Lasers on cholesteric liquid crystals: mode density and lasing threshold
L. M. Blinov
Shubnikov Institute of Crystallography RAS, 119333 Moscow, Russia
LICRYL-CEMIF.CAL, Physics Department, University of Calabria, I-87036, Rende (Cs), Italy
PACS: 42.60.Da, 42.70.Df, 42.70.-a
Abstract
The density of states approach [J. Bendickson et al., Phys. Rev. E
53, 4107 (1996)] was applied to a simple dielectric plate and a formula
was found for the spectrum of the threshold gain for lasing. Then the
validity of the same approach was verified for cholesteric liquid crystals
(CLC) having helical structure. For non-absorbing CLC, the dependences were
found of the minimum threshold gain on the layer thickness and the optical
anisotropy of the material. The contribution of the dye absorption was
discussed separately. The experimental data presented are in good agreement
with threshold gain calculations.