CN112525858A - Gas sensor based on microcavity thermotropic ringing effect and gas concentration measuring method - Google Patents
Gas sensor based on microcavity thermotropic ringing effect and gas concentration measuring method Download PDFInfo
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Abstract
The invention discloses a micro-cavity thermotropic ringing effect-based gas sensor, which comprises a laser, a gas chamber, a gas inlet, a gas outlet, a microsphere cavity, a tapered optical fiber, a photoelectric converter and a current controller, wherein the micro-cavity thermotropic ringing effect is formed by connecting a micro-cavity optical fiber with a micro-cavity; the air inlet and the air outlet are positioned on the outer side of the air chamber, and the microsphere cavity is positioned in the air chamber; the tapered optical fiber penetrates through the air chamber and is hermetically connected with the air chamber, one end, positioned outside the air chamber, of the tapered optical fiber is connected with the laser, the other end of the tapered optical fiber is connected with the photoelectric converter, and the portion, positioned inside the air chamber, of the tapered optical fiber is attached to the surface of the microsphere cavity; and the laser is connected with a current controller. The invention utilizes high-power incident laser to generate stronger thermo-optic effect in the microsphere cavity, and can generate obvious ringing effect when the laser sweeps frequency from low frequency to high frequency. When the gas chamber is filled with external gas, the ringing signal waveform is changed, so that the gas chamber is used for monitoring the methane gas concentration.
Description
Technical Field
The invention relates to the field of optical gas sensors, in particular to a gas sensor based on a microcavity thermotropic ringing effect and a gas concentration measuring method.
Background
Methane (CH)4) Gas is an important component of natural gas and an important energy source. The low-concentration methane gas does not harm human body, but will explode when the concentration reaches a certain value, and the high-concentration methane also can harm human healthAnd even life. Therefore, how to prevent methane from leaking during transportation and delivery and quickly, sensitively and real-timely monitor the trace methane gas in the ambient air is crucial.
The optical echo wall micro-cavity develops a plurality of applications in the fields of small volume, high quality factor optical sensing, nonlinear optics, integrated optics and bio-optics. Conventional microcavity-based sensors generally monitor changes in the line width or center frequency of the whispering gallery mode in the cavity to determine whether the external environment changes, such as: the change of refractive index caused by external environment can cause the shift of mode frequency, and the linear broadening of the mode can be caused by small particles such as molecules falling on the surface of the microcavity. However, the small change of the microcavity mode frequency and the line width caused by the trace gas with low concentration in the environment is difficult to distinguish, so that the difficulty of detecting the trace gas based on the scheme is brought. The ringing effect microcavity sensor utilizes the fact that after light repeatedly comes and goes in a high-quality factor resonant cavity, the effective action length of the light and a substance is effectively increased, and therefore the ultrahigh-sensitivity sensor can be achieved. Based on the method, a high-sensitivity sensor for detecting gas is realized in a Fabry-Perot (FP) microcavity. And ringing is also observed when the incident laser is swept through high quality factor value modes in the whispering gallery microcavity at relatively high sweep speeds. But in the whispering gallery microcavity, ringing is also rarely applied to the probe gas.
If the ringing phenomenon is observed in the whispering gallery microcavity, the microcavity mode needs to be swept at a higher laser sweep rate, and the quality factor of the microsphere cavity is higher (>107) This is why ringing is difficult to observe in typical echo-wall micro-cavities. However, the high quality factor microsphere cavity has high requirements for the external environment, and the quality factor can be ensured only by placing the cavity in an absolutely pure environment. This will face practical and complicated environmental problems, which are detrimental to the long-term stability and reliability of the device. Meanwhile, for the mode with a lower quality factor, the required sweep frequency speed is higher, which also puts higher requirements on a laser control system, and undoubtedly increases the manufacturing cost. The actual detection environment of methane gas is mostly in atmospheric environment, natural gas pipeline, coal mine and the likeThe environment is extremely complex and contains a large amount of pollutants. Therefore, the microsphere cavity is exposed to the environment for a long time, the quality factor value is necessarily degraded, the performance of the sensor is greatly influenced, and even the sensor cannot work normally. Therefore, how to solve the problem that the sensing function based on the micro-cavity internal ringing effect can be ensured under the complex environment has important application value for detecting the trace methane gas.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems, the invention discloses a novel micro-cavity methane gas sensor based on a thermotropic ringing effect.
