Dependence of Striped Domain Growth on Background Wavenumber

We report on the growth of domains of standing waves in electroconvection in a nematic liquid crystal. An ac voltage is applied to the system, forming an initial state that consists of travelling striped patterns with two different wavenumbers, zig and zag rolls. The standing waves are generated by suddenly applying a periodic modulation of the amplitude of the applied voltage that is approximately resonant with the travelling frequency of the pattern. By varying the modulation frequency, we are able to vary the steady-state, average wavenumber. We characterize the growth by measuring the structure factor for the pattern, the amplitude of the pattern, and the domain-wall length. An interesting feature of the growth is that the evolution of the domain-wall length is strongly affected by changing the selected wavenumber; whereas, the evolution of the structure factor is less sensitive to such changes.