Liquid-phase adaptive femtosecond quantum control: Removing intrinsic intensity dependencies Journal Article uri icon



  • Femtosecond adaptive pulse shaping of 800-nm laser pulses is applied to control the multiphoton molecular excitation of the charge-transfer coordination complex [Ru(dpb)3](PF6)2 (where dpb=4,4′-diphenyl-2,2′-bipyridine) dissolved in methanol. A phase-only femtosecond pulse shaper provides a mechanism for multiparameter (128) variation of the incident field, and a closed-loop evolutionary algorithm optimizes pulse shapes within the vast search space. Molecular emission at 620 nm is used as experimental feedback which is proportional to the excited-state population in the long-lived MLCT3 (metal-to-ligand charge-transfer) state. The dominant intensity dependence of the multiphoton excitation process is removed by using second-harmonic generation (SHG) in a thin optical crystal as a general “reference” signal. Successful control of the emission/SHG ratio demands that the field adapt to the electronic structure or dynamic needs of the molecule in solution. This suggests that adaptive femtosecond pulse shaping can provide a general means of finding field shapes capable of selectively exciting molecules based on their unique optical properties.

publication date

  • February 22, 2003

has restriction

  • closed

Date in CU Experts

  • February 1, 2014 3:05 AM

Full Author List

  • Brixner T; Damrauer NH; Kiefer B; Gerber G

author count

  • 4

Other Profiles

International Standard Serial Number (ISSN)

  • 0021-9606

Electronic International Standard Serial Number (EISSN)

  • 1089-7690

Additional Document Info

start page

  • 3692

end page

  • 3701


  • 118


  • 8