title: Tunable ultrafast infrared/visible laser to probe vibrational dynamics.
abstract: A tunable, ultrafast (approximately 100 fs-approximately 1 ps) laser system generating mid-IR (3-10 microm) and UV/visible (392-417 nm, 785-835 nm) radiation is described and its output characterized. The system is designed to explore vibrational dynamics in the condensed phase in a direct, two-pulse, time-resolved manner, using Raman spectroscopy as the probe. To produce vibrational resolution, probe pulses are spectrally narrowed by use of a long doubling crystal. Frequency-resolved optical gating is used to evaluate beam characteristics. An effective method for determining the temporal overlap of the pump and probe pulses for a one-color, 400 nm configuration is illustrated. Representative results from studies of heme and paranitroaniline vibrational dynamics illustrate the effectiveness of the visible pump-visible probe portion of the system in illuminating fast structure and energy dynamics.
authors.affiliation: Center for Chemical Dynamics, Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA.
authors.forename: Tissa C
authors.initials: TC
authors.lastname: Gunaratne
authors.forename: Matthew
authors.initials: M
authors.lastname: Milliken
authors.forename: J Reddy
authors.initials: JR
authors.lastname: Challa
authors.forename: M Cather
authors.initials: MC
authors.lastname: Simpson
mesh_terms: D001704:Biopolymers / Q000032:analysis* / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007834:Lasers; D013055:Spectrophotometry, Infrared / Q000295:instrumentation* / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation* / Q000379:methods; D014732:Vibration
chemical_list: D001704:Biopolymers