H. Ohoka et al., Polarization measurement in nematic liquid crystal based on the pyroelectric response to laser irradiation, MOLEC CRYST, 366, 2001, pp. 2135-2145
The polarization measurement of a nematic liquid crystal has been performed
by a pyroelectric technique using short pulse of a Nd:YAG laser to create
temperature increment. The temperature increment has been evaluated indepen
dently by monitoring temperature dependent birefringence for a He-Ne laser
beam. The sign and absolute magnitude of surface polarization have been eva
luated for both the planar and homeotropic orientation of the nematic liqui
d crystal at a solid substrate. The flexoelectric polarization in a hybrid
cells has also been measured using the same pyroelectric technique. The val
ue of the sum of the flexoelectric coefficients (e(1)+e(3)) for 5CB is nega
tive and about - 13pC/m at room temperature.