Color cone lasing emission in a dye-doped cholesteric liquid crystal with a single pitch

This work investigates a novel color cone lasing emission (CCLE) based on a one-dimensional photonic crystal-like dye-doped cholesteric liquid crystal (DDCLC) film with a single pitch. The lasing wavelength in the CCLE is distributed continuously at 676.7-595.6 nm, as measured at a continuously increasing oblique angle relative to the helical axis of 0-50°. This work demonstrates that lasing wavelength coincides exactly with the wavelength at the long wavelength edge of the CLC reflection band at oblique angles of 0-50°. Simulation results of dispersion relations at different oblique angles using Berreman's 4×4 matrix method agrees closely with experimental results. Some unique and important features of the CCLE are identified and discussed.