Micro-ring resonance gas concentration detection system and method based on quantum ringing effect

Abstract

The invention provides a micro-ring resonance gas concentration detection system and method based on a quantum ringing effect, and can be applied to the technical field of gas concentration detection. The system comprises: an optical frequency comb emitting a first laser beam; the micro-ring resonant cavity enables the first laser beam to interact with gas based on an evanescent field effect to obtain a modulated light beam; the double-pendulum solid angle mirror interferometer delays the reference light beam and the signal light beam corresponding to the modulated light, and adjusts the frequency of the signal light beam in the delay process, so that the delayed reference light beam and the delayed signal light beam interfere with each other; the detector detects the interference light beam to obtain a detection signal; the processor carries out band-pass filtering on data corresponding to the sampling points in the detection signals; envelope detection is carried out on the detection signal component obtained through filtering, and ring-down time is obtained; according to the multiple ring-down times corresponding to the multiple laser frequencies, the concentration of the to-be-detected gas is obtained, the gas concentration detection precision is improved, and the system size is reduced.

Description

Technical Field

[0001] This invention relates to the field of gas concentration detection technology, and more specifically, to a micro-ring resonant gas concentration detection system and method based on the quantum ringing effect. Background Technology

[0002] In fields such as environmental monitoring, industrial production, and medical diagnostics, gas sensing technology is a key means to achieve accurate detection and safe management, especially the high-sensitivity detection of low-concentration gases, which is directly related to environmental quality assessment, production process optimization, and human health protection. Microring resonators, as optical sensing elements with high sensitivity and small size, have attracted widespread attention in the field of gas detection due to their precise response to changes in gas refractive index, becoming an important research direction for improving gas sensing performance.

[0003] In related technologies, gas sensing schemes based on microring resonators mainly analyze gases by detecting the shift in resonant wavelength. However, such schemes still face many challenges in practical applications: on the one hand, the absorption of gas in a specific frequency range will generate intermodal dispersion in the microring resonator, which directly affects the measurement accuracy of the resonant wavelength, causing the detection error to increase and reducing the stability and reliability of the sensor; on the other hand, the overall system size is large. Summary of the Invention

[0004] In view of this, the present invention provides a microring resonant gas concentration detection system and method based on the quantum ringing effect.

[0005] According to one aspect of the present invention, a microring resonant gas concentration detection system based on quantum ringing effect is provided, comprising: an optical frequency comb for emitting a first laser beam; a microring resonant cavity placed in a gas chamber filled with a gas to be measured, for causing the first laser beam to interact with the gas based on the evanescent field effect to obtain a modulated beam when the first laser beam passes through the microring resonant cavity, wherein the scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonant cavity; a double-pendulum stereoscope interferometer for delaying a reference beam and a signal beam corresponding to the modulated beam for a predetermined time, and simultaneously adjusting the frequency of the signal beam during the delay to cause the delayed reference beam and signal beam to interfere with each other to generate an interference beam; a detector for detecting the interference beam to obtain a detection signal; a processor for bandpass filtering the data corresponding to the sampling point in the detection signal; envelope detection of the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and obtaining the concentration of the gas to be measured based on multiple decay times corresponding to multiple laser frequencies.

[0006] According to an embodiment of the present invention, the processor obtains the concentration of the gas to be measured based on multiple decay times corresponding to multiple laser frequencies, including: for each laser frequency, obtaining the gas molecule absorptivity corresponding to each laser frequency based on the decay time corresponding to each laser frequency and the decay time when there is no gas in the gas chamber; and analyzing the gas molecule absorptivity corresponding to multiple laser frequencies based on the Lambert-Beer law to obtain the gas concentration.

[0007] According to an embodiment of the present invention, the processor performs envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam, including: performing full-wave rectification and filtering on the above-mentioned detection signal component to obtain envelope discrete data; and performing least squares fitting on the above-mentioned envelope discrete data to obtain the above-mentioned decay time.

