Reduced-Threshold Emission of Capillary Filled by Doped-Dye Cholesteric Liquid Crystals With Photo-Alignment Polyimide Films
A microcavity laser is reported using dye-doped cholesteric liquid crystals (CLCs) filled in a glass capillary with photo-alignment polyimide films. This laser runs based on the properties that a CLC has a refractive index much higher than that of glass, so whispering-gallery-mode (WGM) laser and distributed-feedback-mode lasers are included in the emission spectrum. We obtain a low threshold energy of <inline-formula><tex-math notation="LaTeX">$4.5\;\mu {\rm{J}} \cdot {\rm{puls}}{{\rm{e}}^{ - 1}} \cdot {\rm{m}}{{\rm{m}}^{ - 2}}$</tex-math></inline-formula>, establish the shift of 3.04 nm of the WGMs in the temperature range 43–48 °C, and investigate electric field tunability.