0548609 - ÚPT 2022 RIV US eng J - Journal Article
Jonáš, Alexandr - Pilát, Zdeněk - Ježek, Jan - Bernatová, Silvie - Jedlička, Petr - Aas, M. - Kiraz, A. - Zemánek, Pavel
Optically Transportable Optofluidic Microlasers with Liquid Crystal Cavities Tuned by the Electric Field.
ACS Applied Materials and Interfaces. Roč. 13, č. 43 (2021), s. 50657-50667. ISSN 1944-8244. E-ISSN 1944-8252
R&D Projects: GA MŠMT ED0017/01/01; GA MŠMT(CZ) LO1212; GA MŠMT(CZ) LD14069
Grant - others:AV ČR(CZ) AP2002
Program: Akademická prémie - Praemium Academiae
Institutional support: RVO:68081731
Keywords : tunable optofluidic microcavity * optofluidic laser * whispering gallery modes * liquid crystals * optical trapping * microfluidics
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 10.383, year: 2021 ; AIS: 1.608, rok: 2021
Method of publishing: Limited access
Result website:
https://pubs.acs.org/doi/10.1021/acsami.1c11936DOI: https://doi.org/10.1021/acsami.1c11936

Liquid crystal microdroplets with readily adjustable optical properties have attracted considerable attention for building reconfigurable optofluidic microsystems for sensing, imaging, and light routing applications. In this quest, development of active optical microcavities serving as versatile integrated sources of coherent light and ultra-sensitive environmental sensors has played a prominent role. Here, we study transportable optofluidic microlasers reversibly tunable by an external electric field, which are based on fluorophore-doped emulsion droplets of radial nematic liquid crystals manipulated by optical tweezers in microfluidic chips with embedded liquid electrodes. Full transparency of the electrodes formed by a concentrated electrolyte solution allows for applying an electric field to the optically trapped droplets without undesired heating caused by light absorption. Taking advantage of independent, precise control over the electric and thermal stimulation of the lasing liquid crystal droplets, we characterize their spectral tuning response at various optical trapping powers and study their relaxation upon a sudden decrease in the trapping power. Finally, we demonstrate that sufficiently strong applied electric fields can induce fully reversible phase transitions in the trapped droplets even below the bulk melting temperature of the used liquid crystal. Our observations indicate viability of creating electrically tunable, optically transported microlasers that can be prepared on-demand and operated within microfluidic chips to implement integrated microphotonic or sensing systems.
Permanent Link: http://hdl.handle.net/11104/0324669