The FLASH optical laser systems

FLASH1 optical laser system

Pulse duration of the FLASH1 high power laser measured at BL1 with 51.7 +- 3 fs.

Ultrafast optical pump-probe laser systems are available at both FLASH experimental halls.

Since the FEL and the optical laser are independent sources of fs-pulses, their synchronized operation is of vital importance to perform well defined pump-probe experiments. The overall timing jitter between the FEL and the optical laser at the experimental endstations is approximately 40 fs rms. More details

The optical lasers can be delayed with respect to the FEL pulses in a range of several ns.


 

FLASH1 pump-probe laser systems 

At the FLASH1 experimental hall two pump probe laser systems are available:

(1) A laser based on Ti:sapphire technology is delivering a high energy pulse (up to 10 mJ, ~ 60 fs FWHM), albeit the repetition rate is limited to 10 pulses per second.

(2) A laser based on optical parametric chirped pulse amplification (OPCPA), provides trains of ~ 20 µJ pulses ( ~ 100 fs FWHM) that map exactly onto the complex timing pattern of the FEL delivering several thousand pulses per second in bursts at 10 Hz with a minimum pulse spacing of 1µs. Both laser systems deliver a central wavelength of 800 nm. Second and third harmonic radiation can be generated at the experimental endstation.

The laser system is highly automated and remotely controllable from the experimental stations. An evacuated laser beam delivery system with relay imaging provides the pulses at BL1, BL2, BL3 and PG2.

References:
H. Redlin et al., The FLASH pump-probe laser system: Setup, characterization and optical beamlines, NIM A 635 , S88 (2011). (Article)

 

FLASH2 pump-probe laser system

The FLASH2 pump-probe laser system is based on optical parametrical chirped pulse amplification (OPCPA).

The laser can be operated in a short pulse mode using the full amplification bandwidth between 700 and 900 nm to produce sub-20 fs pulses.

At reduced spectral bandwidth fast wavelength tuning is available. The central wavelength can be tuned within 30s between 700 and 900 nm keeping pulse energy and pulse duration within 10% of the set-point. After the 30s tuning time, the wavelength stability is better than 5% of the bandwidth.


 

Nominal parameters of the optical pump-probe lasers

parameter
/ beamline

number of pulses


rep.
rate

λc

Δλ

Ep

tp


unit

 

kHz

nm

nm (FWHM)

µJ

fs (FWHM)

µm (1/e2)

beamline

             

BL1

1

 

810

20

5000

60

70

 

1

 

405

3

1000

100

60

 

1

 

271

2

100

50

50

 

1

 

tunable (OPA)

ask

ask

ask

ask

BL2 / BL3

1

 

810

20

5000

60

ask

 

400

1000

810

20

20

100

ask

 

1

 

tunable (OPA)

ask

ask

ask

ask

PG1

400

1000

810

20

20

100

ask

 

400

1000

405

7

5

150

ask

 

400

1000

271

2

1

200

ask

PG2

400

1000

810

20

20

100

ask

 

400

1000

405

7

5

150

ask

FL24

40

50

800

10 < Δλ < 100

200

20 < tp < 100

200

 

40

50

270

ask

ask

100

ask

FL26

40

50

800

10 < Δλ < 100

200

20 < tp < 100

200

 

40

50

270

ask

ask

100

ask

CONTACT

Manschwetus
Bastian Manschwetus
E-Mail: Bastian Manschwetus
Phone: +49 (0)40 8998 6093
Location: 25b / O1.128