Publication: Thermal tuning of spectral emission from optically trapped liquid-crystal droplet resonators
Program
KU-Authors
KU Authors
Co-Authors
Jonas, Alexandr
Pilat, Zdenek
Jezek, Jan
Bernatova, Silvie
Fort, Tomas
Zemanek, Pavel
Aas, Mehdi
Advisor
Publication Date
2017
Language
English
Type
Journal Article
Journal Title
Journal ISSN
Volume Title
Abstract
Surfactant-stabilized emulsion droplets of liquid crystals (LCs) suspended in water and labeled with a fluorescent dye form active, anisotropic optofluidic microresonators. These microresonators can host whispering gallery modes (WGMs), high-quality morphology-dependent optical resonances that are supported due to the contrast of refractive index between the LC droplets and the surrounding aqueous medium. In addition, owing to the refractive index contrast, such LC emulsion droplets can be stably trapped in three dimensions using optical tweezers, enabling long-term investigation of their spectral characteristics. We explore various combinations of fluorescently dyed LC droplets and host liquid-surfactant systems and show that the WGM emission spectra of optical resonators based on optically trapped LC emulsion droplets can be largely and (almost) reversibly tuned by controlled changes of the ambient temperature. Depending on the actual range of temperature modulation and LC phase of the studied droplet, thermally induced effects can either lead to phase transitions in the LC droplets or cause modifications of their refractive index profile without changing their LC phase. Our results indicate feasibility of this approach for creating miniature thermally tunable sources of coherent light that can be manipulated and stabilized by optical forces.
Description
Source:
Journal of The Optical Society of America B-Optical Physics
Publisher:
Optical Soc Amer
Keywords:
Subject
Optics