IONIZATION SPECTRA INDUCED BY PHASE-VARYING FIELDS

We consider the effect of a field with time-varying phase on the final -state spectrum produced by ionization of a single ground-state. Altho ugh the ground-state population still decays according to the Weisskop f-Wigner formula, the final-state spectrum exhibits a redistribution o f population. A single Lorentzian is, in general, no longer obtained a nd the spectrum may be asymmetric. We concentrate on analytically solu ble models with periodic phase-variation, but also briefly consider a random phase and chirp. Finally, the case of two continua is discussed .