CN102507450A - Method and device for measuring refractive index of transparent medium based on Y-shaped-cavity orthogonal polarization laser - Google Patents
Method and device for measuring refractive index of transparent medium based on Y-shaped-cavity orthogonal polarization laser Download PDFInfo
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- CN102507450A CN102507450A CN2011103421174A CN201110342117A CN102507450A CN 102507450 A CN102507450 A CN 102507450A CN 2011103421174 A CN2011103421174 A CN 2011103421174A CN 201110342117 A CN201110342117 A CN 201110342117A CN 102507450 A CN102507450 A CN 102507450A
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Abstract
The invention relates to a method and a device for measuring refractive index of transparent medium based on a Y-shaped-cavity orthogonal polarization laser. The device is composed of a Y-shaped-cavity orthogonal polarization laser, a sample cell, a working point selecting and controlling unit and a signal collecting and processing unit. After the transparent medium is pumped in or pumped out the sample cell, the refractive index of the P sub-segment of the Y-shaped-cavity orthogonal polarization laser can change, therefore the optical length difference of an S sub-cavity and a P sub-cavity changes, the beat frequency difference of S polarized light and P polarized light in the Y-shaped-cavity orthogonal polarization laser also changes, and the change value of the beat frequency difference is proportional to the refractive index of the transparent medium. The device has the characteristics of high resolution ratio, high degree of linearity, direct digital output, simple structure, convenience for operation, fastness and the like. The device can also be used for monitoring the refractive index of the transparent medium in real time.
Description
Technical field
The present invention relates to a kind of transparent medium refractometry method and device, belong to the laser measuring technique field based on Y die cavity cross polarization laser instrument.
Background technology
The refractive index of material has reflected the inner a lot of information of material, and is simultaneously closely related with other some parameters (like density, pressure etc.), therefore to the measurement of material refractive index, all is widely used in many research fields.Usually the method for measuring the transparent medium refractive index be to use the ellipsometer of technology maturation (Sun Shunming, Zhang Liangying, Yao Xi. the principle of ellipse inclined to one side technology and the application [J] in function film characterizes thereof. piezoelectricity and acousto-optic; 1998,20 (3): 209-213) with the Abbe refractometer (Hao Aihua, the Gao Yingjun that use total reflection principle; Ruan Chi, etc. measure the index distribution [J] of large scale sample automatically with reflectometry. photon journal, 2003; 32 (7): existing instrument such as 856-859); Though its accuracy of measurement is high, complicated operation has certain technical requirements.For this reason, constantly the someone proposes new measuring principle and method, wherein more representational comprise interferometric method (Li Mao and, Zhang Meidun. with optical fiber Michelson interferometer refractive Index Measurement [J]. optics journal .2000,9 (20): 1294-1296; Fan Yanbin, Wang Zhengyan. the research [J] of Fabry-Perot interference pattern and refractive index corresponding relation. quantum electronics newspaper, 1999.16 (5): 466-468; SCHUBERT Th; HAASE N; KOCK H, et al.Refractive indexmeasurements using an integrated Mach-Zehnder interferometer [J] .Sensors and Actuators A, 1997; 60 (13): 108-112.), minimum deviation horn cupping, Brewster horn cupping (KEJALAKSHMY N; SRINIVASANK.Simple method of Brewster-angle measurement for the determination of refractive indices intransparent biaxial crystal [J] .Opt Eng, 2001,40 (11): 2594-2597) etc.The requirement that has in these methods is carried out strictness processing to testing sample, and the apparatus structure complicacy that has is huge, and the instrument adjustment is complicated, and surveying work is heavy; The instrument that has adopts image process method, and data volume is big, must depend on area of computer aided and carry out, and the signal reading speed is slow.
Summary of the invention
For overcoming the apparatus structure complicacy of existing transparent medium refractometry method and apparatus; Operation element is heavy; Regulate not high or the like the deficiency of difficulty, precision, the present invention provides a kind of high precision transparent medium refractometry method and device based on Y die cavity cross polarization laser instrument.
