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

Outline Dissociative Ionization Molecular Optics Coherent Control Material Processing

Photodissociation of C 6 H 5 I at 266 nm J. Phys. Chem. A 105, 2001 (2001)

Mechanism at 266 nm Outer Feature Inner Feature

Photodissociation of C 6 H 5 I at 532 nm J. Phys. Chem. A 105, 2001 (2001)

Photodissociation of I nm 564 nm 559 nm 575 nm PRL 86, 2241 (2001)

Kinetic Energy of Iodine nm nm

Dissociative Ionization

Dissociative Ionization of H 2 J. Phys. B 30, 2319 (1997) JCP 104, 8449 (1996)

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

Manipulating Molecules With Light Alignment Orientation Deflection Focusing Trapping

Interaction with a Focused Laser Beam Intensity Potential Force

Dipole Interaction Gaussian electric field Dipole potential r  deflection & focusing   alignment & orientation

Dipole Force Gaussian field Induced potential U 0 (K) = 15 α // (  3 ) I(TW/cm 2 )

Deflecting Molecules in Different M J States E |M| = J M = 0 Li 2 Seideman, 107, (1997)

Stark Shift

CCD 1064 nm 358 nm tof ms MCP Molec. Beam Apparatus

CS 2 Deflection

YanDu

Joyce Joyce Willig

Sujatha Unny

/n6/n6  /n  l n 3  -  l -2 e-e- Seideman, JCP 111, 4397 (1999). Dynamic Polarizability

Molecular Mirror Classical forced oscillator : Sign reversal at high frequency

Possible FEL Experiments Deflect molecules in high Rydberg states Use a near-resonant deflection field

F. Crim Passive Control of Chemical Reactions

Active Control of Chemical Reactions

Interference Between Competing Paths P = P 1 + P 2 + P 12 P = |f 1 + f 2 | 2 = |f 1 | 2 + |f 2 | 2 + f 1 f 2 * + f 1 * f 2

Shapiro, Hepburn, and Brumer, Chem. Phys. Lett. 149, 451 (1988). Coherent Phase Control of Bound-Bound Transitions

Apparatus

Langchi Zhu

Phase Tuning

Controlling Branching Ratios S = A S = B

JPC

The Phase Lag

The Channel Phase The Phase Lag

Molecular Phase

Resonance Phase

Phase Lag Spectrum of HI

Coupling Schemes

CH 2 =CHCl +  3, 3  1 Cl H HCl H2H2

VCl Experimental Setup Polarizer Nd:YAG Laser 532 nm /2 Plate Excimer Laser 308 nm Dye Laser nm TOF/MS  3 =3  1  1 Hg Tripling Cell

Vishal Barge

Possible FEL Experiment Coherent phase control of the ionization and dissociation of the Q 1 states of H 2

Wave Packet Control

Possible FEL Experiment Pump-probe study of time-resolved intersystem crossing in pyrazine Wave packet control of ISC

Pyrazine Intersystem Crossing Ion S1S1 S0S0 T1T1 C4N2H4C4N2H4

Photoelectron Spectrum of Pyrazine JCP 95, 2237 (1991)

Material Processing Biomedical applications Microfluidics Nano-fabrication

Machining Collagen Scaffolds Micro-groovesMesenchymal Stem Cells

Biocompatibility of Collagen Scaffold

Possible FEL Experiment Subdiffraction nanomachining Appl. Phys. B 77, 25 (2003)