Low-voltage-modulated laser based on dye-doped polymer stabilized cholesteric liquid crystal

An electrically-modulated laser was fabricated based on cholesteric liquid crystal photonic band gap. To lower the modulation voltage, the nematic liquid crystals with high dielectric constant was selected, and thus, the emission energy can be modulated with a voltage of less than 10 V. Polymer stabilization was carried out to obtain a stable and switchable helical liquid crystal system. It is noteworthy that visible light initiation system was adopted to prevent the deformation of photonic band gap. The monomer concentration effects on lasing performances were studied and discussed. The results indicate that the laser emission threshold is decreased and the response time is shortened with the increasing of monomer, while the hysteresis may be enhanced. This study provides some new insights into the fabrication, materials improvements and performances of dye-doped liquid crystal laser, and such electrically modulated laser will be a prospective candidate in the laser displays, micro-light-source or the other optical systems. (C) 2013 Optical Society of America