The technical scheme is as follows: in order to solve the problems, the technical scheme provided by the invention is as follows: a gas sensor based on microcavity thermotropic ringing effect comprises a laser (1), a gas chamber (2), a gas inlet (3), a gas outlet (4), a microsphere cavity (6), a tapered optical fiber (7), a photoelectric converter (8) and a current controller (9); the air inlet (3) and the air outlet (4) are connected to the outer side of the air chamber (2), and the microsphere cavity (6) is positioned in the air chamber (2); the tapered optical fiber (7) penetrates through the air chamber (2) and is hermetically connected with the air chamber (2), one end of the tapered optical fiber (7) is connected with the laser (1), the other end of the tapered optical fiber is connected with the photoelectric converter (8), and the portion of the tapered optical fiber (7) located in the air chamber (2) is attached to the surface of the microsphere cavity (6); and the laser (1) is connected with a current controller (9).
During working, the central wavelength of the laser (1) is just positioned at a methane gas absorption peak, real-time tuning of the pumping current of the laser can be realized through the external controller (9), the frequency sweeping function of the laser is realized, and the output power of the laser is more than 30mW to ensure that enough heat effect can be generated in the microsphere cavity. The current controller (9) and the photoelectric converter (8) are used for generating and monitoring the ringing effect generated in the microsphere cavity during the laser back scanning (from low frequency to high frequency). The controller (9) ensures the linear change of the current along with the time, the scanning period can be adjusted within the range of 10Hz to 1kHz, the photoelectric converter (8) can have a response bandwidth of more than 10MHz to ensure the time resolution of the waveform signal, and the specific numerical values can be set according to actual requirements.
Preferably, the air outlet (4) is connected with an air pump (5), such as a hose; and, can place independent air chamber of air pump (5), its aim at, the reducible vibration of its during operation of the air pump of long distance independent placement at first to the influence of microballon system, and secondly, the air chamber can rely on little volume advantage, can place narrow space and be used for monitoring gas.
The invention also provides a method for realizing detection of gas concentration according to the gas sensor based on the microcavity thermotropic ringing effect, which comprises the following steps:
(1) gas is injected from the gas inlet (3), and the central wavelength of the laser (1) is arranged right at a gas absorption peak;
(2) setting the sweep frequency speed of the laser to be a fixed value, enabling the incident power of the laser to be at an initial value, and entering the step (4) if the ringing phenomenon can be observed by the monitoring signal at the moment; if no ringing phenomenon is observed, entering the step (3);
(3) increasing the incident light power value of the laser, keeping the incident light power value unchanged, judging whether a ringing effect can be observed in an output signal of the photoelectric converter (8) in the laser frequency changing process from low to high within the laser frequency changing period range, namely in a reverse sweeping process, and if the ringing effect is observed, if the frequency sweeping speed is equal to or larger than a threshold value for generating the ringing effect, entering the step (4); if no ringing effect is observed, repeating step (3);
(4) and reversely deducing the photon life according to the ringing effect oscillogram, thereby calculating the gas concentration in the environment at the moment.
Preferably, the sweep frequency speed in the step (2) is a constant value and satisfies the following conditions:
γ represents the microsphere lumen loss.
