Rh6G Dye Research Articles

Development of visible-light-driven Ca2Fe1−xSmxBiO6 double perovskites for decomposition of Rhodamine 6G dye

Abstract The main objective of this work was to investigate, for the first time, the photocatalytic activity of double perovskite materials Ca 2 Fe 1− x Sm x BiO 6 ( x = 0, 0.2, 0.4, 0.6, 0.8, 1) in degradation of Rhodamine 6G under visible irradiation. For the synthesis was used sol–gel auto-combustion method with citric acid as combustion agent and ammonium bistmuth citrate as a source for bistmuth cation. Synthesized photocatalysts were structurally investigated by FT-IR spectroscopy to follow the M–O characteristic bands of double perovskite structure and X-ray diffraction (XRD) to confirm the pure phase of catalysts. The catalyst microstructure was characterized by SEM and BET surface areas were measured at the liquid nitrogen temperature by nitrogen adsorption. The Sm concentration optimization yielded an efficient photocatalyst. Surprisingly, the two ends of the series, i.e., Ca 2 FeBiO 6 and Ca 2 SmBiO 6 photocatalysts, are much more active in visible light to the degradation of pollutant Rhodamine 6G than samarium substituted Ca 2 FeBiO 6 materials in different percentages. At an optimum composition of Sm as x = 1 in Ca 2 Fe 1− x Sm x BiO 6 , the photocatalyst exhibited 3.58 times the degradation yield for Rh6G dye in presence of visible light, than its intermediare counterpart.

Use of activated carbon prepared from Prosopis spicigera L. wood (PSLW) plant material for the removal of rhodamine 6G from aqueous solution

The removal of rhodamine 6G dye from aqueous solution using carbon prepared from cheaply available agro-product, Prosopis spicigera L. wood (PSLW), was investigated. This work involves studies of physical and chemical properties of adsorbent, batch sorption experiments, and continuous run in a packed column at laboratory scale. Optimum condition for rhodamine 6G dye adsorption on PSLW carbon was determined by varying pHs, adsorbate concentrations, contact time, adsorbent dosage, and temperature. Lower solution pH favored the adsorption of Rh 6G dye. Adsorption onto the surface, surface mass transfer, and pore diffusion of dye molecules were the main process involved in the removal of Rh 6G dye. The adsorption followed Langmuir isotherm and the maximum adsorption capacity was found to be 8.86 mg/g for an initial concentration of 30 mg/L at 30°C. Thermodynamic parameters indicated that the adsorption interaction was spontaneous and exothermic in nature. The column study was explained using Thomas model.

Studies on the Optogalvanic Effect and Isotope-Selective Excitation of Ytterbium in a Hollow Cathode Discharge Lamp Using a Pulsed Dye Laser

This paper presents studies on the pulsed optogalvanic effect and isotope-selective excitation of Yb 555.648 nm (0 cm(-1) → 17 992.007 cm(-1)) and 581.067 nm (17 992.007 cm(-1) → 35 196.98 cm(-1)) transitions, in a Yb/Ne hollow cathode lamp. The Yb atoms were excited by narrow linewidth (500-1000 MHz) Rh110 and Rh6G dye based pulsed lasers. Optogalvanic signal inversion for ground state transition at 555.648 nm was observed beyond a hollow cathode discharge current of 8.5 mA, in contrast to normal optogalvanic signal at 581.067 nm up to maximum current of 14 mA. The isotope-selective excitation studies of Yb were carried out by recording Doppler limited optogalvanic signals as a function of dye laser wavelength. For the 581.067 nm transition, three even isotopes, (172)Yb, (174)Yb, and (176)Yb, and one odd isotope, (171)Yb, were clearly resolved. These data were compared with selective isotope excitation by 10 MHz linewidth continuous-wave dye laser. For 555.648 nm transition, isotopes were not clearly resolved, although isotope peaks of low modulation were observed.

Sonochemical decolorization of wastewaters containing Rhodamine 6G using ultrasonic bath at an operating capacity of 2 L

In the present work, the sonochemical decolorization of wastewater containing a basic dye, Rhodamine 6G (Rh 6G) has been investigated using an ultrasonic bath at an operating capacity of 2 L. Effect of initial concentration, pH, and use of different additives, such as CCl4, H2O2, air, and UV light in combination with ultrasound on the extent of decolorization has been investigated. The experimental results show that an increase in dye concentration leads to a decrease in the decolorization rate, whereas basic conditions favor the decolorization of the pollutant. Among the use of different additives, maximum effect was observed for the use of hydrogen peroxide where the extent of decolorization was 77.8%. Use of air and CCl4 as an process intensifying additive leads to a moderate increase in the extent of decolorization whereas combination of ultrasound and ultraviolet irradiations resulted in lower effectiveness as compared to the combination of ultrasound and hydrogen peroxide. Kinetic studies have also been carried out for each of the treatment approach to quantify the rate constants for the degradation. It has been demonstrated in the present work that sonochemical reactors in combination with optimized concentration of hydrogen peroxide can be effective in removing Rh 6G dye from the effluent streams.

