CN113030021B - Liquid refractive index in-situ sensor - Google Patents
Liquid refractive index in-situ sensor Download PDFInfo
- Publication number
- CN113030021B CN113030021B CN202110187634.2A CN202110187634A CN113030021B CN 113030021 B CN113030021 B CN 113030021B CN 202110187634 A CN202110187634 A CN 202110187634A CN 113030021 B CN113030021 B CN 113030021B
- Authority
- CN
- China
- Prior art keywords
- liquid
- refractive index
- laser
- light intensity
- cavity
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
Abstract
The invention provides a liquid refractive index in-situ sensor, which belongs to the technical field of liquid refractive index sensors and comprises a prism, wherein a V-shaped groove is formed in the prism and used for containing liquid to be detected; the laser is used for emitting a laser signal and is incident to the prism, and the laser signal is refracted through the liquid to be measured in the V-shaped groove; the FP cavity is used for receiving laser signals refracted by the liquid to be measured in the V-shaped groove; the light intensity detection device is used for detecting the light intensity of the laser signal emitted by the FP cavity and sending the light intensity to the controller; and the controller is used for calculating the refractive index of the liquid to be measured according to the light intensity. According to the invention, the variation of the refractive index of the liquid can be obtained by detecting the variation of the emergent light intensity of the FP cavity through the optical power meter or the CMOS camera, so that the temperature, salt and depth variation of the liquid can be detected.
Description
Technical Field
The invention relates to the technical field of liquid refractive index sensors, in particular to a liquid refractive index in-situ sensor.
Background
The refractive index is an important physical quantity characterizing the optical properties of the transparent medium. The refractive index can be used to understand the optical properties, concentration, composition and dispersion of the transparent liquid. Therefore, the accurate measurement of the refractive index of the material has great significance in engineering and theoretical research.
At present, the existing refractive index measurement methods include other refractive index measurement schemes, including optical refractive index, optical total reflection and fiber grating, surface plasmon resonance, interferometry, abbe's refractive index method, two-dimensional photonic crystals, and the like, in addition to the empirical formula for estimating the refractive index. Among them, the photorefractive method exhibits excellent performance in terms of anti-electromagnetic interference, higher sensitivity, and smaller sensing unit.
Calculating the refractive index of a measured liquid by measuring the deflection angle of light passing through a transparent liquid is a common refractive index measurement scheme. The small deflection angle is measured based on the PSD, the resolution ratio is low, and the measurement resolution ratio is difficult to be improved to 10-7Above order of magnitude, the measurement requirements cannot be met.
Disclosure of Invention
The invention aims to provide a liquid refractive index in-situ sensor based on a V-shaped groove for detecting the refractive index of liquid in real time, so as to solve at least one technical problem in the background technology.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a liquid refractive index in-situ sensor, which comprises:
the liquid detector comprises a prism, wherein a V-shaped groove is formed in the prism and used for containing liquid to be detected;
the laser is used for emitting a laser signal and is incident to the prism, and the laser signal is refracted through the liquid to be measured in the V-shaped groove;
the FP cavity is used for receiving laser signals refracted by the liquid to be measured in the V-shaped groove;
the light intensity detection device is used for detecting the light intensity of the laser signal emitted by the FP cavity and sending the light intensity to the controller;
and the controller is used for calculating the refractive index of the liquid to be measured according to the light intensity.
Preferably, the laser device further comprises a collimator, and a laser signal emitted by the laser device enters the prism after being collimated by the collimator.
Preferably, the laser, the FP cavity, the light intensity detection device, the controller and the collimator are all disposed in a package housing.
Preferably, the prism is arranged at the laser signal emitting end of the packaging shell, and the laser signal is incident to the prism from an emitting port of the laser signal emitting end on the packaging shell.
Preferably, the laser signal emitting end of the package shell is further provided with an incident port, and the laser signal reflected by the prism is incident into the FP cavity in the package shell through the incident port.
Preferably, the device further comprises a focusing lens, and the focusing lens is arranged between the FP cavity and the light intensity detection device.
Preferably, the light intensity detecting device is an optical power meter or a CMOS camera.
The invention has the beneficial effects that: the variation of the refractive index of the liquid can be obtained by detecting the variation of the emergent light intensity of the FP cavity through an optical power meter or a CMOS camera, the detection is accurate, the resolution ratio is high, and therefore the temperature and salinity variation of the detected liquid can be calculated.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a functional schematic block diagram of a liquid refractive index in-situ sensor according to an embodiment of the present invention.
Wherein: 1-a prism; 2-V type groove; 3-liquid to be measured; 4-a laser; 5-FP cavity; 6-light intensity detection means; 7-a controller; 8-a collimator; 9-packaging shell; 10-focusing lens.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by way of the drawings are illustrative only and are not to be construed as limiting the invention.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of describing the patent and for the simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
For the purpose of facilitating an understanding of the present invention, the present invention will be further explained by way of specific embodiments with reference to the accompanying drawings, which are not intended to limit the present invention.
It should be understood by those skilled in the art that the drawings are merely schematic representations of embodiments and that the elements shown in the drawings are not necessarily required to practice the invention.
Examples
As shown in fig. 1, an embodiment of the present invention provides an in-situ liquid refractive index sensor, including:
The angle of the bottom angle of the V-groove 2 and the length of the two sides can be chosen by the person skilled in the art as appropriate for the particular situation.
And the laser 4 is used for emitting laser signals and is incident to the prism 1, and the laser signals are refracted through the liquid 3 to be detected in the V-shaped groove 2. The laser 4 may be a solid laser or a semiconductor laser, and the operating wavelength of the laser 4 is 532nm or other visible light bands.
The FP cavity 5, namely a Fabry-Perot cavity, is used for receiving laser signals refracted by the liquid 3 to be measured in the V-shaped groove 2.
The light intensity detection device 6 is used for detecting the light intensity of the laser signal emitted by the FP cavity 5 and sending the light intensity to the controller 7; and the controller 7 is used for calculating the refractive index of the liquid 3 to be measured according to the light intensity. The controller 7 can control the laser and also process the light intensity collected by the optical power meter or the CMOS camera.
The laser device further comprises a collimator 8, and laser signals emitted by the laser 4 are collimated by the collimator 8 and then enter the prism 1. The laser 4, the FP cavity 5, the light intensity detection device 6, the controller 7 and the collimator 8 are all arranged in a packaging shell 9. The prism 1 is arranged at the laser signal emitting end of the packaging shell 9, and a laser signal is incident to the prism 1 from an emitting port of the laser signal emitting end on the packaging shell 9.
And the laser signal emitting end of the packaging shell 9 is also provided with an incident port, and a laser signal reflected by the prism 1 is incident into the FP cavity 5 in the packaging shell 9 through the incident port.
The device further comprises a focusing lens 10, wherein the focusing lens 10 is arranged between the FP cavity 5 and the light intensity detection device 6. The light intensity detection device 6 is an optical power meter or a CMOS camera.
The variation of the refractive index of the liquid can be obtained by detecting the variation of the emergent light intensity of the FP cavity through an optical power meter or a CMOS camera, the detection is accurate, the resolution ratio is high, and therefore the temperature and salinity variation of the detected liquid can be calculated.
Example 2
In the bulk refractive index in-situ sensor provided in embodiment 2 of the present invention, a bottom angle of the V-shaped groove 2 is 90 degrees, each side of the V-shaped groove 2 is 4 centimeters, a length of the FP cavity 5 is 1 centimeter, light emitted from the laser 4 passes through the collimating lens structure and then becomes collimated light, the collimated light enters the V-shaped groove 2 at an angle of 60 degrees, is refracted after passing through the liquid to be measured 3 in the V-shaped groove 2, the refracted light reaches the FP cavity 5 after being reflected, transmitted light passing through the FP cavity 5 is converged by the focusing lens and then irradiates the optical power meter or the CMOS camera, laser uniformly irradiating a photosensitive surface of the CMOS camera is on pixels of each CMOS camera, and pixel gray values of each CMOS camera are accumulated, the light intensity is calculated through the accumulated pixel gray value, the detected light intensity is input into the controller through the optical power meter or the CMOS camera, and the liquid refractive index is obtained through calculation of the controller.
The concrete steps are as follows:
the light emitted by the laser irradiates the V-shaped groove at a beta angle, and according to the law of refraction, the refraction angle gamma is as follows:
the angle after refraction by the second surface of the V-shaped groove 2 is omega, and the relationship between the incident angle beta and the refraction angle omega is as follows:
wherein n is1Is the refractive index of the prism, n2And theta is the refractive index of the liquid to be measured, and is the bottom angle of the V-shaped groove.
The change of the refractive index of the liquid to be measured can cause the incident angle of incidence to the FP chamber 5 to change, thereby causing the emergent light intensity of the FP chamber 5 to change, and the magnitude relation between the light intensity of the emergent light and the change of the refractive index of the liquid is as follows:
wherein, Delta ItIs the amount of change, Δ n, in the emergent light of the FP cavity2Is the variation of the refractive index of the liquid, delta is the optical path difference of the emergent adjacent light of the FP cavity, R is the reflectivity of the FP cavity, n is the refractive index of the FP cavity, h is the cavity length of the FP cavity, theta is the bottom angle of the V-shaped groove, I0Denotes the intensity of the laser light before it enters FP, and λ denotes the wavelength of the laser light.
The variation of the refractive index of the liquid to be measured can be obtained by detecting the variation of the emergent light intensity of the FP cavity through the optical power meter or the CMOS camera.
The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.
Although the present disclosure has been described with reference to the specific embodiments shown in the drawings, it is not intended to limit the scope of the present disclosure, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive faculty based on the technical solutions disclosed in the present disclosure.
Claims (7)
1. An in situ liquid refractive index sensor, comprising:
the liquid detection device comprises a prism (1), wherein a V-shaped groove (2) is formed in the prism (1), and the V-shaped groove (2) is used for containing liquid (3) to be detected;
the laser device (4) is used for emitting laser signals and is incident to the prism (1), and the laser signals are refracted through the liquid (3) to be detected in the V-shaped groove (2);
the FP cavity (5) is used for receiving laser signals refracted by the liquid (3) to be measured in the V-shaped groove (2); the change of the refractive index of the liquid to be measured can cause the change of the incident angle of the liquid to be measured entering the FP cavity (5), so that the light intensity of a laser signal emitted by the FP cavity (5) is changed;
the light intensity detection device (6) is used for detecting the light intensity of the laser signal emitted by the FP cavity (5) and sending the light intensity to the controller (7);
and the controller (7) is used for calculating the refractive index of the liquid (3) to be measured according to the light intensity.
2. The in situ liquid refractive index sensor of claim 1, wherein:
the laser device is characterized by further comprising a collimator (8), and laser signals emitted by the laser device (4) are collimated by the collimator (8) and then enter the prism (1).
3. The in situ liquid refractive index sensor of claim 2, wherein:
the laser (4), the FP cavity (5), the light intensity detection device (6), the controller (7) and the collimator (8) are all arranged in a packaging shell (9).
4. The in situ liquid refractive index sensor of claim 3, wherein:
the prism (1) is arranged at the laser signal emitting end of the packaging shell (9), and a laser signal is incident to the prism (1) from an emitting port of the laser signal emitting end on the packaging shell (9).
5. The in situ liquid refractive index sensor of claim 4, wherein:
and the laser signal emitting end of the packaging shell (9) is also provided with an incident port, and a laser signal reflected by the prism (1) is incident into the FP cavity (5) in the packaging shell (9) through the incident port.
6. The in situ liquid refractive index sensor of claim 5, wherein:
the LED illumination device further comprises a focusing lens (10), wherein the focusing lens (10) is arranged between the FP cavity (5) and the light intensity detection device (6).
7. The in situ liquid refractive index sensor according to any one of claims 1 to 6, wherein:
the light intensity detection device (6) is an optical power meter or a CMOS camera.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110187634.2A CN113030021B (en) | 2021-02-18 | 2021-02-18 | Liquid refractive index in-situ sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110187634.2A CN113030021B (en) | 2021-02-18 | 2021-02-18 | Liquid refractive index in-situ sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113030021A CN113030021A (en) | 2021-06-25 |
| CN113030021B true CN113030021B (en) | 2022-04-22 |
Family
ID=76461365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110187634.2A Active CN113030021B (en) | 2021-02-18 | 2021-02-18 | Liquid refractive index in-situ sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113030021B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104596559A (en) * | 2015-01-21 | 2015-05-06 | 哈尔滨工业大学深圳研究生院 | Optical fiber F-P multifunctional sensor based on microporous optical reflection diaphragm |
| CN108981810A (en) * | 2018-07-17 | 2018-12-11 | 西安石油大学 | A kind of preparation method of novel optical fiber F-P cavity senser element |
| CN110044847A (en) * | 2019-05-16 | 2019-07-23 | 南开大学 | It is a kind of not by the total internal reflection type refractive index sensing method of light source drift effect |
| CN212364075U (en) * | 2020-07-03 | 2021-01-15 | 重庆科技学院 | Portable refractive index measuring device |
-
2021
- 2021-02-18 CN CN202110187634.2A patent/CN113030021B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104596559A (en) * | 2015-01-21 | 2015-05-06 | 哈尔滨工业大学深圳研究生院 | Optical fiber F-P multifunctional sensor based on microporous optical reflection diaphragm |
| CN108981810A (en) * | 2018-07-17 | 2018-12-11 | 西安石油大学 | A kind of preparation method of novel optical fiber F-P cavity senser element |
| CN110044847A (en) * | 2019-05-16 | 2019-07-23 | 南开大学 | It is a kind of not by the total internal reflection type refractive index sensing method of light source drift effect |
| CN212364075U (en) * | 2020-07-03 | 2021-01-15 | 重庆科技学院 | Portable refractive index measuring device |
Non-Patent Citations (1)
| Title |
|---|
| "基于法布里珀罗干涉仪的液体浓度实时检测系统的研究";杨秀芳 等;《光学学报》;20051031;第25卷(第10期);第1343-1346页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113030021A (en) | 2021-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kasarova et al. | Analysis of the dispersion of optical plastic materials | |
| EP1031828B1 (en) | Integrated-optical sensor and method for integrated-optically sensing a substance | |
| US4436420A (en) | Optical fluid analyzing apparatus and method | |
| CN108594257B (en) | Speed measuring sensor based on Doppler effect and calibration method and measuring method thereof | |
| CN100526821C (en) | Thin film type optical fiber temperature sensor and its temperature sensing method | |
| CN2551992Y (en) | Brine concentration measurer | |
| Zhao et al. | Monitoring technology of salinity in water with optical fiber sensor | |
| CN101476936B (en) | Fabry-Perot cavity based array type miniature optical spectrometer | |
| CN104777077A (en) | Liquid viscous coefficient measuring device and measuring method based on optical trap effect | |
| RU2599410C1 (en) | Method for measuring height of transparent liquid level and device for its implementation | |
| CN113030021B (en) | Liquid refractive index in-situ sensor | |
| CN101813622A (en) | Optical-waveguide two-channel interferometer array | |
| US20190310189A1 (en) | Apparatus and method for determining a refractive index | |
| CN1811361A (en) | Optical fiber temperature measuring instrument | |
| CN108646047B (en) | Speed measuring sensor based on Doppler effect band correction structure and calibration and measurement method | |
| Wuchrer et al. | A compact readout platform for spectral-optical sensors | |
| CN104749137A (en) | Liquid refractive index measurement system and method | |
| US5110208A (en) | Measurement of average density and relative volumes in a dispersed two-phase fluid | |
| RU2506568C2 (en) | Device to measure index of refraction | |
| CN101806731B (en) | Differential solution concentration measuring method and device based on CCD (Charge Coupled Device) and trapezoidal vitreous body | |
| CN113654671B (en) | Narrow-bandgap semiconductor-based optical wavelength demodulation structure, demodulation method and sensor | |
| CN1323980A (en) | Light wavelength measuring technology based on wedged Fabry-Perot interference filter | |
| CN209727122U (en) | A kind of quasi-distributed spr sensor based on few mould twin-core fiber | |
| CN103424377B (en) | For detecting the sensor of liquid refractivity | |
| US20230046089A1 (en) | Method and system for measuring the temperature of a thermochromic liquid crystal |
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 |