If the incident light with larger power is coupled into the micro-cavity, the micro-sphere is locally heated due to the intrinsic light loss in the micro-sphere cavity, and a stronger heat phenomenon is generated. In the normal scanning process, namely the laser frequency is from high to low, when the laser frequency gradually approaches the resonant frequency of the microsphere cavity, the power density in the cavity is rapidly increased, and the approach meets the condition that the difference between the laser frequency and the resonant frequency of the microsphere cavity is less than a preset threshold value. For quartz materials, the induced temperature rise process will cause the microsphere resonance mode to red shift (lower frequency), and the laser frequency sweep direction is consistent with the thermal resonance frequency drift direction. When the laser frequency sweeps through resonance, the temperature in the cavity drops and the resonance frequency returns, which accelerates the frequency sweep rate. Therefore, in the above-mentioned positive scanning process, the Lorentzian line shape in which the microcavity mode is symmetrical originally becomes an inverted triangular line shape.
For the reverse scanning process, namely the laser frequency is from low to high, the drift direction of the thermal resonance frequency is opposite to the scanning direction, which greatly increases the speed of the laser scanning the resonance mode, so the line type of the resonance mode is greatly narrowed. If a high incident light power is adopted, a high enough thermal effect is generated, so that the laser frequency sweeping speed is improved laterally, and the ringing effect is finally observed. The invention realizes the ringing effect in the microsphere cavity by utilizing the thermotropic ringing effect under the lower scanning frequency, and realizes the monitoring and sensing function of methane gas based on the effect.
The invention has the beneficial effects that: compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:
(1) by the technical scheme of the invention, a microsphere cavity with higher laser frequency sweeping speed and higher quality factor is not needed, so that the manufacturing cost is greatly reduced and the yield of devices can be effectively improved. The 1645nm light source is adopted, the absorption efficiency of laser on methane gas can be effectively improved, and the monitoring on trace methane gas in the air can be realized by combining a ringing effect high-sensitivity sensing mechanism. The concentration of the methane gas can be accurately obtained at the same time through the analysis of the collected data;
(2) the thermotropic ringing effect can be observed under the condition of a low-quality factor microsphere cavity or low-speed laser frequency sweeping;
(3) the methane gas has higher absorption efficiency for 1645nm laser and ensures that the quartz microsphere cavity has higher Q value under the wavelength;
(4) the small volume of the microsphere cavity can be suitable for methane gas detection in a narrow space;
(5) compared with the traditional Lorentz symmetrical mode line type of the microsphere cavity, the ringing waveform of the mode in the microsphere cavity can reflect the tiny change of the external environment, so that the sensing effect with higher sensitivity is realized;
(6) in the prior art, the fact that the gas sensing function is realized by adopting the thermotropic ringing effect is not found, so that the technical scheme can be widely applied to other various gas sensing, and has important application value for detecting trace gas in the air.
Drawings
FIG. 1 is a schematic view of a methane gas sensor according to the present invention; the device comprises a laser 1, an air chamber 2, an air inlet 3, an air outlet 4, an air pump 5, a microsphere cavity 6, a tapered optical fiber 7, a photoelectric converter 8 and a current controller 9.
Fig. 2, the monitored ringing effect fluctuation signals under different microcavity intrinsic photon lifetime conditions are simulated by calculation.
Detailed Description
1. Generation of thermally induced ringing effects
This embodiment will be further described with reference to the accompanying drawings, as shown in fig. 1, a DFB semiconductor laser with a wavelength of 1645nm is first coupled into a silica microsphere micro-cavity through a section of tapered fiber, and the optical field amplitude in the cavity satisfies the time-varying equation:
wherein E (t) and Ein(t) denotes the amplitude of the incident laser beam and the cavity, γ and η denote the cavity loss of the microsphere and the coupling efficiency to the biconical taper, τ denotes the lifetime of the photons in the cavity, and Δ ω (t) ═ ωp(t)-ω0(t) represents the incident light frequency and the resonance detuning quantity of the microsphere cavity, omegap(t) and ω0(t) represents the incident laser frequency and the microsphere cavity resonance frequency, respectively.
