Photochemical Switching between a Compensated Nematic Phase and a Twisted Nematic Phase by Photoisomerization of Chiral Azobenzene Molecules

This paper summarizes an effect of trans−cis photoisomerization of a chiral azobenzene compound on a phase structure of the compensated nematic liquid crystal (LC) consisting of the chiral azobenzene compound, nonphotochromic chiral compound with opposite twisting ability, and a host nematic LC. The trans−cis photoisomerization results in the reversible phase transition between the nematic and a cholesteric phases, resulting in a significant change in the transmittance of the sample.