title: Controlling the carrier-envelope phase of few-cycle focused laser beams with a dispersive beam expander.
abstract: We report on a procedure to focalize few-cycle laser pulses in dispersive media with controlled waveform. Stationarity of the carrier-envelope phase for extended depth of focus is attained by shaping the spatial dispersion of the ultrashort beam. An adjustable group velocity is locally tuned in order to match a prescribed phase velocity at focus. A hybrid diffractive-refractive lens system is proposed to drive the wavefield to an immersion microscope objective under convenient broadband modulation. Numerical simulations demonstrate robustness over positioning of this dispersive beam expander.
authors.affiliation: Departamento de Optica, Universidad de Valencia, 46100 Burjassot, Spain. carlos.zapata@uv.es
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Zapata-Rodríguez
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Porras