For a general DFB semiconductor laser, the output laser frequency is generally in direct proportion to the driving current, and the invention can utilize a current controller to generate a linear current signal to drive the semiconductor laser and realize the frequency sweeping function. In this example, the frequency of the laser is swept linearly, i.e. the incident laser frequency satisfies:
ωp(t)＝ω+vt (2)
wherein, ω and v represent the initial frequency and the sweep frequency speed of the sweep frequency laser, and a photoelectric converter is adopted to monitor the transmission signal of the microsphere cavity along with the change of time, and the signal can be expressed as:
Tr(t)＝|1+iηE(t)/Ein(t)| (3)
for low incident power, i.e. no significant thermal effects in the cavity, ringing is observed at the monitoring signal only when the laser sweep rate reaches a threshold value:
from equation (4), it can be seen that if the microcavity loss γ is larger, a larger sweep speed is required to reach the threshold for generating ringing.
The invention is characterized in that the ringing effect, namely the thermally induced ringing effect, can be realized by utilizing the thermal nonlinearity in the micro cavity even under the condition that the micro cavity is greatly lost, namely the quality factor is very low, and the specific realization is as follows:
resonant frequency omega of the micro-sphere cavity due to thermo-optic effect0(t) will vary with its own temperature, and the temperature of the cavity of the microsphere will depend on the optical power density within the cavity. The power density is related to the incident light frequency and the resonant detuning quantity delta omega (t) of the microsphere cavity, so that when the incident light frequency sweeps the resonant frequency of the microsphere cavity, the resonant frequency of the microsphere cavity itself is changed dramatically. As with the swept-frequency laser used above, it is known that the resonant frequency of the microsphere cavity can be viewed as a function of time:
wherein Δ T (t) is a change in temperature caused by the optical power in the cavity，ω0And n0Respectively the resonance frequency and the refractive index at the initial temperature, epsilon represents the correction small quantity, depending on the material itself.
Generally, depending on the material of the microcavity, this represents the relationship between the refractive index of the material and the temperature, which is positive for a quartz microcavity.
As can be seen from equations (2) and (5), when sweeping the frequency velocity v>At 0, ωp(t) increases with time, and as its laser frequency approaches the modal resonance frequency in steps, the rapid increase in intracavity power causes the intracavity to heat up, resulting in ω0(t) is a function that decreases with time. Due to omega in the initial statep(t)<ω0(t), final detuning amount | Δ ω (t) | ═ ω |, ωp(t)-ω0(t) | is a process of acceleration reduction, in other words, the speed of the frequency sweep of the laser with respect to the microcavity resonance frequency is accelerated.
In this embodiment:
(1) gas is injected from the gas inlet (3), the central wavelength of the laser (1) is arranged right at a gas absorption peak, the incident power of the laser is at an initial value, the temperature rise in the microsphere cavity caused by the incident light is not obvious, and general quality factors (c), (d)<107) The ringing effect is difficult to observe with microsphere cavities.
(2) The incident light power is slowly and gradually increased, and along with the increase of the power, when the laser frequency is close to the resonance of the microsphere cavity, an obvious thermal effect is generated in the cavity, so that the frequency sweeping speed is indirectly improved. When the power increases to a certain value, a ringing effect is observed in the monitoring signal, at which point the sensor reaches an operating state. In addition, the problem that the ringing effect generated by the quality factor of the microsphere cavity is weakened or disappeared in the actual use process of the sensor can be solved, the heat effect required by the symbol can be generated by increasing the incident light power, the relative frequency sweeping speed of the laser can be effectively improved, and the ringing effect can be reproduced.
