CN102192884B - Method for imaging of samples by using polarization controllable terahertz waves - Google Patents
Method for imaging of samples by using polarization controllable terahertz waves Download PDFInfo
- Publication number
- CN102192884B CN102192884B CN 201110060516 CN201110060516A CN102192884B CN 102192884 B CN102192884 B CN 102192884B CN 201110060516 CN201110060516 CN 201110060516 CN 201110060516 A CN201110060516 A CN 201110060516A CN 102192884 B CN102192884 B CN 102192884B
- Authority
- CN
- China
- Prior art keywords
- polarization
- thz wave
- bbo crystal
- horizontal
- controlled
- 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
Images
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a method for imaging of samples by using polarization controllable terahertz waves, comprising the following steps: when the polarization state of terahertz waves is linear polarization, the polarization direction is adjusted to a horizontal direction, an image of horizontal terahertz waves formed after interacting with the tested samples is measured; the polarization direction is adjusted to a vertical direction, an image of vertical terahertz waves formed after interacting with the tested samples is measured. Two images of terahertz waves are analyzed, because the reception signal is strong, the image of horizontal terahertz waves can reflect the intensity changes after interacting with the samples; and the image of vertical terahertz waves can reflect the minute changes of the polarization of terahertz waves caused by samples.
Description
Technical field
The present invention relates to the THz wave imaging field, in particular to a kind of controlled THz wave of polarization of utilizing to the method for imaging of samples.
Background technology
Terahertz emission is worth and wide application prospect and have great scientific research at aspects such as satellite communication, Non-Destructive Testing, military radars because it has unique character such as transient state, low energy and coherence.The making of terahertz polarization measurement, Terahertz communication, biomedical imaging, military target identification, chemical composition analysis and Terahertz filter plate etc. all needs the polarization direction of THz wave is accurately controlled.
Excited the polarization direction of the terahertz emission that air plasma produces by double-frequency laser by research, can change the relative phase between fundamental wave and second harmonic in four-wave mixing and control the polarization direction of the THz wave of radiation, utilize the controlled THz wave of this polarization to carry out polarization imaging to object.
In the imaging technique that adopts the electro-optic sampling detection method, the feature of the formation method that exists at present is only to survey Terahertz electric field intensity component in one direction, this just makes some imaging results be difficult to truly be explained, causes the sample image information that obtains comparatively limited.For example, generally be interpreted as that with respect to the reduction of the amplitude of the electric field intensity of reference signal sample causes for absorption and the scattering of terahertz emission for sample signal, but in fact, the rotation of Terahertz electric field intensity can cause reducing of this detected intensity equally.So present formation method can not be considered sample for the birefringent characteristic of THz wave, and except birefringence effect, the reflection after oblique incidence and Multiple Scattering all may cause the change of Terahertz direction of an electric field.
Summary of the invention
The invention provides a kind of controlled THz wave of polarization of utilizing to the method for imaging of samples, in order to the subtle change that the terahertz polarization attitude that causes per sample occurs, obtain more image information.
For achieving the above object, the invention provides a kind of controlled THz wave of polarization of utilizing to the method for imaging of samples, it comprises the following steps: when the polarization state of THz wave is linear polarization, the polarization direction is adjusted into horizontal direction, measures the horizontal component of the THz wave after interacting with sample; Terahertz pulse to horizontal component is analyzed, and obtains the subject image of horizontal polarization THz wave incident; When the polarization state of THz wave is linear polarization, the polarization direction is adjusted into vertical direction, measure the horizontal component of the THz wave after interacting with sample; Terahertz pulse to horizontal component is analyzed, and obtains the subject image of vertical polarization THz wave incident.
Polarization state in THz wave is linear polarization, the polarization direction is adjusted into the horizontal direction step to be comprised: mobile BBO(barium metaborate) crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be horizontal direction, wherein, position corresponding to horizontal direction electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity maximum that obtains.
When the polarization state of THz wave is linear polarization, the polarization direction is adjusted into the vertical direction step to be comprised: mobile bbo crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be vertical direction, wherein, the position that vertical direction is corresponding electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity minimum that obtains.
Control the position of mobile bbo crystal by accurate translation stage.
When the polarization state of THz wave is linear polarization, the polarization direction is adjusted into the horizontal direction step to be comprised: by add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be horizontal direction.
The polarization state of THz wave is controlled to be linear polarization, the polarization direction is adjusted into the vertical direction step to be comprised: by add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be vertical direction.
Sample is for causing the object of terahertz polarization attitude generation subtle change after interacting with THz wave.
In the above-described embodiments, the two width Terahertz images that obtain are analyzed, the image that the THz wave incident of horizontal polarization obtains, signal is stronger owing to receiving, can reflect with sample effect after the variation that occurs of intensity; The image that the THz wave incident of vertical polarization obtains can reflect the subtle change of the terahertz polarization generation that sample causes, such as the edge scatter of sample and sample anisotropy etc., thereby improved the imaging resolution of sample and obtained more sample interior information, overcome electro-optic sampling detection method in the prior art and can not analyze the revolving property of Terahertz electric field intensity, caused the sample interior information limited problem of the image reflection of obtaining.
Description of drawings
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or description of the Prior Art, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is for to utilize the controlled THz wave of polarization object to be carried out the device schematic diagram of imaging according to an embodiment of the invention;
Fig. 2 is that the angle of the polarization direction of THz wave according to an embodiment of the invention and horizontal direction and bbo crystal are to the graph of a relation between the distance of plasma;
Fig. 3 is that the THz wave of incident is in horizontal polarization and vertical two kinds of situations of polarization, sees through azimuthal graph of a relation of transmitance and the material fiber orientation of anisotropic foam materials;
Fig. 4 is the optical photograph of sample and the Terahertz design sketch that sample is carried out two-dimensional imaging.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Based on the embodiment in the present invention, those of ordinary skills belong to the scope of protection of the invention not paying the every other embodiment that obtains under the creative work prerequisite.
Below the description by specifically the polarization direction high precision being controlled, be further described the method that object carries out imaging the controlled THz wave of polarization of utilizing of the present invention.
Fig. 1 is for to utilize the controlled THz wave of polarization object to be carried out the device schematic diagram of imaging according to an embodiment of the invention.In Fig. 1, each device is as follows: 1, lens; 2, bbo crystal; 3, high-accuracy linear translation platform; 4, polyfluortetraethylene plate; 5, throw the face mirror; 6, sample; 7, electro-conductive glass (ITO); 8, ZnTe crystal; 9, catoptron; 10, quarter-wave plate; 11, Wollaston prism; 12, difference detector.In an embodiment of the present invention, adopt double-frequency laser to excite the air induced plasma to produce THz wave, in the present embodiment, the LASER Light Source that double-frequency laser excites air plasma to produce the utilization of Terahertz is the femtosecond laser amplifier that Spectra-Physics produces, its laser pulse average output power is 3.5W, repetition frequency 1KHz, centre wavelength 800nm, pulsewidth 50fs.LASER Light Source can also be selected the laser instrument that produces other wavelength lasers.
Femto-second laser pulse is divided into two-beam through beam splitting chip, and light beam has most energy of incident laser, and after carrying out frequency multiplication by bbo crystal, the fundamental frequency glistening light of waves focuses on rear mixing mutually with frequency doubled light, excites THz wave; Another bundle low power laser passes through crystal detection as detecting light beam and THz wave conllinear.In crystal detection, the Terahertz electric field changes the index ellipsoid of crystal, thereby the polarization state of outgoing detecting light beam is changed.Detecting light beam is surveyed by difference detector through being divided into horizontal polarization and vertical polarization two bundles by wollaston prism after quarter-wave plate.
Excite air to produce in the mechanism of plasma generation THz wave based on double-frequency laser, only during linearly polarized light, the THz wave that excites is also linear polarization when fundamental frequency.Along with the variation of the relative phase of fundamental frequency light and frequency doubled light, the polarization direction of THz wave can change 2 π continuously.The relative phase of fundamental frequency light and frequency doubled light is along with bbo crystal is different and change to the distance of focus, and the variation of the relative phase of fundamental frequency light and frequency doubled light is proportional to the variation of the position of bbo crystal.When the position of bbo crystal recurred variation, the polarization direction of THz wave also can recur variation, and we can utilize this method to come the polarization direction of the THz wave of high-precision control radiation.
Utilize according to an embodiment of the invention the controlled THz wave of polarization to the method for imaging of samples, comprise the following steps:
S102 when the polarization state of THz wave is linear polarization, is adjusted into horizontal direction with the polarization direction, measures the horizontal component of the THz wave after interacting with sample;
S104 analyzes the terahertz pulse of horizontal component, obtains the subject image of horizontal polarization THz wave incident;
S106 when the polarization state of THz wave is linear polarization, is vertical direction with the polarization direction, measures the horizontal component of the THz wave after interacting with sample;
S108 analyzes the terahertz pulse of vertical component, obtains the subject image of vertical polarization THz wave incident.
