Novel Electro‐Optical Storage Effect in a Certain Smectic Liquid Crystal

A novel electro‐optical storage effect has been found in a certain smectic liquid crystal. The optical transmission of a smectic liquid film changes with the application of a dc or an ac exciting voltage and remains in the excited state after the field is removed. Some different effects are observed in a thin (12‐μ) and a thick (100‐μ) sample. The optical contrast ratios of a thin sample are about 10 : 1. The decay of the optical storage effect is a few percent in a week at 42 °C. V–I characteristics of the samples exhibit negative resistance which seems to suggest the change of the molecular state induced by electric fields.