Simple voltage tunable liquid crystal laser

Lasing has been observed in a dye-doped liquid crystal placed between one substrate with a large transparent electrode and the other with a system of parallel nontransparent electrode stripes of 15 mu m period. The stripes operate as a shadow mask providing the spatial modulation of the pump beam and material gain and, with the voltage applied, it additionally creates a Bragg resonator structure due to the spatial modulation of refraction. With that simple cell, a voltage induced tuning of the spectral positions of laser lines over 25 nm has been demonstrated. (c) 2007 American Institute of Physics.