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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:03 |
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Conference: Bucharest University Faculty of Physics 2019 Meeting
Section: Polymer Physics
Title:
Compact Mirrorless Ionic Light Emitters
Authors:
Valentin BARNA(1)
Affiliation:
1) University of Bucharest, Faculty of Physics, PO Box MG 11, Magurele-Bucharest, Romania
E-mail
barnavalentin@yahoo.com
Keywords:
random lasing, ionic liquids, organic dyes, free narrow banded emitters
Abstract:
Light localization and interference effects which survive the multiple scattering events have been invoked to explain random lasing observed in many exotic and complex systems. Optical scattering phenomena (whether week or strong) inside a random medium is thus capable of inducing a phase transition in the photons transport behavior. In a random laser discrete modes, amplified by the disordered medium, have distinct resonant wavelengths, while the spectral interval between adjacent modes is usually in the range of a few nanometers. Ionic liquids (ILs) are presently defined as being organic salts that melt at or below 100° C. ILs (and in particular room temperature ionic liquids) have been intensively studied during last two decades and have drawn plenty of attention in numerous scientific areas including organic chemistry, catalysis, electrochemistry, physical chemistry and engineering due to their special physical and chemical characteristics, such as: low vapor pressure, low flammability, high inherent conductivities, wide range of potential density and viscosity values, liquidity over a wide temperature range, recyclability, high thermal and chemical stability. Taking advantage of all these interesting features, we present the successful use of various types of ionic liquid materials as dielectric hosts for organic dyes in creating highly efficient random laser systems. Ranging from standard cell design to freely suspended thin active media films, these lasers prove to be ultra-compact hazard free narrow banded (0.3 nm FWHM) emitters that excel due to their low lasing threshold, superior effectiveness, long term robustness, uncomplicated manufacture procedure and great diversity of potential configurations.
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