CN114354542A - Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure - Google Patents
Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure Download PDFInfo
- Publication number
- CN114354542A CN114354542A CN202111207064.5A CN202111207064A CN114354542A CN 114354542 A CN114354542 A CN 114354542A CN 202111207064 A CN202111207064 A CN 202111207064A CN 114354542 A CN114354542 A CN 114354542A
- Authority
- CN
- China
- Prior art keywords
- optical
- mach
- zehnder interferometer
- fiber
- salinity
- 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.)
- Pending
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000013307 optical fiber Substances 0.000 claims abstract description 42
- 238000001228 spectrum Methods 0.000 claims abstract description 26
- 238000001514 detection method Methods 0.000 claims abstract description 7
- 238000010183 spectrum analysis Methods 0.000 claims abstract description 3
- 230000003287 optical effect Effects 0.000 claims description 47
- 239000000835 fiber Substances 0.000 claims description 32
- 238000005259 measurement Methods 0.000 claims description 11
- 230000002269 spontaneous effect Effects 0.000 claims description 6
- 230000003595 spectral effect Effects 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 claims 1
- 238000010408 sweeping Methods 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 5
- 238000011161 development Methods 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000005305 interferometry Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Abstract
The invention discloses a device and a method for measuring liquid refractive index (salinity) by using a microwave photonic filter with a Mach-Zehnder interferometer structure. The device comprises a wide-spectrum light source, an electro-optic modulator, two 2 multiplied by 2 optical fiber couplers, two transmission optical fibers, a photoelectric detector and a spectrum analysis module. The liquid to be measured is positioned on one arm of the Mach-Zehnder interferometer structure, and when the refractive index (salinity) of the liquid to be measured is changed, the notch depth of the frequency resonance curve of the microwave photonic filter is changed. The device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure modulate output light by an external modulation method, use a wide-spectrum laser light source, reduce the light source requirement, simultaneously do not need to use a spectrometer to demodulate wavelength, reduce the system cost, realize long-distance liquid refractive index (salinity) detection, and can be applied to ocean salinity detection, detection of salinity in lakes and the like.
Description
Technical Field
The invention relates to the technical field of microwave photonics, microwave photon filters and application of the microwave photon filters to sensing, in particular to a device and a method for measuring liquid refractive index (salinity) by using the microwave photon filters.
Background
Refractive index as one of the most important optical parameters of liquids, in living beings[1]Medical science[2]And chemical industry[3]Concentration and purity determination in other fields[4]Have important applications in. With the development of modern science and technology, new materials are continuously emerging, and higher requirements are put forward on the measurement precision and the measurement range of the refractive index[5]。
Currently, refractive index measurement techniques are mainly based on two broad categories, the law of refraction and interferometry. The measurement method based on the refraction theorem has the advantages of simple measurement principle and convenient operation, but the measurement precision is lower, the measurement precision requirement of the factory production which is increasing cannot be met, and more researchers turn to the deep research of the wading method.
Fiber optic sensing technology has been extensively studied since the 20 th century, the 70 s. With the development of microwave photon technology, the microwave photon technology has shown significant advantages in the aspects of high-frequency electrical signal generation, high-frequency electrical information processing and the like, researchers of optical sensing technology are inspired from the development of the microwave photon technology, the microwave photon technology is applied to optical fiber sensing, information to be measured is extracted through measurement of certain microwave parameters, and a new interdiscipline-microwave photonics is formed. In 2017, researchers have proposed a sensing method using microwave photon filtering technology[6]The demodulation process of the sensor is carried out in the microwave domain[7]。
The device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure do not need to demodulate the wavelength by using a spectrometer, greatly reduce the system cost, have the flexibility in transmission distance, can realize the remote distributed detection of the liquid refractive index (salinity), and meet the application requirements of actual industrial production.
Reference documents:
[1]ALLEN L V.Quality control analytical methods：refractive index[J].International Journal of Pharmaceutical Compounding，2015，19(1)：43-47.
