Detection method and system for optical microcavity sensor

Abstract

A detection method and system for an optical microcavity sensor. The detection method for an optical microcavity sensor is applied to an optical mode localization effect-based optical microcavity sensor. The detection method for an optical microcavity sensor comprises: acquiring an output spectrum of an optical mode localization effect-based optical microcavity sensor, the output spectrum comprising a symmetric peak and an antisymmetric peak; measuring, in the output spectrum, a first resonance amplitude corresponding to the symmetric peak and a second resonance amplitude corresponding to the antisymmetric peak; and on the basis of the first resonance amplitude and the second resonance amplitude, demodulating to obtain a target detection physical quantity of the optical mode localization effect-based optical microcavity sensor. On the basis of the resonance amplitudes of the symmetric peak and the antisymmetric peak, the target detection physical quantity is obtained by means of demodulation, thereby realizing accurate measurement of the target detection physical quantity, and reducing the effect of physical quantity changes in the environment.

Description

Method and system for detecting optical microcavity sensor TECHNICAL FIELD

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

[0002] Since the 21st century, optical microcavities have attracted extensive attention in the fields including nonlinear generation and low threshold laser, and their ultra-high quality factors and extremely small mode volumes have shown great development potential in label-free sensing. When the effective refractive index of an optical waveguide changes with a target substance, the resonance wavelength of the optical microcavity drifts, and thus the change in the resonance wavelength of the optical microcavity is usually used to measure the physical quantity to be measured with high sensitivity.

[0003] However, the fundamental difficulty of such a sensor based on the change in the resonance wavelength is how to amplify the change in the output spectrum under a small change in the effective refractive index. People design complex structures to achieve different coupling requirements between two resonance 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 a sensor has been significantly improved. However, in the face of extreme cases such as single-particle detection, temperature perturbation, and refractive index perturbation, the sensor still faces problems such as insufficient sensitivity and vulnerability to external disturbances.

[0004] Therefore, there is an urgent need to propose a new method for detecting a physical quantity to be measured of an optical microcavity sensor. SUMMARY

[0005] The embodiments of the present application provide a method and system for detecting an optical microcavity sensor, which demodulates a target detection physical quantity based on the resonance amplitudes of symmetric peaks and antisymmetric peaks, realizes accurate measurement of the target detection physical quantity, and reduces the influence of changes in physical quantities in the environment.

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

[0007] The method for detecting the optical microcavity sensor provided in the embodiment of the application is based on the resonance amplitudes of the symmetric peak and the antisymmetric peak in the output spectrum of the optical microcavity sensor to demodulate the target detection physical quantity. Since the resonance amplitudes in the output spectrum are greatly affected by the target detection physical quantity and have a large change range, they are easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor as a whole change, the resonance amplitudes in the output spectrum do not change, so when the environmental temperature of the entire sensor changes, the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor will not be affected.

[0008] Optionally, the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the antisymmetric peak in the output spectrum are determined, including: determining the first wavelength corresponding to the symmetric peak and the second wavelength corresponding to the antisymmetric peak in the output spectrum; and determining the first resonance amplitude corresponding to the first wavelength and the second resonance amplitude corresponding to the second wavelength.

[0009] In this embodiment, the first resonance amplitude and the second resonance amplitude are determined by determining the first wavelength and the second wavelength in the output spectrum, so that the target detection physical quantity is conveniently determined.

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

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

[0012] Optionally, the preset formula includes:

[0013] wherein T(S) is the first resonance amplitude, T(AS) is the second resonance amplitude, and A is the demodulation parameter.

[0014] In this embodiment, the demodulation parameter is calculated by the preset formula, so that the target detection physical quantity is determined according to the demodulation parameter, and the measurement of the target detection physical quantity is realized.

[0015] In some embodiments, a detection system of an optical microcavity sensor is provided, comprising: an optical microcavity sensor based on light mode localization effect and a demodulation device; the optical microcavity sensor based on light mode localization effect is configured to measure a target detection physical quantity and output an output spectrum; the demodulation device is communicatively connected with the optical microcavity sensor based on light mode localization effect, and the demodulation device is configured to acquire the output spectrum output by the optical microcavity sensor based on light mode localization effect; the output spectrum comprises a symmetric peak and an anti-symmetric peak; a first resonance amplitude corresponding to the symmetric peak and a second resonance amplitude corresponding to the anti-symmetric peak in the output spectrum are determined; and the target detection physical quantity of the optical microcavity sensor based on light mode localization effect is demodulated based on the first resonance amplitude and the second resonance amplitude.

[0016] The detection system of the optical microcavity sensor provided in the embodiments of the present application can demodulate the target detection physical quantity based on the resonance amplitude in the output spectrum, the resonance amplitude in the output spectrum is greatly affected by the target detection physical quantity and has a large change range, and is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor based on light mode localization effect change as a whole, the resonance amplitude in the output spectrum does not change, and therefore, when the environmental temperature of the entire sensor changes, the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor are not affected.

[0017] Optionally, the optical microcavity sensor based on light mode localization effect comprises: a bus waveguide, a first resonant cavity and a second resonant cavity; the first resonant cavity is coupled with the bus waveguide, and the second resonant cavity is coupled with the first resonant cavity; and the second resonant cavity is configured to measure the target detection physical quantity.

[0018] In this embodiment, the second resonant cavity is used 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 light mode localization effect is affected. In order to demodulate the target detection physical quantity based on the output spectrum and accurately measure the target detection physical quantity.

[0019] Optionally, the first resonant cavity and the second resonant cavity are the same resonant cavity.

[0020] In this embodiment, the same and coupled first resonant cavity and second resonant cavity are used to realize light mode localization, so that one of the first resonant cavity and the second resonant cavity is used to measure the target detection physical quantity.

[0021] 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.

[0022] 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 anti-symmetric peak in the output spectrum are the same, and in the case of overall change of the target detection physical quantity in the overall environment of the optical microcavity sensor, the resonance amplitudes of the symmetric peak and the anti-symmetric peak are synchronously changed. Therefore, there is no relative change between the resonance amplitudes of the symmetric peak and the anti-symmetric peak, so as not to affect the measurement of the target detection physical quantity, and the system stability is improved.

[0023] Optionally, the first coupling strength and the second coupling strength are both 0.5.

[0024] 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 anti-symmetric peak in the output spectrum are the same, and in the case of overall change of the target detection physical quantity in the overall environment of the optical microcavity sensor, the resonance amplitudes of the symmetric peak and the anti-symmetric peak are synchronously changed. Therefore, there is no relative change between the resonance amplitudes of the symmetric peak and the anti-symmetric peak, so as not to affect the measurement of the target detection physical quantity, and the system stability is improved.

[0025] Optionally, the optical microcavity sensor based on the optical mode localization effect further comprises an SOI substrate, and the bus waveguide, the first resonant cavity and the second resonant cavity are arranged on the SOI substrate.

[0026] In this embodiment, by using the SOI substrate, the reliability of the optical microcavity sensor based on the optical mode localization effect is improved, so as to improve the reliability of the detection system of the optical microcavity sensor. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0028] FIG. 1 is a structural schematic diagram of an optical micro-ring resonant cavity in the related art;

[0029] FIG. 2 is a frequency spectrum waveform diagram generated by the optical micro-ring resonant cavity in the related art;

[0030] FIG. 3 is a structural block diagram of a detection system of an optical microcavity sensor provided by an embodiment of the present application;

[0031] FIG. 4 is a flowchart of a detection method of an optical microcavity sensor provided by an embodiment of the present application;

[0032] FIG. 5 is a frequency spectrum diagram of an optical microcavity sensor based on an optical mode localization effect provided by an embodiment of the present application;

[0033] FIG. 6 is a schematic diagram of an output spectrum according to an embodiment of the present application;

[0034] FIG. 7 is a schematic diagram of changes of first and second resonance amplitudes when a target detection physical quantity is temperature according to an embodiment of the present application;

[0035] FIG. 8 is a schematic diagram of changes of a spectrum at different ambient temperatures according to an embodiment of the present application;

[0036] FIG. 9 is a preset mapping curve of a demodulation parameter and temperature when a target detection physical quantity is temperature according to an embodiment of the present application;

[0037] FIG. 10 is a curve diagram of changes of resonance amplitude and resonance wavelength with temperature according to an embodiment of the present application;

[0038] FIG. 11 is a schematic diagram of a structure of an optical microcavity sensor based on light mode localization effect according to an embodiment of the present application;

[0039] FIG. 12 is an output spectrum diagram corresponding to different coupling strengths according to an embodiment of the present application;

[0040] FIG. 13 is a schematic diagram of a structure of a detection system of an optical microcavity sensor according to an embodiment of the present application.

