A User Perspective · Andreas Galler, European XFEL, SwissFEL Pump-Probe Workshop, 16 th Nov 2012...

Andreas GallerEuropean XFEL (FXE), Hamburg

Lasers at Lightsources -

A User Perspective

SwissFEL Pump-Probe Workshop

Lasers at Lightsources

Outline 2

Andreas Galler, European XFEL, SwissFEL Pump-Probe Workshop, 16th Nov 2012

� Experiments at Lightsources (Synchrotrons & FEL)

� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE

� Pulse Characterization at Sample Interaction Point


Towards Ultrafast Time Resolution 3


Femtosecond X-ray Streak Cameras

�1-2 ps “routine” resolution

�150-300 fs in lab

Femtosecond X-ray Sources

� Laser plasma sources (∼100 fs)�3rd generation SR sources:

Femtosecond electron bunch slicing

�X-Ray Free Electron Lasers


Laser Pump X-ray Probe Strategy at the SLS 4


Swiss Light Source


Laser pump X-ray probe setup at the SLS 5


Gawelda et al.,

AIP conf. proc. 881, 31 (2007)

KB x-rays

CCD

λ/2

IF1 L

SHG

λ=400nm λ=800nm

IF2

I1 I0

P

Sample

-150 -100 -50 0 50 100 1505

0

-5

-10

∆ O

.D. x

103

Time Delay / ps

Work in disordered/dilute systemsSample refreshed for each laser shot

liquid jet


6



� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE



Light-induced low spin to high spin transition in [Fe II(bpy) 3]2+ 7


~0.6 ns

?2+


Iron-tris-bipyridine: what we actually know 8


120 fs

1MLCT

R (Fe-N)

Ene

rgy

5T (HS)2

1A (LS)1

3MLCT

665 ps

20 fs

b)


XAS Studies at kHz rates 9


0.0

0.5

1.0

1.5

7000 7200 7400 7600 7800

-0.1

0.0

0.1

0.2 ∆t = 50 ps

Tra

nsie

nt A

bsor

ptio

n / ∆

χχ χχ

X-Ray probe Energy / eV

[Fe(bpy)3]2+ (aq)

static absorption

Nom

aliz

ed A

bsor

ptio

n

-200 0 200 400 600 800 1000

0

1

Tra

nsie

nt A

bsor

ptio

n / a

.u.

XAFS Optical

Time Delay / ps

0 1 2 3 40

1

2

3

4

5

6

7

FT

Mag

nitu

de |χ

(R)|

/Å-4

Fe-N Bond Length /Å

LS EXAFS HS EXAFS

Gawelda et al., Phys.Rev.Lett. 98, 057401 (2007)

EXAFS analysis

665 ps

70 ps


0

1

0

1

7100 7150

LS

A /

a.u.

HS

: 50 ps

∆A

x 1

03

X-Ray Probe Energy / eV



: 300 fs

C. Bressler et al .Science (2009)

M. Benfatto (INFN Rome)

B


-500 0 500 1000Time Delay / fs

∆RFe-N =0.2 Å



10-12 photons/pulse (2 kHz, 2 eV BW)

250 fs (instrument response):

