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 fc, we find that the amplitude of the ordered flow varies as (f-fc)^0.50±0.03. The axial structure of the ordered flow is sinusoidal near fc, but harmonics become substantial for f-fc large. The main features of the Landau approach to hydrodynamic instabilities are thus confirmed.