Laser Optofluidics in Fighting Multiple Drug Resistance

Author(s): Mihai Boni, Ionut Relu Andrei, Angela Staicu, Viorel Nastasa and Mihail Lucian Pascu

DOI: 10.2174/9781681084985117010019

Lasing by Optically Pumped Pendant Droplets

Pp: 446-470 (25)

Buy Chapters

* (Excluding Mailing and Handling)

  • * (Excluding Mailing and Handling)

Abstract

SHS investigation development is considered from the geographical and historical viewpoint. 3 stages are described. Within Stage 1 the work was carried out in the Department of the Institute of Chemical Physics in Chernogolovka where the scientific discovery had been made. At Stage 2 the interest to SHS arose in different cities and towns of the former USSR. Within Stage 3 SHS entered the international scene. Now SHS processes and products are being studied in more than 50 countries.

Abstract

Pendant droplets have optical properties that reproduce the characteristics of corresponding bulk materials. A particular case is the droplet hanging in air, made of a laser dye solution and optically side-pumped. Here are shown results about laser induced fluorescence (LIF) emitted by a single pendant droplet excited with 532 nm pumping pulsed laser beam when its content is solution of rhodamine 6G in water kept as such, or doped with TiO2. By changing the geometry of fluorescent medium from bulk to pendant droplet and its volume, significant LIF changes occur. The main difference is amplification of emitted fluorescence in pendant droplets, explained by the confinement of light via total internal reflection in droplet. A new technique is shown, developed to distinguish temporal changes of a droplet emission in air. It was observed that the presence in the droplet of rhodamine 6G solution in ultrapure water of TiO2 nanoparticles induces LIF spectra modifications depending on nanoparticles number density and laser beam pumping energy. A concentration of 1011 part/cm3 nanoparticles favours formation of two new emission bands shifted towards blue with respect to main band. The increase with one order of magnitude of TiO2 number density, produces the disappearance of these bands regardless the pumping energy. Data suggest that addition of TiO2 nanoparticles to rhodamine droplet solutions influences emission spectra which can be modulated by varying nanoparticles concentration and pumping beam energy.

Recommended Chapters

We recommend

Favorable 70-S: Investigation Branching Arrow

Authors:Bentham Science Books