CN208738600U - A kind of polarization type laser pulse stretching system - Google Patents
A kind of polarization type laser pulse stretching system Download PDFInfo
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- CN208738600U CN208738600U CN201821431390.8U CN201821431390U CN208738600U CN 208738600 U CN208738600 U CN 208738600U CN 201821431390 U CN201821431390 U CN 201821431390U CN 208738600 U CN208738600 U CN 208738600U
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Abstract
A kind of polarization type laser pulse stretching system category laser diagnostics in combustion field, in tandem, reflecting mirror II and reflecting mirror I are in tandem for Optical Maser System, polarization spectroscope I, wave plate and polarization spectroscope II in the utility model；II center of polarization spectro piece is 113 degree with the angle α for crossing II center tandem of polarization spectro piece to I line of centres of reflecting mirror；II center of reflecting mirror is 67 degree with the angle β for crossing II center tandem of reflecting mirror to I line of centres of polarization spectro piece；The utility model is able to achieve the spatial resolution and utilization ratio of laser energy that can reduce the former high energy P polarization laser pulse that there is the high energy P polarization laser pulse of high-peak power and narrow spaces halfwidth (FWHM) to be changed into low peak power He width FWHM collimation laser optical path work difficulty in laser pulse stretching system, raising laser in lasing region, the intensity and signal-to-noise ratio that gaseous state Raman scattering signal is significantly increased.
Description
Technical field
A kind of the utility model category laser diagnostics in combustion field, and in particular to polarization type laser pulse stretching system.
Background technique
By laser spontaneous Raman scattering spectral measurement methods, the main component under complicated combustion field environment may be implemented
(nitrogen, oxygen, carbon dioxide, hydrocarbon fuel, hydrogen, carbon monoxide etc.), concentration of component (molar fraction) and regional temperature
Detection, and there is untouchable, the several species measurement synchronism of measurement, quantitative and time (nanosecond) and space (grade)
Resolution capability, had been widely used at present such as the various burnings in engine combustion room or under certain closed or atmospheric environment
In system.It is general to select high energy pulse laser since the number density of molecule of gaseous species is small more compared with liquid and solid matter
Pulsewidth halfwidth (FWHM) of the laser of device outgoing as excitation light source and the wider laser pulse of needs.But it is common high
The laser of energy impulse laser emitting generally has high peak power (being greater than 0.4GW (gigawatt)) and narrow FWHM (several to receive
Second), it will cause gas cracking when with its deexcitation gas, light fuel gas and damage sealing is with being quartz window, and it is serious
Gas Raman spectral measurement is influenced or cannot be completed, is less than so need to be dropped to peak power using the outer shaping optical path of certain laser
0.02GW and by FWHM broadening to could complete tens nanoseconds (ns) measure.
The purpose for reducing laser peak power is generally realized using laser pulse stretcher at present.On the one hand, in laser
At least mirrors such as more than ten beam splitters, reflecting mirror and focus lamp are needed to realize in pulse stretcher, it usually needs to pass through craft
Top to bottom, left and right, front and rear and the pitch position of mirror holder are adjusted, to guarantee the collimation of whole laser optical path.But due to more mirrors
These operations are needed, work difficulty can be considerably increased, collimation that is not only time-consuming but also being difficult to reach optimal each section of laser interfascicular is imitated
Fruit, the laser beam after ultimately causing broadening cannot get optimal spatial resolving power in lasing region and pulsed laser energy is concentrated
Effect.On the other hand, when with laser irradiation combustion field environment, other than it can generate the Raman diffused light of gaseous species, also
There is the fluorescence of gaseous species to occur, it can seriously reduce the signal-to-noise ratio of Raman scattering signal.