[0041] FIG. 13 is a schematic diagram of a structure of a detection system of an optical microcavity sensor according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly described below with reference to 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 the embodiments of the present application. Based on the embodiments of the present application, other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0043] Hereinafter, the terms "first", "second", and the like are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0044] In addition, in the present application, the orientation terms such as "upper", "lower", "inner", "outer" and the like are defined relative to the orientation in which the components in the drawings are shown, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation in which the components are placed in the drawings.

[0045] Fig. 1 is a structural schematic diagram of an optical micro-ring resonator in the related art.

[0046] Fig. 1(a) is a structural schematic diagram of an original optical micro-ring resonator, and Fig. 1(b) is a structural schematic diagram of an optical micro-ring resonator integrated with a Bragg grating used in the related art.

[0047] Fig. 2 is a frequency spectrum waveform diagram generated by an optical micro-ring resonator in the related art.

[0048] Fig. 2(a) is a frequency spectrum waveform diagram generated by an original optical micro-ring resonator, and Fig. 2(b) is a frequency spectrum waveform diagram generated by an optical micro-ring resonator integrated with a Bragg grating in the related art.

[0049] In order to facilitate the understanding of the technical solutions of the application, the background art related to the present application will be described first as follows.

[0050] Since the 21st century, optical microcavities have attracted extensive attention in the fields including nonlinear generation, low threshold laser and the like, and 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 an optical waveguide changes with a target substance, the resonant wavelength of the optical microcavity will drift, and therefore the amount of change in the resonant wavelength in the optical microcavity is usually used to measure the physical quantity to be measured with high sensitivity. Specifically, one implementation method is shown in Fig. 1(a) and Fig. 2(a), and the spectrum of the optical microcavity shown in Fig. 1(a) will drift due to the change of the physical quantity to be measured, and therefore the amount of drift of the resonant wavelength in the spectrum of the optical microcavity (shown in Fig. 2(a)) can be used to obtain the physical quantity to be measured.

[0051] Another implementation method is shown in Fig. 1(b) and Fig. 2(b), and the resonant peak splitting generated by the optical micro-ring resonator integrated with a Bragg grating is used, and the local refractive index change of the resonant cavity is caused by changing the protein concentration on the upper surface of the resonant cavity, so that the resonant wavelengths of the two resonant peaks change accordingly (as shown in Fig. 2(b)), and finally the sensitivity of the whole system is 0.0542 nm / RIU.

[0052] Since the current optical microcavity-based sensors are all based on the change of the resonance wavelength to measure the physical quantity to be measured, the requirement for the amplification output of the change of the spectrum is extremely high, the more the amplification multiple of the change, the easier and more accurate the observation of the change. The fundamental difficulty of such sensors is how to amplify the change of the output spectrum under the small effective refractive index change. People design complex structures to realize the different coupling requirements between two resonance modes, so that the change of the output spectrum is amplified, thereby improving the sensing sensitivity. Compared with the conventional devices based on Lorentzian resonance, the performance of such sensors has been significantly improved. However, in the face of extreme cases such as single particle detection, temperature perturbation, refractive index perturbation and other small changes, the sensitivity is still insufficient, and it is easy to be disturbed by the outside. In addition, if the environmental temperature of the entire sensor changes, the wavelength of the sensor will also shift, causing measurement errors.

[0053] Fig. 3 is a structural block diagram of a detection system of an optical microcavity sensor provided by an embodiment of the present application.

[0054] In order to solve the above problems, in combination with Fig. 3, an embodiment of the present application provides a detection system of an optical microcavity sensor, comprising: an optical microcavity sensor based on light mode localization effect 1 and a demodulation device 2. The optical microcavity sensor based on light mode localization effect 1 is configured to measure a target detection physical quantity and output an output spectrum. The demodulation device 2 is communicatively connected with the optical microcavity sensor based on light mode localization effect 1 (schematically connected by a dashed line in Fig. 3), and the demodulation device 2 is configured to acquire the output spectrum output by the optical microcavity sensor based on light mode localization effect 1, and demodulate the target detection physical quantity of the optical microcavity sensor based on light mode localization effect 1 according to the resonance amplitude in the output spectrum.

[0055] The detection system of the optical microcavity sensor provided by the embodiment of the present application can demodulate the target detection physical quantity based on the resonance amplitude in the output spectrum, and the resonance amplitude in the output spectrum is greatly affected by the target detection physical quantity and has a large change range, which is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor as a whole change, the resonance amplitude in the output spectrum will not change, so when the environmental 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.

[0056] Optionally, as shown in Fig. 3, 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), as long as the demodulation device can realize the functions as described above.

