Time Resolved Spectroscopy of Photoreceptive Pig ments with Pico and Femtosecond Pulses

Time Resolved Spectroscopy with Femtosecond X-Ray Pulses

Femtosecond time-resolved photoelectron spectroscopy.

The development of femtosecond time-resolved methods for the study of gas-phase molecular dynamics is founded upon the seminal studies of Zewail and co-workers, as recognized in 1999 by the Nobel Prize in Chemistry.1 This methodology has been applied to chemical reactions ranging in complexity from bond-breaking in diatomic molecules to dynamics in larger organic and biological molecules, and h...

Nonresonant ionization of oxygen molecules by femtosecond pulses: plasma dynamics studied by time-resolved terahertz spectroscopy.

We show that optical pump-terahertz probe spectroscopy is a direct experimental tool for exploring laser-induced ionization and plasma formation in gases. Plasma was produced in gaseous oxygen by focused amplified femtosecond pulses. The ionization mechanisms at 400- and 800-nm excitation wavelengths differ significantly being primarily of a multiphoton character in the former case and a strong...

Interference between femtosecond pulses observed via time-resolved spontaneous fluorescence

We study spontaneous fluorescence excited by a series of phase-controlled femtosecond pulses in an inhomogeneously broadened medium containing a frequency comb of sharp spectral holes. We show that evolution of the spontaneous fluorescence on picosecond time scale is sensitive to interference between the excitation pulses and that varying the relative phase between the excitation pulses changes...

High-precision spectroscopy with counterpropagating femtosecond pulses.

An experimental realization of high-precision direct frequency comb spectroscopy using counterpropagating femtosecond pulses on two-photon atomic transitions is presented. The Doppler broadened background signal, hampering precision spectroscopy with ultrashort pulses, is effectively eliminated with a simple pulse shaping method. As a result, all four 5S-7S two-photon transitions in a rubidium ...