Summary of the invention
The purpose of this utility model is to provide a kind of polarization type laser pulse stretching systems, allow Optical Maser System to go out first
The high energy laser pulse of P (horizontal direction) polarization state of experiment is penetrated, this laser pulse is mapped to according to Brewster angle
On a piece of polarization spectroscope, P-polarized light is occurred by areflexia completely.Then, by a piece of angle rotatable (0 degree~90
Degree) wave plate, by adjusting angle so that from wave plate be emitted light become synthesis P-polarized light and S (vertical direction) polarization
Light.When polarised light of this synthesis also presses Brewster angle incidence to second polarization spectroscope, P-polarized light passes through, and S-polarization
Light is reflected, and returns to first polarization spectroscope via two panels reflecting mirror.This five eyeglasses form a laser pulse circulation
Original laser pulse is finally broadened and is dropped in the outlet of second polarization spectroscope in intracavitary multiple circulation by chamber, laser pulse
Low peak power.Since this broadening system maintains original pulse laser polarization direction and energy, gas can be realized
The maximization of Raman signal, and since polarization state of the fluorescence signal to laser is insensitive, so the fluorescence signal also greatly reduced
Generation, improve the signal-to-noise ratio of gas Raman signal.It can be used in combustion field environment and complete laser raman scattering imaging and object
Kind molar fraction and regional temperature measurement.
The utility model is by Optical Maser System 1, polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, reflecting mirror I 5 and anti-
The composition of mirror II 6 is penetrated, Optical Maser System 1, polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, reflecting mirror I 5, reflecting mirror II 6 are set
On same optical platform；The plated film working face of polarization spectroscope I 2 is towards right front, and the plated film working face of wave plate 3 is towards front, partially
Shake spectroscope II 4 plated film working face towards left front, the plated film working face of reflecting mirror I 5 is towards right front, the plated film of reflecting mirror II 6
Working face is towards right back；Optical Maser System 1, polarization spectroscope I 2, wave plate 3 and polarization spectroscope II 4 are arranged from sequence front to back,
And the center of the pulse laser outlet of Optical Maser System 1, polarization spectroscope I 2, wave plate 3 and polarization spectroscope II 4 is a front and back
On straight line；In tandem, and the center of reflecting mirror II 6 and reflecting mirror I 5 is in a tandem for reflecting mirror II 6 and reflecting mirror I 5
On；II 4 center of polarization spectroscope is with the angle α for crossing II 4 center tandem of polarization spectroscope to I 5 line of centres of reflecting mirror
113 degree；II 6 center of reflecting mirror is 67 with the angle β for crossing II 6 center tandem of reflecting mirror to I 2 line of centres of polarization spectroscope
Degree.
The course of work of the utility model is as follows:
The laser beam Aa of outgoing P polarization is exported by 56.5 degree of incident angles to polarization from 1 pulse laser of Optical Maser System
The center of the plated film working face of spectroscope I 2, and it is formed through the laser beam B b of P polarization.The laser beam B b of P polarization is incident by 0 degree
The center for having rotated the plated film working face of wave plate 3 at 45 degree of angles is incident at angle vertically, and is worn and to be formed laser beam Cc, laser beam
Cc contains P-polarized light and S polarized light.Laser beam Cc is by 56.5 degree of incident angles to II 4 plated film working face of polarization spectroscope
Center, the laser beam Cc containing S-polarization are formed the laser beam Ee of S-polarization by 56.5 degree of angle of reflection, and are polarized containing P
Laser beam Cc pass through II 4 plated film working face of polarization spectroscope the laser beam Dd for being centrally formed P polarization.The laser beam of S-polarization
Ee by 33.5 degree incident angles to reflecting mirror I 5 plated film working face center, then formed by 33.5 degree of angle of reflection
The laser beam F f of S-polarization.The laser beam F f of S-polarization by 33.5 degree incident angles to reflecting mirror II 6 plated film working face
Center, then the laser beam Gg of the angle of reflection formation S-polarization by 33.5 degree.The laser beam Gg of S-polarization presses 56.5 degree of incidence
It is incident on the center of plated film working face, then the new laser beam B b of the angle of reflection formation S-polarization by 56.5 degree in angle.S-polarization
Laser beam B b by 0 degree incident angles to wave plate 3 plated film working face center, be then passed through to be formed polarized containing S it is inclined with P
The new laser beam Cc of vibration.Laser beam Cc is by 56.5 degree of incident angles into the plated film working face of polarization spectroscope II 4
The heart, the laser beam Cc containing P polarization are pierced by form new laser beam Dd, and the laser beam Cc containing S-polarization is anti-by 56.5 degree
Firing angle reflects to form the laser beam Ee of new S-polarization.The one cycle of the laser beam Aa of P polarization is completed to this, it is such to follow
Ring completes n times, ultimately forms the laser beam Ee of the P polarization of synthesis.