In the present embodiment, can adopt the electro-optic sampling Detection Techniques to THz wave the component on a direction measure, this is because the electro-optic sampling Detection Techniques can only be measured the component of THz wave on a direction, if the crystallographic axis of electro-optic crystal is arranged on the direction of measuring the THz wave horizontal component, when the incident THz wave was vertical polarization, the terahertz polarization that is caused by sample can accurately measure to the small deflection that horizontal direction occurs.Equally, if the crystallographic axis of electro-optic crystal is arranged on the direction of measuring the THz wave vertical component, when the incident THz wave was horizontal polarization, the terahertz polarization that is caused by sample can accurately measure to the small deflection that vertical direction occurs.
In the present embodiment, the two width Terahertz images that obtain are analyzed, the image that the THz wave incident of horizontal polarization obtains, signal is stronger owing to receiving, can reflect with sample effect after the variation that occurs of intensity; The image that the THz wave incident of vertical polarization obtains can reflect the subtle change of the terahertz polarization generation that sample causes, such as the edge scatter of sample and sample anisotropy etc., thereby improved the imaging resolution of sample and obtained more sample interior information, overcome electro-optic sampling detection method in the prior art and can not analyze the revolving property of Terahertz electric field intensity, caused the sample interior information limited problem of the image reflection of obtaining.
In an embodiment of the present invention, utilize the THz wave of different polarization direction to carry out two-dimensional imaging to object, horizontal polarization and vertically just better selection of polarization, this is because other polarization direction also can decompose on this both direction.
For example, can control the polarization direction of THz wave to the position of plasma by adjusting bbo crystal.Along the position of direction of beam propagation scanning bbo crystal, the bbo crystal position when the THz wave intensity that finds the electro-optic sampling detection to obtain is minimum and maximum, the polarization direction of the corresponding THz wave that produces is horizontal direction and vertical direction respectively.
Fig. 2 is that the angle of the polarization direction of THz wave according to an embodiment of the invention and horizontal direction and bbo crystal are to the graph of a relation between the distance of plasma.Shown in figure change bbo crystal to plasma apart from the time, the polarization direction of THz wave is with respect to the consequential variation of the angle of horizontal direction.Continuously change in experimental provision shown in Figure 1 bbo crystal to plasma apart from d, measure respectively the polarization angle of THz wave under different distance d, can obtain curve shown in Fig. 2.The method of wherein measuring the polarization angle of THz wave is prior art, does not repeat them here.
As can be drawn from Figure 2, when bbo crystal was 48mm to the distance of plasma, the polarization angle of THz wave was 90 ° (polarization direction is vertical direction); When bbo crystal was 60mm to the distance of plasma, the polarization angle of THz wave was 0 ° (polarization direction is horizontal direction).
Correspondingly, when the polarization state of THz wave is linear polarization, the polarization direction is adjusted into the horizontal direction step to be comprised: mobile bbo crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be horizontal direction, wherein, position corresponding to horizontal direction electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity maximum that obtains.
Correspondingly, when the polarization state of THz wave is linear polarization, the polarization direction is adjusted into the vertical direction step to be comprised: mobile bbo crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be vertical direction, wherein, the position that vertical direction is corresponding electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity minimum that obtains.
For example, for accurately controlling the polarization direction of the THz wave of radiation, in the mechanism that excites air plasma generation THz wave based on double-frequency laser, bbo crystal can be fixed on one dimension electric precise translation stage, accurately control bbo crystal to the distance of plasma by the movement of translation stage.
Again for example, also can be by inserting the quartz crystal of a pair of wedge shape between bbo crystal and plasma, insert by adjusting it polarization direction that THz wave is accurately controlled in position in light beam.
Correspondingly, polarization state in THz wave is linear polarization, the polarization direction is adjusted into the horizontal direction step to be comprised: by add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be horizontal direction.
Correspondingly, the polarization state of THz wave is controlled to be linear polarization, the polarization direction is adjusted into the vertical direction step to be comprised: by add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be vertical direction.
In an embodiment of the present invention, sample is for causing the object of terahertz polarization attitude generation subtle change after interacting with THz wave.
Fig. 3 is that the THz wave of incident is in horizontal polarization and vertical two kinds of situations of polarization, sees through azimuthal graph of a relation of transmitance and the material fiber orientation of anisotropic foam materials.Transmitance and azimuthal measuring and calculating are state of the art, repeat no more in the present invention.
Fig. 4 is the optical photograph of sample and the Terahertz design sketch that sample is carried out two-dimensional imaging.Wherein, left figure is the optical photograph of sample, and sample is by two even thickness but different bonding the forming of space flight foam of fiber orientation, and dash area (imaging region) has been indicated the zone of THz wave scanning.Right figure carries out the Terahertz image of the controlled imaging of polarization to left figure sample, top is that the incident THz wave is the Terahertz image of horizontal polarization, and the bottom is that the incident THz wave is the Terahertz image of vertical polarization.By two width Terahertz images are analyzed, can obtain more information about space flight foam 1 and space flight foam 2 bondings.
Above-mentioned formation method of the present invention is applicable to adopt difference diode receiving system and the focal plane Real Time Image System of electro-optic sampling detection method.
One of ordinary skill in the art will appreciate that: accompanying drawing is the schematic diagram of an embodiment, and the module in accompanying drawing or flow process might not be that enforcement the present invention is necessary.
One of ordinary skill in the art will appreciate that: the module in the device in embodiment can be described according to embodiment and be distributed in the device of embodiment, also can carry out respective change and be arranged in the one or more devices that are different from the present embodiment.The module of above-described embodiment can be merged into a module, also can further split into a plurality of submodules.
One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can be completed by the hardware that programmed instruction is correlated with, aforesaid program can be stored in a computer read/write memory medium, this program is carried out the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: the various media that can be program code stored such as ROM, RAM, magnetic disc or CD.
It should be noted that at last: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme that previous embodiment is put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of embodiment of the present invention technical scheme.
Claims (7)
1. one kind is utilized the controlled THz wave of polarization to the method for imaging of samples, it is characterized in that, comprises the following steps:
When the polarization state of THz wave is linear polarization, the polarization direction is adjusted into horizontal direction, measure the horizontal component of the THz wave after interacting with sample;
Terahertz pulse to described horizontal component is analyzed, and obtains the subject image of horizontal polarization THz wave incident;
When the polarization state of THz wave is linear polarization, the polarization direction is adjusted into vertical direction, measure the horizontal component of the THz wave after interacting with sample;
Terahertz pulse to described horizontal component is analyzed, and obtains the subject image of vertical polarization THz wave incident.
2. method according to claim 1, is characterized in that, is linear polarization in the polarization state of THz wave, the polarization direction is adjusted into the horizontal direction step comprises:
Mobile bbo crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be horizontal direction, wherein, position corresponding to described horizontal direction electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity maximum that obtains.
3. method according to claim 1, is characterized in that, when the polarization state of THz wave is linear polarization, the polarization direction is adjusted into the vertical direction step comprises:
Mobile bbo crystal is to change bbo crystal to the distance of plasma, the polarization direction of THz wave is controlled to be vertical direction, wherein, the position that described vertical direction is corresponding electro-optic sampling for along the position of direction of beam propagation scanning bbo crystal the time is surveyed the position of the bbo crystal of the THz wave intensity minimum that obtains.
4. according to claim 2 or 3 described methods, is characterized in that, controls the position of mobile bbo crystal by accurate translation stage.
5. method according to claim 1, is characterized in that, is linear polarization in the polarization state of THz wave, the polarization direction is adjusted into the horizontal direction step comprises:
By add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be horizontal direction.
6. method according to claim 1, is characterized in that, the polarization state of THz wave is controlled to be linear polarization, the polarization direction is adjusted into the vertical direction step comprises:
By add the quartz crystal of a pair of wedge shape between bbo crystal and plasma, adjust its position of inserting in light beam the polarization direction of THz wave is controlled to be vertical direction.
