We report on optically recorded microlenses in conventional liquid crystal cells doped with the azo-dye methyl-red. The focal length can be tuned electrically with low external voltage and changed in a wide range with just a small variation of the applied dc field. No patterned electrodes, built-in polymeric lens or patterned molecular reorientation are required.
The effect underlying the proposed fabrication method is connected to the surface induced nonlinear effect (SINE) observed a few years ago in dye doped liquid crystals.
Acknowledgments
Authors are grateful to Professor Victor Reshetniak for valuable discussions and to Professor Francesco Simoni for both valuable discussions and support.