Lasing Characteristics of a Dye-Doped Nematic Liquid Crystal Layer Sandwiched by Two Polymeric Cholesteric Liquid Crystals

摘要

We have studied the lasing characteristics from a dye-doped nematic layer sandwiched by two polymeric cholestenc liquid crystal (PCLC) films as photonic band gap materials. The nematic layer possessing birefringence brings about the following remarkable optical characteristics; (1) reflectance in the photonic band gap (PBG) region exceeds 50% due to the retardation effect, being unpredictable from a single CLC film, (2) efficient lasing occurs either at the notch of PBG or at the photonic band edge, (3) the lasing emissions contain both right- and left-circular polarizations, and (4) tunable lasing can be achieved by the reorientation of nematic liquid crystal molecules under the application of an electric field.