The technical solution adopted for the present invention to solve the technical problems is:
Device of the present invention comprises Y die cavity cross polarization laser instrument, sample cell, working point selection and control module and signals collecting and processing unit.
Wherein, Y die cavity cross polarization laser instrument comprises cavity, the first high reflectance eyeglass, the second high reflectance eyeglass, the 3rd high reflectance eyeglass, polarization beam splitter, helium-neon discharge tube, first piezoelectric ceramics and second piezoelectric ceramics.
Cavity comprises common sections, S section and P section.Common sections and S section adopt microcrystal glass material and the integrated processing of bore process, a shared end face.The first high reflectance eyeglass is attached on first end face of common sections with the mode of optical cement, and first piezoelectric ceramics is installed on the first high reflectance eyeglass.The second high reflectance eyeglass is attached on first end face of S section with the mode of optical cement.Polarization beam splitter is coated on the shared end face of S section and common sections.The S polarized light of propagating in the common sections gets into S section after the polarization beam splitter reflection.The first high reflectance eyeglass, the second high reflectance eyeglass, polarization beam splitter constitute the resonator cavity of S polarized light, are called for short in " the sub-chamber of S ".P section adopts microcrystal glass material and bore process processing.P section is provided with air hole.The 3rd high reflectance eyeglass is attached on first end face of P section with the mode of optical cement, and second piezoelectric ceramics is installed on the 3rd high reflectance eyeglass.The public end face of second end face of P section and common sections and sub section of S is connected with the mode of optical cement.The P polarized light of propagating in the common sections is transmitted through P section behind polarization beam splitter.The first high reflectance eyeglass, polarization beam splitter and P section constitute the resonator cavity of P polarized light, are called for short in " the sub-chamber of P ".
Sample cell is made up of the polarization beam splitter of Y die cavity cross polarization laser instrument and the airtight kapillary between the high reflectance eyeglass, also can between polarization beam splitter and high reflectance eyeglass, place container as sample cell in addition.
The working point is selected to receive the sub-section of S of Y die cavity cross polarization laser instrument and the S polarized light and the P polarized light of P section output with control module, adopts aplanatic method that two polarization state longitudinal modes are stabilized on the gain trace about the symmetrical position of centre frequency; It links to each other with anode with the negative electrode of the helium-neon discharge tube of Y die cavity cross polarization laser instrument, for the helium-neon discharge tube of Y die cavity cross polarization laser instrument provides pumping voltage; It is connected with second piezoelectric ceramics of Y die cavity cross polarization laser instrument, through regulating the voltage of second piezoelectric ceramics, makes the frequency difference of two polarized lights in the Y die cavity cross polarization laser instrument greater than the locking threshold value.
Signals collecting is connected with the common sections of processing unit with Y die cavity cross polarization laser instrument, receives the output frequency difference of Y die cavity cross polarization laser instrument, and carries out filtering, counting, computing and demonstration.
Helium-neon discharge tube comprises gain region, negative electrode and anode.Gain region places common sections, is filled with the He-Ne mixed gas in it, and the air pressure ratio of helium and neon is about 7: 1.
Sample cell places P section, and transparent medium to be measured is through opening suction or extraction on the sample cell.
Wherein, the working point of measurement mechanism is meant the relative position of longitudinal mode on its gain trace in the Y die cavity cross polarization laser instrument.The working point is selected to comprise first photodetector, second photodetector, working point selection and control circuit with control module.First photodetector receives the S polarized light of Y die cavity cross polarization laser instrument S section outgoing, and is translated into voltage signal.Second photodetector receives the P polarized light of Y die cavity cross polarization laser instrument P section outgoing, and is translated into voltage signal.The negative electrode and the anode of working point selection and control circuit and Y die cavity cross polarization laser instrument are for helium-neon discharge tube provides pumping voltage; It links to each other with first photodetector, second photodetector, first piezoelectric ceramics; Through comparing the light intensity magnitude of S polarized light and P polarized light; Adopt aplanatic method; Through regulating the voltage of first piezoelectric ceramics, make S polarized light longitudinal mode and P polarized light longitudinal mode symmetrical about centre frequency on gain trace; It links to each other with second piezoelectric ceramics, through regulating the voltage of second piezoelectric ceramics, makes the frequency difference of two polarized lights in the Y die cavity cross polarization laser instrument greater than the locking threshold value.
Signals collecting and processing unit comprise polaroid, the 3rd photodetector, counting and signal processing circuit.S polarized light and P polarized light produce beat frequency along the component of the polarization direction of polaroid.The 3rd photodetector is sent in counting and the signal processing circuit after beat signal is converted into voltage signal.Counting is measured the frequency of beat signal with signal processing circuit, and carries out filtering, computing and demonstration.
Groundwork process of the present invention is following:
Behind transparent medium suction or the extraction sample cell; The refractive index of P section can change in the Y die cavity cross polarization laser instrument; Thereby cause the variation of sub-chamber of S and the sub-chamber of P optical length difference; The beat frequency frequency difference of S polarized light and P polarized light also will change in the Y die cavity cross polarization laser instrument, and according to the standing-wave condition of laser instrument, the changing value of this beat frequency frequency difference is directly proportional with the refractive index of transparent medium.
The invention has the beneficial effects as follows:
(1) described transparent medium refractometry method and apparatus; The output signal is the beat frequency frequency difference of S polarized light and P polarized light; Be digital signal, can adopt counter directly to read, the signal readout equipment is simple, portable; This method and apparatus has very high response speed, can be used for the real-time monitoring of transparent medium refractive index;
(2) described transparent medium refractometry method and apparatus, the beat frequency frequency difference that the refractive index of transparent medium is converted into Y die cavity cross polarization laser instrument changes, and scale factor is big;
(3) in the described transparent medium refractometry method and apparatus; S polarized light and the shared gain region of P polarized light in the Y die cavity cross polarization laser instrument; The beat frequency rate that the difference on the frequency movable property of two polarized lights is given birth to has been eliminated the influence of the temperature variation of gain region to laser instrument frequency difference stability basically; Therefore the frequency difference stability of Y die cavity cross polarization laser instrument is higher, has guaranteed that described displacement measurement method and device have higher zero stability partially, higher resolution.
Description of drawings
Fig. 1 is the principle assumption diagram of Y die cavity cross polarization laser instrument in the transparent medium apparatus for measuring refractive index;
Fig. 2 is the overall construction drawing based on the transparent medium apparatus for measuring refractive index of Y die cavity cross polarization laser instrument;
Fig. 3 is the principle assumption diagram of Y die cavity cross polarization laser instrument in the transparent medium refractive index on-Line Monitor Device.
Embodiment
In Fig. 1, Y die cavity cross polarization laser instrument 100 comprises piezoelectric ceramics 101, the first high reflectance eyeglass 103, the second high reflectance eyeglass 104, the 3rd high reflectance eyeglass 105, polarization beam splitter 106, helium-neon discharge tube 107, common sections 108, S section 109 and P section 110.
Be filled with the He-Ne mixed gas in the helium-neon discharge tube 107, the air pressure ratio of helium and neon is about 7: 1.
In Fig. 2, the inventive system comprises Y die cavity cross polarization laser instrument 100, sample cell 111, working point selection and control module, signals collecting and processing unit 300.
The working point is selected to comprise that with control module first photodetector 201, second photodetector 202, working point select and control circuit 203.First photodetector 201 receives the S polarized light of Y die cavity cross polarization laser instrument 100S section outgoing; And be translated into voltage signal; Second photodetector 201 receives the P polarized light of Y die cavity cross polarization laser instrument 100P section outgoing, and is translated into voltage signal.The working point is selected and control circuit 203 has three major functions; First function is for helium-neon discharge tube high voltage to be provided; Second function is to regulate the voltage of piezoelectric ceramics 102; Make the frequency difference of two polarized lights in the Y die cavity cross polarization laser instrument 100 greater than the locking threshold value, the 3rd function is the output voltage according to first photodetector 201 and second photodetector 202, adopts aplanatic method frequency stabilization; Promptly, make S polarized light longitudinal mode and P polarized light longitudinal mode symmetrical about centre frequency on gain trace through regulating the voltage of piezoelectric ceramics 101.
Signals collecting and processing unit 300 comprise polaroid 301, the 3rd photodetector 302 and counting and signal processing circuit 303.The S polarized light of common sections output and P polarized light produce beat frequency along the component of the polarization direction of polaroid 301; The 3rd photodetector 302 receives beat signal; And send in counting and the signal processing circuit 303 after being translated into voltage signal; Counting is measured the frequency of beat signal with signal processing circuit 303, and carries out filtering, counting, computing and demonstration.
Fig. 3 is other a kind of structure of Y die cavity cross polarization laser instrument 100 among Fig. 2, and this structure can be used for the on-line real time monitoring of transparent medium refractive index.Sample cell 111 is provided with two openings, first opening 112 and second opening 113.Transparent medium flows into from first opening 112; Flow out from second opening 113; Perhaps flow into, flow out from first opening 112, when the transparent medium refractive index changes from second opening 113; The beat frequency frequency difference of Y die cavity cross polarization laser instrument can change, thereby realizes the on-line real time monitoring to transparent medium refractive index to be measured.
Claims (5)
1. based on the transparent medium apparatus for measuring refractive index of Y die cavity cross polarization laser instrument, comprise Y die cavity cross polarization laser instrument, sample cell, working point selection and control module, signals collecting and processing unit, it is characterized in that:
Die cavity cross polarization laser instrument comprises cavity, the first high reflectance eyeglass, the second high reflectance eyeglass, the 3rd high reflectance eyeglass, polarization beam splitter, helium-neon discharge tube, first piezoelectric ceramics and second piezoelectric ceramics;
Cavity comprises common sections, S section and P section; Common sections and S section adopt microcrystal glass material and the integrated processing of bore process, a shared end face; The first high reflectance eyeglass is attached on first end face of common sections with the mode of optical cement, and first piezoelectric ceramics is installed on the first high reflectance eyeglass; The second high reflectance eyeglass is attached on first end face of S section with the mode of optical cement; Polarization beam splitter is coated on the shared end face of S section and common sections; The S polarized light of propagating in the common sections gets into S section after the polarization beam splitter reflection; The first high reflectance eyeglass, the second high reflectance eyeglass, polarization beam splitter constitute the resonator cavity of S polarized light, are called for short in " the sub-chamber of S "; P section is provided with air hole; The 3rd high reflectance eyeglass is attached on first end face of P section with the mode of optical cement, and second piezoelectric ceramics is installed on the 3rd high reflectance eyeglass; The public end face of second end face of P section and common sections and sub section of S is connected with the mode of optical cement; The P polarized light of propagating in the common sections is transmitted through P section behind polarization beam splitter; One high reflectance eyeglass, polarization beam splitter and P section constitute the resonator cavity of P polarized light, are called for short in " the sub-chamber of P ";
The working point is selected to receive the sub-section of S of Y die cavity cross polarization laser instrument and the S polarized light and the P polarized light of P section output with control module, adopts aplanatic method that two polarization state longitudinal modes are stabilized on the gain trace about the symmetrical position of centre frequency; It links to each other with anode with the negative electrode of the helium-neon discharge tube of Y die cavity cross polarization laser instrument, for the helium-neon discharge tube of Y die cavity cross polarization laser instrument provides pumping voltage; It is connected with second piezoelectric ceramics of Y die cavity cross polarization laser instrument, through regulating the voltage of second piezoelectric ceramics, makes the frequency difference of two polarized lights in the Y die cavity cross polarization laser instrument greater than the locking threshold value;
Signals collecting is connected with the common sections of processing unit with Y die cavity cross polarization laser instrument, receives the output frequency difference of Y die cavity cross polarization laser instrument, and carries out filtering, counting, computing and demonstration.
2. the transparent medium apparatus for measuring refractive index based on Y die cavity cross polarization laser instrument according to claim 1; It is characterized in that; Sample cell is made up of the polarization beam splitter of Y die cavity cross polarization laser instrument and the airtight kapillary between the high reflectance eyeglass, also can between polarization beam splitter and high reflectance eyeglass, place container as sample cell in addition.
3. the transparent medium apparatus for measuring refractive index based on Y die cavity cross polarization laser instrument according to claim 1 is characterized in that helium-neon discharge tube comprises gain region, negative electrode and anode.Gain region places common sections, is filled with the He-Ne mixed gas in it, and the air pressure ratio of helium and neon is about 7: 1.
4. the transparent medium apparatus for measuring refractive index based on Y die cavity cross polarization laser instrument according to claim 1 is characterized in that sample cell is provided with first opening.
5. the transparent medium apparatus for measuring refractive index based on Y die cavity cross polarization laser instrument according to claim 1 is characterized in that sample cell is provided with two openings, first opening and second opening.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018200A (en) * | 2012-11-30 | 2013-04-03 | 清华大学 | Monitoring device and method for refractive index of transparent medium |
| CN103105377A (en) * | 2012-11-30 | 2013-05-15 | 清华大学 | Device and method for measuring refractive index of transparent medium |
| CN103471815A (en) * | 2013-09-11 | 2013-12-25 | 中国科学院光电技术研究所 | Method for simultaneously measuring S-polarized light reflectivity and P-polarized light reflectivity of high reflecting mirror |
| CN113092385A (en) * | 2021-05-10 | 2021-07-09 | 山东大学 | Middle and high-rise atmospheric refractive index measuring device and method |
| CN114384018A (en) * | 2021-12-27 | 2022-04-22 | 中国科学院福建物质结构研究所 | Measuring device for measuring weak anisotropy in large-size isotropic transparent medium, measuring method and application |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101782593A (en) * | 2010-03-01 | 2010-07-21 | 龙兴武 | Double Y-shaped cavity double-frequency laser accelerometer |
-
2011
- 2011-11-02 CN CN2011103421174A patent/CN102507450A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101782593A (en) * | 2010-03-01 | 2010-07-21 | 龙兴武 | Double Y-shaped cavity double-frequency laser accelerometer |
Non-Patent Citations (4)
| Title |
|---|
| GUANGZONG XIAO等: "A novel orthogonal polarized dual-frequency laser using a Y-shaped cavity", 《OPTICS & LASER TECHNOLOGY》 * |
| 肖光宗等: "Precise force measurement method by a Y-shaped cavity dual-frequency laser", 《CHINESE OPTICS LETTERS》 * |
| 肖光宗等: "Y型腔正交偏振激光器的模竞争和光强调谐特性", 《中国激光》 * |
| 龙兴武等: "一种新型的高精度激光加速度计", 《光学学报》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018200A (en) * | 2012-11-30 | 2013-04-03 | 清华大学 | Monitoring device and method for refractive index of transparent medium |
| CN103105377A (en) * | 2012-11-30 | 2013-05-15 | 清华大学 | Device and method for measuring refractive index of transparent medium |
| CN103018200B (en) * | 2012-11-30 | 2015-02-18 | 清华大学 | Monitoring device and method for refractive index of transparent medium |
| CN103471815A (en) * | 2013-09-11 | 2013-12-25 | 中国科学院光电技术研究所 | Method for simultaneously measuring S-polarized light reflectivity and P-polarized light reflectivity of high reflecting mirror |
| CN103471815B (en) * | 2013-09-11 | 2016-07-06 | 中国科学院光电技术研究所 | A kind of method simultaneously measuring high reflective mirror S and P polarization luminous reflectance |
| CN113092385A (en) * | 2021-05-10 | 2021-07-09 | 山东大学 | Middle and high-rise atmospheric refractive index measuring device and method |
| CN113092385B (en) * | 2021-05-10 | 2022-03-22 | 山东大学 | Middle and high-rise atmospheric refractive index measuring device and method |
| CN114384018A (en) * | 2021-12-27 | 2022-04-22 | 中国科学院福建物质结构研究所 | Measuring device for measuring weak anisotropy in large-size isotropic transparent medium, measuring method and application |
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