Random Laser of R6G Dye and TiO<sub>2</sub> Nanoparticals Doped in PMMA Polymer

Abstract

The random laser (RL) based on organic Rhodamine 6G (R6G) laser-dye and Titanium dioxide (TiO2) suspended nanoparticles have been prepared with polymethylmethacrylate (PMMA) as a host. Both liquid and spray-coated homogeneous film samples of 22.4 µm-30.1 µm thickness range were use. Optimum concentrations have been determined depending on the normal fluorescence spectra which give evidence that the laser dye provides amplification and TiO 2 nanoparticles as scatter center. At the optimum concentrations, results of the random laser (RL) under second harmonic Nd: YAG laser excitation show that the values of bandwidth at full width half-maximum (FWHM) and the threshold energy are about 9 nm and 15 mJ respectively, which represent the minimum value for the liquid samples in the current research. Correspondly, these values become 14 nm and 15 mJ for film sample. The broadening that can be attributed to the concentration quenching of a laser dye at high concentration levels has been observed.

Low-threshold and narrow linewidth diffusive random lasing in rhodamine 6G dye-doped polyurethane with dispersed ZrO_2 nanoparticles

“…Increasing the NP concentration causes the FWHM to collapse to its lasing value at a much faster rate and, once lasing, the FWHM is smaller for higher NP concentrations. These effects are consistent with previous measurements of other Rh6G NP/host combinations [26][27][28].…”

“…From Tables I and II we see that the lasing threshold decreases as either the dye and/or particle concentration increases. These results are consistent with our FWHM measurements and previous measurements of RL in different Rh6G dye-doped NP/host combinations [27,28]. Plotting the threshold values from Table I NP concentration (see Figure 7) we find that the threshold depends on the particle concentration via a power function of the form…”

Detection of Random Laser Action from Silica Xerogel Matrices Containing Rhodamine 610 Dye and Titanium Dioxide Nanoparticles

“…The results of random laser measurements show that the minimum band width at FWHM was 11 nm at 25 mJ and laser threshold at 3 mJ for a homogeneous silica xerogel sample doped with 10 −4 mol/l of R610 dye and 4.5 × 10 13 cm −3 of TiO 2 . This threshold was considered to be lower than that of organic hosts such as polymers [25]. It was also found that titanium particles contribute for small photodegradation of the dye molecules.…”

Preparation and Photoluminescence Spectra of Organometallic Complexes Containing Nanoparticles as Random Gain Media

“…As of late, different interchanges, natural, biomedical, and space applications have been created by using irregular addition media as laser sources known as "random lasers" [1]. Additionally, the continuous and extraordinary improvements in nanotechnology have prompted uncommon advancements in the plan and manufacture of irregular increase media [2][3]. 8-Hydroxyquinoline zinc has many advantages, such as simple synthesis conditions [4].…”