140(30) fs hard x-ray pulse115(10) fs laser pulse


XES studies at kHz rates 12


G. Vankó et al Angew. Chem. Int. Ed. 2010, 49

� Higher time resolution required � Ideally suited for single wavelength

XFEL experiments


Lessons learned 13


� Lasers have become widely available at synchrotrons

� Synchronization is not a problem anymore

� Tunability is required for optimal sample exciation

� User access to laser beam is favorable


14



� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE



MHz studies 15



MHz studies 16


Time Resolved RIXS becomes feasible


Lessons learned 17


� MHz lasers make much better use of the storage ring

� Synchronization has become very reliable

� MHz lasers can be portable �� Users can bring their own laser


18



� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE



TR-XAS [Fe(bpy) 3]2+ at XPP/LCLS 19


7110 7120 7130 7140

0,0000

0,0025

Tra

nsie

nt X

AN

ES

X-Ray Probe Energy / eV

0,00

0,02

0,04

0,06

DC

B

XA

NE

S

A

-500 0 500 1000 1500-0,001

0,000

0,001

0,002

0,003

X-R

ay T

rans

ient

Abs

orpt

ion

Laser-X-Ray Time Delay / fs

Science 2009 Fit curve 2009 XPP 2010

-5 0 0 0 5 0 0 1 0 0 0

0 ,0 3 2

0 ,0 3 4

0 ,0 3 6

Tra

nsie

nt X

AN

ES

L a s e r X -R a y T im e D e la y / fs


20


Need for time arrival detector


21



� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE



Lasers at FXE 22



Lasers at FXE 23



MHz NOPA… on the road, reached 500 kHz 24


Third Harmonic Generation

Third Harmonic Generation

Second Harmonic

Generation

Second Harmonic

Generation

Continuum Generation

Continuum GenerationTangerine FCPA

Tangerine FCPA

3ωωωω-pumped NOPA




CompressorCompressor

CompressorCompressor

� Type I BBO crystals� Noncollinear geometry

600 700 800 900 1000 11000,0

0,2

0,4

0,6

0,8

1,0

No

rmal

ized

in

ten

sity

Wavelength (nm)

NOPA 2ωωωωNOPA 3ωωωω

500 600 700 800 900 1000 11000,0

0,2

0,4

0,6

0,8

1,0

No

rmal

ized

in

ten

sity

Wavelength (nm)� Tunable : [480-1000] nm � Tunable : [625-1000] nm

courtesy of J. Nillon


MHz NOPA next steps 25


What is available :NOPA 3ωωωω

�Repetition rate : 0-500 kHz�Tunable : [480-1000] nm

�E > 200 nJ for λ∈[510-1000] nm�Emax = 700 nJ @ 620 nm

�∆t < 20 fs for λ∈[510-700] nm

NOPA 2ωωωω

�Repetition rate : 0-500 kHz�Tunable : [625-1000] nm

�E > 500 nJ for λ∈[700-1000] nm�Emax = 2,2 µJ @ 900 nm

�∆t < 30 fs for λ∈[700-1000] nm

What as to be done :

� Increase the repetition rate to 2 MHz� Compression of the pulses� SHG of amplified pulses for extended UV-Vis tunability :

� [250-350] SHG NOPA 3ω� [350-500] SHG NOPA 2ω� [500-700] NOPA 2ω� [700-1000] NOPA 2ω

� Transfer to the industry for product development (collaboration with Amplitude Systèmes)

200 300 400 500 600 700 800 900 1000 1100

10

100

1000

NOPA 3w NOPA 2w SHG NOPA 3w (estimated) SHG NOPA 2w (estimated)

En

erg

y (

nJ)

Wavelength (nm)

courtesy of J. Nillon


Lasers at FXE 26


�keep laser paths as short as possible

�Realize as much tunability as possible (HG, NOPA)

�keep laser paths as short as possible

�Details on the Laser system will be presented by Ma x Lederer


Lasers at FXE

FXE will also have an in-house laser lab

�� kHz laser system

�� transient absorption setup

�� fluorescence upconversion setup

27



28



� kHz experiments

� MHz experiments

� FEL experiments

� Lasers at FXE



Pulse Characterization at Interaction Point 29


KB x-rays

CCD

λ/2

IF1 L

SHG

λ=400nm λ=800nm

IF2

I1 I0

P

Sample

BBO




original laser fs pulse

pulse propagated through 5cm of SQ1 glass a GVD of 3500 fs2 was imposed to pulse




A. Galler and T.Feurer, Appl. Phys. B 90, 427-430 (2008)

FROG vs iFROG


Acknowledgements 32


S. L. Johnson (ETHZ)C. Milne (SwissFEL)

D. GrolimundC. Borca

R. Abela (SwissFEL)

Christian Bressler Wojciech Gawelda

Thomas Tschentscher

P. Glatzel (ESRF)G. Vankó (KFKI, Budapest)M. Chergui (Lausanne)M. Nielsen (Copenhagen)V. Sundström (Lund)

D. Fritz (XPP)M. Cammarata (XPP)

T. Feurer (UniBe)

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A User Perspective · Andreas Galler, European XFEL, SwissFEL Pump-Probe Workshop, 16 th Nov 2012...

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