Levitated microdrop quantum dot and dye laser in a modified Paul trap

We used a modified Paul trap and created a near-perfect spherical liquid droplet by trapping and levitating a charged, micrometer sized liquid droplet in air. The spherical micro-drop acts as a whispering gallery mode resonator. A suitable lasing material (rhodamine 6G or Rh6G dye, water soluble CdSe/ZnS core-shell quantum dots(QDs)) was dissolved in glycerol and used to create charged microdrops with the help of electrospray. One of the charged micro drops was selectively trapped and stabilized in the trap. It was then optically excited by 532 nm green lasers. The lasing spectra was detected and studied.

Luminescent Dye-Doped KAP Nanorods Obtained by Template Assisted Crystallization

Luminescent nanorods of potassium acid phthalate (KAP) doped with rhodamine 6G (Rh 6G) dye molecules were grown by template assisted crystallization. Pores with diameters ranging from tens of nanometers to few micrometers were obtained in polycarbonate foils after heavy-ion irradiation and subsequent chemical etching of the damage trails along the ion trajectories. Crystallization from solution was employed for filling of the pores with the dye-doped KAP rods. These nanostructures were characterized using scanning electron microscopy, optical absorption spectroscopy and photoluminescence detection. X-ray diffraction was used for structural analysis. The luminescence of the dye-doped rods undergoes a redshift when the diameter of the structures decreases. This shift is probably caused by increasing dye concentration in the rods with decreasing pore diameter. The luminescence originating from the Rh 6G presence is up-converted due to the second-harmonic generation in KAP.

Mesoporous Metal–Organic Framework with Rare etb Topology for Hydrogen Storage and Dye Assembly

More holes than Swiss cheese: A new MOF with the largest reported 1D hexagonal nanotube-like channels of 24.5 Å×27.9 Å and rare etb topology has been synthesized (see picture). It exhibits good fluorescence properties and substantial hydrogen uptake. For the first time, the compound was assembled with Rh6G dye molecules, and the product showed favorable temperature-dependent luminescent properties.

Optical properties of Rh 6G dye in liquid and solid polymer

Rhodamine 6G dye doped in liquid MMA (monomer) and solid polymer (PMMA) has been studied and its spectra compared with the one dissolved in n-BA solvent. The effect of temperature and laser power on the emissive characteristics of dye in polymer and in solvent has also been compared.

Visible sub-60-femtosecond dye laser with GaAs based semiconductor saturable absorber mirror

A GaAs based semiconductor saturable absorber mirror (SESAM) has been fabricated using molecular beam epitaxy and applied to a hybridly modelocked Rh6G dye laser. The generated pulse was as short as 56 fs at the centre wavelength of 580 nm, which shows the shortest centre wavelength in these kinds of dye laser.

Visible wavelength autocorrelation based on the two-photon absorption in a SiC photodiode

The two-photon absorption of a SiC photodiode was utilized to obtain autocorrelation signals of the pulses from a mode-locked Rh6G dye laser. The autocorrelation signals were in good agreement with those obtained by a conventional autocorrelator using a second harmonic crystal and photomultiplier tube. The sensitivity of the autocorrelator with the SiC photodiode was about <TEX>$4{\times}10^3 {(mW)}^2$</TEX> . From these results it was demonstrated that the SiC photodiode is suitable as a nonlinear device for an autocorrelation measurement in the visible range.

Diffraction filtered resonator for Rh6G dye laser transversely pumped by a copper vapor laser

The output from a transverse pumped dye laser usually has poor beam quality and high divergence asymmetry along horizontal and vertical directions. In this paper, it is demonstrated that diffraction filtered resonators can be applied to such small cross-section lasers with significant improvements in the output beam quality. A copper vapor laser pumped dye laser was operated with output divergence of 0.55 mrad in horizontal and vertical directions as compared to 5.2 mrad and 4.5 mrad respectively with a conventional plane-plane resonator.

Temporal dynamics of a ring dye laser with a stimulated Brillouin scattering mirror

We present a numerical study of the temporal dynamics of a stimulated Brillouin scattering ring resonator. A coaxial flash-lamp-pumped Rh6G dye laser is assumed. The influence of the most important parameters on the temporal evolution of the resonator is analyzed, namely, the acoustic decay time of the nonlinear material, the features of the external injection pulse - its pulse width, energy, and spatial quality - and the coupling mirror reflectivity. We found the conditions to initiate and maintain laser oscillation in the ring resonator as long as the duration of the pumping system pulse persisted.