[2]JIN Y L，CHEN J Y，XU L，et al.Refractive index measurement for biomaterial samples by total internal Reflection[J].Physics in Medicine and Biology，2006，51(20)：N371-N379.
[3]MIIA M，HAST J，RISTO M.Refractive index detection with self-mixing interferometry for biosensing applications[C].International Society for Optics and Photonics，SPIE BiOS，2007，6445：64450V-64450V-10.
[4]KUHN S，HEIN S，HUPEL C，et al.Modelling the refractive index behavior of Al，P-doped SiO2，fabricated by means of all-solution doping，in the vicinity of Al∶P＝1∶1[J].Optical Materials Express，2018，8(5)：1328-1340.
[5] suyudong, weiyong, wuliang, et al. step-index multimode fiber-clad plasmon resonance sensor [ J ] optical precision engineering, 2019, 27 (12): 2525-2533.
[6]HERVAS J，RICCHIUTI A L，LI W，et al.Microwave photonics for optical sensors[J].IEEE J.Sel.Top.Quantum Electron.，2017，23(2)：327-339.
[7]WEI T，HUANG J，LAN X W，et al.Optical fiber sensor based on a radio frequency Mach-Zehnder interferometer[J].Opt.Lett.，2012，37(4)：647-649.
Disclosure of Invention
The invention aims to provide a method for measuring the refractive index (salinity) of liquid by using a microwave photon filter, and the technical scheme of the invention is as follows in order to achieve the aim:
the invention provides a device for measuring the refractive index (salinity) of liquid by using a microwave photon filter with a Mach-Zehnder interferometer structure, which comprises:
a broad spectrum light source (101) for generating Amplified spontaneous emission light (Amplified spontaneous emission light), an output port of which is connected with an input port of the electro-optical modulator (102);
an electro-optical modulator (102) for modulating a frequency range f1-f2The radio frequency signal is modulated on the electro-optical modulator, namely a frequency spectrum taking FSR (free spectral range) as a period is formed, wherein FSR is a free spectral range of a microwave photon filter, and FSR is c/(2 n)e|L2-L1C is the propagation velocity of light, neIs the refractive index of the sensing fiber and the reference fiber, L1And L2Are respectively a transmissionLengths of the optical sensing fiber (203) and the reference fiber (204), and f1And f2Satisfies the following conditions: l f2-f1-nFSR; the electro-optical modulator (102) comprises two ports, wherein an input port of the electro-optical modulator is connected with an output port of the wide-spectrum light source (101), and an output port of the electro-optical modulator is connected with one input port of the Mach-Zehnder interferometer (103);
a Mach-Zehnder interferometer (103) comprising an input port a and an input port b, and an output port c and an output port d, wherein the a port or the b port of the Mach-Zehnder interferometer (103) is connected with the output port of the electro-optical modulator (102); the Mach-Zehnder interferometer (103) is used for forming microwave photon interference, one arm of the Mach-Zehnder interferometer (103) comprises two different types of optical fiber joints, the two different types of optical fiber joints are connected, a solution to be measured is positioned between the two different types of optical fiber joints of one arm of the Mach-Zehnder interferometer (103), and when the refractive index (salinity) of the liquid to be measured is changed, the radio frequency loss of one arm of the Mach-Zehnder interferometer (103) is changed, so that the frequency response of the microwave photon filter is influenced;
a photodetector (104) connected to the c-port or d-port of the Mach-Zehnder interferometer (103) for converting the optical signal modulated with the radio frequency signal into an electrical signal;
and the spectrum analysis module (105) is used for converting the electric signals output by the photoelectric detector into frequency domain output, and forming the frequency response of the microwave photon filter by responding to the electric signals with different frequencies, namely displaying the spectrum of the output signal.
