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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. Outline. Dissociative Ionization Molecular Optics Coherent Control Material Processing. Photodissociation of C 6 H 5 I at 266 nm.
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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
Outline • Dissociative Ionization • Molecular Optics • Coherent Control • Material Processing
Photodissociation of C6H5I at 266 nm J. Phys. Chem. A 105, 2001 (2001)
Mechanism at 266 nm Outer Feature Inner Feature
Photodissociation of C6H5I at 532 nm J. Phys. Chem. A 105, 2001 (2001)
Photodissociation of I2 532 nm 559 nm 564 nm 575 nm PRL 86, 2241 (2001)
Kinetic Energy of Iodine 556.0 nm 574.7 nm
Dissociative Ionization of H2 JCP 104, 8449 (1996) J. Phys. B 30, 2319 (1997)
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 U0(K) = 15 α//(3) I(TW/cm2)
Deflecting Molecules in Different MJ States E Li2 |M| = J M = 0 Seideman, 107, 10420 (1997)
Apparatus Molec. Beam 1064 nm 358 nm tof ms MCP CCD
YanDu Yan Du
Joyce Joyce Willig
Dynamic Polarizability e- a/n6103 a/n6 a-wl-2 wl n3 Seideman, JCP 111, 4397 (1999).
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
Interference Between Competing Paths P = P1 + P2 + P12 P = |f1 + f2|2 = |f1 |2 + |f2|2 + f1f2* + f1*f2
Coherent Phase Control of Bound-Bound Transitions Shapiro, Hepburn, and Brumer, Chem. Phys. Lett. 149, 451 (1988).
Controlling Branching Ratios S = A S = B
The Channel Phase The Phase Lag
CH2=CHCl + 3, 31 Cl H HCl H2
Excimer Laser Dye Laser 308 nm 404.6 nm TOF/MS Hg Tripling Cell w1 w3=3w1 532 nm Nd:YAG Laser Polarizer /2 Plate VCl Experimental Setup
Possible FEL Experiment • Coherent phase control of the ionization and dissociation of the Q1 states of H2
Possible FEL Experiment • Pump-probe study of time-resolved intersystem crossing in pyrazine • Wave packet control of ISC
Pyrazine Intersystem Crossing Ion S1 T1 S0 C4N2H4
Photoelectron Spectrum of Pyrazine JCP 95, 2237 (1991)
Material Processing • Biomedical applications • Microfluidics • Nano-fabrication
Machining Collagen Scaffolds Micro-grooves Mesenchymal Stem Cells