7. method according to claim 1, is characterized in that, described sample is for causing the object of terahertz polarization attitude generation subtle change after interacting with THz wave.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110060516 CN102192884B (en) | 2011-03-14 | 2011-03-14 | Method for imaging of samples by using polarization controllable terahertz waves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110060516 CN102192884B (en) | 2011-03-14 | 2011-03-14 | Method for imaging of samples by using polarization controllable terahertz waves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102192884A CN102192884A (en) | 2011-09-21 |
| CN102192884B true CN102192884B (en) | 2013-06-19 |
Family
ID=44601381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110060516 Expired - Fee Related CN102192884B (en) | 2011-03-14 | 2011-03-14 | Method for imaging of samples by using polarization controllable terahertz waves |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102192884B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102445420A (en) * | 2011-10-13 | 2012-05-09 | 中国科学院上海微系统与信息技术研究所 | Transmission imaging device and method based on tera-hertz quantum device |
| CN103091255B (en) * | 2013-01-15 | 2016-03-30 | 首都师范大学 | Terahertz time-space resolution imaging system, formation method and application thereof |
| CN103411903B (en) * | 2013-07-29 | 2015-04-29 | 南开大学 | THz radiation reinforcing method through light line array |
| CN107015414A (en) * | 2016-01-28 | 2017-08-04 | 首都师范大学 | A kind of system and method for changing terahertz polarization state |
| CN106483096B (en) * | 2016-11-25 | 2023-04-25 | 首都师范大学 | System and method for generating high-intensity terahertz waves by exciting air plasmas through laser |
| CN113720784B (en) * | 2021-10-11 | 2023-03-24 | 阜阳师范大学 | Chromium-based spinel test system based on terahertz waveband magneto-optical spectrum |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101726362A (en) * | 2009-11-23 | 2010-06-09 | 首都师范大学 | Terahertz polarization analyzer and terahertz polarization measurement method |
| CN101354358B (en) * | 2008-09-05 | 2010-08-04 | 中国计量学院 | Electro-optical heterodyne detection type THz wave rapid two-dimension imaging apparatus |
| CN101832940A (en) * | 2010-03-16 | 2010-09-15 | 首都师范大学 | Terahertz polarization real-time imaging method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008147575A2 (en) * | 2007-01-11 | 2008-12-04 | Rensselaer Polytechnic Institute | Systems, methods, and devices for handling terahertz radiation |
| WO2008110017A1 (en) * | 2007-03-15 | 2008-09-18 | University Of Northern British Columbia | Systems and methods for monitoring wood product characteristics |
-
2011
- 2011-03-14 CN CN 201110060516 patent/CN102192884B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354358B (en) * | 2008-09-05 | 2010-08-04 | 中国计量学院 | Electro-optical heterodyne detection type THz wave rapid two-dimension imaging apparatus |
| CN101726362A (en) * | 2009-11-23 | 2010-06-09 | 首都师范大学 | Terahertz polarization analyzer and terahertz polarization measurement method |
| CN101832940A (en) * | 2010-03-16 | 2010-09-15 | 首都师范大学 | Terahertz polarization real-time imaging method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102192884A (en) | 2011-09-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102192884B (en) | Method for imaging of samples by using polarization controllable terahertz waves | |
| CN101813619B (en) | Method utilizing polarization-controllable T-Hz wave to measure optical axis direction of birefringent crystal | |
| CN101726362B (en) | Terahertz polarization analyzer and terahertz polarization measurement method | |
| US5589936A (en) | Optical measuring apparatus for measuring physichemical properties | |
| CN104390935A (en) | Device and method for testing nonlinear polarization coefficient and absorption coefficient at terahertz band | |
| US8759779B2 (en) | Terahertz wave generation element, terahertz wave detection element, and terahertz time domain spectral device | |
| CN203745385U (en) | Laser ultrasonic optical interference detection device | |
| CN111442733A (en) | Nondestructive testing method for rubber composite material based on terahertz time-domain spectral imaging | |
| CN103154720B (en) | Measuring apparatus and measuring method for metallic microstructures ormaterial properties | |
| CN108593106A (en) | A kind of system and device of detection stimulated Brillouin scattering transient state ultrasonic grating spectrum | |
| CN105067528A (en) | Two dimension confocal microscopynon-linear intensity scanning system and measurement method | |
| CN102004080A (en) | Transmission-type terahertz spectral analysis method independent of reference light | |
| CN108344711B (en) | Method and system for improving terahertz pulse imaging resolution | |
| CN102645408A (en) | Phase object Z-scan-based pump-probe method | |
| CN109883350A (en) | A kind of high precision measuring system and measurement method of abnormal curved surface inside configuration pattern | |
| CN102636337A (en) | Method for measuring optical fiber dispersion | |
| Zhai et al. | Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes | |
| US20230318244A1 (en) | Apparatus and method for measuring and controlling chirp of ultrafast laser pulse | |
| CN111272881A (en) | Laser ultrasonic system and method for detecting thermal diffusivity of nano film in non-contact mode | |
| CN216771491U (en) | Polarization resolution second harmonic testing device | |
| CN110132886B (en) | High-sensitivity terahertz spectrum detection device and method for liquid concentration | |
| JPH10115573A (en) | Method and apparatus for measurement of tertiary nonlinear susceptibility rate | |
| CN105806800A (en) | Terahertz optical fiber sensing device and pollutant detection method using the same | |
| CN109931885B (en) | Device for accurately measuring incidence angle of light beam | |
| CN102636830B (en) | Bar-type phase diaphragm and 4f phase-concerned nonlinear imaging system and nonlinear refractive index metering method based on same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| 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: 20130619 Termination date: 20150314 |
|
| EXPY | Termination of patent right or utility model |