title: Spatial mode control of radiation generated by frequency difference in periodically poled crystals.
abstract: We demonstrate the possibility to control the spatial mode of a narrow-linewidth, continuous-wave, infrared radiation beam generated by difference frequency in a periodically poled crystal. This can be achieved by acting directly on a few experimental parameters. We show that hollow beams can be generated. A numerical routine has been developed and results agree with experimental observations, without requiring any free parameters. The relevance of these results for high-resolution spectroscopy and atom manipulation is discussed.
authors.affiliation: Istituto Nazionale di Ottica Applicata (INOA), Largo Fermi 6, I-50125 Firenze, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Giusfredi
authors.forename: D
authors.initials: D
authors.lastname: Mazzotti
authors.forename: P
authors.initials: P
authors.lastname: Cancio
authors.forename: P
authors.initials: P
authors.lastname: De Natale