Optical Heterodyne Study of the Taylor Instability in a Rotating Fluid

The Taylor instability in a rotating fluid confined between two cylinders has been investigated by light scattering. For rotation rates $f$ asymptotically close to the critical rotation rate $f_c$, we find that the amplitude of the ordered flow varies as ${(f-f_c)}^{0.50\pm 0.03}$. The axial structure of the ordered flow is sinusoidal near $f_c$, but harmonics become substantial for $f-f_c$ large. The main features of the Landau approach to hydrodynamic instabilities are thus confirmed.