CN205843814U - A kind of THz wave frequency measuring equipment based on CARS effect - Google Patents
A kind of THz wave frequency measuring equipment based on CARS effect Download PDFInfo
- Publication number
- CN205843814U CN205843814U CN201620658586.5U CN201620658586U CN205843814U CN 205843814 U CN205843814 U CN 205843814U CN 201620658586 U CN201620658586 U CN 201620658586U CN 205843814 U CN205843814 U CN 205843814U
- Authority
- CN
- China
- Prior art keywords
- light
- sample
- mobile platform
- baffle plate
- spectroscope
- 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.)
- Expired - Fee Related
Links
Abstract
The utility model discloses a kind of THz wave frequency measuring equipment based on CARS effect, including laser instrument, spectroscope, off axis paraboloidal mirror, convex lens, sample, baffle plate, stepping mobile platform and computer, the laser vertical incidence successively of laser instrument injection is to spectroscope and off axis paraboloidal mirror, laser and light to be detected after spectroscope and off axis paraboloidal mirror reflect are incident to sample by after convex lens focus, absorbed by baffle plate by the light part after sample, another part forms anti-Stokes light, the rear of baffle plate is provided with the detection device for detecting anti-Stokes light, the side, front of stepping mobile platform is provided with scale, scale connects the information acquisition device for gathering slit location information.This utility model device has that measurement scope is wide, highly sensitive, reliability is high, compact conformation, low cost and the feature that can work at ambient temperature, it is adaptable to Terahertz scientific research field and the practical application area of Terahertz Technology.
Description
Technical field
This utility model relates to a kind of Electromagnetic Wave Detection technology, specifically, relates to a kind of phase based on space folding
The device of dry anti-Stokes (being called for short BOX CARS) effect measurement Terahertz (THZ).
Background technology
The most a lot of different types of terahertz emission sources are obtained for the biggest development, and are widely used in into
In the fields such as picture, spectrum analysis.At tera-hertz spectra analysis field, terahertz time-domain spectroscopic technology realizes number owing to being typically only capable to
The spectrally resolved ability of ten GHz, can not meet the demand of reality in certain applications.In this context, Ren Menti
Go out various more accurate method to detect the frequency of THZ, but have weak point, specific as follows:
What Terahertz long-wave band frequency measurement at present was commonly used is heterodyne method, and it is suitable with frequency by measured signal
Local oscillated signal difference frequency, the intermediate-freuqncy signal exported by analysis obtains the frequency of tested THz wave.But it is high for THz
Output pulses ripple, heterodyne method still suffers from following two defect: one is that THz local oscillations source is little, and expensive；Two by
The pulse width surveying THz pulse ripple is the shortest, it is impossible to ensures the effect of local continuous wave signal and impulse wave mixing, thus have impact on
Certainty of measurement.
A kind of method also having the THZ of measurement frequency is to utilize FP interferometer to remove detection, FP interferometer measurement THz wave frequency
After the principle of rate is THz wave vertical incidence FP interferometer, when metallic mesh to the reflectance of incidence wave bigger time, transmission light
There is multiple-beam interference, by the light path between mobile FP interferometer two metallic mesh spacing regulation transmission light two adjacent beams
Difference, interfering beam is through lens post-concentration on the detector.Test the different spacing by gathering FP interferometer two metallic mesh
Corresponding transmitted light intensity, carries out curve fitting, just can draw the spacing of adjacent two light intensity peak, calculates Terahertz frequency
Rate.Being characterized in that interferometer fineness is high, measurement result is accurate, and shortcoming is to need to use special technique to make metallic mesh, and
The live width of the metallic mesh made, thickness and cycle are all in micron dimension, it is difficult to preserve, additionally, build Fabry-Perot
It is difficult to install and ensure the depth of parallelism of two metallic meshes during interferometer.Improving this method selection has the metallic mesh of substrate to build
Fabry-Perot interferometer has compact when measuring narrow linewidth terahertz emission wavelength, it is easy to install, regulate, ensure the depth of parallelism,
It is easy to the advantage preserved, but fineness decreases.
Except two kinds of THZ frequency sonding methods above, also it is operated in the Fourier transform spectrometer, of terahertz wave band
Can be used for measuring the frequency spectrum of THZ, but the detector that uses of this technology only under the temperature conditions of liquid nitrogen cooling
Low frequency THz wave detection and high sensitivity detection can be carried out.
Utility model content
The purpose of this utility model is to overcome deficiency of the prior art, it is provided that a kind of based on space folding relevant
The Terahertz frequency measuring equipment of anti-Stokes effect (BOX CARS), this device have measurement scope wide, highly sensitive,
Reliability height, compact conformation, low cost and the feature that can work at ambient temperature, it is adaptable to Terahertz scientific research field and
The practical application area of Terahertz Technology.
The purpose of this utility model is achieved through the following technical solutions:
A kind of THz wave frequency measuring equipment based on CARS effect, including laser instrument, spectroscope, off axis paraboloid mirror
Mirror, convex lens, sample, baffle plate, stepping mobile platform and computer, the laser vertical incidence successively of described laser instrument injection is to dividing
Light microscopic and off axis paraboloidal mirror, laser and light to be detected after spectroscope and off axis paraboloidal mirror reflect pass through described convex lens
Being incident to described sample after focusing, absorbed by described baffle plate by the light part after described sample, another part is formed instead
Stokes light, the rear of described baffle plate is provided with the detection device for detecting described anti-Stokes light, described detection device
By the slit being successively set on described stepping mobile platform, collimating element, dispersion element, concentrating element and CCD-detector structure
Becoming, the side, front of described stepping mobile platform is additionally provided with scale, and described scale connects to be had for gathering slit location information
Information acquisition device, described information acquisition device, CCD-detector are all connected with described computer by cable with stepping mobile platform.
Described laser instrument is made up of continuous wide band laser instrument.
The surface of described off axis paraboloidal mirror is coated with Aurum metallicum.
The precision of described scale is below nanoscale or nanoscale.
Compared with prior art, the technical solution of the utility model is had the benefit that
1. this utility model measurement apparatus low cost, error is little, precision is high, and has measuring speed faster, permissible
Be widely used in going in for the study Terahertz association area laboratory in.
2. measure scope wide, except the frequency of whole THZ wave band can be measured, it is also possible to measure far infrared and microwave band
Wave frequency.
3., after device holistic conformation, during measurement, only need stepping mobile platform to occur to obtain anti-Stokes optical signal
When strengthening point, the position data of detection device, finally by computer data acquisition and calculating, easy to operate, measuring speed
Hurry up.
4. can increase multicomponent light microscopic, convex lens, sample and baffle plate on the basis of measurement apparatus accordingly, thus survey
Organize light frequency to be measured much, take after the meansigma methods organizing light frequency to be measured as final light frequency to be measured so that measurement data essence
The most reliable, precision is high.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model.
Fig. 2 is phase matched principle schematic in frequency measurement.
Fig. 3 is the structural representation of this utility model wherein embodiment.
Reference: 1-laser instrument 2-smooth 3-spectroscope 4-off axis paraboloidal mirror 5-convex lens 6-sample to be detected
7-baffle plate 8-scale 9-slit 10-collimating element 11-dispersion element 12-concentrating element 13-CCD detector 14-stepping
Mobile platform 15-computer 16-information acquisition device
Detailed description of the invention
The utility model will be further described below in conjunction with the accompanying drawings:
As it is shown in figure 1, a kind of THz wave frequency measuring equipment based on CARS effect, including laser instrument 1, spectroscope 3,
Off axis paraboloidal mirror 4, convex lens 5, sample 6, baffle plate 7, stepping mobile platform 14 and computer 15, laser instrument 1 is by continuous wide band
Laser instrument is constituted, for launching the laser of continuous wide band；Off axis paraboloidal mirror 4 is used for light path of transferring, and its surface is coated with Aurum metallicum；
Convex lens 5 is for converging at sample 6 by two bundle laser and a branch of light to be detected 2, and light 2 to be detected is the light needing detection, this
Its frequency is set to ω by enforcement2；The focal point that Raman frequency shift is bigger and is located at convex lens 5 selected by sample 6；Baffle plate 7
For filtering some unwanted light.
The laser vertical incidence successively of laser instrument 1 injection is to spectroscope 3 and off axis paraboloidal mirror 4, light splitting in the present embodiment
The parameter of mirror is 1/2 absorbance, 1/2 reflectance, the laser after spectroscope 3 and off axis paraboloidal mirror 4 reflect and light to be detected 2
Being incident to sample 6 after being focused on by convex lens 5, absorbed by baffle plate 7 by the light part after sample 6, another part is formed
Anti-Stokes light, the rear of baffle plate 7 is provided with the detection device for detecting anti-Stokes light, and detection device is by setting gradually
Slit 9, collimating element 10, dispersion element 11, concentrating element 12 and CCD-detector 13 on stepping mobile platform 14 are constituted,
The effect of slit 9 is the object point forming spectrogrph imaging system under the irradiation of incident illumination；Collimating element 10 makes slit 9 send
Light becomes directional light；Dispersion element 11 generally uses grating, makes optical signal spatially become a plurality of light beam by wavelength dispersion；
Concentrating element 12 focuses on the light beam after dispersion so that it is form the picture of a series of entrance slit 9, each of which picture point on focal plane
Corresponding to a specific wavelength；CCD-detector 13 is positioned over focal plane, for measuring the light intensity of each wavelength picture point.Stepping is moved
The side, front of platform 14 is additionally provided with the high-precision scale 8 for observing and demarcate slit 9 position, and the precision of scale 8 is for receiving
Below meter level or nanoscale；Scale 8 link information harvester 16, information acquisition device 16, CCD-detector 13 and stepping mobile platform
14 are all connected with computer 15 by cable, and the programme-control stepping mobile platform 14 of computer 15 is along the direction stepping of scale 8
Motion, information acquisition device 16 will appear from the position data of the slit 9 when anti-Stokes optical signal strengthens and passed to computer 15,
Computer 15 operating measurement program, reads the digital voltage value of information acquisition device 16 output, stepping mobile platform 14 is sent work
Instruct, finally calculate measurement result for user.
The principle of this utility model measurement apparatus is as follows:
As shown in Figure 1: owing to laser instrument 1 is a wideband laser, contains various frequency, wherein certainly exist
Certain frequencies omega1Meet formula (1.1)
ω1-ω2=ωVFormula (1.1)
In formula: ωvFor the frequency of vibration of the Raman active of sample 6, wherein ωvThe known quantity determined that.
ω2It it is the frequency of light 2 to be detected.ω1It is the laser frequency of laser instrument 1 incidence, has two bundles: by continuous print broadband
The light that laser instrument 1 is launched is divided into two in early stage light path, and a part has passed through the top of convex lens 5, and a part has been passed through convex
The lower section of lens 5.
Theoretical from coherent antistockes Raman spectroscopy (CARS): the two incident illumination dissipates corresponding to excited Raman
Pump light (the ω penetrated1=ωL) and stokes light (ω2=ωS).Frequency is ω1And ω2Light produced by stimulated Raman scattering
Give birth to the vibration excited state molecule that population density is the biggest.As nonlinear dielectric, these excited state molecules utilize frequencies omega1's
Incident illumination produces ωa=2 ω1-ω2Anti-Stokes light.As in figure 2 it is shown, meeting phase-matching condition(Thus formula can be calculated) after, the intensity of the anti-Stokes optical signal obtained will be than spontaneous Raman light
Spectrum signal big 104～105Times.
The coherent (BOX CARS) of this utility model patent utilization space folding replaces normally used common
The coherent (CARS) of line.Thus overcome a defect (two bundle incident laser and signal beams parallel to each other
It is spatially overlapping, it is necessary to expensive spectral filtering sheet, they are made a distinction).Select in the present embodiment is price
Relatively low continuous wide band laser instrument.The sample 6 that the frequency of vibration of a Raman active is higher, detection device is selected to move along with stepping
Moving platform 14 moves, in the position meeting phase matched, it will the point that anti-Stokes optical signal strengthens occur, record
Position data d of detector this moment.Below equation group can be obtained according to correlation computations:
In formulaIt is ω respectively1、ω2、ω3Wave vector, its direction and angle [alpha] are as depicted in figs. 1 and 2；
It is respectivelyCorresponding modulus value, c is the light velocity.
Simultaneous formula (1.1) again, the formula that can obtain light frequency to be measured is:
To improve accuracy and reliability further, reduce error (the micro-change of properties of samples, noise signal interference etc.), can
To add two each and every one 3, convex lens 5 of spectroscope and a kind of new samples 6 on the basis of Fig. 1, as shown in Figure 3.Work as detection
The when that device moving from top to bottom, it finds that the position that two anti-Stokes optical signals are uprushed, record position respectively
Information.According to the calculation in formula (1.3), it is possible to obtain two frequencies treating light-metering and be respectivelyWithIf
FindWithDiffer bigger, then just explanation may have occurred the structural property change of material or occurs in that mistake greatly
Difference, remeasures after needing to improve；If it find thatWithOf substantially equal, then both meansigma methods can be chosen as
After the frequency treating light-metering, to eliminate random error.
Further, multicomponent light microscopic, lens and sample can be added again and a series of anti-Stokes occurs to gather
The location point that optical signal strengthens.Such that it is able to calculate many groups light frequency to be measuredIf
Many class frequencys are of substantially equal, and the most final light frequency calculating formula to be measured is
The measuring method of a kind of THz wave frequency measuring equipment based on CARS effect, comprises the following steps:
(1) open laser instrument 1, mobile stepping mobile platform 14, make detection device move along with stepping mobile platform 14；
(2) detection device detects the point that anti-Stokes optical signal strengthens, by scale and calculating in moving process
Machine record detects the position data of device under this moment；
(3) light frequency to be measured is obtained by the frequency computing formula (1.3) of light to be detected；
(4) for making measurement data accurately reliable, on the basis of described measurement apparatus, two spectroscopes are increased accordingly
3, a convex lens 5, a sample 6 and a baffle plate 7, move stepping mobile platform 14 from top to bottom, make detection device along with
Stepping mobile platform 14 moves；
In two spectroscopes 3 being closer in Fig. 3, parameter located above is 1/4 reflectance, 3/4 absorbance；Another
Individual parameter is 1/3 reflectance, 2/3 absorbance；
(5) detection device detects the point that two anti-Stokes optical signals strengthen in moving process, records respectively
The position data of device is detected under two moment；
(6) two light frequencies to be measured are obtained by the frequency computing formula of light to be detected, if the two light frequency to be measured
Value difference is relatively big, then remeasure；If differing small, then take as light frequency to be measured after both meansigma methodss, to eliminate with chance error
Difference.
Preferably, on the basis of described measurement apparatus, multicomponent light microscopic 3, convex lens 5, sample 6 He are increased accordingly
Baffle plate 7, thus record many groups light frequency to be measured by step (2), (3), if the value difference organizing light frequency to be measured small more, then adopt
It is calculated the most accurate light frequency to be measured with formula (1.4).
Claims (4)
1. a THz wave frequency measuring equipment based on CARS effect, it is characterised in that include laser instrument, spectroscope, from
Axis paraboloidal mirror, convex lens, sample, baffle plate, stepping mobile platform and computer, the laser of described laser instrument injection is the most vertical
Being incident to spectroscope and off axis paraboloidal mirror, laser and light to be detected after spectroscope and off axis paraboloidal mirror reflect pass through institute
It is incident to described sample after stating convex lens focus, is absorbed by described baffle plate by the light part after described sample, another part
Being formed with anti-Stokes light, the rear of described baffle plate is provided with the detection device for detecting described anti-Stokes light, described
Detection device is by slit, collimating element, dispersion element, concentrating element and the CCD being successively set on described stepping mobile platform
Detector is constituted, and the side, front of described stepping mobile platform is additionally provided with scale, and described scale connects to be had for gathering slit position
The information acquisition device of confidence breath, described information acquisition device, CCD-detector and stepping mobile platform are all by cable and described calculating
Machine is connected.
A kind of THz wave frequency measuring equipment based on CARS effect, it is characterised in that described
Laser instrument is made up of continuous wide band laser instrument.
A kind of THz wave frequency measuring equipment based on CARS effect, it is characterised in that described
The surface of off axis paraboloidal mirror is coated with Aurum metallicum.
A kind of THz wave frequency measuring equipment based on CARS effect, it is characterised in that described
The precision of scale is below nanoscale or nanoscale.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620658586.5U CN205843814U (en) | 2016-06-24 | 2016-06-24 | A kind of THz wave frequency measuring equipment based on CARS effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620658586.5U CN205843814U (en) | 2016-06-24 | 2016-06-24 | A kind of THz wave frequency measuring equipment based on CARS effect |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205843814U true CN205843814U (en) | 2016-12-28 |
Family
ID=57621791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620658586.5U Expired - Fee Related CN205843814U (en) | 2016-06-24 | 2016-06-24 | A kind of THz wave frequency measuring equipment based on CARS effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205843814U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106092321A (en) * | 2016-06-24 | 2016-11-09 | 天津大学 | A kind of THz wave frequency measuring equipment based on CARS effect and method |
| CN110755042A (en) * | 2019-10-21 | 2020-02-07 | 华中科技大学 | Time pulse light sheet tomography method and system for realizing large-volume high-resolution |
-
2016
- 2016-06-24 CN CN201620658586.5U patent/CN205843814U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106092321A (en) * | 2016-06-24 | 2016-11-09 | 天津大学 | A kind of THz wave frequency measuring equipment based on CARS effect and method |
| CN106092321B (en) * | 2016-06-24 | 2018-05-25 | 天津大学 | A kind of measuring method of the THz wave frequency measuring equipment based on CARS effects |
| CN110755042A (en) * | 2019-10-21 | 2020-02-07 | 华中科技大学 | Time pulse light sheet tomography method and system for realizing large-volume high-resolution |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8693004B2 (en) | Dual-etalon cavity ring-down frequency-comb spectroscopy with broad band light source | |
| KR100917913B1 (en) | Spectral analyzer for measuring the thickness and identification of chemicals of organic thin films using CARS microscopy | |
| JP6266719B1 (en) | Terahertz time domain spectrometer | |
| US8213012B2 (en) | Stability for optical computing system | |
| US9200961B2 (en) | Systems and methods for high resolution spatial heterodyne raman spectroscopy | |
| CN110730903B (en) | Spectrum measuring method, spectrum measuring apparatus, and broadband pulse light source unit | |
| CN106404713A (en) | Double-detector micro near-infrared spectrometer with whole spectral band of 800-2,500nm | |
| CN103344623A (en) | Coherent anti-stokes raman scattering optical comb spectrum detection method for improving precision | |
| WO2005074525A2 (en) | Entangled-photon fourier transform spectroscopy | |
| CN104914089B (en) | The method for carrying out semi-quantitative analysis to trace mixture with SERS | |
| Li et al. | A liquid crystal tunable filter-based hyperspectral LiDAR system and its application on vegetation red edge detection | |
| KR20150037977A (en) | Dual spectrometer | |
| US10048196B2 (en) | Cavity enhanced spectroscopy using off-axis paths | |
| CN111522018B (en) | Double-femtosecond laser frequency comb distance measuring device and method | |
| CN102507511A (en) | On-line in situ detecting device for infrared-ultraviolet double pulse laser induced breakdown spectroscopy | |
| CN102507512A (en) | On-line in situ detecting method for infrared-ultraviolet double pulse laser induced breakdown spectroscopy | |
| CN110806266A (en) | Selection method of polarization state analyzer in polarization state detection system | |
| CN106596058B (en) | Diffraction efficiency of grating spectral measurement device and measurement method | |
| CN103499391A (en) | Spectrum measuring system | |
| CN205843814U (en) | A kind of THz wave frequency measuring equipment based on CARS effect | |
| CN105181656A (en) | Laser differential confocal induced breakdown-Raman spectroscopy imaging detection method and laser differential confocal induced breakdown-Raman spectroscopy imaging detection apparatus | |
| CN105158165B (en) | A kind of ultrafast ellipsometer device and measuring method | |
| CN202351175U (en) | Infrared ultraviolet double-pulse laser induced impact breakdown spectrum online in-situ detecting device | |
| CN111239072A (en) | Method for accurately measuring temperature of combustion gas | |
| CN103884692A (en) | Ultrahigh-space-resolution LIBS (laser-induced breakdown spectroscopy) solid-phase isotope measurement device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20161228 Termination date: 20170624 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |