CN104022427A - Generation device of wave-shape controllable terahertz radiation - Google Patents
Generation device of wave-shape controllable terahertz radiation Download PDFInfo
- Publication number
- CN104022427A CN104022427A CN201410172822.8A CN201410172822A CN104022427A CN 104022427 A CN104022427 A CN 104022427A CN 201410172822 A CN201410172822 A CN 201410172822A CN 104022427 A CN104022427 A CN 104022427A
- Authority
- CN
- China
- Prior art keywords
- stepping motor
- stainless steel
- steel blade
- waveform
- wedge
- 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.)
- Pending
Links
- 230000005855 radiation Effects 0.000 title abstract 3
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 27
- 239000010935 stainless steel Substances 0.000 claims abstract description 27
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000013519 translation Methods 0.000 claims abstract description 11
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 230000003287 optical effect Effects 0.000 claims description 3
- 239000005350 fused silica glass Substances 0.000 abstract description 5
- 230000000737 periodic effect Effects 0.000 abstract 2
- 238000000034 method Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 125000002950 monocyclic group Chemical group 0.000 description 2
- 230000005374 Kerr effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000010329 laser etching Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
A generation device of waveform controllable terahertz radiation is characterized by comprising a periodic magnitude infrared light source, wherein a fused quartz wedge plate pair, a plane reflector, a concave reflector and a stainless steel blade are sequentially arranged along the laser output direction of the periodic magnitude infrared light source, one fused quartz wedge plate in the fused quartz wedge plate pair is arranged on a stepping motor translation table, the stepping motor translation table drives the fused quartz wedge plate to move along the long right-angle side direction of the wedge plate under the driving of a stepping motor, the stainless steel blade is positioned outside the focus of the concave reflector and is arranged on the stepping motor, and the stainless steel blade moves along the light propagation direction under the driving of the stepping motor. The terahertz radiation generated by the invention has the characteristics of adjustable waveform and adjustable amplitude.
Description
Technical field
The present invention relates to terahertz emission and produce, the particularly controlled terahertz emission generation device of a kind of waveform.
Background technology
Ultrashort pulse excites air plasma to become the method for silk to propose [Cook as far back as 2000, D.J.and R.M.Hochstrasser Intense terahertz pulses by four-wave rectification in air, Opt.Lett., (2000), 25 (16): 1210-1212.].Due to ultra-short pulse laser long-distance transmissions one-tenth silk, the absorption that can avoid Terahertz to cause at air transmission steam etc., realizes long-range generation and detection.Compare crystal medium, be not the damaged restriction of threshold value of air plasma, can use more high-octane laser pumping, obtains strong terahertz emission simultaneously.
Become the method for silk can be divided into monochromatic field and double-colored field according to the different air of driving light source.Common tens have higher energy conversion efficiency to hundreds of femtosecond double color field than monochromatic field.If but laser field envelope intercarrier vibration is while only having minority photoperiod, do not need assisting of two frequency multiplication light fields can produce stronger terahertz emission [Kresz yet, M., et al.Determination of the carrier-envelope phase of few-cycle laser pulses withterahertz-emission spectroscopy, Nat Phys (2006), 2 (5): 327-331.].Physical process is as follows: cycle magnitude light field is because the light field non-symmetrical features self having can will be converted to terahertz wave band under driving light frequency to electronics accelerator by photo ionization and light field.The method of cycle magnitude light field excited gas plasma, can produce monocyclic terahertz emission.
Summary of the invention
The object of the present invention is to provide the controlled terahertz emission generation device of a kind of waveform, the terahertz emission that this device produces has waveform and the adjustable feature of amplitude.
The solution of the present invention is as follows:
The generation device of the controlled terahertz emission of a kind of waveform, feature is that its formation comprises cycle magnitude infrared light supply, vitreous silica wedge pair successively along the Laser output direction of this cycle magnitude infrared light supply, plane mirror, concave mirror and stainless steel blade, a vitreous silica wedge of described vitreous silica wedge centering is placed on stepping motor translation stage, this stepping motor translation stage drives this piece vitreous silica wedge to move along the long right-angle side direction of wedge under the driving of stepping motor, it is outer and be placed on another stepping motor that described stainless steel blade is positioned at the focus of described concave mirror, this stainless steel blade moves along optical propagation direction under the driving of described stepping motor.
Blocking of described stainless steel blade is prevented from chevilled silk, and the terahertz emission that only has the chevilled silk part not being blocked to produce is collected detection in far field.
Principle of the present invention is as follows:
According to photoelectric current model description, terahertz emission comes from the transient current of asymmetrical beam field excitation, and after light field effect finishes, the residual current that still has non-zero exists, and the direction of motion of electric current has determined the polarity of monocycle Terahertz electric field.Conventionally terahertz emission waveform depends on the carrier oscillation of pulse, therefore regulates the carrier envelope phase of light field can control the waveform that produces Terahertz.Because the length of chevilled silk is greater than the Rayleigh range of line focus light beam conventionally, and the polarity that different section silk produces residue photoelectric currents are also different, and therefore the present invention also proposes the way with blade control filament length degree, obtains the Terahertz waveform of opposed polarity.
Advantage of the present invention:
1, the present invention adopts the control method to Few-cycle pulse original carrier envelope phase and chevilled silk length simultaneously, can realize the control of Terahertz electric field waveform.
2, the method that adopts stainless steel blade to block into a process in the present invention can be controlled chevilled silk length accurately, and the blade of chopping is positioned on stepping motor, moves along laser propagation direction.
3, cycle magnitude light field two frequencys multiplication that do not need to superpose just can produce terahertz emission.
Brief description of the drawings
Fig. 1 is the controlled terahertz emission generation device schematic diagram of waveform of the present invention.
Fig. 2 is schematic diagram and the stainless steel blade photo of plasma chevilled silk photo, blade gear silk.
Fig. 3 is one group of THz wave graphic data utilizing apparatus of the present invention regulating cycle magnitude pulse carrier envelope phase to record.
Fig. 4 is one group of THz wave graphic data utilizing apparatus of the present invention to regulate chevilled silk length to record.
Embodiment
Below in conjunction with drawings and Examples, the invention will be further described, but should not limit the scope of the invention with this.
2, first refer to Fig. 1, Fig. 1 is the generation device structural representation of the controlled terahertz emission of waveform of the present invention.As seen from the figure, the generation device of the controlled terahertz emission of waveform of the present invention, formation comprises: cycle magnitude infrared light supply 1, that vitreous silica wedge is to 2 successively along the Laser output direction of this cycle magnitude infrared light supply 1, plane mirror 4, concave mirror 5 and stainless steel blade 7, described vitreous silica wedge is placed on stepping motor translation stage 3 a vitreous silica wedge in 2, this stepping motor translation stage 3 drives this piece vitreous silica wedge to move along the long right-angle side direction of wedge under the driving of stepping motor, it is outer and be placed on another stepping motor 8 that described stainless steel blade 7 is positioned at the focus of described concave mirror 5, this stainless steel blade 7 moves along optical propagation direction under the driving of another described stepping motor 8.
Described concave mirror 5 forms one section of chevilled silk 6 for femtosecond light being focused on to air, and stainless steel blade 7 for blocking chevilled silk, regulates chevilled silk length for the length of controlling chevilled silk.
The now operation principle of explanation apparatus of the present invention as an example of the Terahertz waveform result of one group of experiment measuring example.
The infrared infrared light supply 1 output laser pulse centre wavelength 1.8 μ m of cycle magnitude, full width at half maximum 10fs (～1.7 photoperiod).Ultrashort pulse energy is about 300 μ J, spherical mirror through concave mirror 5 focal distance f=150mm (f/6) focuses in air, under the nonlinear interactions such as Kerr effect and plasma generation, form the plasma chevilled silk 6 of length～12mm, see Fig. 2 (a).
If want the waveform of control cycle magnitude light field, need to change the carrier envelope phase (CEP) of pulse.Experimentally conventionally adopt pulse is seen through to the transparent medium that length is L, as quartzy wedge 2, dispersion meeting causes CEP to add change amount:
Here n is the refractive index of transparent medium.If the thickness of medium just makes the CEP that sees through pulse change π, thickness is defined as dephasing length so,
for common transparent medium, dephasing length is about tens microns.For 1.8 μ m centre wavelengths, fused silica material
dephasing length L
deph=37.6 μ m.
Quartz wedge is 3 ° to 2 the angle of wedge, and quartzy wedge is placed by Brewster angle (56.7 °), and wherein a quartzy wedge moves along long right-angle side direction on stepping motor translation stage (KSA050-12 stands upright) 3.Move wedge taking 0.145mm as step-length, 7.5 μ m are measured in thickness change, change 0.2 π of Few-cycle pulse CEP.In Fig. 3, result has clearly shown the change that 2 π occur as CEP, and Terahertz electric field waveform experience amplitude modulation(PAM) and change in polarity, become original waveform again.What note waveform here we pay close attention to is monocyclic Terahertz waveform vibration, and follow-up vibration comes from the reasons such as steam absorption.
