Fluorescence Characteristics of Random Gain Media Fabricated from Fluorescein Dye Containing Zinc Oxide Nanoparticles in Transparent Organic Hosts

Abstract

In this work, ZnO nanoparticles with different weights (0.01-0.09 mg) were incorporated into a solution of 6x10^-6 M Fluorescein dye dissolved in transparent resin in order to fabricate random gain media. The fluorescence and gain characteristics of these media were introduced when excited with a 405 nm laser source. The addition of ZnO nanoparticles to the Fluorescein dye dissolved in a transparent resin host leads to an observable enhancement in the fluorescence intensity of random gain media fabricated from such systems. The active role of ZnO nanoparticles as scattering centers can be observed by the enhanced optical feedback and optical gain of these media. The ZnO nanoparticles do not change the electronic structure of the Fluorescein dye and their effects specifically lie on scattering and re-absorption processes. The weights used in this work confirm that the random gain media did not cause quenching due to aggregation or excess absorption, therefore, significant losses were avoided. The accurate control of nanoparticles concertation in the random gain medium is an effective tool to control the emission or fluorescence characteristics to serve the practical purposes for which such random lasers are used.