the optical microcavity sensor 1 based on the optical mode localization effect is affected. In this way, the target detection physical quantity is obtained based on the output spectrum demodulation, and the target detection physical quantity is accurately measured.

[0101] Specifically, Fig.11 As shown, end A is the signal input end of the bus waveguide 11, and end B is the signal output end of the bus waveguide 11. Arrow C is the propagation direction of the signal in the first resonant cavity 12, and arrow D is the propagation direction of the signal in the second resonant cavity 13. Exemplarily, the antisymmetric peak is formed by the first resonant cavity 12, and the symmetric peak is formed by the second resonant cavity 13.

[0102] Optionally, the first resonant cavity 12 and the second resonant cavity 13 are the same resonant cavity.

[0103] In this embodiment, the same and coupled first resonant cavity 12 and second resonant cavity 13 are used to realize optical mode localization, so as to realize the measurement of the target detection physical quantity based on one of the first resonant cavity 12 and the second resonant cavity 13.

[0104] Specifically, optical mode localization means that when two identical resonant cavities are weakly coupled, a small disturbance in one resonant cavity will cause the energy of the entire system to be unevenly distributed. This unevenly distributed energy is ultimately reflected by the resonance amplitude of the entire system, so the resonance amplitude is closely related to the size of the disturbance.

[0105] Optionally, the first resonant cavity 12 and the second resonant cavity 13 are both ring resonant cavities.

[0106] Specifically, the first resonant cavity 12 and the second resonant cavity 13 are both square ring resonant cavities, circular ring resonant cavities or elliptical ring resonant cavities.

[0107] Optionally, the coupling strength between the bus waveguide 11 and the first resonant cavity 12 is a first coupling strength. The coupling strength between the first resonant cavity 12 and the second resonant cavity 13 is a second coupling strength. The first coupling strength is equal to the second coupling strength.

[0108] In this embodiment, based on the first coupling strength being equal to the second coupling strength, the resonance amplitudes of the symmetric peak and the antisymmetric peak in the output spectrum are the same, and in the case where the overall physical quantity of the target detection changes in the overall environment of the optical microcavity sensor 1 based on the optical mode localization effect, the resonance amplitudes of the symmetric peak and the antisymmetric peak change synchronously. Therefore, there will be no relative change between the resonance amplitudes of the symmetric peak and the antisymmetric peak, thereby not affecting the measurement of the physical quantity of the target detection, and improving the stability of the system.

[0109] Specifically, the coupling strengths of the first resonant cavity 12, the bus waveguide 11 and the second resonant cavity 13 are the same, so the optical microcavity sensor 1 based on the optical mode localization effect is completely symmetrical, and the energy is evenly and symmetrically distributed therein, which is reflected in the output spectrum as the amplitudes of the two split resonance peaks are equal. When one of the resonant cavities is covered by the object to be measured (such as the temperature change at the second resonant cavity 13 when measuring temperature, or the second resonant cavity 13 is immersed in liquid when measuring liquid density), the local effective refractive index of the entire optical microcavity sensor 1 based on the optical mode localization effect changes, and the symmetry of the optical microcavity sensor 1 based on the optical mode localization effect is broken, resulting in uneven distribution of energy in the optical microcavity sensor 1 based on the optical mode localization effect, which is reflected in the output spectrum as the amplitudes of the two split resonance peaks change symmetrically (one increases and the other decreases), and high-sensitivity sensing of the target detection physical quantity can be achieved by measuring the relative changes in the amplitudes of the two resonance peaks.

[0110] Optionally, the first coupling strength and the second coupling strength are both 0.5.

[0111] In this embodiment, based on limiting the first coupling strength and the second coupling strength to 0.5, a symmetrical optical microcavity system is formed to achieve uniform distribution of energy in the resonant cavity. Any local disturbance will break the symmetry of the system, resulting in uneven energy distribution in the system, thereby achieving optical mode localization, so as to facilitate the measurement of the target detection physical quantity based on one of the first resonant cavity 12 and the second resonant cavity 13.

[0112] Fig.12 Output spectrum diagram corresponding to different coupling strengths provided in the embodiment of the present application.

[0113] Specifically, different coupling strengths can produce different output spectra. Fig.12 It can be seen that each curve corresponds to a different coupling strength (that is, a different first coupling strength and a different second coupling strength), and the temperature corresponding to the peak of each curve is obviously different. Therefore, different coupling strengths can be selected according to the target detection temperature range to obtain different detection effects. Fig.12 In the curve L 11 The corresponding coupling strength is K0, and the curve L 12 The corresponding coupling strength is 0.8K0, and the curve L 13 The corresponding coupling strength is 0.6K0, and the curve L 14 The corresponding coupling strength is 0.4K0. For example, when the temperature changes within the range of 5K, it is clear that the curve L 11 The resonant amplitude change rate is the largest, indicating that the curve L 11 The corresponding coupling strength is most suitable for measurements within the temperature range of 5K, that is, the curve can be measured more accurately. When the temperature changes within the range of 10K, it is obvious that the curve L 12 The amplitude change rate is the largest, which shows that the curve L 12 The corresponding coupling strength is most suitable for measurements in the temperature range around 10K.

[0114] Optionally, the optical microcavity sensor 1 based on the optical mode localization effect further includes: a SOI (Silicon-On-Insulator) substrate. The bus waveguide 11, the first resonant cavity 12 and the second resonant cavity 13 are arranged on the SOI substrate.

[0115] In this embodiment, the reliability of the optical microcavity sensor 1 based on the optical mode localization effect is improved by using an SOI substrate, thereby improving the reliability of the detection system of the optical microcavity sensor 1 based on the optical mode localization effect.

[0116] Specifically, during the preparation process, the chip was placed in an acetone solution and an IPA solution for 10 minutes each to remove S1813, and then blow-dried. ZEP-520A electron beam photoresist was coated on the sample chip with a thickness of 300 nanometers, and then forward-baked on a 180-degree hot plate for 3 minutes. Espacer was coated on the upper surface of ZEP-520A to enhance the conductivity during the exposure process. During the exposure stage, an electron beam lithography machine was used to expose the written structure. After the electron beam exposure, the exposed area was developed using ZED-N50 developer: the chip was first rinsed with deionized water and then immersed in ZEP-N50 for development. During the development process, the chip needs to be shaken continuously to allow the solution to fully react with the photoresist, and the development process is expected to take 100 seconds. Subsequently, the chip was immersed in an IPA solution for 45 seconds to remove the developer. Subsequently, the 220-nanometer silicon layer was fully etched using inductively coupled plasma etching to achieve the final structure.

[0117] Exemplarily, the parameters of the optical microcavity sensor used in the embodiment of the present application are as follows: The optical microcavity sensor uses 220 nanometer silicon on insulating substrate (SOI) as a platform. The waveguide is 220 nanometers high and 400 nanometers wide. The first resonant cavity 12 and the second resonant cavity 13 are both ring resonant cavities, and the radius of a single ring resonant cavity is 28 micrometers. The spacing between the first resonant cavity 12 and the second resonant cavity 13 and the bus waveguide 11 is 250 nanometers, and the length of the coupling region is 2.2 micrometers.

[0118] Fig.13 A schematic diagram of the structure of a detection system of an optical microcavity sensor provided in an embodiment of the present application.

[0119] Optionally, combined Fig.13 As shown, the detection system of the optical microcavity sensor also includes: a laser 3 and a photodetector 4. The propagation direction of the light signal in the detection system of the optical microcavity sensor is as follows: Figure 3 As shown by arrows G and H. The light output by the laser 3 enters the optical microcavity sensor based on the optical mode localization effect through the A end of the bus waveguide 11, propagates in the optical microcavity sensor 1 based on the optical mode localization effect, and outputs the optical signal from the B end of the bus waveguide 11. The photodetector 4 receives the optical signal output from the B end of the bus waveguide 11 and transmits it to the demodulation device 2 for demodulation.

[0120] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the application 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 technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope of the present application is indicated by the claims.

[0121] 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. A detection method of an optical microcavity sensor, characterized in that: The detection method of the optical microcavity sensor is applied to an optical microcavity sensor based on the optical mode localization effect, and the optical microcavity sensor based on the optical mode localization effect comprises: a bus waveguide, a first resonant cavity and a second resonant cavity; the first resonant cavity is coupled to the bus waveguide, and the second resonant cavity is coupled to the first resonant cavity; the second resonant cavity is configured to measure a target detection physical quantity; The detection method of the optical microcavity sensor comprises: Acquiring an output spectrum of the optical microcavity sensor based on the optical mode localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; measuring a first resonance amplitude corresponding to the symmetric peak and a second resonance amplitude corresponding to the antisymmetric peak in the output spectrum; Based on the first resonance amplitude and the second resonance amplitude, the target detection physical quantity of the optical microcavity sensor based on the optical mode localization effect is obtained by demodulation.

2. The detection method of the optical microcavity sensor according to claim 1, characterized in that: The measuring of the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the antisymmetric peak in the output spectrum includes: In the output spectrum, determining a first wavelength corresponding to the symmetric peak and a second wavelength corresponding to the antisymmetric peak; The first resonant amplitude corresponding to the first wavelength and the second resonant amplitude corresponding to the second wavelength are determined.

3. The detection method of the optical microcavity sensor according to claim 1, characterized in that: The demodulating to obtain the target detection physical quantity of the optical microcavity sensor based on the first resonance amplitude and the second resonance amplitude includes: Based on the first resonance amplitude and the second resonance amplitude, a demodulation parameter is calculated according to a preset formula; In a preset mapping curve, the target detection physical quantity corresponding to the demodulation parameter is queried; the preset mapping curve includes the target detection physical quantity corresponding to each demodulation parameter.

4. The detection method of the optical microcavity sensor according to claim 3, characterized in that: The preset formula includes: ； Among them, the is the first resonance amplitude, the is the second resonance amplitude, the is the demodulation parameter.

5. A detection system for an optical microcavity sensor, characterized in that: include: Optical microcavity sensors and demodulation devices based on the optical mode localization effect; The optical microcavity sensor based on the optical modal localization effect is configured to measure a target detection physical quantity and output an output spectrum; The demodulation device is in communication connection with the optical microcavity sensor based on the optical mode localization effect, and the demodulation device is configured to obtain the output spectrum output by the optical microcavity sensor based on the optical mode localization effect; the output spectrum includes a symmetric peak and an antisymmetric peak; and the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the antisymmetric peak in the output spectrum are measured; Based on the first resonance amplitude and the second resonance amplitude, demodulating to obtain the target detection physical quantity of the optical microcavity sensor based on the optical mode localization effect; The optical microcavity sensor based on the optical mode localization effect comprises: a bus waveguide, a first resonant cavity, and a second resonant cavity; The first resonant cavity is coupled to the bus waveguide, and the second resonant cavity is coupled to the first resonant cavity; The second resonant cavity is configured to measure the target detection physical quantity.

6. The detection system of the optical microcavity sensor according to claim 5, characterized in that: The first resonant cavity and the second resonant cavity are the same resonant cavity.

7. The detection system of the optical microcavity sensor according to claim 5, characterized in that: The coupling strength between the bus waveguide and the first resonant cavity is a first coupling strength; The coupling strength between the first resonant cavity and the second resonant cavity is a second coupling strength; The first coupling strength is equal to the second coupling strength.

8. The detection system of the optical microcavity sensor according to claim 7, characterized in that: The first coupling strength and the second coupling strength are both 0.

5.

9. The detection system of the optical microcavity sensor according to claim 5, characterized in that: The optical microcavity sensor based on the optical mode localization effect further includes: An SOI substrate, the bus waveguide, the first resonant cavity and the second resonant cavity are arranged on the SOI substrate.

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