Figure 5
Speckle contrast measured after passing through a chiral nematic LC device (E7 + 4.7 wt% BDH1281, pitch 310 nm) under a square wave electric field of amplitude 13.6 Vµm−1 and a frequency of 75 Hz at a range of camera integration times. The cell thickness was d = 20 µm, cell temperature T = 25 °C. The data points were obtained from measurements and the solid red line is a fit of the form ax−0.5 + b which shows that C reduces approximately by \(1/\sqrt \tau\). Inset speckle images shown for (a) 1 ms, C = 0.555, (b) 10 ms, C = 0.277, (c) 2 s, C = 0.108 integration time and speckle contrast values, respectively.