Due to the existence of phase shift variations in plasma chevilled silk, the polarity that different section silks produce residue photoelectric current is different.The way of stainless steel blade control filament length degree for the present invention, by surveying the terahertz emission of different length chevilled silk generation, obtains the Terahertz waveform of opposed polarity.
Here we have used a stainless steel blade 7, and size～0.2mm × 4mm × 20mm is placed into plasma filament region, sees mistake! Do not find Reference source.Experiment photo and schematic diagram shown in 2 (b)-(c).Due to stopping of blade, chevilled silk ends at stainless steel blade front end.The sword of stainless steel blade is placed in face of the direction of laser propagation, is arranged on (KSA050-12 stands upright) on mobile platform, and translation stage moves forward and backward along laser propagation direction.Object is in order that reduce as far as possible the impact of stainless steel blade on silk and generation Terahertz like this.The terahertz emission that the silk not being blocked like this produces is collected and surveys.In order to ensure to control the accuracy of filament length degree, the data of every measurement one ***ine length, stainless steel blade position all up translation, allow laser beat on new stainless steel blade sword once.Broached-tooth design in Fig. 2 (d) on stainless steel blade is the result of laser etching on blade, and the depth capacity of etching is less than 0.5mm.
Experimentally the length of the Position Control silk by mobile stainless steel blade, measures terahertz signal.In order to facilitate us to define the coordinate of silk, initial point is set as silk foremost, and Terahertz just has the position of detectable signal.By moving forward stainless steel blade position, the length of silk reduces, and Terahertz intensity is also weakening.When a little less than terahertz emission to just can not surveying when, small-signal has been submerged in noise, is at this moment defined as initial point with regard to mark stepper motor steps.Next silk length we be all initial according to the initial point of this definition.What Fig. 4 (a) showed is the contrast of filament length degree Terahertz waveform while being 3mm and 10mm.Although two length Terahertz amplitude contrasts are very large, are 1:5, still can obviously find out that both reversion have occurred polarity.We infer that change may occur the phase place of cycle magnitude light field in silk.Further, by move stainless steel blade position taking 0.5mm as step-length, the finer filament length degree that changes over, has measured the Terahertz waveform that a series of filament length degree change, the X-Y scheme as shown in Fig. 4 (b).Terahertz emission changes amplitude and polarity gradually with the increase of filament length.Particularly, in the position of filament length 5mm, it is zero that terahertz emission weakens, and polarity inversion then occurs.So we have produced the controlled terahertz emission of waveform by the length that changes silk experimentally.
Claims (1)
1. the terahertz emission generation device that waveform is controlled, be characterised in that its formation comprises: cycle magnitude infrared light supply (1), that vitreous silica wedge is to (2) successively along the Laser output direction of this cycle magnitude infrared light supply (1), plane mirror (4), concave mirror (5) and stainless steel blade (7), described vitreous silica wedge is placed on stepping motor translation stage (3) a vitreous silica wedge in (2), this stepping motor translation stage (3) drives this piece vitreous silica wedge to move along the long right-angle side direction of wedge under the driving of stepping motor, after described stainless steel blade (7) is positioned at the focus of described concave mirror (5) and be placed on stepping motor (8), this stainless steel blade (7) moves along optical propagation direction under the driving of described stepping motor (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410172822.8A CN104022427A (en) | 2014-04-28 | 2014-04-28 | Generation device of wave-shape controllable terahertz radiation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410172822.8A CN104022427A (en) | 2014-04-28 | 2014-04-28 | Generation device of wave-shape controllable terahertz radiation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104022427A true CN104022427A (en) | 2014-09-03 |
Family
ID=51439058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410172822.8A Pending CN104022427A (en) | 2014-04-28 | 2014-04-28 | Generation device of wave-shape controllable terahertz radiation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104022427A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577647A (en) * | 2015-01-09 | 2015-04-29 | 中国科学院上海光学精密机械研究所 | Elliptic polarization modulation method of terahertz waves |
