Electrically controllable optical element, in particular thin-film cell having an optically active surface profile, and method for the production thereof

An electrically controllable optical element in a form of a film cell, said film cell comprising:

• a first substrate having an inner surface on which a first conductive layer is applied;
• a second substrate having an inner surface in which a second conductive layer is applied;
• and
• a starting Kerr mixture filled between the first conductive layer and the second conductive layer;
• wherein the starting Kerr mixture comprises a mixture of dipolar, rod-shaped molecules and semi-mesogens as active components,
• wherein said semi-mesogens impart steric disorder that prevents formation of liquid crystalline phases without an electric field in a temperature range at which the film cell is operable and have a composition according to Formula I, Formula II, Formula III, Formula IV or Formula V below:
• (I)
• wherein R1 is selected from —CH3 or —C2H5,
• wherein R2 is selected from H or R1,
• wherein R is —CN,
• wherein m=n, and
• wherein m and n are integers 2, 3 or 4,
• (II)
• wherein R1 is selected from —CN, —NCS or a halogen,
• (III)
• wherein R1 is selected from —CN, —NCS or a halogen,
• (IV)
• wherein the starting Kerr mixture is a layer with a photopolymerization-produced, mesh, anisotropic network formed between the first conductive layer and the second conductive layer of the film cell,
• wherein the active components, without an electric field in a temperature range at which the film cell is operable, are isotropic and do not represent a blue phase,
• wherein by electrically continuous adjustment of voltage or by applying a constant voltage, a change in a voltage induced phase shift or in a refractive index deviation is generated in the optical element, and
• wherein, in addition to the respective first conductive layer and/or the second conductive layer, an optically effective surface profile is incorporated on one or both of the inner surface of the first substrate and the inner surface of the second substrate.