Nonlinear alignment between conical emissions generated in a four-wave parametric mixing process.

Abstract. The dependence of the yellow conical emission angle on pump laser intensity is studied experimentally in dense Na vapor under near-resonant one-photon excitation of the sodium 4[sup 2]P levels. A numerical model developed to describe mechanisms involved in the conical emission generation processes indicates that the saturation observed is due to the opposite angular tuning of the near-infrared and yellow conical emission generated in the same process. The mechanisms responsible are assigned to (self)induced phase modulation processes of the waves involved. [ABSTRACT FROM AUTHOR]