research on sn contrast ratio for sgii-pw laser system jianqiang zhu, guang xu, xiaoping ouyang and...

Research on SN Research on SN contrast ratio for SGII-contrast ratio for SGII-

PW laser System PW laser System Jianqiang Zhu, Guang Xu, Xiaoping

Ouyang and Xinglong Xie 23/4/18

2

Outline

Introduction

SG-II PW laser facility and recent achievements

SN contrast ratio study in SG-II PW laser facility

Programs of ultra short lasers in NLPLP

Conclusion

3

Outline

Introduction




Conclusion

4

Introduction—from Shanghai to Tel-Aviv

Shanghai

China

Tel-Aviv

Israel

5

Development of Lab

YEARYEAR

SG-I facility was accepted with 1.6kJ/1ns(1ω)

the NLHP Lab was founded

SG-II multi-functional high-power laser system(the 9th beam) was accepted with 5kJ/3ns(1ω)

SG-II facility was began to launch

SG-II facility was accepted with 6kJ/1ns(1ω

SG-II-up facility will be completed and reach 24KJ/3ns(3ω)) and the 9th beam will reach 1KJ/(1-10)ps(1ω).

SG-II-up facility was officially launched

2001

2006

2007

2014

1987

1995

1986

6

Development of Facility

Aperture ○250mm○200mm ○350mm □350mm

3kJ/3ω/1ns6kJ/1ω/1ns

SG-Ⅱ(2000)

8 beam

(1973)

1 beam SG-Ⅰ(1986)

2 beam

24kJ/3ω/3ns40kJ/1ω/3ns

~1kJ/~ps

8 beam

SG- UpⅡ( ～ 2012)

6 beams(1980)

6 beam

1.6kJ/1ω/1ns5kJ/3ω/3ns

1 beam

9th beam(2006)

180J/1ω50J/1ω

○70mm○40mm

Since

1964

7

About SG-II Facility

8 Pulsed Laser BeamsEnergy 6KJ/1W/1ns 2KJ/3W/1ns

1KJ/1W/130ps

8 Pulsed Laser BeamsEnergy 6KJ/1W/1ns 2KJ/3W/1ns

1KJ/1W/130ps

8


9th Pulsed Laser BeamEnergy 5KJ/1W/3ns 3KJ/3W/3ns

300J/1W/100ps

9th Pulsed Laser BeamEnergy 5KJ/1W/3ns 3KJ/3W/3ns

300J/1W/100ps

9


ICF Target ChamberX-ray Target Chamber

9th Laser Beams InjectionPrecision 20μm(rms)

ICF Target ChamberX-ray Target Chamber

9th Laser Beams InjectionPrecision 20μm(rms)

10


No.9 Laser Beam injectingICF Target Chamber andX-ray Target Chamber

have 3 styles.

No.9 Laser Beam injectingICF Target Chamber andX-ray Target Chamber

have 3 styles.

11

SG-II Facility Experiment Function

Neutron production 4×10 ９

1000 times target compression

Physical experiments ：Black cavity radiation physics

Implosion physics

Hydrodynamic instability

Radiation opacity

SG-II has achieved about 4000

shots since 2000, the success rate

more than 80%

Radiation-driven shock wave

Temperature and density plasma physics

Production and application of X-Ray

12

SG-II Facility Physical Experiment

pole

Drive laser

310mCH sphere

tt

11

22

33

44

55

light

1ns1ns

Cylindrical target compression and hot spot status diagnosis tests

Physicists diagnosed the self-luminous time-integration image when the

cylindrical target was directly driven by 8 laser beams or when the spherical

target implode inside by using the 2-3keV KB low-energy band of KB imaging

system and observed obvious extreme intensity distribution at the center of

both chambers.

13


Nature Physics 6 ， DOI Number:10.1038/ NPHYS1790, 2010, 10

14


Under the support of “Joint research on high energy density physics

with Japan and South Korea”, the three parties successfully carried out

collision-free shock wave experiments on SG device on September 16, Ⅱ

which provides important evidence on the cause of collision-free shock

wave phenomena in astrophysics. The output laser quality has reached

international advanced level.

