CN114152327A - Vibration detection method based on cavity ring-down technology - Google Patents
Vibration detection method based on cavity ring-down technology Download PDFInfo
- Publication number
- CN114152327A CN114152327A CN202111518691.0A CN202111518691A CN114152327A CN 114152327 A CN114152327 A CN 114152327A CN 202111518691 A CN202111518691 A CN 202111518691A CN 114152327 A CN114152327 A CN 114152327A
- Authority
- CN
- China
- Prior art keywords
- cavity
- ring
- vibration
- signal
- output signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 45
- 238000005516 engineering process Methods 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 51
- 230000003287 optical effect Effects 0.000 claims abstract description 27
- 238000001228 spectrum Methods 0.000 claims abstract description 21
- 238000012544 monitoring process Methods 0.000 claims abstract description 11
- 238000012545 processing Methods 0.000 claims description 7
- 230000005540 biological transmission Effects 0.000 claims description 6
- 238000004364 calculation method Methods 0.000 claims description 6
- 238000004458 analytical method Methods 0.000 claims description 5
- 238000011896 sensitive detection Methods 0.000 claims description 5
- 238000005311 autocorrelation function Methods 0.000 claims description 3
- 238000012512 characterization method Methods 0.000 claims description 2
- 230000010363 phase shift Effects 0.000 claims description 2
- 238000000411 transmission spectrum Methods 0.000 claims description 2
- 230000007613 environmental effect Effects 0.000 abstract description 12
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 230000001052 transient effect Effects 0.000 abstract description 6
- 238000011897 real-time detection Methods 0.000 abstract description 2
- ORILYTVJVMAKLC-UHFFFAOYSA-N Adamantane Natural products C1C(C2)CC3CC1CC2C3 ORILYTVJVMAKLC-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 239000009759 San-Chi Substances 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
Abstract
The invention provides a vibration detection method based on a cavity ring-down technology, which comprises the following steps: the method comprises the steps of building a ring-down cavity structure, adjusting the ring-down cavity to output a stable optical cavity output signal with certain strength, monitoring the change dynamics of the optical cavity output signal, collecting the optical cavity output signal, analyzing and extracting environmental vibration information by using a signal vibration resolving method, outputting a vibration detection result, and realizing high-sensitivity detection of the environmental vibration information. The method is based on the cavity ring-down system to carry out environment vibration detection, can quickly and qualitatively judge the vibration type and quantitatively obtain information such as vibration frequency spectrum and the like through monitoring and analyzing the output signal of the cavity, can realize real-time detection of transient micro vibration, and has the advantages of simple structure, novel method, convenient operation, high sensitivity, high bandwidth and the like compared with the traditional detection method.
Description
Technical Field
The invention relates to the field of vibration signal detection, in particular to a vibration detection method based on an optical cavity ring-down technology.
Background
Vibration signal detection is increasingly important in the fields of geological disaster prevention, engineering structure monitoring, experimental environment vibration detection and the like, but the conventional vibration sensors have more problems, such as poor detection precision and low sensitivity of a mechanical detection method, large influence of a distributed sensor on a light source, complex detection monitoring structure system and the like. The Cavity ring-down (CRD) technique is a high-sensitivity and high-precision optical detection technique, and is widely used in the fields of absorption spectrum measurement, high-reflectivity measurement, optical fiber sensing, and the like. (Abhijit Maity, Sanchi Maithani, Manik Pradhan, "visual Ring-Down Spectroscopy: Recent technical advances, Techniques, and Applications," Analytical Chemistry, 2021, 93, 388-416; Lecheng, Gong cell, optical Cavity Ring-Down high reflectance measurement Techniques review, Adam. In. Adam. et. Adam. No. Adam. In. Adam. et. In. Adam. A. Adam. of laser and optoelectronics, 2010, 47: 021203). The high sensitivity and high fineness of the cavity ring-down technology can also play a certain value in the field of vibration signal detection. On the basis of early experimental observation and theoretical research, the invention provides a vibration detection method based on an optical cavity ring-down technology. The theoretical basis of the method is as follows: in a vibration detection system based on the optical cavity ring-down technology, the transient micro-imbalance of a ring-down cavity system can be caused by environmental micro-vibration, so that the cavity loss is slightly changed, and finally vibration information is amplified and presented in an optical cavity resonance output signal. Because the cavity ring-down signal is extremely sensitive to cavity loss change caused by fine cavity disorder, and environmental vibration is extremely easy to cause disturbance of the cavity ring-down quantity, the sensitive detection of environmental vibration information can be realized based on the cavity ring-down technology.