[0008] According to an embodiment of the present invention, the intrinsic photon lifetime of the microring resonator and the externally coupled photon lifetime of the straight waveguide device coupled to the microring resonator are equal.

[0009] According to an embodiment of the present invention, the free spectral range of the microring resonator is equal to the repetition frequency of the optical frequency comb, and the intrinsic scanning frequency is the maximum scanning frequency at which the laser beam passing through the microring resonator will not experience a ringing effect.

[0010] According to an embodiment of the present invention, the above-mentioned double-pendulum solid angle mirror interferometer includes: a laser for emitting a second laser beam, wherein the wavelength difference between the center wavelength of the second laser beam and the center wavelength of the first laser beam is within a predetermined range; a reflector for transmitting the modulated beam at a predetermined position and reflecting the second laser beam to obtain a fused beam; and a beam splitter for splitting the fused beam to obtain a reference beam and a signal beam.

[0011] According to an embodiment of the present invention, the above-mentioned double-pendulum stereoscope interferometer further includes: a first corner mirror adjustment unit for delaying the reference beam for a predetermined duration; and a second corner mirror adjustment unit for delaying the signal beam for a predetermined duration, while simultaneously adjusting the frequency of the signal beam by swinging the arm in the second corner mirror adjustment unit during the delay process.

[0012] According to an embodiment of the present invention, the processor is further configured to: generate a spectral map based on the detection signal; and determine the sampling point based on the zero point position of the spectral map.

[0013] According to an embodiment of the present invention, the processor performs full-wave rectification and filtering on the above-mentioned detection signal components to obtain envelope discrete data, including: filtering the full-wave rectified signal using a low-pass filter with a cutoff frequency lower than the radio frequency to obtain the above-mentioned envelope discrete data.

[0014] According to another aspect of the present invention, a method for detecting the concentration of a microring resonant gas based on the quantum ringing effect is provided, comprising: emitting a first laser beam using an optical frequency comb; causing the first laser beam to interact with the gas based on the evanescent field effect to obtain a modulated beam when the first laser beam passes through the microring resonant cavity, wherein the scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonant cavity; delaying a reference beam and a signal beam corresponding to the modulated beam for a predetermined time using a double-pendulum stereoscope interferometer, and simultaneously adjusting the frequency of the signal beam during the delay to cause the delayed reference beam and signal beam to interfere with each other to generate an interference beam; detecting the interference beam to obtain a detection signal; performing bandpass filtering on the data corresponding to the sampling point in the detection signal using a processor; performing envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and obtaining the concentration of the gas to be measured based on multiple decay times corresponding to multiple laser frequencies.

[0015] According to an embodiment of the present invention, the microring resonant gas concentration detection system based on the quantum ringing effect uses a variable wavelength optical frequency comb as a light source. The first laser beam output from the optical frequency comb is coupled into a microring resonant cavity placed in a sealed gas chamber. The ringing time of photons in the microring resonant cavity is used to replace the traditional frequency intensity measurement of the concentration of the gas to be measured, fundamentally eliminating the influence of intermodal dispersion on the detection results and obtaining a high-precision concentration of the gas to be measured. At the same time, a double-pendulum stereo mirror interferometer is introduced during the detection process, reducing the system size while converting the optical frequency signal into a radio frequency signal, thus reducing the detection difficulty. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

[0017] Figure 1 A schematic diagram of a microring resonant gas concentration detection system based on the quantum ringing effect according to an embodiment of the present invention is shown.

[0018] Figure 2 A flowchart of a microring resonant gas concentration detection method based on the quantum ringing effect according to an embodiment of the present invention is shown. Detailed Implementation

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0021] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0022] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0023] In related technologies, gas sensing schemes based on microring resonators mainly analyze gases by detecting the shift in resonant wavelength. However, these schemes have the following problems: 1) Absorption of gas in a specific frequency range will generate intermodal dispersion in the microring resonator, causing an imbalance between the resonant point inside the microring resonator and the comb teeth of the optical frequency comb, which directly affects the measurement accuracy of the resonant wavelength, increases the detection error, and reduces the stability and reliability of the sensor; 2) Traditional detection methods use spectrometers to detect signals, resulting in a large overall system size.