Under the support of “Joint research on high energy density physics

with Japan and South Korea”, the three parties successfully carried out

collision-free shock wave experiments on SG device on September 16, Ⅱ

which provides important evidence on the cause of collision-free shock

wave phenomena in astrophysics. The output laser quality has reached

international advanced level.

Experimental results of collision-free shock wave

Results published on “Plasma Physics and Controlled Fusion”(2008, 50, 124057) and was invited to the 8th Pacific Rim International Conference on Laser and Optoelectronics report.

The experimental results were included in the “Large scientific facilities of the Chinese Academy of Sciences” (2008-2009 ）

15

Summary

——SG-II facility is an important platform for inertial confinement fusion

(ICF) research and national physical researches, which also represents

the general technology achievement in high power laser physics.

——SG-II facility have 9 laser beams, provide:

8 laser beams: 750J/beam/1w/1ns, 250J/beam/3w/1ns,

120J/beam/1w/130ps

No.9 laser beam: 5000J/beam/1w/3ns, 3000J/beam/3w/3ns

500J/beam/1w/300ps

10J/beam/1w or 3w/30ps

——SG-II up facility will be completed and reach 24KJ/3ns(3ω)) ， and the

9th beam will reach 1KJ/(1-10)ps(1ω).

——SG-II facility is an important platform for inertial confinement fusion

(ICF) research and national physical researches, which also represents

the general technology achievement in high power laser physics.

——SG-II facility have 9 laser beams, provide:

8 laser beams: 750J/beam/1w/1ns, 250J/beam/3w/1ns,

120J/beam/1w/130ps

No.9 laser beam: 5000J/beam/1w/3ns, 3000J/beam/3w/3ns

500J/beam/1w/300ps

10J/beam/1w or 3w/30ps

——SG-II up facility will be completed and reach 24KJ/3ns(3ω)) ， and the

9th beam will reach 1KJ/(1-10)ps(1ω).

16

Outline

Introduction




Conclusion

17

PW laser in SGII-UP facility

8 beams

Energy: 3000J/beam at 351nm

Pulse width: 3ns

1 beams

Energy: 1000J at 1053nm

Pulse width: 1~10ps

Intensity: 1020W/cm2

Contrast: 106~108

Ps pulse

Ns pulses

18

Introduction – fast ignition and PW lasers

Fast ignition is a new approach to inertial confinement fusion.

19

Oscillator Stretcher OPCPA Amplifier Compressor Chamber

230fs 3.2ns 1~10ps1.7ns

PW laser in SGII-UP facility

20

Recent achievements in SG-II PW laser facility

Pulse energy : 380J

Time width: 5ps

Beam size: 105*290mm ( elliptical )

Focal spot: 1.3DL(2013 年实验数据 :E50%=5.1DL)

Grating size: 300*340mm( 1740g/mm)

21

Outline

Introduction


SN contrast ratio study in SG-II PW laser facilitySN contrast ratio simulations for PW laser pulses

SN contrast ratio test for SG-II PW laser

SN contrast ratio improvement for SG-II PW laser


Conclusion

22

Ul tra short pul se contrast(Si mul ati on)

1. 00E- 12

1. 00E- 09

1. 00E- 06

1. 00E- 03

1. 00E+00

- 1000 - 900 - 800 - 700 - 600 - 500 - 400 - 300 - 200 - 100 0 100

Ti me (ps)

Inte

nsit

y (P

W)

Pre-pulse from oscillator

Pedestal from stretcher

Satellite from non-linear chirped

SN contrast ratio Simulations for PW laser pulses

Different noise before main pulse

23

Pulse contrast test

Schematic of cross-correlation

Time delay

SHG

Cross-correlation

Detector

Measurement for repetition pulse, time delay is caused by

movement of delaying mirror pairs.

