Controlling Matter with Light

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Controlling Matter with Light
Robert J. Gordon University of Illinois at Chicago
DUV-FEL Seminar January 6, 2004
NSF, DOE, PRF, UIC/CRB, Motorola
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Outline

• Dissociative Ionization
• Molecular Optics
• Coherent Control
• Material Processing

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Photodissociation of C6H5I at 266 nm
J. Phys. Chem. A 105, 2001 (2001)
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Mechanism at 266 nm
Outer Feature
Inner Feature
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Photodissociation of C6H5I at 532 nm
J. Phys. Chem. A 105, 2001 (2001)
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Photodissociation of I2
532 nm
559 nm
564 nm
575 nm
PRL 86, 2241 (2001)
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Kinetic Energy of Iodine
556.0 nm
574.7 nm
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Dissociative Ionization
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Dissociative Ionization of H2
JCP 104, 8449 (1996)
J. Phys. B 30, 2319 (1997)
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Possible FEL Experiments

• 90 100 nm single photon excitation
• Pump-probe photoelectron-photoion coincidence
  (Hayden)
• Photoelectron angular distributions of aligned
  molecules

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Manipulating Molecules With Light
Alignment
Orientation
Deflection
Focusing
Trapping
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Interaction with a Focused Laser Beam
Intensity
Potential
Force
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Dipole Interaction
Gaussian electric field
Dipole potential
r ? deflection focusing ? ? alignment
orientation
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Dipole Force
Gaussian field
Induced potential
U0(K) 15 a//(?3) I(TW/cm2)
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Deflecting Molecules in Different MJ States
E
Li2
M J
M 0
Seideman, 107, 10420 (1997)
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Stark Shift
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Apparatus
Molec. Beam
1064 nm
358 nm
tof ms
MCP
CCD
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CS2 Deflection
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YanDu
Yan Du
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Joyce
Joyce Willig
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Sujatha Unny
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Dynamic Polarizability
e-
a/n6
a - wl-2
wl n3

Seideman, JCP 111, 4397 (1999).
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Molecular Mirror
Classical forced oscillator
Sign reversal at high frequency
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Possible FEL Experiments

• Deflect molecules in high Rydberg states
• Use a near-resonant deflection field

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Passive Control of Chemical Reactions
F. Crim
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Active Control of Chemical Reactions
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Interference Between Competing Paths
  P P1 P2 P12   P f1 f22   f1 2
f22 f1f2 f1f2
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Coherent Phase Control of Bound-Bound Transitions
Shapiro, Hepburn, and Brumer, Chem. Phys.
Lett. 149, 451 (1988).
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Apparatus
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Langchi Zhu
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Phase Tuning
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Controlling Branching Ratios
S A
S B
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JPC
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The Phase Lag
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The Channel Phase
The Phase Lag
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Molecular Phase
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Resonance Phase
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Phase Lag Spectrum of HI
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Coupling Schemes
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CH2CHCl ?3, 3?1
Cl
H
HCl
H2
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VCl Experimental Setup
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Vishal Barge
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Possible FEL Experiment

• Coherent phase control of the ionization and
  dissociation of the Q1 states of H2

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Wave Packet Control
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Possible FEL Experiment

• Pump-probe study of time-resolved intersystem
  crossing in pyrazine
• Wave packet control of ISC

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Pyrazine Intersystem Crossing
Ion
S1
T1
S0
C4N2H4
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Photoelectron Spectrum of Pyrazine
JCP 95, 2237 (1991)
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Material Processing

• Biomedical applications
• Microfluidics
• Nano-fabrication

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Machining Collagen Scaffolds
Micro-grooves
Mesenchymal Stem Cells
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Biocompatibility of Collagen Scaffold
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Possible FEL Experiment

• Subdiffraction nanomachining

Appl. Phys. B 77, 25 (2003)