Experimental determination of multiple instability regions by Fourier filtering methods in a single-mirror feedback scheme

In this study, a special Fourier filtering scheme is utilized to give an experimental demonstration of a basic property of many optical pattern forming systems. This is the existence of a sequence of tongue-like instability regions at increasing values of transverse wave numbers. This work determines the boundaries of the tongues, i.e. the marginal stability curve, and compare the results with theoretical ones.