Femtosecond light source for phase-controlled multiphoton ionization - art. no. 033402

We describe a femtosecond Raman light source with more than an octave of op tical bandwidth. We use this source to demonstrate phase control of multiph oton ionization under conditions where ionization requires eleven photons o f the lowest frequency of the spectrum or five photons of the highest frequ ency. The nonlinearity of the photoionization process allows us to characte rize the light source. Experiment-to-theory comparison implies generation o f a near single-cycle waveform.