Furthermore, the microwave photon sensing system forms microwave photon interference through the optical path difference between the upper and lower arm optical signals of the Mach-Zehnder interferometer (103);
further, the Mach-Zehnder interferometer (103) is composed of an input 2 × 2 optical coupler (201) and an output 2 × 2 optical coupler (202);
further, the input 2 × 2 optical coupler (201) comprises two input optical ports a1 and b1 and two output optical ports c1 and d1, wherein a1 and b1 are respectively used as an a port and a b port of the mach-zehnder interferometer (103), c1 and d1 are respectively connected with the sensing optical fiber (203) and the reference optical fiber (204), or c1 and d1 are respectively connected with the reference optical fiber (204) and the sensing optical fiber (203);
further, an output 2 × 2 optical coupler (202) comprising two input optical ports a2 and b2, and two output optical ports c2 and d2, wherein c2 and d2 respectively serve as a c port and a d port of the mach-zehnder interferometer (103), a2 and b2 respectively connect the sensing fiber (203) and the reference fiber (204), or a2 and b2 respectively connect the reference fiber (204) and the sensing fiber (203);
furthermore, an optical attenuator (205) is added to one arm of the Mach-Zehnder interferometer (103) including a reference fiber (204), and the notch depth E of the frequency resonance curve of the microwave photonic filter is adjusted by adjusting the optical attenuator (205)r(dB) is large;
further, the notch depth E of the frequency resonance curve of the microwave photon filterr(dB) is defined as: the difference between the measured maximum RF power value and the measured minimum RF power value in the swept spectrum, i.e. Er＝Pmax-Pmin，PminIs the minimum radio frequency power value, P, in the swept spectrummaxIs the maximum rf power value in the swept spectrum.
Further, the reference fiber (204) comprises two different types of fiber connectors, namely an APC (angle Physical contact) type fiber end face and a PC (Physical contact) type fiber end face, and the two different types of fiber connectors are connected;
furthermore, the end face of the APC (angle Physical contact) type optical fiber is in inclined Physical contact, the end face of the optical fiber is usually ground into an inclined plane with an angle of 8 degrees, so that the end face of the optical fiber is tighter, the PC (Physical contact) type port is an optical fiber port which is in Physical contact by adopting a micro-sphere surface grinding and polishing technology, the surface of a ferrule of the PC (Physical contact) type port is ground into a slight spherical surface, and the fiber core of the optical fiber is positioned at the highest point of bending, so that an air gap between the optical fiber components can be effectively reduced, and the end faces of the two optical fibers are in Physical contact;
further, in the system, the liquid to be measured is placed between two different types of connected optical fiber joints included in the reference optical fiber (204);
further, the microwave photonic filter sensing system may employThe measurement method is characterized in that when the refractive index of the end face of the optical fiber in contact with the liquid changes, the intensity of the detected radio frequency signal changes, so that the notch depth E of the microwave photon filter is changedrIn which ErIs the difference between the maximum and minimum values in the frequency response of the microwave photonic filter.
Further, the sensing system of the microwave photonic filter of the present invention has the following features:
the minimum radio frequency power at the resonant frequency of the microwave photonic filter may be determined according to the following method:
a) determining output light power P of a broad spectrum light sourceBOSAnd the power of the radio frequency signal loaded on the electro-optical modulator, or the radio frequency voltage value corresponding to the radio frequency power;
b) under the refractive index (salinity) of each liquid, measuring the sweep frequency spectrum of the photoelectric detector,
reading n minimum values P in swept spectrumminn(dBm)，{Pmin1，Pmin2...Pminn}; calculating n minimum values
Average value of (i), i.e.
c) Or measuring the sweep frequency spectrum of the photoelectric detector under the refractive index (salinity) of each liquid,
reading one of n minimum values in the swept spectrum, repeating the sweep n1 times, and calculating n1 minimum values
Average value of (i), i.e.
d) The above-mentioned methods of measuring according to a) and b) or according to a) and c) are formed into a database.
Further, in actual measurement, the refractive indexes of different liquids to be measured are measured by the detection method, and the obtained result is compared with the database formed in the method.