[0057] Optionally, in combination with the detection system of the optical microcavity sensor shown in FIG. 3, the detection system of the optical microcavity sensor further comprises a laser 3 and a photodetector 4. The propagation direction of the optical signal in the detection system of the optical microcavity sensor is shown by arrows E and F in FIG. 3. The laser 3 outputs light into the optical microcavity sensor based on the effect of light mode localization, propagates in the optical microcavity sensor based on the effect of light mode localization, and outputs an optical signal from the optical microcavity sensor based on the effect of light mode localization; the photodetector 4 receives the optical signal output from the optical microcavity sensor based on the effect of light mode localization, and transmits the optical signal to the demodulation device 2 for demodulation.

[0058] FIG. 4 is a flowchart of a detection method of an optical microcavity sensor provided in an embodiment of the present application.

[0059] In combination with the detection system of the optical microcavity sensor shown in FIG. 3, an embodiment of the present application further provides a detection method of an optical microcavity sensor. The execution subject of the detection method of the optical microcavity sensor can be a demodulation device. The detection method of the optical microcavity sensor is applied to an optical microcavity sensor based on the effect of light mode localization. As shown in FIG. 4, the detection method of the optical microcavity sensor comprises steps S100-S300, and specifically as follows.

[0060] In step S100, an output spectrum of the optical microcavity sensor is acquired. The output spectrum comprises a symmetric peak and an anti-symmetric peak.

[0061] FIG. 5 is a spectrum diagram of an optical microcavity sensor based on the effect of light mode localization provided in an embodiment of the present application.

[0062] In combination with FIG. 5, the output spectrum output from the optical microcavity sensor based on the effect of light mode localization provided in an embodiment of the present application is different from the output spectrum of a conventional single microcavity resonator system. The output spectrum of the present application exhibits a split peak with periodicity. The reason is that when two resonant cavities are coupled, the symmetry and degeneracy of the resonant mode are broken. The originally single resonant peak is split into two separate resonant peaks, which are respectively referred to as a symmetric peak and an anti-symmetric peak, and their propagation directions are counterclockwise and clockwise, respectively.

[0063] Specifically, the split peak in FIG. 5 includes multiple periods. The split peak between wavelengths λ1 and λ2 in FIG. 5 is one period of the split peak, which includes a symmetric peak M1 and an anti-symmetric peak M2.

[0064] FIG. 6 is a diagram of an output spectrum provided in an embodiment of the present application. The spectrum shown in FIG. 6 is the spectrum between wavelengths λ1 and λ2 in the spectrum shown in FIG. 5.

[0065] It should be understood that the output spectrum used in the present application has symmetrical peaks and anti-symmetrical peaks with one period, i.e., only one symmetrical peak and one anti-symmetrical peak, as shown in FIG. 6.

[0066] In step S200, the first resonant amplitude corresponding to the symmetrical peak and the second resonant amplitude corresponding to the anti-symmetrical peak in the output spectrum are determined.

[0067] Optionally, in combination with FIG. 6, the determination of the first resonant amplitude corresponding to the symmetrical peak and the second resonant amplitude corresponding to the anti-symmetrical peak in the output spectrum includes steps S201 and S202:

[0068] In step S201, the first wavelength λ3 corresponding to the symmetrical peak and the second wavelength λ4 corresponding to the anti-symmetrical peak in the output spectrum are determined.

[0069] In step S202, the first resonant amplitude Φ1 corresponding to the first wavelength and the second resonant amplitude Φ2 corresponding to the second wavelength are determined.

[0070] In this embodiment, the first resonant amplitude and the second resonant amplitude are determined by determining the first wavelength and the second wavelength in the output spectrum, thereby facilitating the determination of the target detection physical quantity.

[0071] Specifically, in combination with FIG. 6, the first resonant amplitude is the transmittance Φ1, and the second resonant amplitude is the transmittance Φ2.

[0072] Exemplarily, the target detection physical quantity includes, but is not limited to, physical quantities such as temperature or density.

[0073] FIG. 7 is a schematic view of the changes of the first resonant amplitude and the second resonant amplitude when the target detection physical quantity is temperature according to an embodiment of the present application.

