Cross-phase-modulation-induced self-focusing
in parametric oscillators

M. Vaupel ¹ and O. Mandel ²

¹ Laboratoire Kastler Brossel, University P. et M. Curie - Case 74, 75252 Paris, France
² Physikalisch-Technische Bundesanstalt - 38116 Braunschweig, Germany

(received 13 March 1998; accepted in final form 15 October 1998)

PACS. 42.65Jx - Beam trapping, self-focusing, and thermal blooming.
PACS. 42.60Fc - Modulation, tuning, and mode locking.
PACS. 42.65Hw - Phase conjugation, optical mixing, and photorefractive effect.

Abstract:

The dependence of spatial self-focusing on resonator detuning is experimentally investigated in the active medium of a photorefractive oscillator which is a parametric oscillator with narrow gain linewidth. Beam diameter of the -mode and beat frequency of the -mode and another simultaneously emitted transverse mode depend on detuning like a dispersion-shaped function. The maximum strength of self-focusing and the corresponding frequency shift are in the resonator strongly reduced with respect to single-pass wave mixing.

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