Bichromatic random laser from a powder of rhodamine-doped sub-micrometer silica particles

Abstract

Articles you may be interested inTiO2@Silica nanoparticles in a random laser: Strong relationship of silica shell thickness on scattering medium properties and random laser performance Appl. Phys. Lett. 104, 081909 (2014); 10.1063/1.4865092SiO 2 nanoparticles as scatterers for random organic laser action in red fluorescent dye 4-(dicyanomethylene)-2tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4 H -pyran doped polystyrene films Random lasing emission from a red fluorescent dye doped polystyrene film containing dispersed polystyrene nanoparticles Appl. Phys. Lett. 91, 091115 (2007);We studied the random laser (RL) bichromatic emission (BCE) from a powder consisting of silica particles infiltrated with Rhodamine 640 (Rh640) molecules. The BCE is attributed to Rh640 monomers and dimers. Because of the efficient monomer-dimer energy transfer, we observed RL wavelength switching from % 620 nm to %650 nm and the control of the emitted wavelength was made by changing only the excitation laser intensity. None of external parameters such as excitation laser spot size or radiation detector position was changed as in previous experiments. Two laser thresholds associated either to monomers or dimers were clearly observed. Moreover, an effect analog to frequency-pulling among two coupled oscillators was identified measuring the RL spectra as a function of the excitation laser intensity. A wavelength shift, Dk, was measured between the monomer and dimer resonance wavelengths, changing only the excitation laser intensity. The maximum value of Dk % 16 cm À1 was obtained for laser pulses of 7 ns with 30 lJ. V C 2014 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4863308] 043515-3Barbosa-Silva et al.

Observation of photonic paramagnetic to spin-glass transition in a specially designed TiO_2 particle-based dye-colloidal random laser

“…Dye-based RLs are highly efficient, and have been used as a platform for demonstration of optical effects such as the bichromatic emission due to monomers and dimers in Rhodamines [15][16][17], multi-photon excitation [18][19], and low spatial coherence [20]. In spite of the promising characteristics of dye-based RLs, the dye photodegradation, enhanced due to the presence of the scatterers is a drawback for the basic investigation and practical application of these systems [21,23].…”

Bichromatic coherent random lasing from dye-doped polymer stabilized blue phase liquid crystals controlled by pump light polarization

“…[3] Later on, the bichromatic emission phenomena in the systems consisting rhodamine 640 in methanol and TiO 2 particles were studied by Sha et al [8,9] Recently, the bichromantic RL was also observed from the alumna porous ceramic infiltrated with rhodamine B and the powder of rhodamine-doped submicrometer silica particles. [10,11] However, in the previous research, the full width at half maximum (FWHM) of the bichromatic lasing peaks was several nanometers; in other words, only the bichromatic incoherent RL was observed. To date, the bichromatic coherent RL emission, the FWHM of which is less than 0.4 nm, has not been demonstrated experimentally.…”

Single bead near-infrared random laser based on silica-gel infiltrated with Rhodamine 640

“…However, in spite of the large amount of studies related to the PL properties of dyes doped sol-gel samples, only few reports on RL emission were presented. 15,[25][26][27][28] For instance, besides the work reported in Ref.…”

“…10-14, there are other possibilities to control the dye photoluminescence (PL) by changing the electronic structure of the molecules, their mutual interaction, the excitation laser intensity, and the influence of the environment. For instance, by exploiting ET processes between monomers and dimers of Rh640, Barbosa-Silva et al 15 demonstrated bichromatic emission that was tuned by adjusting the energy pulse excitation (EPE) incident on a powder consisting of sub-micrometer silica particles, synthesized by the St€ ober modified method, 16 infiltrated with Rh640.…”

“…28, alumina porous ceramic was used as Rhodamine B host, and bichromatic emission due to monomers and dimers was observed as in Ref. 15.…”