Electro-tunable liquid-crystal laser

Lasing that is color-tunable via application of an electric field has been demonstrated at the edge of the 1D photonic band of a dye-doped chiral smectic liquid crystal with a periodic spiral structure. The lasing wavelength, which can be shifted by 40 nm using a relatively low electric field, is tuned by the electric field adjusting the periodicity of the helical structure (see Figure).