Experimental evidence for detuning induced pattern selection in nonlinear optics.

We give quantitative experimental evidence of the influence of cavity detuning in determining the pattern selection in a one-dimensional large Fresnel number optical oscillator. The issues of the selection of the transverse mode close to threshold and the value of the pump parameter at threshold are addressed. Competition between right and left traveling waves, resulting in a winner takes all dynamics, is also reported. Experimental results are in quantitative agreement with the theoretical predictions formulated for a broad class of systems comparable to the one here considered.