Single-Shot Absorption Spectroscopy with Chirped Femtosecond Laser Pulses

Xiaohong Song, Shangqing Gong, Weifeng Yang +3 more

M. Wollenhaupt, A. Präkelt, Cristian Sarpe +2 more

Mizuho Fushitani, Y. Hikosaka, Akitaka Matsuda +8 more

Single-shot photoelectron spectroscopy of nonresonant two-color two-photon ionization of He has been carried out using an intense free-electron laser (FEL) at 59.7 nm and a femtosecond UV laser at 268 nm. By shot-by-shot analysis of photoelectron spectra, the cross section for nonresonant two-color ionization of He is determined to be ${\ensuremath{\sigma}}^{(2)}=4.1(6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}52}$ cm${}^{4}$ s. The cross-correlation trace derived from the nonresonant signals shows that the temporal resolution of the system is 0.36(3) ps, which is mainly governed by the timing jitter between the FEL and UV laser pulses.

Olavi Ollikainen, Jürgen Gallus, Urs P. Wild +1 more

Summary form only given. Coherent optical transients such as photon echo are a versatile method far measurement of the homogeneous absorption spectrum of molecular systems in the presence of strong inhomogeneous broadening. Such experiments require measurement of the decay of the optical coherence, typically accomplished by gradually varying the time delay between the excitation pulses. Time-domain information is then Fourier transformed to frequency domain by a computer. In this paper we demonstrate a new method that yields the homogeneous spectrum in a single shot of femtosecond laser pulse illumination by performing Fourier transformation of coherent optical transient signal with a lens. We apply this method to measure the homogeneous spectrum of dye molecules in a polymer film in a broad range of temperatures.

Valentin P. Petrov, Wolfgang Rudolph, B. Wilhelmi

Han-gyeol Lee, Hyosub Kim, Hanlae Jo +1 more

Complete population inversion of two-level atoms in a magneto-optical trap is demonstrated by off-resonant two laser pulses shaped from a single ultrafast laser pulse. The observed phenomenon is explained in the context of femto-second laser version of Stark-chirped rapid adiabatic passage.