Once the vibration detection system based on the ring-down cavity structure is built, the whole ring-down cavity structure can be used as a sensor to comprehensively sense the environmental vibration. In addition, the method can rapidly and qualitatively judge the vibration type and quantitatively obtain information such as vibration frequency spectrum and the like through real-time monitoring and analysis processing of the cavity ring-down output signal, realizes high-sensitivity detection of transient micro-vibration, and has the advantages of simple structure, novel method, convenience in operation, high detection sensitivity and the like compared with the traditional detection method.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the vibration sensor commonly used in the field of vibration signal detection at present has the problems of poor detection precision, low sensitivity, complex detection monitoring structure system and the like, and a vibration detection method with simple and novel structure and high detection precision and sensitivity is needed.
The technical scheme adopted by the invention to solve the technical problem is as follows: a vibration detection method based on a cavity ring-down technology is used for establishing a vibration detection system based on the cavity ring-down technology. The method comprises the steps of firstly building a ring-down cavity, adjusting the ring-down cavity to output a stable optical cavity output signal with certain intensity, monitoring the change dynamic state of the optical cavity output signal, collecting the optical cavity output signal, analyzing and extracting environmental vibration information by using a signal vibration resolving method, outputting a vibration detection result, and realizing high-sensitivity and high-precision detection of the environmental vibration information.
The method comprises the following concrete steps:
and (1) constructing a ring-down cavity structure, and monitoring a ring-down cavity transmission signal by using a Photoelectric Detector (PD).
The ring-down cavity structure is OF various cavity ring-down system structures, including traditional ring-down cavity structures, on-chip or chip micro-cavity structures and the like, and the adopted cavity ring-down (CRD) technology comprises a pulse cavity ring-down technology (P-CRD), a phase-shift cavity ring-down technology (PS-CRD), a narrow-spectrum continuous cavity ring-down technology (NBCW-CRD), an optical feedback cavity ring-down technology (OF-CRD) and the like.
And (2) adjusting the ring-down cavity to form a stable cavity resonance output signal, collecting the cavity resonance output signal, and acquiring signal spectrum information.
The cavity detuning state is not required to be specially required in the process of the cavity detuning stage, a certain cavity detuning amount such as cavity mirror inclination or cavity axis deflection can exist, and the adjusted optical cavity resonance output signal is stable.
The cavity resonance output signal is related characterization parameters directly or indirectly reflecting cavity loss, such as a cavity ring-down curve, a ring-down cavity transmission light intensity signal, a ring-down cavity transmission light spot form, a ring-down cavity transmission spectrum and the like. The cavity adjusting result requires stable optical cavity resonance output signals, and vibration error influence caused by system factors is reduced.
And (3) processing and analyzing signal frequency spectrum information by using a signal vibration resolving method, extracting environment vibration information, outputting a vibration detection result, and finishing sensitive detection on the environment vibration information.
The signal vibration calculation method can be any spectrum calculation analysis algorithm, including a periodogram method, an autocorrelation function method, a maximum entropy estimation method and the like. And improved periodogram methods including Bartlett's method and Welch's method spectral estimation.
The vibration detection result includes vibration type, vibration frequency, vibration intensity, vibration duration and the like.