The peak power of the laser beam Ee of this P polarization finally synthesized is less than the peak work of the laser beam Aa of P polarization
Rate, pulsewidth halfwidth (FWHM) are greater than the FWHM of the laser beam Aa of P polarization.
The utility model is able to achieve can will be former using only two panels polarization spectroscope, a piece of 1/2 wave plate and two panels reflecting mirror
High energy P polarization laser pulse with high-peak power and narrow spaces halfwidth (FWHM) is changed into low peak power and width FWHM
High energy P polarization laser pulse, difficulty that collimation laser optical path in laser pulse stretching system works can be reduced, improve laser
Spatial resolution and utilization ratio of laser energy in lasing region, the intensity and noise that gaseous state Raman scattering signal is significantly increased
Than.Laser beam Ee can inspire Raman scattering optical signal in combustion field environment, then complete gaseous species by Raman spectrum system
Component, concentration of component and temperature quantitative measurment.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of linear polarization formula laser pulse stretching system
Fig. 2 is timing diagram before and after laser pulse stretching
Wherein: 1. Optical Maser System, 2. polarization spectroscope, I 3.1/2 wave plate, 4. polarization spectroscope, II 5. reflecting mirror I 6.
II a. laser beam A b. laser beam B c. laser beam C d. laser beam D e. laser beam E f. laser beam F g. laser beam of reflecting mirror
G
Specific embodiment
The utility model is described with reference to the accompanying drawing.
As shown in Figure 1, the utility model is by Optical Maser System 1, polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, anti-
Mirror I 5 and reflecting mirror II 6 is penetrated to form, Optical Maser System 1, polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, reflecting mirror I 5,
Reflecting mirror II 6 is set on same optical platform；The plated film working face of polarization spectroscope I 2 is towards right front, the plated film working face of wave plate 3
Towards front, towards left front, the plated film working face of reflecting mirror I 5 reflects the plated film working face of polarization spectroscope II 4 towards right front
The plated film working face of mirror II 6 is towards right back；Optical Maser System 1, polarization spectroscope I 2, wave plate 3 and polarization spectroscope II 4 are certainly preceding extremely
Sequence arranges afterwards, and in the pulse laser outlet of Optical Maser System 1, polarization spectroscope I 2, wave plate 3 and polarization spectroscope II 4
The heart is on a tandem；In tandem, and the center of reflecting mirror II 6 and reflecting mirror I 5 exists for reflecting mirror II 6 and reflecting mirror I 5
On one tandem；II 4 center of polarization spectroscope is to I 5 line of centres of reflecting mirror and crosses before and after II 4 center of polarization spectroscope directly
The angle α of line is 113 degree；II 6 center of reflecting mirror is to I 2 line of centres of polarization spectroscope and crosses II 6 center tandem of reflecting mirror
Angle β be 67 degree.
Requirement during utility model works is as follows:
Optical Maser System 1 is powered and preheats, and knob position and parameter is arranged.
Accurately adjust each optical device center various dimensions position: the 532nm that Optical Maser System 1 is emitted debugging energy (receives
Rice) visible laser beam Aa, finely tunes Optical Maser System 1, polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, reflecting mirror I 5
With the height and position of the equipment supporter of reflecting mirror II 6 and mirror holder, left and right and front-rear position, inclination angle and the angle position of pitching, make
Laser beam Aa, laser beam B b, laser beam Cc, laser beam Dd, laser beam Ee, laser beam F f, laser beam Gg are obtained in same level
It is interior so that laser beam Aa, laser beam B b, laser beam Cc and laser beam Dd be on same straight line so that J laser beam F f in parallel with
Laser beam Aa, laser beam B b, laser beam Cc and laser beam Dd, so that laser beam Aa, laser beam Cc and laser beam G incidence angles
It is 56.5 degree, so that the angle of reflection of laser beam Ee is 56.5 degree, so that the incidence angle and laser beam of laser beam Ee and laser beam F f
The angle of reflection of Ff and laser beam Gg are 33.5 degree.Rotating wave plate 3 is 45 degree of angles.
It measures laser polarization state: by the optical path of the probe insertion laser beam Cc of polarization measurement instrument, observing the P of laser beam Cc
Polarization and S-polarization.
