JOURNAL OF THE KOREAN PHYSICAL SOCIETY, v.46, no.2, pp.265 - 268
Abstract
We have studied the lasing characteristics from a dye-doped nematic liquid crystal layer sandwiched by two polymeric cholesteric liquid crystal 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 at the notch of PBG; (3) the lasing emissions contain both right- and left-circular polarizations. In this study, we demonstrate that a 100-μm-thick nematic liquid crystal layer system shows several dips, resulting in multi-mode lasing actions just at the dips within PBG.