Compared with the prior art, the invention has the following beneficial effects:
further, in actual measurement, the refractive indexes of different liquids to be measured are measured by the detection method, and the obtained result is compared with the database formed in the method.
Compared with the prior art, the invention has the following beneficial effects:
1. the light source used by the device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure is a wide-spectrum light source, the output performance is more stable, and any polarization control device is not required to be used in the system.
2. The device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure modulate the output light by an external modulation method;
3. the invention provides a device and a method for measuring the refractive index (salinity) of liquid by utilizing a microwave photonic filter with a Mach-Zehnder interferometer structure, wherein the end face of an optical fiber is used as a sensing device;
4. the device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure provided by the invention measure the end face liquid refractive index through the output electric spectrum amplitude change, and a spectrometer is not needed to demodulate the wavelength, so that the system cost is reduced;
5. the device and the method for measuring the liquid refractive index (salinity) by using the microwave photonic filter with the Mach-Zehnder interferometer structure can realize long-distance measurement of the liquid refractive index (salinity).
Drawings
FIG. 1 is a schematic diagram of a 2x2 optical coupler for forming a Mach-Zehnder interferometer according to the present invention
FIG. 2 is a schematic diagram of a system for measuring liquid refractive index (salinity) by using a microwave photonic filter with a Mach-Zehnder interferometer structure (without adding an optical attenuator (205))
FIG. 3 is a schematic diagram of a system for measuring liquid refractive index (salinity) by using a microwave photonic filter with a Mach-Zehnder interferometer structure (with an optical attenuator (205) added) according to the present invention
FIG. 4 is a schematic diagram of two different types of optical fiber connectors connected to each other for detecting a liquid to be detected according to the present invention
FIG. 5 is a microwave photon response curve diagram for detecting different liquid refractive indexes (salinity) by adopting the invention
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the drawings and examples.
As shown in fig. 1, the 2x2 optical coupler for forming a mach-zehnder interferometer provided by the present invention includes two input ports and two output ports;
as shown in FIG. 2, Amplified Spontaneous Emission (ASE) emitted from a broad-spectrum light source (101) passes through an electro-optical modulator (102), modulating with radio frequency signal, the modulated microwave signal passes through Mach-Zehnder interferometer (103), in the interferometer, an optical signal is divided into two paths of optical signals through an input port of an input 2x2 optical coupler (201), one path of optical signal reaches the output 2x2 optical coupler (202) through a reference optical fiber (204) positioned on the upper arm of the Mach-Zehnder interferometer (103), the other path of optical signal reaches the output 2x2 optical coupler (202) after passing through two different types of optical fiber end faces connected with a sensing optical fiber (203), because the two paths of signals have optical path difference, interference is finally formed, the interference is received by the photoelectric detector (105), and finally the interference is demodulated and enters the spectrum analyzer (106) for data acquisition so as to be used for data processing subsequently.
As shown in FIG. 3, Amplified Spontaneous Emission (ASE) emitted from a broad-spectrum light source (101) passes through an electro-optical modulator (102), modulating with radio frequency signal, the modulated microwave signal passes through Mach-Zehnder interferometer (103), in the interferometer, an optical signal is divided into two paths of optical signals through an input port of an input 2x2 optical coupler (201), one path of optical signal reaches an output 2x2 optical coupler (202) through a reference optical fiber (204) and an optical attenuator (205) which are positioned on the upper arm of a Mach-Zehnder interferometer (103), the other path of optical signal reaches the output 2x2 optical coupler (202) after passing through two different types of optical fiber end faces connected with a sensing optical fiber (203), because the two paths of signals have optical path difference, interference is finally formed, the interference is received by the photoelectric detector (105), and finally the interference is demodulated and enters the spectrum analyzer (106) for data acquisition so as to be used for data processing subsequently.
As shown in fig. 4, (a) and (b) are two different types of optical fiber connector connection modes for connecting the sensing optical fiber (204), and one of the connection modes can be selected in specific implementation.
