Photoinduced effects in the vicinity of the smectic-A-smectic-C*A transition: polarization, tilt angle, and response time studies.

We report detailed measurements of the photoinduced effects on the electric polarization, tilt angle, response time, and rotational viscosity in the vicinity of the smectic-A-antiferroelectric-smectic-C (Sm-C*(A)) transition of a guest-host system consisting of photoactive azobenzene-based guest molecules and nonphotoactive host molecules. In the Sm-C*(A) phase all the parameters, except the tilt angle, exhibit both the primary and secondary photoferroelectric effects. The tilt angle dependence of the polarization in the absence of light and in light-on conditions have been analyzed in terms of the predictions of the generalized mean-field and microscopic models.