TEM(00)-mode and single-longitudinal-mode laser operation with a cholesteric liquid-crystal laser end mirror

Electrically controllable multicolor cholesteric laser

A new strategy to obtain multicolor lasing from cholesteric liquid crystals is presented. A four layer cell is prepared with three different cholesteric layers and a layer containing a photoluminescent dye. The three cholesteric mixtures are prepared so that their photonic band gaps are partially overlapped. Through this combination, two laser lines are obtained in the same spot under the pumping beam irradiation. Eventually, one of the laser lines can be switched off if an electric field is applied to the first or the last cholesteric layer.

Wide band gap materials as a new tuning strategy for dye doped cholesteric liquid crystals laser

A new tuning strategy for mirror-less liquid crystals laser is presented. A three layer cell is prepared with two cholesteric layers sandwiching a layer containing an isotropic mixture of a photoluminescent dye. One of the chiral layers contains a wide band gap material while the second layer consists of a series of small band gap materials. Through the combination of these two layers, a set of mirrors that can selectively reflect different wavelengths is obtained. A different laser wavelength is emitted from different regions of the cell under the pumping beam irradiation.