[0074] Exemplarily, under different temperature changes, the output spectrum of the optical microcavity sensor corresponds to the curve L1, the curve L2, the curve L3, the curve L4 and the curve L5, respectively. Among them, the initial temperature of 0K corresponds to the curve L1, the temperature change of 2K corresponds to the curve L2, the temperature change of 4K corresponds to the curve L3, the temperature change of 6K corresponds to the curve L4, and the temperature change of 8K corresponds to the curve L5. As can be seen, with the gradual increase of the temperature, the resonant amplitude of the symmetrical peak in the output spectrum gradually decreases, and the resonant amplitude of the anti-symmetrical peak gradually increases, i.e., the first resonant amplitude (the lowest point on the left side in the same curve in FIG. 7) gradually decreases, and the second resonant amplitude (the lowest point on the right side in the same curve in FIG. 7) gradually increases. Therefore, the relationship between the first resonant amplitude and the second resonant amplitude in different output spectrums can be determined by using the change of the resonant amplitude, and the current temperature can be determined. Thus, the temperature is detected.

[0075] It should be understood that when the target detection physical quantity is another physical quantity, the output spectrum can also refer to the output spectrum shown in FIG. 7.

[0076] FIG. 8 is a schematic diagram of the change of the spectrum at different ambient temperatures according to an embodiment of the present application.

[0077] Exemplarily, at different ambient temperatures, the output spectrum of the optical microcavity sensor corresponds to curve L6, curve L7 and curve L8 respectively. Wherein, the initial ambient temperature of 0K corresponds to curve L6 (solid line), the ambient temperature changes to 4K corresponds to curve L7 (dashed line), and the ambient temperature changes to 8K corresponds to curve L8 (dotted line). It can be seen that with the overall increase of the ambient temperature, the first resonance amplitude and the second resonance amplitude in the output spectrum do not change (i.e. the minimum transmittance of each curve does not change), only the overall shift of the wavelength occurs (the overall left or right shift of the curve), since the wavelength is not used when the target detection physical quantity is measured, therefore, the detection method of the present application is not affected by the overall change of the ambient temperature.

[0078] It should be understood that when the overall ambient physical quantity changes, the overall shift of the wavelength in the output spectrum is caused, and the resonance amplitude of the output wavelength is not affected, therefore, the present application is not affected by the overall change of other ambient physical quantities.

[0079] Step S300, based on the first resonance amplitude and the second resonance amplitude, demodulating to obtain the target detection physical quantity of the optical microcavity sensor.

[0080] Optionally, based on the first resonance amplitude and the second resonance amplitude, demodulating to obtain the target detection physical quantity of the optical microcavity sensor, comprising steps S301 and S302, specifically as follows:

[0081] Step S301, based on the first resonance amplitude and the second resonance amplitude, calculating a demodulation parameter according to a preset formula.

[0082] Step S302, querying the target detection physical quantity corresponding to the demodulation parameter in a preset mapping curve; the preset mapping curve includes the target detection physical quantity corresponding to each demodulation parameter.

[0083] In this embodiment, based on the first resonance amplitude and the second resonance amplitude, a demodulation parameter is calculated, so as to determine the target detection physical quantity according to the demodulation parameter, thereby realizing the measurement of the target detection physical quantity.

[0084] Optionally, the preset formula comprises:

[0085] Wherein, T(S) is the first resonance amplitude, T(AS) is the second resonance amplitude, and A is the demodulation parameter.

[0086] In the embodiment, the demodulation parameter is calculated by a preset formula, so that the target detection physical quantity is determined according to the demodulation parameter, and the measurement of the target detection physical quantity is realized.

[0087] FIG. 9 is a preset mapping curve of the demodulation parameter and the temperature when the target detection physical quantity is the temperature according to an embodiment of the present application.

[0088] For example, as shown in FIG. 9, different demodulation parameters correspond to different temperature data. After the demodulation parameter is calculated according to the preset formula, the first resonance amplitude and the second resonance amplitude, the corresponding temperature can be found on the curve L9 in FIG. 9, and the temperature is measured.

[0089] Specifically, the demodulation parameter in the present application is the resonance amplitude variation.

[0090] FIG. 10 is a curve diagram of the resonance amplitude variation and the resonance wavelength variation changing with the temperature according to an embodiment of the present application.

[0091] For example, in FIG. 10, the curve L9 is the resonance amplitude variation changing with the temperature, and the curve L 10 is the resonance wavelength variation changing with the temperature. As shown in FIG. 10, the resonance amplitude variation increases significantly compared with the resonance wavelength variation with the change of the temperature, which indicates that the change of the resonance amplitude is larger and easier to observe. The slope of the curve L9 is calculated to obtain the sensing sensitivity of the system, which is 10.77% / K, while the corresponding sensing sensitivity obtained by the curve L 10 is only 0.0043% / K. Therefore, the detection method of the optical microcavity sensor based on the resonance amplitude detection provided in the embodiment has a sensitivity of 3 orders of magnitude higher than that of the traditional detection method based on the resonance wavelength variation, and high-sensitivity sensing of the optical microcavity sensor is realized.

