Ac Stark splitting of two-photon spectra

Albert M. F. Lau

The author develops a theory of ac Stark (or Autler-Townes) splitting occurring in double optical resonances, one of which is a two-photon transition. It includes both laser bandwidth and collisional broadening effects. Theoretical results are in excellent agreement with Goldsmith's observation of two-peaked structures in the multiphoton excitation spectra of atomic hydrogen in atmospheric-pressure flames. This is believed to be the first study demonstrating that the peak asymmetry in an ac Stark doublet can be reversed due to pressure broadening.

Terry Rudolph, Z. Ficek, Helen S. Freedhoff

P. L. Knight

Autler-Townes splitting of photoelectron energy distributions in resonant two-photon ionisation is predicted using standard Heitler-Ma techniques.

M. M. Ashraf

Matthias Albert

This paper reports excellent agreement between theory and Goldsmith's unexpected observation of two-peaked resonance structures in the multiphoton excitation spectra of hydrogen atoms in a hydrogen-air diffusion flame.1 We show that the phenomenon is ac Stark (or Autler-Townes) splitting with abnormal peak asymmetry. This is the first study demonstrating that the peak asymmetry in an ac Stark doublet is reversed due to pressure broadening.

P. L. Knight