Abstract

Cholesteric liquid crystals, due to their periodic structure and large birefringence, are 1-d photonic band-gap materials. Circularly polarized light of the same handedness as the cholesteric structure cannot propagate in the reflection band. We have studied the effects of this band-gap structure on the fluorescence spectrum of dyes dissolved in the cholesteric liquid crystal, as well as on the fluorescence spectrum of the liquid crystal itself. We have found that emission is enhanced at the band edges, and, above a certain pump threshold, lasing occurs both in dye-doped and in pure liquid crystals. Extremely low lasing thresholds and high efficiencies were observed in dye-doped systems. The results suggest an active energy transfer mechanism between the LC host and the fluorescent dye molecules.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.