Measurement for single shot pulse, time delay is caused by

tilting of two wide beams.

Phase plane

Tim

e delay

55º

24

•PsSNR1500

For repetition pulses

Dynamic range:

108@1mJ,10ps

≥1010@fs pulse

Time range: 1500ps

Time resolution: 20fs

Chinese Journal of Lasers, 2009, Vol 36(3), pp742

-160 -120 -80 -40 0 40 801E-8

1E-7

1E-6

1E-5

1E-4

1E-3

0.01

0.1

1

No

rma

lize

d O

utp

ut

Delay Time(ps)

2008-04-10-TOA-Clean


25


•PsContrast80

For single shot pulse

Dynamic range:

106@1mJ,10ps

≥108@1ms 1ps

Time range: 80ps

Time resolution: 1ps Peak of signal: 1×107mV ， Noise: 7mV

Tested under pulse with 1mJ,10ps

26

Far field

Pulse width

Sampling energy

Pulse contrast

Dia

gnos

tics

for

SG

IIN

inth

Bea

m

Large aperture calorimeterParabolic mirror in target chambe

Sampling mirror

Down-collimator

G1

G2

G4

G3

Lens1

Lens2

BS1BS2

BS3

T=1%

T=2%

Compressor

8:1

1700J/1.7ns

Final test for SG-II PW laser

27


Compressed Pulse Diagnostics

PW laser: 100J, 5ps

Test on PW laser:

28

1 SN contrast ratio control in pulse stretcher

2 SN contrast ratio control in OPCPA pre-amplifier

3 Spectrum shape for chirped laser pulse

4 Controlling smoothness of the optics surface

5 Plasma mirror

SN contrast ratio improvement for SG-II PW laser

29

R1

R2Grating

SN contrast ratio control in pulse stretcher

1) Pulse contrast can be improved by decreasing tolerance of mirror’s curvature in stretcher.

2) Pulse contrast can be improved by decreasing tolerance of mirror’s tilt in stretcher

Offner Stretcher

Pulse contrast by

curvature error

(ΔS=R1/2-R2)

Pulse contrast

by tilt error

30

SN contrast ratio control in OPCPA pre-amplifier

1) Noise from parameter fluorescence is avoid by non-collinear(1-3°) mode in OPCPA.

2) pulse contrast ratio can be improved by time lag between pump laser and signal. In this method, noise before main pulse of signal will not be amplified.

Chirped pulse

Pump pulse

Non-collinear mode in OPCPA Time lag between pump laser

and signal

31

OMEGA EP, 2009.Sep, OMEGA EP测试方案1000J 、 10ps


In OMEGA EP facility, fluorescence Noise is undetectable after the main amplifier chain

32


fluorescence Noise test and analysis

Experimental data Calculated data

Dashed lines ： SN after OPCPA ( when compressed to 20ps)

Solid lines: SN after main amplifier chain(1500J 、 compressed to 10ps)

1.3ns

Pulse contrast ratio improvement is verified in experiment in OMEGA EP

33


Time delay between pump pulse and chirped pulse in OPCPA

OPCPA front-end prototype High-energy OMEGA EP pulse

~100uJ 、 20ps 500J 、 10ps

34

Spectrum shape for chirped laser pulse

-3 -2 -1 0 1 2 3 4 5 6 7

x 10-9

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Gain narrowing in Nd glass amplifier

Pulse contrast for 1ps pulse (simulation)

1) Gain narrowing in Nd glass amplifier will distort temporal shape and spectral shape of chirped pulse.

2) Distorted pulse shape contained more noise than Gaussian pulse shape.

input output

35

controlling smoothness of the optics surface

Surface smoothing of optics

Roughness noise (GRMS) of optic surface Pulse contrast by roughness

For SN contrast ratio higher than 10-12:1, the GRMS of the roughness of optic surface should be smaller than λ/75/cm @ 633nm

36

Plasma mirror

PM1

PM2

Parabolic mirror 1

Parabolic mirror 2

PsContrast80

Ps pulse10mJ, 12ps f=30mm

f=30mm

I=1016W/cm2

φ30mm

Schematic of double PMs experiment

Plasma mirror is considered in our PW laser. It is designed as the following figure. And it will be tested under ps pulse laser in the future.

