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Full-Text Articles in Physical Sciences and Mathematics
Ultraviolet Lasing In Cholesteric Liquid Crystals, A. F., Peter Palffy-Muhoray, B. Taheri
Ultraviolet Lasing In Cholesteric Liquid Crystals, A. F., Peter Palffy-Muhoray, B. Taheri
Peter Palffy-Muhoray
We report the observation of stimulated emission and mirrorless lasing in pure cholesteric liquid crystals. The lasing action is attributed to the combination of the fluorescence and the distributed feedback that are due to the inherent periodic structure of the liquid crystal. If the reflection band matches the intrinsic emission of the cholesteric liquid crystal, the crystal becomes a natural laser material, which will self-lase, without any optical elements or the addition of dyes, under picosecond excitation at 355 nm. Samples have been made to lase at different wavelengths in the near UV by shifting of the edge of the …
Comment On "A Check Of Prigogine's Theorem Of Minimum Entropy Production In A Rod In A Nonequilibrium Stationary State", Peter Palffy-Muhoray
Comment On "A Check Of Prigogine's Theorem Of Minimum Entropy Production In A Rod In A Nonequilibrium Stationary State", Peter Palffy-Muhoray
Peter Palffy-Muhoray
No abstract provided.
Optically Induced Periodic Structures In Smectic-C Liquid Crystals, Antal Jákli, A. Vajda, E. Benkler, Janossy, Peter Palffy-Muhoray
Optically Induced Periodic Structures In Smectic-C Liquid Crystals, Antal Jákli, A. Vajda, E. Benkler, Janossy, Peter Palffy-Muhoray
Peter Palffy-Muhoray
We explore periodic structures of smectic-C (SmC) liquid crystals, induced optically by a polarization grating. The studied cells contain a passive surface of rubbed polyimide and an active photosensitive substrate of ate-dye doped polyimide. In a nematic phase the director field can be periodic independent of the angle between the grating vector and the rubbing direction. In the SmA phase periodic structure can be induced only by layer undulations. The SmC behaves similarly to the nematic phase, but the director can rotate only on a cone, which results in a more complex geometry. The periodic pattern is superimposed with four …