| CN108549160A (en) * | 2018-04-20 | 2018-09-18 | 北京工业大学 | A kind of device and method of continuous adjustment laser filament length |
| CN108809427A (en) * | 2018-04-18 | 2018-11-13 | 俞俊生 | Based on the adjustable Terahertz wireless communication system of the phased wave beam of optics and communication means |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040196660A1 (en) * | 2001-09-21 | 2004-10-07 | Mamoru Usami | Terahertz light apparatus |
| EP1598695A2 (en) * | 2004-05-19 | 2005-11-23 | Aisin Seiki Kabushiki Kaisha | Terahertz wave-generator and terahertz waves detector |
| WO2006092874A1 (en) * | 2005-03-01 | 2006-09-08 | Osaka University | High-resolution high-speed terahertz spectrometer |
| JP2007333379A (en) * | 2004-09-13 | 2007-12-27 | Univ Of Tokyo | Measuring method employing high-frequency electromagnetic wave |
| CN103234643A (en) * | 2013-04-15 | 2013-08-07 | 中国科学院上海光学精密机械研究所 | Method for measuring carrier-envelop phase positions of few-circle femtosecond laser pulses |
-
2014
- 2014-04-28 CN CN201410172822.8A patent/CN104022427A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040196660A1 (en) * | 2001-09-21 | 2004-10-07 | Mamoru Usami | Terahertz light apparatus |
| EP1598695A2 (en) * | 2004-05-19 | 2005-11-23 | Aisin Seiki Kabushiki Kaisha | Terahertz wave-generator and terahertz waves detector |
| JP2007333379A (en) * | 2004-09-13 | 2007-12-27 | Univ Of Tokyo | Measuring method employing high-frequency electromagnetic wave |
| WO2006092874A1 (en) * | 2005-03-01 | 2006-09-08 | Osaka University | High-resolution high-speed terahertz spectrometer |
| CN103234643A (en) * | 2013-04-15 | 2013-08-07 | 中国科学院上海光学精密机械研究所 | Method for measuring carrier-envelop phase positions of few-circle femtosecond laser pulses |
Non-Patent Citations (1)
| Title |
|---|
| 白亚等: "周期量级激光脉冲激发等离子产生太赫兹辐射研究", 《激光与光电子学进展》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577647A (en) * | 2015-01-09 | 2015-04-29 | 中国科学院上海光学精密机械研究所 | Elliptic polarization modulation method of terahertz waves |
| CN108809427A (en) * | 2018-04-18 | 2018-11-13 | 俞俊生 | Based on the adjustable Terahertz wireless communication system of the phased wave beam of optics and communication means |
| CN108549160A (en) * | 2018-04-20 | 2018-09-18 | 北京工业大学 | A kind of device and method of continuous adjustment laser filament length |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| You et al. | Off-axis phase-matched terahertz emission from two-color laser-induced plasma filaments | |
| Kostin et al. | Ionization-induced conversion of ultrashort Bessel beam to terahertz pulse | |
| CN103557941B (en) | Broadband TeraHertz wave time domain detection and light spot imaging integrated device and adjustment method | |
| KR101693339B1 (en) | Method and apparatus for generating high power terahertz | |
| CN103841744A (en) | Laser wake field accelerator and method for generating high-light attosecond light pulses | |
| CN104022427A (en) | Generation device of wave-shape controllable terahertz radiation | |
| Fang et al. | Simple Nd: YAG laser generates vector and vortex beam | |
| CN103246064A (en) | Gradual change refractive index plasma lens-based device and method for generating hollow light beam | |
| Hort et al. | Postcompression of high-energy terawatt-level femtosecond pulses and application to high-order harmonic generation | |
| CN103234643B (en) | Method for measuring carrier-envelop phase positions of few-circle femtosecond laser pulses | |
| Xie et al. | A VCSEL end-pumped high-energy Q-switched Nd: YAG laser | |
| Uno et al. | Glass drilling by longitudinally excited CO2 laser with short laser pulse | |
| CN105790045A (en) | High-energy few-cycle ultra-high-signal to noise ratio femtosecond seed pulse generation device | |
| Singh et al. | Stimulated Raman backscattering of filamented hollow Gaussian beams | |
| Chen et al. | Scaling of the terahertz emission from liquid water lines by plasma reshaping | |
| Pang et al. | Phase-matching control of high-order harmonics with circular Airy-Gaussian beams | |
| Otsuka | Laser-fluctuation measurements in a bath of strong Gaussian noise | |
| CN208782237U (en) | Controllable passive Q-adjusted infrared laser | |
| Zhang et al. | Terahertz photonics of microplasma and beyond | |
| CN109066281A (en) | Controllable passive Q-adjusted ultraviolet laser | |
| CN217528517U (en) | Uniform line light spot laser cleaning device | |
| CN109038202A (en) | Controllable passive Q-adjusted green (light) laser | |
| TWM469131U (en) | A fiber pulse laser system | |
| CN103941517A (en) | Optical limiter with small limiting threshold value | |
| Jin et al. | Terahertz Photonics in Liquids |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20140903 |