The principle of the invention is as follows: in a vibration detection system based on the optical cavity ring-down technology, the transient micro-imbalance of a ring-down cavity system can be caused by environmental micro-vibration, so that the cavity loss is slightly changed, and finally vibration information is amplified and presented in an optical cavity resonance output signal. Because the cavity ring-down signal is extremely sensitive to cavity loss change caused by fine cavity disorder, and environmental vibration is extremely easy to cause disturbance of the cavity ring-down quantity, the sensitive detection of environmental vibration information can be realized based on the cavity ring-down technology.
Compared with the prior art, the invention has the following advantages: the method can rapidly qualitatively judge the vibration type and quantitatively obtain information such as vibration frequency spectrum and the like by monitoring and analyzing the output signal of the optical cavity, can realize real-time detection of transient micro vibration, and has the advantages of simple structure, novel method, convenient operation, high sensitivity, high bandwidth and the like compared with the traditional detection method.
Drawings
FIG. 1 is a schematic diagram of a cavity ring down system of the present invention;
FIG. 2 is a graph of the optical cavity output signal without ambient vibration in accordance with the present invention;
FIG. 3 is a diagram of the output signal of the optical cavity in the presence of transient micro-vibration of the environment according to the present invention.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
As shown in fig. 1, a specific implementation method of the vibration detection method based on the cavity ring-down technique of the present invention is as follows:
step (1), a traditional two-cavity-mirror direct-type ring-down cavity structure is built, a Photoelectric Detector (PD) is added at the tail end of the ring-down cavity, and the PD is used for monitoring a transmitted light intensity signal of the ring-down cavity.
Wherein the cavity mirror M1 and the cavity mirror M2 are concave high-reflection mirrors, and the curvature radius of the concave mirrors is 1M. The cavity length is 0.6m, and the stable cavity condition is met. The laser beam and the ring-down cavity are coaxially injected into the ring-down cavity. The Photodetector (PD) receives the transmitted beam ring down signal from the cavity mirror M2. In this embodiment, the laser light source is a continuous semiconductor laser with a center wavelength OF 635nm, and the cavity ring-down technique is an optical feedback cavity ring-down technique (OF-CRD).
And (2) adjusting the ring-down cavity to form a stable cavity ring-down output signal, wherein the ring-down signal is acquired by a data acquisition card (M2i.3010, 80MHz, Spectrum) and transmitted to a computer (PC) for analysis and processing, and signal Spectrum information is acquired. Because the formation of cavity resonance in the cavity ring-down system is not particularly sensitive to the cavity detuning state, the cavity adjusting standard in the embodiment can be properly relaxed, and a certain cavity tilt and other cavity detuning amount can exist in the cavity adjusting process. The resonant output signal of the optical cavity in this embodiment is a ring-down cavity transmitted light intensity signal, and the acquisition time is 20 ms.
And (3) processing and analyzing signal frequency spectrum information by using any frequency spectrum calculation analysis algorithm of a signal vibration calculation method, such as a periodogram method, an autocorrelation function method, a maximum entropy estimation method and the like, extracting environment vibration information, outputting vibration detection results of vibration types, vibration frequencies, vibration intensities, vibration durations and the like, and finishing sensitive detection on the environment vibration information. In this embodiment, the signal vibration solution method is an improved Welch method, and first, point data x of the signal vibration region is calculatedN(n) dividing the power spectrum into L sections for processing, wherein the length of each section is M, the sections are overlapped by data, and the power spectrum of each section is recorded as
In the formula
Is a normalization factor, d (n) is a window function. Then, the power spectrum estimation of the L-section signal vibration area obtained by the periodogram method is summed and averaged to obtain the whole signal vibration area xN(n) estimating the power spectrum as
In this embodiment, the window function for each segment of data processing is a rectangular window function. And finally, analyzing environmental vibration information such as vibration frequency, vibration intensity, vibration duration and the like from the obtained power spectrum estimation diagram.
Those skilled in the art will appreciate that the invention may be practiced without these specific details.
Claims (6)
1. A vibration detection method based on a cavity ring-down technology is characterized by comprising the following implementation steps:
step (1), constructing a ring-down cavity structure, and monitoring a ring-down cavity transmission signal by using a Photoelectric Detector (PD);
adjusting the ring-down cavity to form a stable cavity resonance output signal, collecting the cavity output signal, and acquiring signal spectrum information;
and (3) processing and analyzing signal frequency spectrum information by using a signal vibration resolving method, extracting environment vibration information, outputting a vibration detection result, and finishing sensitive detection on the environment vibration information.
2. The method of claim 1 for vibration detection based on cavity ring-down techniques, wherein: the ring-down cavity structure in the step (1) is various cavity ring-down system structures, including a traditional ring-down cavity structure, an on-chip or chip micro-cavity structure, and the adopted cavity ring-down (CRD) technology comprises a pulse cavity ring-down technology (P-CRD), a phase shift cavity ring-down technology (PS-CRD), a narrow spectrum continuous cavity ring-down technology (NBCW-CRD) and an optical feedback cavity ring-down technology (OF-CRD).
3. The method of claim 1 for vibration detection based on cavity ring-down techniques, wherein: the cavity-tuning stage process in the step (2) does not make specific requirements on the cavity detuning state, a certain cavity detuning amount can exist, including cavity mirror inclination and cavity axis offset, and only the tuned optical cavity resonance output signal is stable.
4. The method of claim 1 for vibration detection based on cavity ring-down techniques, wherein: the optical cavity resonance output signal in the step (2) is related characterization parameters which directly or indirectly reflect the cavity loss, and comprises an optical cavity ring-down curve, a ring-down cavity transmission light intensity signal, a ring-down cavity transmission light spot form and a ring-down cavity transmission spectrum, and the cavity adjusting result requires that the optical cavity resonance output signal is stable, so that the vibration error influence caused by the system factors is reduced.
5. The method of claim 1 for vibration detection based on cavity ring-down techniques, wherein: the signal vibration calculation method in the step (3) can be any spectrum calculation analysis algorithm, including a periodogram method, an autocorrelation function method, a maximum entropy estimation method, and an improved periodogram method including Bartlett method and Welch method spectrum estimation.
6. The method of claim 1 for vibration detection based on cavity ring-down techniques, wherein: and (4) the vibration detection result in the step (3) comprises vibration type, vibration frequency, vibration intensity and vibration duration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111518691.0A CN114152327B (en) | 2021-12-13 | 2021-12-13 | Vibration detection method based on cavity ring-down technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111518691.0A CN114152327B (en) | 2021-12-13 | 2021-12-13 | Vibration detection method based on cavity ring-down technology |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114152327A true CN114152327A (en) | 2022-03-08 |
| CN114152327B CN114152327B (en) | 2023-12-22 |
Family
ID=80450443
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111518691.0A Active CN114152327B (en) | 2021-12-13 | 2021-12-13 | Vibration detection method based on cavity ring-down technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114152327B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114720402A (en) * | 2022-03-31 | 2022-07-08 | 中国科学院光电技术研究所 | Calibration device for composite sensing passive cavity |
| CN114719953A (en) * | 2022-03-31 | 2022-07-08 | 中国科学院光电技术研究所 | Straight cavity vibration detection device |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1730497A1 (en) * | 2004-03-15 | 2006-12-13 | Evanesco Limited | Cavity ring-down sensing apparatus and methods |
| CN101404772A (en) * | 2008-11-19 | 2009-04-08 | 中国科学院光电技术研究所 | VLSI image compression encoder based on wavelet transformation |
| CN203365317U (en) * | 2013-05-08 | 2013-12-25 | 浙江师范大学 | Device for detecting explosive TATP (triacetone triperoxide) on basis of cavity ring-down absorption spectrum technology |
| CN203443662U (en) * | 2013-09-23 | 2014-02-19 | 安徽大学 | Apparatus capable of improving signal to noise ratio of laser micro-vibration sensing system |
| CN103925985A (en) * | 2014-04-10 | 2014-07-16 | 华中科技大学 | Vibrating sensor based on core-free optical fiber and detection device based on vibrating sensor |
| US20150226666A1 (en) * | 2012-08-30 | 2015-08-13 | Newsouth Innovations Pty Limited | Multiplexed spectroscopic absorbance from crds wave forms |
| CN107037003A (en) * | 2017-05-04 | 2017-08-11 | 南昌航空大学 | A kind of system that moisture content in high-purity gas is detected based on cavity ring down spectroscopy technology |
| US20180306713A1 (en) * | 2017-04-25 | 2018-10-25 | Adelphi University | Ultra-sensitive, real-time trace gas detection using a high-power, multi-mode semiconductor laser and cavity ringdown spectroscopy |
| CN108775954A (en) * | 2018-06-06 | 2018-11-09 | 岭南师范学院 | A kind of adjustable dual wavelength LD of resolution ratio is from mixing vibration measuring instrument and its measurement method |
| CN109596206A (en) * | 2019-01-25 | 2019-04-09 | 武汉理工大学 | Vibrating sensor based on liquid filling photonic crystal fiber |
| CN110514287A (en) * | 2019-08-19 | 2019-11-29 | 南京邮电大学 | Based on single mode-less fundamental mode optical fibre coupler vibrating sensor |
| AU2020102296A4 (en) * | 2020-03-20 | 2020-10-29 | Jilin University | A distributed optical fiber sensing system based on heterodyne detection technology |
| CN212843957U (en) * | 2020-07-27 | 2021-03-30 | 吉林大学 | Vibration sensing device based on optical fiber annular ring-down cavity |
| CN113588066A (en) * | 2021-07-22 | 2021-11-02 | 武汉理工大学 | Micro-vibration sensing device based on macro-bending effect of weak light guide fiber |
| CN113688482A (en) * | 2021-09-02 | 2021-11-23 | 西南石油大学 | Simulation method for drill string stick-slip vibration dispersion quality |
-
2021
- 2021-12-13 CN CN202111518691.0A patent/CN114152327B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1730497A1 (en) * | 2004-03-15 | 2006-12-13 | Evanesco Limited | Cavity ring-down sensing apparatus and methods |
| CN101404772A (en) * | 2008-11-19 | 2009-04-08 | 中国科学院光电技术研究所 | VLSI image compression encoder based on wavelet transformation |
| US20150226666A1 (en) * | 2012-08-30 | 2015-08-13 | Newsouth Innovations Pty Limited | Multiplexed spectroscopic absorbance from crds wave forms |
| CN203365317U (en) * | 2013-05-08 | 2013-12-25 | 浙江师范大学 | Device for detecting explosive TATP (triacetone triperoxide) on basis of cavity ring-down absorption spectrum technology |
| CN203443662U (en) * | 2013-09-23 | 2014-02-19 | 安徽大学 | Apparatus capable of improving signal to noise ratio of laser micro-vibration sensing system |
| CN103925985A (en) * | 2014-04-10 | 2014-07-16 | 华中科技大学 | Vibrating sensor based on core-free optical fiber and detection device based on vibrating sensor |
| US20180306713A1 (en) * | 2017-04-25 | 2018-10-25 | Adelphi University | Ultra-sensitive, real-time trace gas detection using a high-power, multi-mode semiconductor laser and cavity ringdown spectroscopy |
| CN107037003A (en) * | 2017-05-04 | 2017-08-11 | 南昌航空大学 | A kind of system that moisture content in high-purity gas is detected based on cavity ring down spectroscopy technology |