Time domain waveform before and after measurement laser pulse stretching: laser beam is observed respectively with photoelectric converter and ondograph
The time domain waveform of Aa and laser beam Dd obtain curve shown in Fig. 2, observe broadening effect.
Embodiment:
As shown in Figure 1, Optical Maser System 1 is the LS2137 type Optical Maser System of Byelorussia LOTIS TII company, go out
532nm (nanometer) laser beam Aa is penetrated, laser spot diameter is about 8mm (millimeter), laser beam divergence 0.8mrad, pulsewidth half
High width (FWHM) is about 7ns (nanosecond), and frequency is 10Hz (hertz), and experiment laser energy E is 420mJ (millijoule).
Polarization spectroscope I 2, wave plate 3, polarization spectroscope II 4, reflecting mirror I 5 and reflecting mirror II 6 are chosen in Byelorussia
LOTIS TII company is 532nm surface enhanced plated film.
Laser energy is calculated as the QED12 attenuator of Canadian gentec-eo company, QE12LP-H-MB probe and solo2 table
Head.
Photoelectric converter is U.S. Thorlabs company DET02AFC type silicon photoelectric diode, and ondograph is Taiwan
The GDS3352 type digital oscilloscope of GWINSTEK company.
Polarization measurement instrument is the PAX1000VIS type polarization measurement instrument of U.S. Thorlabs company.
The length of laser beam Aa is that the length of 650mm, laser beam B b and laser beam Cc are 250mm, laser beam Ee and is swashed
Light beam Gg is 350mm, and laser beam F f is 650mm.
As shown in Figure 2, in which: A is the time domain waveform of laser beam Aa, peak power 0.06GW, FWHM 7ns；B is sharp
The time domain waveform of light beam Dd, peak power 0.02GW, FWHM 35ns；A1 is the frequency of laser beam Aa, laser beam Dd, is
10Hz。
Claims (1)
1. a kind of polarization type laser pulse stretching system, it is characterised in that: by Optical Maser System (1), polarization spectroscope I (2), wave
Piece (3), polarization spectroscope II (4), reflecting mirror I (5) and reflecting mirror II (6) composition, Optical Maser System (1), polarization spectroscope I
(2), wave plate (3), polarization spectroscope II (4), reflecting mirror I (5), reflecting mirror II (6) are set on same optical platform；Polarization spectroscope
The plated film working face of I (2) is towards right front, and the plated film working face of wave plate (3) is towards front, the plated film work of polarization spectroscope II (4)
Face left front, the plated film working face of reflecting mirror I (5) is towards right front, and the plated film working face of reflecting mirror II (6) is towards right back；
Optical Maser System (1), polarization spectroscope I (2), wave plate (3) and polarization spectroscope II (4) are arranged from sequence front to back, and laser
The pulse laser outlet of device system (1), polarization spectroscope I (2), wave plate (3) and polarization spectroscope II (4) center before one
Afterwards on straight line；In tandem, and the center of reflecting mirror II (6) and reflecting mirror I (5) is one for reflecting mirror II (6) and reflecting mirror I (5)
On tandem；Polarization spectroscope II (4) center is to reflecting mirror I (5) line of centres and before crossing polarization spectroscope II (4) center
The angle α of straight line is 113 degree afterwards；Reflecting mirror II (6) center is to polarization spectroscope I (2) line of centres and crosses in reflecting mirror II (6)
The angle β of heart tandem is 67 degree.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821431390.8U CN208738600U (en) | 2018-09-03 | 2018-09-03 | A kind of polarization type laser pulse stretching system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821431390.8U CN208738600U (en) | 2018-09-03 | 2018-09-03 | A kind of polarization type laser pulse stretching system |
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| CN208738600U true CN208738600U (en) | 2019-04-12 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110275154A (en) * | 2019-07-05 | 2019-09-24 | 哈尔滨工业大学 | A kind of laser radar Polarization Detection optics regulating mechanism |
-
2018
- 2018-09-03 CN CN201821431390.8U patent/CN208738600U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110275154A (en) * | 2019-07-05 | 2019-09-24 | 哈尔滨工业大学 | A kind of laser radar Polarization Detection optics regulating mechanism |
| CN110275154B (en) * | 2019-07-05 | 2021-11-02 | 哈尔滨工业大学 | Laser radar polarization detection optical adjusting mechanism |
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