2. Monitoring of methane gas concentration
According to the above process, when an appropriate incident optical power is selected for coupling into the microsphere cavity, a ringing effect is observed in the monitoring signal, which is a series of fluctuating signals that gradually decay over time, as shown in figure 2 of the specification. The characteristic shape of the fluctuation signal can be influenced by various parameters. For the methane gas sensor mentioned in this invention, the main change in the system due to the higher absorption efficiency of 1654nm laser by methane gas is the increase in the intracavity optical loss γ. With other parameters unchanged, the process causes the ringing effect to produce a wave that becomes shallower. The gas exemplified by the invention is methane gas, and can be any gas in practice, and the condition to be met is that the central wavelength of the laser (1) is just positioned at a gas absorption peak.
Description figure 2 shows the calculated and simulated ringing effect fluctuation signals monitored under different microcavity intrinsic photon lifetime conditions (i.e. different cavity losses). Because the absorption loss of methane gas with different concentrations to light is different, the methane environment under different concentrations of the microcavity can be well reflected by setting different microcavity intrinsic losses. The loss is mainly generated by absorption or scattering of the optical field in the cavity by the microcavity itself or the external environment, and other physical quantities of the system can be considered not to change in the monitoring process. It is surmised that high concentrations of methane gas lead to greater light absorption and reduced microcavity intrinsic photon lifetimes. From simulation results, it can be known that high concentration of methane gas can reduce the lifetime of photons in the cavity and increase the cavity loss, thereby causing the reduction of the ringing waveform amplitude and the existence duration. Therefore, the photon lifetime can be deduced reversely according to the ringing oscillogram, so that the concentration of methane in the environment can be calculated.
The specific implementation is as follows:
according to the attached drawing 1, the air chamber is placed in the environment, external air can be effectively sucked into the air chamber and the optical field in the microsphere cavity through the small air pump to act, methane gas with different concentrations can introduce different losses to the optical field, and the concentration of the methane gas at the moment can be accurately calculated through calculation of ringing signals. In addition, for different gas detection, a DFB semiconductor laser corresponding to the gas absorption band can be adopted to replace the 1645nm laser, and other devices can be adjusted finely.
All structural equivalents made by using the contents of the specification and the drawings are included in the scope of the present invention.
Claims (4)
1. A gas sensor based on microcavity thermotropic ringing effect is characterized by comprising a laser (1), a gas chamber (2), a gas inlet (3), a gas outlet (4), a microsphere cavity (6), a tapered optical fiber (7), a photoelectric converter (8) and a current controller (9); the air inlet (3) and the air outlet (4) are connected to the outer side of the air chamber (2), and the microsphere cavity (6) is positioned in the air chamber (2); the tapered optical fiber (7) penetrates through the air chamber (2) and is hermetically connected with the air chamber (2), one end, located on the outer side of the air chamber (2), of the tapered optical fiber (7) is connected with the laser (1), the other end of the tapered optical fiber is connected with the photoelectric converter (8), and the portion, located inside the air chamber (2), of the tapered optical fiber (7) is attached to the surface of the microsphere cavity (6); the laser (1) is connected with a current controller (9).
2. A microcavity thermotropic ringing-based gas sensor according to claim 1, wherein the gas outlet (4) is connected to a gas pump (5).
3. The method for detecting the concentration of the gas based on the microcavity thermotropic ringing effect gas sensor according to any one of claims 1-2, is characterized by comprising the following steps of:
(1) gas is injected from the gas inlet (3), and the central wavelength of the laser (1) is arranged right at a gas absorption peak;
(2) setting the sweep frequency speed of the laser to be a fixed value, enabling the incident power of the laser to be at an initial value, and entering the step (4) if the ringing phenomenon can be observed by the monitoring signal at the moment; if no ringing phenomenon is observed, entering the step (3);
(3) increasing the incident light power value of the laser, keeping the incident light power value unchanged, judging whether a ringing effect can be observed in an output signal of the photoelectric converter (8) in the laser frequency changing process from low to high within the laser frequency changing period range, namely in a reverse sweeping process, and if the ringing effect is observed, if the frequency sweeping speed is equal to or larger than a threshold value for generating the ringing effect, entering the step (4); if no ringing effect is observed, repeating step (3);
(4) and reversely deducing the photon life according to the ringing effect oscillogram, thereby calculating the gas concentration in the environment at the moment.
4. The method for detecting gas concentration according to claim 3, wherein the sweep rate in the step (2) is a constant value satisfying:
γ represents the microsphere lumen loss.
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| CN114199785A (en) * | 2021-11-18 | 2022-03-18 | 国网浙江省电力有限公司诸暨市供电公司 | Echo wall micro-cavity sensing method based on GAN data enhancement |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101419161A (en) * | 2008-10-24 | 2009-04-29 | 中北大学 | Gas detecting method and gas sensor based on plane annular micro-cavity |
| CN107941735A (en) * | 2017-11-10 | 2018-04-20 | 吉林大学 | Infrared double aperture slit waveguide microcavity spectroscopic gas sensor and its application method in one kind |
| CN108872123A (en) * | 2018-08-03 | 2018-11-23 | 广州米德红外科技有限公司 | A kind of middle infrared active micro-loop gas sensor of high sensitivity |
| CN109557049A (en) * | 2018-11-21 | 2019-04-02 | 暨南大学 | A kind of hydrogen gas sensor and preparation method thereof |
| CN109900641A (en) * | 2019-01-16 | 2019-06-18 | 西北大学 | A kind of poly- hexamethyl biguanides film package microsphere resonator CO2Sensor and manufacture craft |
| CN111313218A (en) * | 2020-02-20 | 2020-06-19 | 南京大学 | Preparation method of microsphere cavity |
-
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- 2020-11-27 CN CN202011362801.4A patent/CN112525858B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101419161A (en) * | 2008-10-24 | 2009-04-29 | 中北大学 | Gas detecting method and gas sensor based on plane annular micro-cavity |
| CN107941735A (en) * | 2017-11-10 | 2018-04-20 | 吉林大学 | Infrared double aperture slit waveguide microcavity spectroscopic gas sensor and its application method in one kind |
| CN108872123A (en) * | 2018-08-03 | 2018-11-23 | 广州米德红外科技有限公司 | A kind of middle infrared active micro-loop gas sensor of high sensitivity |
| CN109557049A (en) * | 2018-11-21 | 2019-04-02 | 暨南大学 | A kind of hydrogen gas sensor and preparation method thereof |
| CN109900641A (en) * | 2019-01-16 | 2019-06-18 | 西北大学 | A kind of poly- hexamethyl biguanides film package microsphere resonator CO2Sensor and manufacture craft |
| CN111313218A (en) * | 2020-02-20 | 2020-06-19 | 南京大学 | Preparation method of microsphere cavity |
Non-Patent Citations (1)
| Title |
|---|
| 王鹏飞 等: "回音壁模式光学微腔器件的封装与集成", 《光子学报》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114199785A (en) * | 2021-11-18 | 2022-03-18 | 国网浙江省电力有限公司诸暨市供电公司 | Echo wall micro-cavity sensing method based on GAN data enhancement |
| CN114199785B (en) * | 2021-11-18 | 2023-09-26 | 国网浙江省电力有限公司诸暨市供电公司 | Echo wall microcavity sensing method based on GAN data enhancement |
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Effective date of registration: 20240105 Address after: 221100, 3rd Floor, Building A2, National Security Science and Technology Industrial Park, High tech Industrial Development Zone, Xuzhou City, Jiangsu Province Patentee after: Mid infrared laser Research Institute (Jiangsu) Co.,Ltd. Patentee after: Jiangsu Normal University Address before: 221100 Room 302, building 2, zone a, national security science and Technology Industrial Park, Xuzhou hi tech Industrial Development Zone, Xuzhou City, Jiangsu Province Patentee before: Mid infrared laser Research Institute (Jiangsu) Co.,Ltd. |