As shown in FIG. 5, the length L of the sensing fiber (203) is selected13m, the length L of the reference fiber (204)2The microwave photon response curve is measured when the refractive index (salinity) of the liquid is 0 per thousand, 5 per thousand, 10 per thousand, 15 per thousand, 20 per thousand, 25 per thousand, 30 per thousand, 35 per thousand and 40 per thousand respectively by adopting the scheme of the invention shown in the figure 2.
Claims (7)
1. An apparatus for measuring refractive index (salinity) of liquid by using a microwave photonic filter of a Mach-Zehnder interferometer structure includes:
a broad spectrum light source (101) for generating Amplified spontaneous emission light (Amplified spontaneous emission light), an output port of which is connected with an input port of the electro-optical modulator (102);
an electro-optical modulator (102) for modulating a frequency range f1-f2The radio frequency signal is modulated on the electro-optical modulator, namely a frequency spectrum taking FSR (free spectral range) as a period is formed, wherein FSR is a free spectral range of a microwave photon filter, and FSR is c/(2 n)e|L2-L1C is the propagation velocity of light, neIs the refractive index of the sensing fiber and the reference fiber, L1And L2The lengths of the sensing fiber (203) and the reference fiber (204), respectively, and f1And f2Satisfies the following conditions: l f2-f1-nFSR; the electro-optical modulator (102) comprises two ports, an input port of the electro-optical modulator is connected with an output port of the wide-spectrum light source (101), and an output port of the electro-optical modulator is connected with one input of the Mach-Zehnder interferometer (103)A port;
a Mach-Zehnder interferometer (103) comprising an input port a and an input port b, and an output port c and an output port d, wherein the a port or the b port of the Mach-Zehnder interferometer (103) is connected with the output port of the electro-optical modulator (102); the Mach-Zehnder interferometer (103) is used for forming microwave photon interference, one arm of the Mach-Zehnder interferometer (103) comprises two different types of optical fiber joints, the two different types of optical fiber joints are connected, a solution to be measured is positioned between the two different types of optical fiber joints of one arm of the Mach-Zehnder interferometer (103), and when the refractive index (salinity) of the liquid to be measured is changed, the radio frequency loss of one arm of the Mach-Zehnder interferometer (103) is changed, so that the frequency response of the microwave photon filter is influenced;
a photodetector (104) connected to the c-port or d-port of the Mach-Zehnder interferometer (103) for converting the optical signal modulated with the radio frequency signal into an electrical signal;
and the spectrum analysis module (105) is used for converting the electric signals output by the photoelectric detector into frequency domain output, and forming the frequency response of the microwave photon filter by responding to the electric signals with different frequencies, namely displaying the spectrum of the output signal.
2. The system of claim 1, wherein:
the Mach-Zehnder interferometer (103) includes:
an input 2x2 optical coupler (201) comprising two input optical ports a1 and b1 and two output optical ports c1 and d1, wherein a1 and b1 are respectively used as an a port and a b port of a Mach-Zehnder interferometer (103), c1 and d1 are respectively connected with a sensing optical fiber (203) and a reference optical fiber (204), or c1 and d1 are respectively connected with the reference optical fiber (204) and the sensing optical fiber (203);
an output 2 × 2 optical coupler (202) comprising two input optical ports a2 and b2, and two output optical ports c2 and d2, wherein c2 and d2 respectively serve as a c port and a d port of a mach-zehnder interferometer (103), a2 and b2 respectively connect a sensing fiber (203) and a reference fiber (204), or a2 and b2 respectively connect the reference fiber (204) and the sensing fiber (203);
a sensing fiber (203) having a length L1The sensing optical fiber comprises two different types of optical fiber joints, the two different types of optical fiber joints are connected, and the solution to be detected is positioned between the two different types of optical fiber joints;
a reference fiber (204) having a length L2And the microwave photonic interference device is placed in a place with stable temperature and stress to form microwave photonic interference.
3. The system of claim 1, wherein:
the sensing fiber (203) includes two different types of fiber connectors, a PC (Physical contact) type fiber connector and an APC (angle Physical contact) type fiber connector.
4. The system of claim 1, wherein:
in order to ensure that the microwave photonic filter can work normally and realize sensing with higher sensitivity, an optical attenuator (205) is added in a reference optical fiber (204), and the notch depth E of the frequency resonance curve of the microwave photonic filter is enabled to be adjusted by adjusting the optical attenuator (205)r(dB) is larger, wherein the notch depth Er (dB) of the frequency resonance curve of the microwave photon filter is defined as: the difference between the maximum RF power value and the minimum RF power value in the swept spectrum, i.e. Er＝Pmax-Pmin，PmaxFor sweeping the maximum RF power value in the spectrum, PminIs the minimum rf power value in the swept spectrum.
5. The system of claim 1, wherein:
when the liquids to be detected are different, the detected minimum radio frequency signal power is changed due to the fact that the refractive indexes of the liquids are different; the liquid refractive index (salinity) sensing system of the microwave photonic filter can be obtained by adopting a method for measuring the minimum radio frequency power at the resonant frequency of the microwave photonic filter.
6. The system of claim 1, wherein the first and second optical elements are selected from the group consisting of a laser, and a laser,
the minimum radio frequency power at the resonant frequency of the microwave photonic filter may be determined according to the following method:
a) determining output light power P of a broad spectrum light sourceBOSAnd the power of the radio frequency signal loaded on the electro-optical modulator, or the radio frequency voltage value corresponding to the radio frequency power;
b) under the refractive index (salinity) of each liquid, measuring the sweep frequency spectrum of the photoelectric detector,
reading n minimum values P in swept spectrumminn(dBm)，{Pmin1，Pmin2...Pminn}; calculating n minimum values
Average value of (i), i.e.
c) Or measuring the sweep frequency spectrum of the photoelectric detector under the refractive index (salinity) of each liquid,
reading one of n minimum values in the swept spectrum, repeating the sweep n1 times, and calculating n1 minimum values
Average value of (i), i.e.
d) The above-mentioned methods of measuring according to a) and b) or according to a) and c) are formed into a database.
7. The system of claim 1, wherein:
in actual measurement, for different liquids to be measured, the corresponding detection method in claim 6 is used for measurement, and the obtained result is compared with the database formed in the method in claim 6, so as to obtain the refractive index (salinity) of the liquids to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111207064.5A CN114354542A (en) | 2021-10-10 | 2021-10-10 | Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111207064.5A CN114354542A (en) | 2021-10-10 | 2021-10-10 | Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114354542A true CN114354542A (en) | 2022-04-15 |
Family
ID=81095533
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111207064.5A Pending CN114354542A (en) | 2021-10-10 | 2021-10-10 | Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114354542A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100772557B1 (en) * | 2006-06-15 | 2007-11-02 | 경북대학교 산학협력단 | Apparatus for measurement based on micro-optic mach-zehnder interferometer |
| CN105092531A (en) * | 2015-08-31 | 2015-11-25 | 浙江大学 | Dual-ring resonant cavity-based Mach-Zehnder interferometer optical biosensor |
| CN107941754A (en) * | 2017-11-14 | 2018-04-20 | 陈志忠 | A kind of measuring method of gas refracting index |
| US20190273562A1 (en) * | 2018-03-01 | 2019-09-05 | Thales | Dual-band photonic device and method for converting frequency |
| CN112834070A (en) * | 2020-12-30 | 2021-05-25 | 上海第二工业大学 | Method for measuring temperature of optical fiber end face contact gas by using microwave photon filter |
| CN112857609A (en) * | 2020-12-30 | 2021-05-28 | 上海第二工业大学 | Microwave photonic filter system and method for measuring refractive index of contact liquid on end face of optical fiber |