[0092] The detection method of the optical microcavity sensor provided in the embodiment demodulates the target detection physical quantity based on the resonance amplitudes of the symmetric peaks and the anti-symmetric peaks in the output spectrum of the optical microcavity sensor. Since the resonance 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 resonance amplitude in the output spectrum does not change, so when the environmental temperature of the entire sensor changes, it does not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0093] Corresponding to the detection method of the optical microcavity sensor, the embodiment of the present application further provides a detection system of an optical microcavity sensor, comprising: an optical microcavity sensor based on light mode localization effect 1 and a demodulation device 2. The optical microcavity sensor based on light mode localization effect 1 is configured to measure a target detection physical quantity and output an output spectrum; the demodulation device 2 is communicatively connected with the optical microcavity sensor based on light mode localization effect 1, and the demodulation device 2 is configured to acquire the output spectrum output by the optical microcavity sensor based on light mode localization effect 1; the output spectrum comprises a symmetric peak and an anti-symmetric peak; a first resonance amplitude corresponding to the symmetric peak and a second resonance amplitude corresponding to the anti-symmetric peak in the output spectrum are determined; and the target detection physical quantity of the optical microcavity sensor based on light mode localization effect 1 is demodulated based on the first resonance amplitude and the second resonance amplitude.

[0094] The detection system of the optical microcavity sensor provided by the embodiment of the present application can demodulate the target detection physical quantity based on the resonance amplitude in the output spectrum, and the resonance amplitude in the output spectrum is greatly affected by the target detection physical quantity and has a large change range, which is easy to observe and measure. Moreover, when the environmental parameters of the optical microcavity sensor based on light mode localization effect 1 change as a whole, the resonance amplitude in the output spectrum does not change, so that the change of the environmental temperature of the whole sensor does not affect the size and accuracy of the target detection physical quantity detected by the optical microcavity sensor.

[0095] FIG. 11 is a structural schematic diagram of an optical microcavity sensor based on light mode localization effect provided by the embodiment of the present application.

[0096] Optionally, in combination with FIG. 11, the optical microcavity sensor based on light mode localization effect 1 comprises: a bus waveguide 11, a first resonant cavity 12 and a second resonant cavity 13. The first resonant cavity 12 is coupled with the bus waveguide 11, and the second resonant cavity 13 is coupled with the first resonant cavity 12. The second resonant cavity 13 is configured to measure the target detection physical quantity.

[0097] 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 based on light mode localization effect 1 is affected. In order to demodulate the target detection physical quantity based on the output spectrum and accurately measure the target detection physical quantity.

[0098] Specifically, as shown in FIG. 11, the A end is the signal input end of the bus waveguide 11, and the B end is the signal output end of the bus waveguide 11. The arrow C is the propagation direction of the signal in the first resonant cavity 12, and the arrow D is the propagation direction of the signal in the second resonant cavity 13. Exemplarily, the anti-symmetric peak is formed by the first resonant cavity 12, and the symmetric peak is formed by the second resonant cavity 13.

[0099] Optionally, the first resonant cavity 12 and the second resonant cavity 13 are the same resonant cavity.

[0100] In this embodiment, by using the same and coupled first resonant cavity 12 and second resonant cavity 13, light mode localization is achieved, so as to realize measurement of the target detection physical quantity based on one of the first resonant cavity 12 and the second resonant cavity 13.

[0101] Specifically, the light mode localization refers to that when two completely same resonant cavities are weakly coupled, a slight disturbance in one resonant cavity will cause uneven distribution of energy of the whole system. The unevenly distributed energy is finally reflected by the resonance amplitude of the whole system, so that the resonance amplitude is closely related to the size of the disturbance.

[0102] Optionally, the first resonant cavity 12 and the second resonant cavity 13 are both ring resonant cavities.

[0103] 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.

[0104] 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.

[0105] 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 anti-symmetric peak in the output spectrum are the same. In the overall environment of the optical microcavity sensor 1 based on the light mode localization effect, the resonance amplitudes of the symmetric peak and the anti-symmetric peak are synchronously changed in the case of overall change of the target detection physical quantity. Therefore, there is no relative change between the resonance amplitudes of the symmetric peak and the anti-symmetric peak, so as not to affect the measurement of the target detection physical quantity, and the system stability is improved.