Spectral Asymmetry by Group Velocity Dispersion and Self-phase Modulation in Hybridly Mode-locked Rh6G Dye Laser with a Pair of Brewster Prisms

In a hybridly mode-locked continuous-wave dye laser with a Rh6G saturable gain and a 3,3′-diethyloxadicarbocyanine iodide saturable absorber, a pair of Brewster prisms were used to control the grou...

Temporal dynamics of an external-injection dye laser with a stimulated Brillouin scattering reflector

Temporal dynamics of an external-injection stimulated Brillouin scattering laser resonator has been numerically modelled. A flash-lamp-pumped Rh6G dye laser is assumed. The main parameters affecting its performance were numerically analysed in order to understand their influence on the temporal evolution of the laser. These parameters were: the acoustic decay time of the nonlinear material, the energy of the external-injection pulse (input pulse), the pulsewidth, the coupling mirror reflectivity, and the spatial quality of the incident pulse. It was found that in order to have laser oscillation in the resonator, the acoustic decay time must be in a well-defined range, the input pulse energy is to be greater than a minimum value, and the beam divergence must not be greater than a certain limit value.

A tunable three-wavelength copper-vapor laser pumped dye laser with collinear output

Collinear operation at multiple wavelengths in dye lasers is difficult to maintain because of gain competition between the lasing wavelengths. Also, it is difficult to ensure the same linewidth for all the lasing wavelengths due to differences in the resonator characteristics. In this paper a new resonator geometry, using a combination of two gratings, is proposed to obtain collinear, tunable, three-wavelength emission with the same linewidth. A Rh6G dye laser, pumped by a copper-vapor laser was operated at three wavelengths. Two of the three wavelengths can be independently tuned. Alternatively, two wavelengths with a fixed interval can be simultaneously tuned, keeping the third wavelength fixed.

Characterization of biaxial crystals for tangentially phase-matched frequency conversion

Ultraviolet radiation has been generated by tangentially phase-matched sum-frequency mixing in biaxial L-arginine phosphate (LAP) crystal for the first time using Nd:YAG output at 1064 nm and Rh 6G dye laser output at 560 nm as the two input sources. Characterization has also been made of such a cheap, biaxial crystal for its possible use in devices for tangentially phase-matched short wavelength generation. If the crystal is of proper cut, thickness and quality so that its maximum capability can be exploited it can replace the potassium dihydrogen phosphate (KDP) group of crystals for various applications.

Dye laser pumped Pr/sup 3+/-doped fiber lasers: basic parameter investigation, CW operation, and Q-switched operation

An investigation of a Pr/sup 3+/-doped Al/sub 2/O/sub 3/-SiO/sub 2/ glass fiber is described. The basic material parameters like fluorescence lifetime and stimulated emission cross section, measured around 1048 nm, where the fiber has a strong emission band, are discussed. The pump source was a Rh6G dye laser at 590 nm. Continuous wave (CW,) operation with a slope efficiency of 26% and a pump threshold of 1.2 mW was obtained. The Q-switched operation, yielding a repetition rate up to 10 kHz with a maximum peak power of 30 W and a minimum pulsewidth of 25 ns, is described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

HIGH POWER SUM FREQUENCY GENERATION OF 230.8—223.2nm IN BBO CRYSTAL

Continuously tunable second harmonic generation of 294.8-282.5 nm was obtained by Q-switched YAG laser pumped Rh·6G dye laser in a 45°cut β-BaB2O4 (BBO) crystal. The output energy of the harmonic wave is about 8mJ around 285 nm. The continuously tunable output over the range of 230.8-223.2 nm was also obtained by the sum frequency mixing between the residual pump fundamental wave (1064nm) and the second harmonic wave of Rh 6G dye laser in an other 45°cut BBO crystal. The sum frequency output energy is about 120 μJ around 226 nm, the corresponding peak power is 12 kW. The key techniques of the sura frequency generation were indicated.

Photoacoustic spectral characteristics of Rh6G and RhB dye solutions in mixtures and on Al_2O_3 surfaces

Photoacoustic spectral characteristics of Rh6G and RhB solutions in mixtures and on Al(2)O(3) surfaces are reported. An enhancement of the photoacoustic signal is observed for dye mixtures, between 480 and 530 nm. This could be due to the dominance of the resonance excitation transfer process. In addition, the spectra of the mixtures show a blue shift due to dimer formation in Rh6G. Compared with those, the spectra of Rh6G and RhB on Al(2)O(3) surfaces show red shifts which may be due to photobleaching.

Femtosecond luminescence spectroscopy with 60 fs compressed pulses

We report compression of the pulses from a synchronously pumped Rh 6G dye laser to 60 fs using a fiber-prism compressor. Average power in excess of 150 mW has been obtained. Using this compressed laser and the sum-frequency-generation technique, we have demonstrated the capability of measuring luminescence spectra with 65 fs time resolution. Initial results on GaAs and AlGaAs are presented.