[0024] In view of this, the present invention provides a micro-ring resonant gas concentration detection system and method based on the quantum ringing effect, which can be applied to the field of gas concentration detection technology.

[0025] Figure 1 A schematic diagram of a microring resonant gas concentration detection system based on the quantum ringing effect according to an embodiment of the present invention is shown.

[0026] like Figure 1As shown, the microring resonant gas concentration detection system based on the quantum ringing effect may include an optical frequency comb 110, a microring resonant cavity 120, a double-pendulum stereoscope interferometer 130, a detector 140, and a processor 150. The microring resonant cavity 120 can be placed in a gas chamber 101 filled with the gas to be measured.

[0027] The source of the gas to be tested in gas chamber 101 can be determined according to the actual situation. Figure 1 The embodiments of the present invention are merely illustrative of the gas to be tested in gas cylinder 102 and are not intended to limit the source of the gas to be tested. The gas to be tested may be, for example, carbon monoxide, carbon dioxide, oxygen, or hydrogen sulfide gas.

[0028] The optical frequency comb 110 can be used to emit the first laser beam.

[0029] When the first laser beam emitted from the optical frequency comb 110 enters the micro-ring resonator 120, which is placed within a gas chamber 101 filled with the gas to be measured, the first laser beam is coupled into the micro-ring through a straight waveguide device in the micro-ring resonator 120 and interacts with the gas. During this interaction, the output wavelength of the optical frequency comb 110 changes periodically. The optical frequency comb 110 sequentially inputs different laser beams with periodically changing wavelengths into the micro-ring resonator 120. The different laser beams with periodically changing wavelengths output from the optical frequency comb 110 form the first laser beam.

[0030] The microring resonator 120 can be used to modulate a first laser beam by having the first laser beam interact with the gas based on the evanescent field effect when the first laser beam passes through the microring resonator. The microring resonator has a high quality factor.

[0031] Among them, the rate of change of the laser output from the optical frequency comb 110 is the normalized scanning frequency of the optical frequency comb. The conditions for the ringing effect to occur should be met so that the concentration of the gas to be measured can be obtained from the decay time corresponding to the ringing effect.

[0032] For example, the scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonator. The intrinsic scanning frequency is the maximum scanning frequency at which the laser beam passing through the microring resonator 120 will not experience ringing. The scanning frequency of the normalized optical frequency comb and the intrinsic scanning frequency of the microring resonator satisfy the relationship shown in formula (1).

[0033] (1);

[0034] in, The normalized scanning frequency of the optical frequency comb. is the intrinsic scanning frequency of the microring resonator. , This is the actual scanning frequency of the optical frequency comb 110. This represents the intrinsic photon lifetime of the microring resonator 120.

[0035] The modulated beam T output from the micro-ring resonator 120 satisfies the relationship shown in formula (2).

[0036] (2);

[0037] in, . The decay time corresponds to the ringing effect in the modulated beam. Let be the laser frequency of the i-th laser output from the optical frequency comb. This is the resonant frequency of the micro-ring resonator. . The total photon lifetime of the microring resonator is denoted by t, where t is the detection time. j is the imaginary unit. erf() is the error function. Indicate T and Proportional. This refers to the externally coupled photon lifetime of the straight waveguide device coupled to the microring resonator. The laser frequency of the i-th laser output from the optical frequency comb can also be simply referred to as the i-th laser frequency.

[0038] According to an embodiment of the present invention, the gas chamber 101 filled with the gas to be measured and the micro-ring resonator 120 placed therein can serve as a sensing module to detect the concentration of the gas to be measured. The modulated beam output from the sensing module can be split into a signal beam and a reference beam by a beam splitter in a double-pendulum stereoscope interferometer 130. The signal beam and the reference beam rejoin and interfere after undergoing different processes in the double-pendulum stereoscope interferometer 130, and are then received by the detector 140.