[0106] Specifically, the first resonant cavity 12 has the same coupling strength with the bus waveguide 11 and the second resonant cavity 13, and thus the optical microcavity sensor 1 based on the light mode localization effect is completely symmetrical, and the energy is uniformly and symmetrically distributed in the optical microcavity sensor 1, which is reflected in the output spectrum as two split resonance peaks with equal amplitudes. When one of the resonant cavities is covered by the object to be measured (for example, the temperature change at the second resonant cavity 13 when measuring the temperature, or the second resonant cavity 13 is immersed in the liquid when measuring the liquid density), the local effective refractive index of the entire optical microcavity sensor 1 based on the light mode localization effect changes, and the symmetry of the optical microcavity sensor 1 based on the light mode localization effect is broken, thereby causing the energy in the optical microcavity sensor 1 based on the light mode localization effect to be unevenly distributed, which is reflected in the output spectrum as the amplitudes of the two split resonance peaks change symmetrically (one increases and the other decreases). The relative change of the amplitudes of the two resonance peaks can be measured to achieve high-sensitivity sensing of the target detection physical quantity.

[0107] Optionally, the first coupling strength and the second coupling strength are both 0.5.

[0108] In this embodiment, based on the definition that the first coupling strength and the second coupling strength are both 0.5, a symmetrical optical microcavity system is formed, and uniform distribution of energy in the resonant cavity is achieved. Any local disturbance will break the symmetry of the system, causing uneven distribution of energy in the system, thereby realizing light mode localization, so as to realize measurement of the target detection physical quantity based on one of the first resonant cavity 12 and the second resonant cavity 13.

[0109] FIG. 12 is an output spectrum diagram corresponding to different coupling strengths provided by the embodiment of the present application.

[0110] Specifically, different coupling strengths can obtain different output spectra. As can be seen from FIG. 12, each curve corresponds to a different coupling strength (i.e., a different first coupling strength and a different second coupling strength), and the temperature corresponding to the peak value of each curve is obviously different. Therefore, different coupling strengths can be selected according to the temperature range of the target detection temperature to obtain different detection effects. In FIG. 12, curve L 11 corresponds to a coupling strength of K0, curve L 12 corresponds to a coupling strength of 0.8K0, curve L 13 corresponds to a coupling strength of 0.6K0, curve L 14 corresponds to a coupling strength of 0.4K0. Exemplarily, in the case of a temperature change of 5K, it is obvious that the resonance amplitude change rate of curve L 11 is the largest, indicating that the coupling strength corresponding to curve L 11 is the most suitable for measurement in the temperature change range of 5K, that is, it can more accurately measure the curve. In the case of a temperature change of 10K, it is obvious that the resonance amplitude change rate of curve L12 The amplitude change rate of the curve L 12 The corresponding coupling strength is most suitable for measurement in a range of 10K.

[0111] Optionally, the optical microcavity sensor 1 based on the optical mode localization effect further comprises an 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.

[0112] In this embodiment, by using the SOI substrate, the reliability of the optical microcavity sensor 1 based on the optical mode localization effect is improved, thereby improving the reliability of the detection system of the optical microcavity sensor 1 based on the optical mode localization effect.

[0113] Specifically, during the preparation process, the chip is placed in the acetone solution and the IPA solution respectively for 10 minutes to remove S1813, and then blow-drying treatment is performed. ZEP-520A electron beam resist is coated on the sample chip with a thickness of 300 nanometers, and then pre-baking is performed on a 180-degree hot plate for 3 minutes. Espacer is coated on the upper surface of ZEP-520A to enhance the conductivity during the exposure process. In the exposure stage, the written structure is exposed using an electron beam lithography machine. After the end of the electron beam exposure, the exposed area is developed using ZED-N50 developer: the chip is first rinsed with deionized water, and then developed by soaking in ZEP-N50. During the development process, the chip needs to be shaken constantly to make the solution fully react with the resist, and the development process is expected to be 100 seconds. Then, the chip is soaked in the IPA solution for 45 seconds to remove the developer. Then, the 220-nanometer silicon layer is etched using inductively coupled plasma etching to realize the final structure.

[0114] 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-insulator (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 distance 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.

[0115] FIG. 13 is a structural schematic diagram of a detection system of an optical microcavity sensor provided by the embodiment of the present application.

[0116] Optionally, in combination with the illustration of Fig. 13, the detection system of the optical microcavity sensor further comprises a laser 3 and a photodetector 4. The propagation direction of the optical signal in the detection system of the optical microcavity sensor is shown as arrow G and arrow H in Fig. 3. The light outputted by the laser 3 enters into the optical microcavity sensor based on the effect of light mode localization through the A end of the bus waveguide 11, propagates in the optical microcavity sensor based on the effect of light mode localization, and the optical signal is outputted by the B end of the bus waveguide 11. The photodetector 4 receives the optical signal outputted by the B end of the bus waveguide 11, and transmits to the demodulation device 2 for demodulation.

[0117] It is to be understood that even though numerous characteristics and embodiments of the application have been set forth in the foregoing disclosure, the exact details are not to be construed as limiting, and that the scope of the application is to be interpreted broadly. While the application has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the application. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from the central inventive concept of the application. Therefore, it is intended that the application not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope of the application. The disclosure is to be considered as illustrative only and as not restrictive of the inventive concepts disclosed herein. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0118] It is to be understood that the application is not limited to particular details described herein and is capable of numerous rearrangements and modifications, and of being implemented by other means, without departing from the scope of the application. The scope of the application is only limited by the claims.

Claims

1. A detection method for an optical microcavity sensor, characterized in that, The detection method of the optical microcavity sensor is applied to an optical microcavity sensor based on a light mode localization effect, and the detection method of the optical microcavity sensor comprises the following steps: An output spectrum of the optical microcavity sensor based on the light mode localization effect is acquired; the output spectrum comprises a symmetric peak and an anti-symmetric peak; A first resonance amplitude corresponding to the symmetric peak and a second resonance amplitude corresponding to the anti-symmetric peak in the output spectrum are determined; Based on the first resonance amplitude and the second resonance amplitude, a target detection physical quantity of the optical microcavity sensor based on the light mode localization effect is demodulated.

2. The method of claim 1, wherein the optical microcavity sensor is a Fabry-Perot sensor. The determination of the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the anti-symmetric peak in the output spectrum comprises the following steps: In the output spectrum, a first wavelength corresponding to the symmetric peak and a second wavelength corresponding to the anti-symmetric peak are determined; The first resonance amplitude corresponding to the first wavelength and the second resonance amplitude corresponding to the second wavelength are determined.

3. The method of claim 1, wherein the optical microcavity sensor is a Fabry-Perot sensor. The demodulation of the target detection physical quantity of the optical microcavity sensor based on the first resonance amplitude and the second resonance amplitude comprises the following steps: 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 comprises the target detection physical quantity corresponding to each demodulation parameter.

4. The method of claim 3, wherein the optical microcavity sensor is a Fabry-Perot sensor. The preset formula includes: Wherein, T(S) is the first resonance amplitude, T(AS) is the second resonance amplitude, and A is the demodulation parameter.

5. A detection system for an optical microcavity sensor, characterized in that It comprises: An optical microcavity sensor based on a light mode localization effect and a demodulation device; The optical microcavity sensor based on the light mode localization effect is configured to measure a target detection physical quantity and output an output spectrum; The demodulation device is communicatively connected with the optical microcavity sensor based on the light mode localization effect, and the demodulation device is configured to acquire the output spectrum output by the optical microcavity sensor based on the light mode localization effect; the output spectrum comprises a symmetric peak and an anti-symmetric peak; the first resonance amplitude corresponding to the symmetric peak and the second resonance amplitude corresponding to the anti-symmetric peak in the output spectrum are determined; Based on the first resonance amplitude and the second resonance amplitude, the target detection physical quantity of the optical microcavity sensor based on the light mode localization effect is demodulated.

6. The detection system of an optical microcavity sensor according to claim 5, wherein, The optical microcavity sensor based on the light mode localization effect comprises: A bus waveguide, a first resonant cavity and a second resonant cavity; The first resonant cavity is coupled with the bus waveguide, and the second resonant cavity is coupled with the first resonant cavity; The second resonant cavity is configured to measure the target detection physical quantity.

7. The detection system of the optical microcavity sensor according to claim 6, wherein The first resonant cavity and the second resonant cavity are the same resonant cavity.

8. The detection system of the optical microcavity sensor according to claim 6, wherein 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.

9. The detection system of the optical microcavity sensor according to claim 8, wherein, The first coupling strength and the second coupling strength are both 0.

5.

10. The detection system of an optical microcavity sensor according to claim 6, wherein, The optical microcavity sensor based on the light mode localization effect further comprises: An SOI substrate, wherein the bus waveguide, the first resonant cavity and the second resonant cavity are arranged on the SOI substrate.

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