Five kinds of H-shaped reactive monomers with different central likage groups were newly designed and synthesized for obtaining the negative dispersion of retardation. The H-shaped molecules were mixed with cylindrical...

Five kinds of T-shaped reactive molecules were newly synthesized for optical retarder films. The retarder films were fabricated using the mixtures of rodlike reactive mesogen (RM) and the T-shaped molecules. The effect of the chemical structure of the T-shaped molecules on the optical anisotropy of the retarder films was investigated. The retarder films with the T-shaped molecules resulted in a greater magnitude of an in-plane retardation. Among the five kinds of the T-shaped molecules, the molecule with five benzene rings along the longitudinal direction and two benzene rings along the lateral molecular direction showed the widest liquid crystalline phase and the largest optical retardation. In addition, the NZ coefficients of the films were greater than 1 implying that the films were negative biaxial.

Polarimetry is a powerful characterization technique that uses a wealth of information from electromagnetic waves, including polarization. Using the rich information provided by polarimetry, it is being actively studied in biomedical fields such as cancer and tumor diagnosis. Despite its importance and potential in agriculture, polarimetry for living plants has not been well studied. A Stokes polarimetric imaging system was built to determine the correlation between the polarization states of the light passing through the leaf and the growth states of lettuce. The Stokes parameter s3 associated with circular polarization increased over time and was strongly correlated with the growth of lettuce seedlings. In the statistical analysis, the distribution of s3 followed the generalized extreme value (GEV) probability density function. Salt stress retarded plant growth, and the concentration of treated sodium chloride (NaCl) showed a negative correlation with the location parameter μ of GEV. The clear correlation reported here will open the possibility of polarization measurements on living plants, enabling real-time monitoring of plant health.