| CN108775954A (en) * | 2018-06-06 | 2018-11-09 | 岭南师范学院 | A kind of adjustable dual wavelength LD of resolution ratio is from mixing vibration measuring instrument and its measurement method |
| CN109596206A (en) * | 2019-01-25 | 2019-04-09 | 武汉理工大学 | Vibrating sensor based on liquid filling photonic crystal fiber |
| CN110514287A (en) * | 2019-08-19 | 2019-11-29 | 南京邮电大学 | Based on single mode-less fundamental mode optical fibre coupler vibrating sensor |
| AU2020102296A4 (en) * | 2020-03-20 | 2020-10-29 | Jilin University | A distributed optical fiber sensing system based on heterodyne detection technology |
| CN212843957U (en) * | 2020-07-27 | 2021-03-30 | 吉林大学 | Vibration sensing device based on optical fiber annular ring-down cavity |
| CN113588066A (en) * | 2021-07-22 | 2021-11-02 | 武汉理工大学 | Micro-vibration sensing device based on macro-bending effect of weak light guide fiber |
| CN113688482A (en) * | 2021-09-02 | 2021-11-23 | 西南石油大学 | Simulation method for drill string stick-slip vibration dispersion quality |
Non-Patent Citations (1)
| Title |
|---|
| 赵宏太 等: "光腔衰荡技术与高灵敏吸收探测", 《物理》, vol. 30, no. 04, pages 217 - 219 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114720402A (en) * | 2022-03-31 | 2022-07-08 | 中国科学院光电技术研究所 | Calibration device for composite sensing passive cavity |
| CN114719953A (en) * | 2022-03-31 | 2022-07-08 | 中国科学院光电技术研究所 | Straight cavity vibration detection device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114152327B (en) | 2023-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114152327A (en) | Vibration detection method based on cavity ring-down technology | |
| CN103344623B (en) | One carries high-precision coherent anti-stokes raman scattering light comb optical spectrum detecting method | |
| CN101532951B (en) | Optical fiber mixed gas quantitative measurement system and measurement method | |
| WO2018009953A1 (en) | Photothermal interferometry apparatus and method | |
| CN103913299B (en) | Optical resonator pattern based on optical cavity ring-down method and loss measurement apparatus and method | |
| CN111829981B (en) | Gas heterodyne detection device and detection method based on TDLAS | |
| CN110411960B (en) | Optical cavity ring-down spectrometer system | |
| EP3870944B1 (en) | Device and method for the spectroscopic analysis of brillouin scattered light | |
| CN105865628A (en) | Spectral analysis system and method based on stimulated Brillouin effect | |
| CN113433072A (en) | Gas concentration sensor and gas concentration detection device | |
| CN113552212B (en) | Radial cavity quartz enhanced photoacoustic spectrum sound detector and gas detection device thereof | |
| CN110231332B (en) | Coherent anti-Stokes Raman scattering spectrum device and method simplified by utilizing super-steep filter plate | |
| CN111829657B (en) | Coherent spectrum analysis device and method based on optical fiber Rayleigh scattering | |
| CN113984670A (en) | Double-sensor cavity adjusting method for cavity ring-down high-reflectivity measurement | |
| CN114018402B (en) | Optical resonant cavity sensing signal enhancement method | |
| CN111956233B (en) | Blood glucose measuring device and blood glucose measuring method | |
| CN114719953A (en) | Straight cavity vibration detection device | |
| CN111551110B (en) | Nano particle size information measuring device and method | |
| CN113029957A (en) | Gas sensor based on evanescent wave | |
| CN210376134U (en) | Terahertz-based indoor environmental pollutant detection device | |
| Roland et al. | Intensities in pure rotational CARS of air | |
| CN110487745A (en) | A kind of THZ-SPRi biological sensing system and its negative-feedback algorithm | |
| Mao et al. | Fast interrogation of dynamic fiber Bragg grating using neighborhood average algorithm | |
| CN110031102A (en) | A kind of high speed spectrometer | |
| CN210427340U (en) | Cavity ring-down spectrometer system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |