CN108106723A - A kind of device and method for enhancing Terahertz Electro-optic sampling detectivity - Google Patents

A kind of device and method for enhancing Terahertz Electro-optic sampling detectivity Download PDF

Info

Publication number
CN108106723A
CN108106723A CN201711364883.4A CN201711364883A CN108106723A CN 108106723 A CN108106723 A CN 108106723A CN 201711364883 A CN201711364883 A CN 201711364883A CN 108106723 A CN108106723 A CN 108106723A
Authority
CN
China
Prior art keywords
laser light
exploring laser
polarization
electro
polarized components
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201711364883.4A
Other languages
Chinese (zh)
Other versions
CN108106723B (en
Inventor
谢文
龚鹏伟
马红梅
杨春涛
谌贝
姜河
张鹤鸣
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Institute of Radio Metrology and Measurement
Original Assignee
Beijing Institute of Radio Metrology and Measurement
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Beijing Institute of Radio Metrology and Measurement filed Critical Beijing Institute of Radio Metrology and Measurement
Priority to CN201711364883.4A priority Critical patent/CN108106723B/en
Publication of CN108106723A publication Critical patent/CN108106723A/en
Application granted granted Critical
Publication of CN108106723B publication Critical patent/CN108106723B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01JMEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00Photometry, e.g. photographic exposure meter
    • G01J1/02Details
    • G01J1/04Optical or mechanical part supplementary adjustable parts
    • G01J1/0407Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01JMEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00Photometry, e.g. photographic exposure meter
    • G01J1/42Photometry, e.g. photographic exposure meter using electric radiation detectors
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01JMEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J11/00Measuring the characteristics of individual optical pulses or of optical pulse trains
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01JMEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00Photometry, e.g. photographic exposure meter
    • G01J1/42Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J2001/4238Pulsed light

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

The present invention discloses a kind of device and method for enhancing Terahertz Electro-optic sampling detectivity.Apparatus of the present invention include:Linear polarizer, for exploring laser light to be converted to linear polarization;Electro-optic crystal, for exploring laser light to be converted to elliptical polarization by linear polarization;Brewster window, for removing s polarized components extra in exploring laser light;Quarter-wave plate, for exploring laser light to be converted to approximate circular polarization state;Wollaston prism, for separating the s polarized components and p-polarization component in exploring laser light;Photodetector is balanced, for measuring the strength difference of s polarized components and p-polarization component in exploring laser light.The method that the present invention also specifically provides enhancing Terahertz Electro-optic sampling detectivity.The present invention utilizes the polarization state dependent attenuation characteristic of Brewster window, removes the garbage component included in exploring laser light signal, enhances the detectivity of Electro-optic sampling on the basis of it need not improve exploring laser light energy.

Description

A kind of device and method for enhancing Terahertz Electro-optic sampling detectivity
Technical field
The present invention relates to THz wave field of detecting.It is visited more particularly, to a kind of enhancing Terahertz Electro-optic sampling Survey the device and method of sensitivity.
Background technology
THz wave refers to electromagnetic wave of the frequency in the range of 0.1THz~10THz, in electromagnetic spectrum millimeter wave and Between infrared ray.
Terahertz Electro-optic sampling is a kind of typical THz wave Detection Techniques.It is caused using THz wave electric field Electrooptical material birefringence effect detect THz wave.Its principle is to make exploring laser light pulse signal and tested THz wave same When through electro-optic crystal, THz wave electric field causes electro-optic crystal birefringence effect so as to change the inclined of exploring laser light pulse signal Polarization state, the variation of polarization state is directly proportional to the size of THz wave electric field, by changing exploring laser light pulse signal with being tested The relative time relationship of THz wave, and measure exploring laser light pulse two using balance photodetector and be mutually perpendicular to polarization point The difference of amount obtains the time domain waveform result of THz wave.
Due to the tested usual intensity very little of terahertz wave signal, need to enhance electro-optic sampling skill when detecting it The detectivity of art, traditional method are the increasings for the energy realization Electro-optic sampling detectivity for improving exploring laser light By force, but for exploring laser light polarization state variation balance photodetector there are input energy threshold value, more than input energy threshold The exploring laser light energy of value can cause balance photodetector saturation, cause Electro-optic sampling detectivity that cannot expire completely Sufficient application demand improves exploring laser light energy and is also required to additional amplification compensation device, can greatly increase system complex in addition Degree and cost, are unfavorable for implementing.
Accordingly, it is desirable to provide a kind of device and method for enhancing Terahertz Electro-optic sampling detectivity, more just Just the detectivity of Terahertz Electro-optic sampling, is effectively enhanced.
The content of the invention
It is an object of the invention to provide a kind of devices for enhancing Terahertz Electro-optic sampling detectivity.
It is another object of the present invention to provide it is a kind of enhance Terahertz Electro-optic sampling detectivity method, Using the polarization state dependent attenuation characteristic of Brewster window, the garbage component included in exploring laser light signal is removed, Need not improve enhances the detectivity of Electro-optic sampling on the basis of exploring laser light energy.
In order to achieve the above objectives, the present invention uses following technical proposals:
Present invention firstly provides it is a kind of enhance Terahertz Electro-optic sampling detectivity device, including:
Linear polarizer, for exploring laser light to be converted to linear polarization;
Electro-optic crystal, for exploring laser light to be converted to elliptical polarization by linear polarization;
Brewster window, for removing s polarized components extra in the exploring laser light of elliptical polarization;
Quarter-wave plate, for the exploring laser light for removing s polarized components to be converted to approximate circular polarization state;
Wollaston prism, for separating the s polarized components and p-polarization component in the exploring laser light of approximate circular polarization state;
Photodetector is balanced, for measuring the strength difference of s polarized components and p-polarization component in exploring laser light.
Further, the Brewster window can be including at least a Brewster window group.
The present invention provides a kind of method for enhancing Terahertz Electro-optic sampling detectivity, comprises the following steps:
1) exploring laser light is converted into linear polarization:
By exploring laser light by linear polarizer, rotational line linear polarizer so that the exploring laser light linear polarization penetrated is vertical Nogata to, the exploring laser light after linear polarizer can use Jones vector by way of be expressed as:
2) exploring laser light is converted into elliptical polarization by linear polarization:
Make exploring laser light with tested THz wave simultaneously through electro-optic crystal, by the electric light by THz wave electric field action Exploring laser light after crystal is converted to elliptical polarization by linear polarization, is expressed as by the exploring laser light after electro-optic crystal:
L1=CLin (2)
Wherein, C represents the electro-optic crystal Jones matrix under THz wave electric field action:
Wherein, φ is amount of delay, THz wave effect under can regard electro-optic crystal as phase retarders, amount of delay φ and THz wave electric field level is directly proportional;
3) s polarized components extra in the exploring laser light of elliptical polarization are removed:Exploring laser light is entered with Brewster's angle Brewster window was shot through, can be expressed as by the exploring laser light after Brewster window using Jones matrix:
L2=BCLin (4)
Wherein, B represents the Jones matrix of Brewster window:
Wherein, t represents light intensity transmitance of the Brewster window to s polarized components in exploring laser light,It declines as electric field Decrement, Brewster window are 100% to the p-polarization component transmitance in exploring laser light;
4) exploring laser light for removing s polarized components is converted into approximate circular polarization state:Exploring laser light is made to penetrate a quarter Wave plate, adjustment quarter-wave plate fast axis direction make it at 45 ° with s polarization directions, are swashed by the detection after quarter-wave plate The Jones matrix of light is expressed as:
L=QBCLin (7)
Wherein, Q is the Jones matrix of quarter-wave plate:
5) the s polarized components in the exploring laser light of approximate circular polarization state and p-polarization component are separated and measures its strength difference: The s polarized components light in exploring laser light and p-polarization light components are separated using wollaston prism, can be calculated by formula (7) The expression matrix form for obtaining final exploring laser light is:
Using balance photodetector measurement s polarized components light and the strength difference of p-polarization light components, final measurement obtains S polarized components and p-polarization component intensity difference normalization result S be:
In actual test, terahertz wave signal intensity is very low, and φ values are minimum and φ<<T, therefore can be by simplified formula For:
Beneficial effects of the present invention are as follows:
The exploring laser light two that a kind of method for enhancing Terahertz Electro-optic sampling detectivity of the present invention obtains is partially The intensity difference normalization result S of component of shaking is proportional to the detectivity of Electro-optic sampling, is understood by step (3) in formula T represents Brewster window to s polarized components transmitance in exploring laser light, and the value of t is necessarily smaller than 1, therefore uses present invention side Method can improve detectivityTimes, in addition if forming group of windows using n pieces Brewster window, can will detect Sensitivity improvesTimes.
Description of the drawings
The specific embodiment of the present invention is described in further detail below in conjunction with the accompanying drawings.
Fig. 1 shows to enhance the scheme schematic diagram of Terahertz Electro-optic sampling sensitivity in embodiment;
Fig. 2 is shown in embodiment using the scheme and exploring laser light polarization state of tested THz wave Electric Field Modulated exploring laser light Variation diagram;
Fig. 3 show in embodiment removal through the scheme of s polarized components extra in the exploring laser light after electro-optic crystal and Exploring laser light polarization state variation diagram;
The exploring laser light that Fig. 4 shows to will transmit through after Brewster window is converted to the scheme of approximate circular polarization state and detection swashs Polarization state variation diagram;
Fig. 5 shows to separate the s polarized components in exploring laser light in embodiment and p-polarization component and measures its strength difference Scheme and exploring laser light polarization state variation diagram;
Fig. 6 shows the Comparative result obtained according to the THz wave measurement result that embodiment method obtains with conventional method Figure.
In figure:1 linear polarizer, 2 electro-optic crystals, 3 Brewster window groups, 4 quarter-wave plates, 5 wollaston prisms, 6 balance photodetectors.
Specific embodiment
In order to illustrate more clearly of the present invention, the present invention is done further with reference to preferred embodiments and drawings It is bright.Similar component is indicated with identical reference numeral in attached drawing.It will be appreciated by those skilled in the art that institute is specific below The content of description is illustrative and be not restrictive, and should not be limited the scope of the invention with this.
A kind of device for enhancing Terahertz Electro-optic sampling detectivity, including:
Linear polarizer 1, for exploring laser light to be converted to linear polarization;
Electro-optic crystal 2, for exploring laser light to be converted to elliptical polarization by linear polarization;
Brewster window 3, for removing s polarized components extra in the exploring laser light of elliptical polarization;
Quarter-wave plate 4, for the exploring laser light for removing s polarized components to be converted to approximate circular polarization state;
Wollaston prism 5, for separating the s polarized components and p-polarization component in the exploring laser light of approximate circular polarization state;
Photodetector 6 is balanced, for measuring the strength difference of s polarized components and p-polarization component in exploring laser light.
Heretofore described Brewster window can be including at least a Brewster window group.
Terahertz wave signal is generated in a manner that femtosecond laser encourages terahertz light lead antenna, is enhanced using above device The method of Terahertz Electro-optic sampling detectivity, comprises the following steps:
1) exploring laser light is converted into linear polarization:Exploring laser light selects centre wavelength 800nm, and pulse width is less than The femtosecond laser of 150fs.By exploring laser light by linear polarizer 1, rotational line linear polarizer 1 is so that the exploring laser light line penetrated is inclined Direction shake for vertical direction, is expressed as in a manner that the exploring laser light after linear polarizer 1 can use Jones vector:
2) exploring laser light is converted into elliptical polarization by linear polarization:Make exploring laser light and tested THz wave saturating simultaneously Electro-optic crystal 2 is crossed, electro-optic crystal 2 can select the tangential GaP crystal for [110], can be regarded it as under THz wave effect Phase retarders, amount of delay φ is directly proportional to THz wave electric field level, and Jones is used by the exploring laser light after electro-optic crystal 2 Matrix is expressed as:
L1=CLin (2)
Wherein, C represents 2 Jones matrix of electro-optic crystal under THz wave electric field action:
Change through the exploring laser light polarization state before and after electro-optic crystal 2 as shown in Fig. 2, by by THz wave electric field action Electro-optic crystal 2 after exploring laser light elliptical polarization is become from linear polarization.
3) s polarized components extra in the exploring laser light of elliptical polarization are removed:Exploring laser light is entered with Brewster's angle Brewster window 3 was shot through, Brewster window 3 is ideally to the p-polarization component transmitance in exploring laser light 100%, it is t to s polarized components light intensity transmitance in exploring laser light, since Jones matrix is using the polarization of electric field form expression light Component, during using a Brewster window,It, can by the exploring laser light after Brewster window 3 as field decay amount Jones matrix to be used to be expressed as:
L2=BCLin (4)
Wherein, B represents the Jones matrix of Brewster window 3:
The group of windows that four Brewster windows 3 form is used in the present embodiment as s polarized components in exploring laser light Attenuator, therefore the complete attenuation effect of group of windows should be expressed as:
Changed by the exploring laser light polarization state of Brewster window group as shown in figure 3, often passing through a Brewster window Mouthful, the extra s polarized components in exploring laser light are smaller, ellipticity (s polarized light components and the p-polarization light of exploring laser light polarization state The ratio of component) it is smaller, the Electro-optic sampling detectivity that can finally obtain is higher.
4) exploring laser light for removing s polarized components is converted into approximate circular polarization state:Exploring laser light is made to penetrate a quarter Wave plate 4, adjustment 4 fast axis direction of quarter-wave plate make it at 45 ° with s polarization directions, pass through the detection after quarter-wave plate 4 Laser can be expressed as using Jones matrix:
L=QBCLin (7)
Wherein Q is the Jones matrix of quarter-wave plate 4:
It is as shown in Figure 4 by the exploring laser light polarization state variation of quarter-wave plate 4
5) the s polarized components in the exploring laser light of approximate circular polarization state and p-polarization component are separated and measures its strength difference: The s polarized components light in exploring laser light and p-polarization light components are separated using wollaston prism 5, pass through wollaston prism 5 Front and rear exploring laser light is as shown in figure 5, measure the strength difference of two light components using balance photodetector, by formula (7) The expression matrix form that final exploring laser light can be calculated is:
Then the strength difference of two light components is measured using balance photodetector 6, finally measures obtained s polarizations point Amount normalizes result S with p-polarization component intensity difference:
In actual test, terahertz wave signal intensity is very low, therefore φ values are minimum and φ<<T, therefore can be by formula It is reduced to:
Above-mentioned polarized component intensity difference S is directly proportional to Electro-optic sampling detectivity, according to what is provided in embodiment Method can improve sensitivityTimes, if selecting the Brewster window made by refractive index ZnSe materials, to detection Sensitivity can be improved about 20 times by s polarized components light intensity transmitance t ≈ 0.22 in laser according to method provided by the invention, It is as shown in Figure 6 to promote effect.
Obviously, the above embodiment of the present invention is only intended to clearly illustrate example of the present invention, and is not pair The restriction of embodiments of the present invention for those of ordinary skill in the art, may be used also on the basis of the above description To make other variations or changes in different ways, all embodiments can not be exhaustive here, it is every to belong to this hair The obvious changes or variations that bright technical solution is extended out is still in the row of protection scope of the present invention.

Claims (7)

1. a kind of device for enhancing Terahertz Electro-optic sampling detectivity, which is characterized in that including:
Linear polarizer, for exploring laser light to be converted to linear polarization;
Electro-optic crystal, for exploring laser light to be converted to elliptical polarization by linear polarization;
Brewster window, for removing s polarized components extra in the exploring laser light of elliptical polarization;
Quarter-wave plate, for the exploring laser light for removing s polarized components to be converted to approximate circular polarization state;
Wollaston prism, for separating the s polarized components and p-polarization component in the exploring laser light of approximate circular polarization state;
Photodetector is balanced, for measuring the strength difference of s polarized components and p-polarization component in exploring laser light.
A kind of 2. method for enhancing Terahertz Electro-optic sampling detectivity, which is characterized in that comprise the following steps:
1) exploring laser light is converted into linear polarization;
2) exploring laser light is converted into elliptical polarization by linear polarization;
3) s polarized components extra in the exploring laser light of elliptical polarization are removed
4) exploring laser light for removing s polarized components is converted into approximate circular polarization state;
5) the s polarized components in the exploring laser light of approximate circular polarization state and p-polarization component are separated and measures its strength difference.
3. according to the method described in claim 2, it is characterized in that:
The step 1) is specially by linear polarizer by exploring laser light, and rotational line linear polarizer causes the exploring laser light line penetrated Polarization direction is vertical direction, is expressed as in a manner that the exploring laser light after linear polarizer is using Jones vector:
4. according to the method described in claim 2, it is characterized in that:
The step 2) is specially to make exploring laser light with tested THz wave simultaneously through electro-optic crystal, by by THz wave electricity Exploring laser light after the electro-optic crystal of field action is converted to elliptical polarization by linear polarization, is swashed by the detection after electro-optic crystal Light representations are:L1=CLin, wherein, C represents the electro-optic crystal Jones matrix under THz wave electric field action:Wherein, φ is amount of delay.
5. according to the method described in claim 2, it is characterized in that:
The step 3) is specially to pass through Brewster window through Brewster window with brewster angle incidence by exploring laser light Exploring laser light after mouthful is expressed as using Jones matrix:L2=BCLin, wherein, B represents Jones's square of Brewster window Battle array:Wherein, t represents light intensity transmitance of the Brewster window to s polarized components in exploring laser light,Make For field decay amount.
6. according to the method described in claim 2, it is characterized in that:
The step 4) is specially to make exploring laser light through quarter-wave plate, adjustment quarter-wave plate fast axis direction make its with S polarization directions are at 45 °, are expressed as by the Jones matrix of the exploring laser light after quarter-wave plate:L=QBCLin, In, Q is the Jones matrix of quarter-wave plate:
7. according to the method described in claim 2, it is characterized in that:
The step 5) is specially to be divided the s polarized components light in exploring laser light and p-polarization light components using wollaston prism From the expression matrix form that final exploring laser light is calculated is:It uses Photodetector measurement s polarized components light and the strength difference of p-polarization light components are balanced, finally measures obtained s polarized components It is with p-polarization component intensity difference normalization result S:
CN201711364883.4A 2017-12-18 2017-12-18 Device and method for enhancing detection sensitivity of terahertz electro-optic sampling technology Active CN108106723B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711364883.4A CN108106723B (en) 2017-12-18 2017-12-18 Device and method for enhancing detection sensitivity of terahertz electro-optic sampling technology

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711364883.4A CN108106723B (en) 2017-12-18 2017-12-18 Device and method for enhancing detection sensitivity of terahertz electro-optic sampling technology

Publications (2)

Publication Number Publication Date
CN108106723A true CN108106723A (en) 2018-06-01
CN108106723B CN108106723B (en) 2020-09-18

Family

ID=62209820

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711364883.4A Active CN108106723B (en) 2017-12-18 2017-12-18 Device and method for enhancing detection sensitivity of terahertz electro-optic sampling technology

Country Status (1)

Country Link
CN (1) CN108106723B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103217870A (en) * 2013-04-19 2013-07-24 中国科学院上海光学精密机械研究所 Droplet target control system guided by laser beam
CN103658977A (en) * 2012-09-21 2014-03-26 昆山思拓机器有限公司 Etching device adopting square light spot to etch double faced ITO glass
CN104515602A (en) * 2014-12-10 2015-04-15 北京环境特性研究所 Terahertz pulse detector based on electro-optic sampling principle
CN205176310U (en) * 2015-12-01 2016-04-20 苏州谱道光电科技有限公司 Reflecting prism for optical resonator and optical resonator and spectral measurement appearance thereof
CN107036721A (en) * 2016-11-11 2017-08-11 中国人民解放军国防科学技术大学 Terahertz pulse time domain waveform detection method and system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103658977A (en) * 2012-09-21 2014-03-26 昆山思拓机器有限公司 Etching device adopting square light spot to etch double faced ITO glass
CN103217870A (en) * 2013-04-19 2013-07-24 中国科学院上海光学精密机械研究所 Droplet target control system guided by laser beam
CN104515602A (en) * 2014-12-10 2015-04-15 北京环境特性研究所 Terahertz pulse detector based on electro-optic sampling principle
CN205176310U (en) * 2015-12-01 2016-04-20 苏州谱道光电科技有限公司 Reflecting prism for optical resonator and optical resonator and spectral measurement appearance thereof
CN107036721A (en) * 2016-11-11 2017-08-11 中国人民解放军国防科学技术大学 Terahertz pulse time domain waveform detection method and system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
陆启生等: "《半导体材料和器件的激光辐照效应》", 31 December 2015, 国防工业出版社 *

Also Published As

Publication number Publication date
CN108106723B (en) 2020-09-18

Similar Documents

Publication Publication Date Title
Auston et al. Cherenkov radiation from femtosecond optical pulses in electro-optic media
Chen et al. Polarization modulation in optoelectronic generation and detection of terahertz beams
Fleury et al. Electric-field-induced Raman effect in paraelectric crystals
CN101701852B (en) Electro-optic sampling device used for measuring terahertz optical pulse and measuring method thereof
CN103063315B (en) Based on single signal-to-noise ratio measuring method and the device of chirped pulse characteristic
CN105203857B (en) Space strong electric field measuring system based on electric light quadratic effect
CN101178355A (en) Page quantitative determination device and methods based on terahertz time-domain spectroscopic technology
CN105699297B (en) A kind of single-shot time material light Kerr coefficient measuring device
CN109115690A (en) Real-time polarization sensitive terahertz time-domain ellipsometer and optical constant measuring method
CN202511762U (en) Semiconductor wafer thickness detection system
CN108106723A (en) A kind of device and method for enhancing Terahertz Electro-optic sampling detectivity
CN111272285B (en) Polarization state measurement analyzer with high-speed real-time response
Zemon et al. Frequency spectrum of acoustic waves generated in photoconducting CdS in high electric fields
KR20140030050A (en) Sensor for capturing a moving material web
Gorelov et al. Terahertz Cherenkov radiation from ultrafast magnetization in terbium gallium garnet
CN115241725B (en) Terahertz balance detection system and method based on laser-air effect
CN106644084B (en) A kind of detecting system for light beam and the lower polarization state time-resolved spectrum of magneto-optic memory technique effect
US10161792B2 (en) Device and method for realizing spectral polarization-independent measurement based on frequency domain depolarization structure
JPH08146066A (en) Electrical signal-measuring method and device
US11885841B2 (en) Electric field sensor
CN110057775B (en) Method for detecting anisotropy of lanthanum, calcium, manganese and oxygen based on terahertz wave
CN201540244U (en) Electro-optic sampling device for measuring tera-hertz optical pulse
US7079246B2 (en) Method and apparatus for measuring polarization
CN105841814B (en) A kind of Terahertz multiple-pulse transient state time-domain spectroscopy instrument
Ebara et al. Highly sensitive birefringence measurement in THz frequency region and its application to stress measurement

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