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Abstract
The laser intensity modulation method (LIMM), a pyroelectric technique for investigating spatially resolved polarization and charge distributions has been applied to sandwich cells containing the ferroelectric liquid crystal side-chain polysiloxane P8*S. Nonuniform polarization distributions in samples with a thickness of the LCP layer larger than the helical pitch were investigated. Maxima of opposite sign at the boundaries caused by symmetrical surface anchoring of the molecules were found. Application of a static external electric field allows the investigation of helix unwinding and screening effects due to impurities in the LC. In the latter case charge layers contribute to the distribution. Variation of the sample temperature causes not only a change in response values due to the temperature dependence of the pyroelectric coefficient but also changes the shape of the measured pyrospectrum. The resulting changes in the polarization distribution may be caused by the temperature variation of the pitch.