Liquid-crystal-droplet optical microcavities

ABSTRACT

The use of liquid-crystal droplets as optical microcavities and lasers is reviewed and possible applications are discussed. Liquid-crystal droplets are prepared by simple methods that enable scalable production since their internal structure is formed by self-assembly. Light is trapped in droplets due to total internal reflection on the surface due to refractive index mismatch or because of a photonic bandgap structure in cholesteric liquid crystals (CLCs). Light confinement gives rise to a variety of optical modes and by employing a fluorescent dye end external optical pumping, lasing can be achieved. Liquid-crystal-droplet cavities are largely tunable by applying an electric field or a temperature change. Such cavities can be used as temperature and chemical sensors, and tunable light sources and filters in future integrated soft photonic circuits.

GRAPHICAL ABSTRACT

KEYWORDS:

• Liquid-crystal droplets
• optical cavities
• lasers
• whispering-gallery modes
• cholesteric lasers

Acknowledgments

I would like to thank I. Muševič, M. Ravnik and S. Pajk for their valuable contribution to this work.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The work was supported by Marie Curie International Outgoing Fellowship Number 627274 within the 7th European Community Framework Programme and by the Slovenian Research Agency under the contracts P1-0099, PR-01557, J1-9728 and J1-3612; Directorate-General for Research and Innovation: [Grant Number 627274]; Slovenian Research Agency: [Grant Number P1-0099, PR-01557, J1-9728, J1-3612].