ultrafast laser interactions

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Ultrafast Laser Interactions

with atoms, molecules, and ions

Jarlath McKenna

Supervisor: Prof. Ian Williams

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

QUB Ion Beam Apparatus

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

QUB Ion Beam Apparatus

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

QUB Ion Beam Apparatus

B

IonsMagnet

Aperture

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

QUB Ion Beam Apparatus

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

QUB Ion Beam Apparatus

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

The Experiment….

UCL Neutral Target ApparatusFocussed Laser Beam

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Selective Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Selective Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Selective Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Selective Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

and scanning techniques….

z

x

y

Intensity Selective Scan

focussed laser direction

ion beam direction

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

…Sequential ionization

Walker et al PRL, 73, 1227 (1994)

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

S

…Sequential ionization

Walker et al PRL, 73, 1227 (1994)

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

SNS

…Nonsequential ionization

Walker et al PRL, 73, 1227 (1994)

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

SNS

…Nonsequential ionization

Walker et al PRL, 73, 1227 (1994)

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

nal (

arb.

)

Linear

Circular

…Xe results!!

Xe → Xe+

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

nal (

arb.

)

Linear

Circular

…Xe results!!

Xe → Xe+

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Sig

nal (

arb.

)

Z Position (mm)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

na

l (a

rb.)

Linear

Circular

…Xe results!!

Xe → Xe2+

Xe+ from Xe

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Sig

nal (

arb.

)

Z Position (mm)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

na

l (a

rb.)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Sig

na

l (a

rb.)

Linear

Circular

…Xe results!!

Xe → Xe3+

Xe+ from Xe

Xe2+ from Xe

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Sig

nal (

arb.

)

Z Position (mm)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

na

l (a

rb.)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Sig

na

l (a

rb.)

Sig

na

l (a

rb.)

Linear

Circular

…Xe results!!

Xe+ → Xe3+Xe2+ from Xe

Xe3+ from Xe

Xe+ from Xe

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Sig

nal (

arb.

)

Z Position (mm)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

na

l (a

rb.)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Sig

na

l (a

rb.)

Sig

na

l (a

rb.)

Linear

Circular

…Xe results!!

Xe2+ → Xe3+

Xe+ from Xe

Xe2+ from Xe

Xe3+ from Xe

Xe3+ from Xe+

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Sig

nal (

arb.

)

Z Position (mm)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Z Position (mm)

Sig

na

l (a

rb.)

-15 -10 -5 0 5 10 15

0.0

0.2

0.4

0.6

0.8

1.0

Sig

na

l (a

rb.)

Sig

na

l (a

rb.)

-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50

0.0

0.2

0.4

0.6

0.8

1.0

Linear

Circular

…Xe results!!

Xe+ → Xe2+

Xe+ from Xe

Xe2+ from Xe

Xe3+ from Xe

Xe3+ from Xe+

Xe3+

from Xe2+

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

Vibrational Trapping in H2+?

0

1

2

3

1sg

2pu

Internuclear separation R (a.u.)1 2 3 4 5 6 7 8 9 10

0

-1

-2

-3

-4

-5

Fie

ld-d

ress

ed p

oten

tial e

nerg

y (e

V)

v = 0

v = 9

v = 5v = 4v = 3

H neutrals from H2+

AMP Talk June 2004

Intense Field Femtosecond Laser Interactions

…So what’s next??

Position Sensitive Detector

resolve vibrational levels of H2+

Cool vibrational levels of H2+

electrostatic ion trap

electric quadrupole

Shorter pulses (~10 fs)hollow fibre (gas cell)freeze vibrational motion

Frequency double laser (i.e. 800nm → 400nm)larger shift of photon dressed states of H2

+