Light-transmission study of coarsening in a nematic liquid crystal

We have used light transmission to follow for four decades in time the annealing of defects generated by pressure jumps in a uniaxial liquid crystal. Two distinct scaling regimes for the light intensity as a function of time were observed: an early-time regime in which light propagates diffusively to the detector, and a late-time regime in which unscattered light dominates the signal reaching the detector. The measured values for the scaling exponent for the string density st- are within 10% of the expected value =1 over the time interval 10 msec<t<100 sec.