Figure 5.

(a) Top: Polarizing microscopy texture of compound 1a in a 6 μm thick IPS cell (T = 25 °C), Bottom: corresponding SHG microscopy texture recorded in the field-free state (the image width is 330 μm). The arrows indicate the orientation of the polarizer and analyzer. (b) Field dependence of the SHG signal close to the transition to the isotropic phase, (c) and (d) kinetics of the SHG induction, and relaxation respectively, in response to the application of 25 V μm^–1. The red curves are single exponential fits with a rise time of 6.0 s, and the relaxation time of 3.4 s. The measurements were performed at T = 75 °C for (b–d).