-
2021
- 2021-10-10 CN CN202111207064.5A patent/CN114354542A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100772557B1 (en) * | 2006-06-15 | 2007-11-02 | 경북대학교 산학협력단 | Apparatus for measurement based on micro-optic mach-zehnder interferometer |
| CN105092531A (en) * | 2015-08-31 | 2015-11-25 | 浙江大学 | Dual-ring resonant cavity-based Mach-Zehnder interferometer optical biosensor |
| CN107941754A (en) * | 2017-11-14 | 2018-04-20 | 陈志忠 | A kind of measuring method of gas refracting index |
| US20190273562A1 (en) * | 2018-03-01 | 2019-09-05 | Thales | Dual-band photonic device and method for converting frequency |
| CN112834070A (en) * | 2020-12-30 | 2021-05-25 | 上海第二工业大学 | Method for measuring temperature of optical fiber end face contact gas by using microwave photon filter |
| CN112857609A (en) * | 2020-12-30 | 2021-05-28 | 上海第二工业大学 | Microwave photonic filter system and method for measuring refractive index of contact liquid on end face of optical fiber |
Non-Patent Citations (1)
| Title |
|---|
| QIAN CHEN，LIN GUI: "Research on type sensing of optical fiber connector using microwave photonic interference", 《PROCEEDINGS OF SPIE》, 8 January 2021 (2021-01-08) * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112857609B (en) | Microwave photon filter system and method for measuring refractive index of contact liquid of optical fiber end face | |
| CN107727365B (en) | A kind of system using reflectance spectrum fineness measurement optical waveguide loss | |
| CN112834070B (en) | Method for measuring contact gas temperature of optical fiber end face by utilizing microwave photon filter | |
| CN109186643B (en) | Accurate sensing system and sensing method based on reflection function resonant filter | |
| CN106225666A (en) | A kind of quantum fibre optic interferometer | |
| CN105044030A (en) | Coupling refractive index meter for evanescent field among optical fibers and detecting method of coupling refractive index meter | |
| US20110295511A1 (en) | Apparatus and method for detecting the presence of an agent | |
| CN207300268U (en) | Fiber Bragg Grating FBG demodulating equipment | |
| CN107314888B (en) | The polarization property measurement method of multi-functional lithium niobate integrated device | |
| Li et al. | Reflective microring sensing probe based on narrowband microwave photonic notch filter | |
| CN105526971A (en) | A temperature/refractive index two-parameter sensor based on cascading coupled micro-cavities | |
| CN111537445A (en) | Ring resonant cavity enhanced liquid component and concentration sensor based on evanescent wave | |
| CN110389111A (en) | One kind being based on bimodulus core shift optical fiber interference type index sensor | |
| Yang et al. | Highly sensitive integrated photonic sensor and interrogator using cascaded silicon microring resonators | |
| CN205825899U (en) | A kind of quantum fibre optic interferometer | |
| CN112710248A (en) | Reflective birefringence interference strain sensor based on fully polarization-maintaining optical fiber | |
| CN114354542A (en) | Device and method for measuring liquid refractive index (salinity) by using microwave photonic filter with Mach-Zehnder interferometer structure | |
| CN101413886B (en) | Apparatus for detecting liquid refractive index by plasma resonance optical fiber sensor | |
| CN103344607A (en) | Laser wavelength detection control device in TDLAS (Tunable Diode Laser Absorption Spectroscopy) and control method thereof | |
| Feng et al. | Intensity-modulated liquid-level and temperature sensor based on cascaded air bubble and fiber Bragg grating interferometer | |
| CN111751330B (en) | Plasmon gas sensor based on D-shaped optical fiber graphene heterojunction | |
| CN205958141U (en) | Temperature -detecting device based on receive long period fiber grating sensor a little | |
| CN211697472U (en) | Mach-Zehnder interferometer type CO based on optical fiber taper2Sensor with a sensor element | |
| CN113218913A (en) | Temperature-compensated chirped fiber grating sensor for measuring solution concentration | |
| CN206832671U (en) | A kind of Sagnac interferometer hydrogen gas sensors based on optical fiber ring laser |
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 |