[0039] The highly stable second laser beam generated by the laser 131 in the double pendulum stereo mirror interferometer 130 can enter the double pendulum stereo mirror interferometer 130 together with the modulated beam output from the micro-ring resonator 120.

[0040] The double-pendulum solid angle mirror interferometer 130 can be used to delay the reference beam and signal beam corresponding to the modulation light for a predetermined time, and at the same time adjust the frequency of the signal beam during the delay, so that the delayed reference beam and signal beam interfere with each other to generate an interference beam.

[0041] For example, the reference beam travels through the first solid corner mirror 1341 in the double-pendulum solid corner mirror interferometer 130, reaches the first reflecting mirror 1342, and returns along the same path. After the signal beam reaches the moving second solid corner mirror 1351, the control arm 1352 swings, causing the path difference between the two optical paths to change at a speed... Uniform change, introducing Doppler frequency shift ( The i-th comb tooth (i.e., the i-th laser frequency) returns via the second reflector 1353, recombines with the delayed reference beam on the beam splitter 133, and interferes to obtain an interference beam. After being reflected by the beam splitter 133 and the third reflector 136 in the double-pendulum solid angle mirror interferometer 130, the interference beam can be received by the detector 140.

[0042] Interference beam The expression is shown in formula (3).

[0043] (3);

[0044] in, , This refers to the periodic frequency of the wavelength variation of the laser output by the optical frequency comb. Let be the Fourier series of the nth harmonic component corresponding to the i-th tooth of the optical frequency comb. The time taken for Fourier calculations.

[0045] Detector 140 can be used to detect the interference beam and obtain a detection signal. The detection signal output by detector 140 is a radio frequency interference signal. Detector 140 is a radio frequency band detector.

[0046] According to an embodiment of the present invention, a double-pendulum stereomicroscope interferometer 130 delays the reference beam and signal beam corresponding to the modulation light for a predetermined time, and simultaneously adjusts the frequency of the signal beam during the delay, so that the delayed reference beam and signal beam interfere with each other to generate an interference beam. This allows the subsequent processor 150 to separate the data corresponding to multiple laser frequencies from the detection signal corresponding to the interference beam, and then calculate the multiple decay times corresponding to the multiple laser frequencies to obtain the concentration of the gas to be measured.

[0047] According to an embodiment of the present invention, the interference beam received by the detector 140 includes the ringing time corresponding to different laser frequencies. This enables the measurement of the concentration of the gas to be tested.

[0048] The processor 150 can be used to perform bandpass filtering on the data corresponding to the sampling point in the detection signal; perform envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and obtain the concentration of the gas to be measured based on the multiple decay times corresponding to multiple laser frequencies.

[0049] For example, the processor 150 can be used to invert the infrared spectrum based on the detection signal and perform equal optical path difference sampling on the interference positions in the spectrum.

[0050] For example, the processor 150 can perform bandpass filtering on the data corresponding to the sampling point in the detection signal according to the i-th laser frequency corresponding to the i-th laser in the first laser beam, to separate the radio frequency component (i.e., the detection signal component) corresponding to the i-th comb tooth, where i is a positive integer. Envelope detection is then performed on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam, thus obtaining the decay time corresponding to the i-th laser frequency.

[0051] According to an embodiment of the present invention, the microring resonant gas concentration detection system based on the quantum ringing effect uses a variable wavelength optical frequency comb as a light source. The first laser beam output from the optical frequency comb is coupled into a microring resonant cavity placed in a sealed gas chamber. The ringing time of photons in the microring resonant cavity is used to replace the traditional frequency intensity measurement of the concentration of the gas to be measured, fundamentally eliminating the influence of intermodal dispersion on the detection results and obtaining a high-precision concentration of the gas to be measured. At the same time, a double-pendulum stereo mirror interferometer is introduced during the detection process to separate the ringing-down spectral lines, reducing the system size while converting the optical frequency signal into a radio frequency signal, thus reducing the detection difficulty.

[0052] According to an embodiment of the present invention, the microring resonant gas concentration detection system based on the quantum ringing effect achieves high-precision detection of the gas to be measured by utilizing the ringing effect of the microring resonant cavity.

[0053] According to an embodiment of the present invention, the intrinsic photon lifetime of the microring resonator and the externally coupled photon lifetime of the straight waveguide device coupled to the microring resonator are equal. In other words, the loss of the first laser beam caused by the microring resonator is equal to the loss of the first laser beam caused by the straight waveguide device coupled to the microring resonator.

[0054] According to an embodiment of the present invention, by making the intrinsic photon lifetime of the microring resonator and the externally coupled photon lifetime of the straight waveguide device coupled to the microring resonator equal, the initial state of the microring resonator is ensured to be strictly coupled.

[0055] According to an embodiment of the present invention, the free spectral range of the microring resonator is equal to the repetition frequency of the optical frequency comb. The free spectral range of the microring resonator is the frequency interval between two adjacent resonant peaks.

[0056] For example, the free spectral range of the microring resonator and the repetition frequency of the optical frequency comb satisfy the relationship shown in formula (4).

[0057] (4);

[0058] Wherein, FSR is the free spectral range of the microring resonator. This is the repetition frequency of the optical frequency comb.

[0059] According to an embodiment of the present invention, by making the free spectral range of the microring resonator equal to the repetition frequency of the optical frequency comb, the resonance peak of the microring resonator is ensured to strictly correspond to the comb teeth (i.e., laser frequency) of the optical frequency comb, thereby ensuring that the processor can calculate multiple decay times corresponding to multiple laser frequencies and obtain the concentration of the gas to be measured based on the multiple decay times.

[0060] The processor 150 is also used to: generate a spectrum based on the detection signal; and determine the sampling point based on the zero point position of the spectrum.

[0061] The processor 150 performs envelope detection on the filtered detection signal component to obtain the oscillation time corresponding to the ringing effect in the modulated beam. This can include: performing full-wave rectification and filtering on the detection signal component to obtain discrete envelope data; and performing least-squares fitting on the discrete envelope data to obtain the oscillation time.

[0062] According to an embodiment of the present invention, the processor performs curve fitting on the envelope discrete data using the least squares method to obtain the exponential decay term. Extract from this attenuation term .in, Let be the decay time corresponding to the i-th laser frequency.

[0063] The processor 150 can obtain the concentration of the gas to be measured based on multiple decay times corresponding to multiple laser frequencies, including: for each laser frequency, obtaining the gas molecule absorptivity corresponding to each laser frequency based on the decay time corresponding to each laser frequency and the decay time when there is no gas in the gas chamber; and analyzing the gas molecule absorptivity corresponding to multiple laser frequencies based on the Lambert-Beer law to obtain the gas concentration.

[0064] For example, the processor can obtain the gas molecule absorption rate corresponding to each laser frequency based on the decay time corresponding to each laser frequency and the decay time when there is no gas in the gas chamber according to the following formula (5).

[0065] (5);

[0066] in, The gas molecule absorption rate corresponding to the i-th laser frequency, Let c be the ringing time when there is no gas in the gas chamber corresponding to the i-th laser frequency, and c be the speed of light.

[0067] The processor 150 performs full-wave rectification and filtering on the detected signal components to obtain discrete envelope data, which may include: using a low-pass filter with a cutoff frequency lower than the radio frequency to filter the full-wave rectified signal to obtain discrete envelope data.

[0068] For example, the radio frequency can be 300kHz.

[0069] According to an embodiment of the present invention, smooth envelope discrete data is obtained by filtering the full-wave rectified signal using a low-pass filter with a cutoff frequency lower than the radio frequency.

[0070] like Figure 1 As shown, the double-pendulum solid corner mirror interferometer 130 may include a laser 131, a reflector 132, a beam splitter 133, a first corner mirror adjustment unit, and a second corner mirror adjustment unit. The first corner mirror adjustment unit may include a first solid corner mirror 1341 and a first reflector 1342. The second corner mirror adjustment unit may include a second solid corner mirror 1351, a pendulum arm 1352, and a second reflector 1353. The first solid corner mirror 1341 and the second solid corner mirror 1351 have the same structure. The first reflector 1342 and the second reflector 1353 are the same reflector. The first adjustment structure formed by the first solid corner mirror 1341 and the first reflector 1342 is symmetrical with the second adjustment structure formed by the second solid corner mirror 1351 and the second reflector 1353, and is symmetrical based on the plane where the beam splitter 133 is located.

[0071] Laser 131 can be used to emit a second laser beam. The wavelength difference between the center wavelength of the second laser beam and the center wavelength of the first laser beam is within a predetermined range.

[0072] The reflector 132 can be used to transmit the modulated beam at a predetermined position while reflecting the second laser beam to obtain a fused beam.

[0073] Beam splitter 133 can be used to split the fused beam into a reference beam and a signal beam. The modulated beam corresponds to the signal beam, and the reference beam corresponds to the second laser beam.

[0074] According to an embodiment of the present invention, the wavelength difference between the center wavelength of the second laser beam and the center wavelength of the first laser beam is within a predetermined range to ensure that the delayed reference beam and the signal beam can interfere with each other.

[0075] The first corner mirror adjustment unit can be used to delay the reference beam for a predetermined duration.

[0076] The second corner mirror adjustment unit can be used to delay the signal beam for a predetermined duration, and at the same time, the frequency of the signal beam can be adjusted by the swing of the arm in the second corner mirror adjustment unit during the delay.

[0077] According to an embodiment of the present invention, a reference beam and an interference beam are generated sequentially by emitting a second laser beam using a laser, ensuring that the interference beam has a high intensity and the detection signal obtained by the detector has a high intensity, and the processor 150 can identify the sampling point from the spectrum generated based on the detection signal.

[0078] The double-pendulum solid angle mirror interferometer 130 may also include a third reflecting mirror 136 for reflecting the interference beam so that the reflected beam can enter the detector 140.

[0079] The beam splitter 133 can also interfere with the reference beam and the signal beam when they arrive at the beam splitter 133 again after the delay, to obtain an interference beam, and then transmit the interference beam to the third reflector 136.

[0080] According to embodiments of the present invention, the microring resonant gas concentration detection system based on the quantum ringing effect analyzes gases by detecting the shift in resonant wavelength, unlike related technologies. It measures photon ring-down time based on the ringing effect, eliminating the influence of intermodal dispersion on the system and improving detection accuracy, thus achieving higher precision. Furthermore, the system simplifies the structure by combining a single microring with a double-pendulum stereoscope interferometry technique, eliminating the need for multi-ring cascades and facilitating miniaturization, resulting in a smaller volume.

[0081] According to embodiments of the present invention, a microring resonant gas concentration detection system based on the quantum ringing effect utilizes a variable-wavelength optical frequency comb of the output laser to generate a ringing effect with a microring resonant cavity. Gas concentration can be calculated by measuring the optical ring-down time. A Doppler frequency shift is introduced using the pendulum arm in a double-pendulum stereoscope interferometer to accurately measure the gas absorptivity on a specific comb tooth. Compared to other gas sensing methods based on microring resonant cavities, this invention measures photon ring-down time instead of the resonant wavelength, eliminating the influence of intermodal dispersion and improving detection accuracy. The double-pendulum stereoscope interferometer introduces a Doppler frequency shift to separate ring-down spectral lines, further reducing the system size.

[0082] According to an embodiment of the present invention, the steps for detecting gas concentration based on any of the above-mentioned microring resonant gas concentration detection systems based on the quantum ringing effect are as follows: 1) Adjusting the wavelength of the laser output from the microring resonant cavity with a center wavelength of 1550 nm to vary periodically, so that the scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonant cavity; 2) Adjusting the microring coupling coefficient in the microring resonant cavity to ensure that the microring and the straight waveguide device are in a strictly coupled state; 3) Adjusting the microring so that its FSR is equal to the tooth spacing of the optical frequency comb (i.e., the repetition frequency of the optical frequency comb). ); ); ); CO and H2S gases are introduced into the gas chamber, and the gases interact fully with the microring resonator to change the light intensity at the corresponding frequency; 5) The light beam after interacting with the gas leaves the microring resonator through a straight waveguide and enters the double-pendulum solid angle mirror interferometer; 6) The pendulum arm in the double-pendulum solid angle mirror interferometer is controlled to make the optical path difference between the reference path and the signal path change at a speed of Uniform change, introducing Doppler frequency shift 7) The detector receives the interference signal from the double pendulum stereo mirror interferometer and obtains the detection signal; 8) The gas molecule absorptivity is calculated using the ring-down time in the interference signal, and the gas molecule absorptivity corresponding to multiple laser frequencies is analyzed based on Lambert-Beer's law to obtain the gas concentration.

[0083] Based on the above-mentioned micro-ring resonant gas concentration detection system based on the quantum ringing effect, this embodiment of the invention provides a micro-ring resonant gas concentration detection method based on the quantum ringing effect.

[0084] Figure 2 A flowchart of a microring resonant gas concentration detection method based on the quantum ringing effect according to an embodiment of the present invention is shown.

[0085] like Figure 2 As shown, the microring resonant gas concentration detection method based on the quantum ringing effect in this embodiment may include operations S210 to S250.

[0086] When operating S210, the optical frequency comb emits the first laser beam.

[0087] In operation S220, when the first laser beam passes through the microring resonator, the first laser beam interacts with the gas based on the evanescent field effect to obtain a modulated beam. The scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonator.

[0088] When operating S230, the double-pendulum solid angle mirror interferometer delays the reference beam and signal beam corresponding to the modulation light for a predetermined time. At the same time, the frequency of the signal beam is adjusted during the delay so that the delayed reference beam and signal beam interfere with each other to generate an interference beam.

[0089] When operating S240, the detector detects the interference beam and obtains the detection signal.

[0090] In operation S250, the processor performs bandpass filtering on the data corresponding to the sampling point in the detection signal; performs envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and obtains the concentration of the gas to be measured based on the multiple decay times corresponding to multiple laser frequencies.

[0091] According to embodiments of the present invention, the micro-ring resonant gas concentration detection system and method based on the quantum ringing effect has the following two major advantages: First, the time-domain detection mechanism based on the ringing effect eliminates the influence of intermodal dispersion on the detection of the gas concentration, significantly improving accuracy; second, the system size is reduced and the detection difficulty is lowered by using a double-pendulum stereoscope interferometer. Compared with traditional micro-ring sensing schemes, the solution provided by the present invention significantly improves detection accuracy and reduces size, providing a better solution for trace gas analysis in fields such as environmental monitoring and industrial production.

[0092] It should be noted that the micro-ring resonant gas concentration detection method based on quantum ringing effect in the embodiments of the present invention corresponds to the micro-ring resonant gas concentration detection system based on quantum ringing effect in the embodiments of the present invention. For a detailed description of the micro-ring resonant gas concentration detection method based on quantum ringing effect, please refer to the micro-ring resonant gas concentration detection system based on quantum ringing effect, which will not be repeated here.

[0093] Those skilled in the art will understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention can be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0094] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of the invention is defined by the appended embodiments and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A micro-ring resonant gas concentration detection system based on the quantum ringing effect, characterized in that, include: An optical frequency comb is used to emit the first laser beam. A microring resonator, placed in a gas chamber filled with the gas to be measured, is used to make the first laser beam interact with the gas based on the evanescent field effect to obtain a modulated beam when the first laser beam passes through the microring resonator. The scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonator. A double-pendulum stereomicroscope interferometer is used to delay a reference beam and a signal beam corresponding to the modulation light for a predetermined time, while adjusting the frequency of the signal beam during the delay, so that the delayed reference beam and the signal beam interfere with each other to generate an interference beam. A detector is used to detect the interference beam and obtain a detection signal; The processor is used to perform bandpass filtering on the data corresponding to the sampling point in the detection signal; to perform envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and to obtain the concentration of the gas to be measured based on the multiple decay times corresponding to multiple laser frequencies.

2. The system according to claim 1, characterized in that, The processor obtains the concentration of the gas to be measured based on multiple decay times corresponding to multiple laser frequencies, including: For each laser frequency, the gas molecule absorptivity corresponding to each laser frequency is obtained based on the decay time corresponding to each laser frequency and the decay time when there is no gas in the gas chamber. Based on Beer-Lambert's law, the absorption rate of gas molecules corresponding to multiple laser frequencies was analyzed to obtain the gas concentration.

3. The system according to claim 1, characterized in that, The processor performs envelope detection on the filtered detection signal components to obtain the decay time corresponding to the ringing effect in the modulated beam, including: The detected signal components are subjected to full-wave rectification and filtering to obtain envelope discrete data; The least squares method is used to fit the envelope discrete data to obtain the oscillation time.

4. The system according to claim 1, characterized in that, The inherent photon lifetime of the microring resonator is equal to the externally coupled photon lifetime of the straight waveguide device coupled to the microring resonator.

5. The system according to claim 1, characterized in that, The free spectral range of the microring resonator is equal to the repetition frequency of the optical frequency comb, and the intrinsic scanning frequency is the maximum scanning frequency that prevents the laser beam passing through the microring resonator from ringing.

6. The system according to claim 1, characterized in that, The double-pendulum solid angle mirror interferometer includes: A laser for emitting a second laser beam, wherein the wavelength difference between the center wavelength of the second laser beam and the center wavelength of the first laser beam is within a predetermined range; A reflector is used to transmit the modulated beam at a predetermined position while reflecting the second laser beam to obtain a fused beam; A beam splitter is used to split the fused beam into a reference beam and a signal beam.

7. The system according to claim 6, characterized in that, The double-pendulum solid angle mirror interferometer also includes: The first corner mirror adjustment unit is used to delay the reference beam for a predetermined duration; The second corner mirror adjustment unit is used to delay the signal beam for a predetermined time, and at the same time, the frequency of the signal beam is adjusted by the swing of the swing arm in the second corner mirror adjustment unit during the delay.

8. The system according to claim 1, characterized in that, The processor is also used for: A spectrum is generated based on the detected signal; The sampling point is determined based on the zero point position of the spectrum.

9. The system according to claim 3, characterized in that, The processor performs full-wave rectification and filtering on the detected signal components to obtain envelope discrete data, including: The envelope discrete data is obtained by filtering the full-wave rectified signal using a low-pass filter with a cutoff frequency lower than the radio frequency.

10. A method for detecting the concentration of a microring resonant gas based on the quantum ringing effect, characterized in that, include: An optical frequency comb emits the first laser beam; When the first laser beam passes through the microring resonator, the first laser beam interacts with the gas based on the evanescent field effect to obtain a modulated beam, wherein the scanning frequency of the normalized optical frequency comb is greater than the intrinsic scanning frequency of the microring resonator. The double-pendulum solid angle mirror interferometer delays the reference beam and signal beam corresponding to the modulation light for a predetermined time, and simultaneously adjusts the frequency of the signal beam during the delay, so that the delayed reference beam and signal beam interfere with each other to generate an interference beam; The detector detects the interference beam and obtains a detection signal; The processor performs bandpass filtering on the data corresponding to the sampling point in the detection signal; performs envelope detection on the filtered detection signal component to obtain the decay time corresponding to the ringing effect in the modulated beam; and obtains the concentration of the gas to be measured based on the multiple decay times corresponding to multiple laser frequencies.

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