37

Plasma mirror design

Pulse contrast improved by

Double plasma mirrors (DPM)

Opitcs Letters Vol.32(3), pp310

Contrast is improved 104 in France (2007) and in German (2013) .

38

•Threshold ： 1012W/cm2

•Saturated power ： 1015W/cm2

•Energy density for high quality beam ： 90J/cm2

•Maximum reflection ： R=68%

•Status: under design

Plasma mirror design

39

Outline

Introduction




Conclusion

40

Project of 10PW 808nm Laser

10PW (30fs/300J) 808nm laser project has been supported

Goals:

In the following 2 or 3 years – 10 PW facility provided for fundamental physical experiments


41

Schematic for 10PW ultra short laser design

Three stages:（ 1 ） front end: pulse energy 150mJ 、

spectrum 80nm,chirped pulse width 2.0ns.

For high SN contrast ratio reason, we chose OPCPA technology

（ 2 ） pre-amplificationBeam size 100mm ， chirped pulse width

2.0ns,spectrum 50nm, pulse energy 10J.For the following reasons we chose the

CPA technologyCommercial laser can provide 1PW

outputStability for engineering usageMaturation of the technologySIOM has built a 1PW CPA laser system

that can be a base

42

（ 3 ） Energy amplification for 10PW outputBeam size 200mm ， LBO crystalPUMP source: width 3.0ns ， 1500J 527nmOUTPUT: pulse energy 300J ， spectrum 45-50nmCompressed pulse: 20-30 fs.

In the design of the main amplification, we chose OPCPA technology for the following reasons:

OPCPA technology bears high SN contrast pulsesAnd also can decease the uncompressed noise by

nonlinear process.When goes to large beam size, CPA technology has low

efficiency and noise will be increased by the transverse oscillation.

For engineering reason, we can use the SG-II and the Ninth Beam as the PUMP source for OPCPA design.

Schematic for 10PW ultra short laser design

43

750mJ

0.5GW/cm2200J

0.8GW/cm2

1500J1.5GW/cm2

OPCPA-I CPA-IICPA-III OPCPA-IV

150mJ 1-2J 20J 300J

1.5J（ 50%） 400J(50%)

3000J(50%)

CPAPre-OPCPA OPCPA

Energy fluence design for 10PW laser

44

Φ6mm,150mJ

1.5m

1.5m 5m

14m

Φ100mm,40J

PUMP

Φ50mm,10J

Φ110mm,270J

3ns,flat

F=1.3m 2.6m

S=1.5m 2m

F=0.73m 6.1m

S=0.8m 1m

Φ55mm,65J

3ns,平顶

Φ8mm,0.75J

3ns,平顶

OPCPA1.5m*4m

展宽器

1.5m*3.5m

CPA

Layout of 10PW laser amplification chain

The pump beams of SG-II laser

45

7m

4.5m

4.5m

2m

Φ230mm,300J

Φ260mm,1500J,2ns (from 9th beam)

Φ 400mm,300J

F=2m 4.25m

S=1.7 5.8m

F=1.6m 3.7m

S=1.5m 4.2m

46

Outline

Introduction




Conclusion

47

Conclusion

In conclusion

SG-II PW laser and recent progress are introduced.

Factors that affect the SN contrast ratio of SG-II PW laser are discussed.

We have measured the SN contrast ratio for the output of SG-II PW laser at 100J@5ps.

Program of ultra short and ultra high power 10 PW laser has been designed based on SG-II and SG-Ninth beam, our goal is in three to five years the laser can be provided for fundamental physical experiments.

48

Thank You for Your Attention !

research on sn contrast ratio for sgii-pw laser system jianqiang zhu, guang xu, xiaoping ouyang and...

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