Rhodamine 6G Dye Laser Research Articles

The Effect of Mixing Nanoparticles on the Suspension Physical Stability

Energy transfer in a hybrid mixture of Rhodamine 6G (Rh6G) dye laser as a donor and nanoparticles (NPs) as an acceptor were studied. The absorption spectra of 1×10-5M of Rh6G in Distilled Water show increase in the intensity when adding NPs. noticeable, improve the spectra when adding Aluminum Oxide Al2O3 NPs. Adding NPs quench the fluorescence spectra of Rh6G due to Förster resonance energy transfer (FRET). The efficiency of energy transfer increase with increasing concentration of NPs. Best value of efficiency of energy transfer found in Rh6G/ Magnesium Oxide MgO NPs. Strong relationship was in Rh6G/ Al2O3 NPs.

Investigating The Effects of The Different Rhodamine 6G Laser Dye Volume Ratios on The Optical Properties of PMMA/PC Films

Rhodamine 6G – polymethylmethacrylate/polycarbonate (Rh6G–PMMA/PC) were prepared by a casting method at room temperature with diverse volume ratios of Rh6G dye solution (5, 10, 15, 20 and 25) ml. The as-prepared films were categorised via UV–Vis spectrophotometer, and the optical properties were investigated in the wavelength range of (200-800) nm. The absorption peaks for pure PMMA/PC film were affected by inserting Rh6G dye solution, the wavelength of absorption peak of pure PMMA/PC film is at 300 nm and 340 nm while there are different behaveior at different concentration of RG6 after mixing with PMMA/PC films; there are red shift for concentrations (10 and 25 ml) of RG6 after mixing with PMMA/PC films by appear another peaks at 530 nm and 535 nm respectively. In addition, there is a blue shift for concentrations (15 and 20 ml) of RG6 after mixing with PMMA/PC films, as evidenced by the appearance of new peaks at wavelength 265 nm. Furthermore, new peaks appeared and were absorbed while the energy band gap was influenced, with values ranging from 4.3 eV for pure PMMA/PC film to 4.18 eV for mixtures 10 and 25 ml concentration of Rh6G/ PMMA/PC belonging to the red shift to 4.9 eV and 4.85 eV for mixtures 15 and 20 ml concentration of Rh6G/ PMMA/PC belonging to the blue shift.

Quantized molecular intercalations of Rhodamine 6G laser dye onto polymethylmethacrylate host exciplex

Polymethylmethacrylate (PMMA) and Rhodamine 6G (R6G), were used to achieve an electronically excited R6G/PMMA complex of definite stoichiometry as an active laser exciplex, pumped by different laser sources. This paper is the first that is capable of interpretation of the interactions of the reactants to form the exciplex on the molecular level using DFT. The system was prepared by thermochemical polymerization, and structurally identified using FTIR, XRD and SEM in conjunction with DSC. In low-to moderate-loading of R6G, FTIR and XRD studies indicated a good interaction between PMMA and R6G to give poor-or semi-crystalline structures. Higher dye loadings were achieved for the synthesized exciplex; loading of PMMA with 0.25 Wt-% R6G decreased the glass transition temperature from 98.74 °C to 70.08 °C. However, increasing the loading with R6G to 5 Wt-% and 20 Wt-% increased the Tg values to 86.26 and 91.90 °C, respectively. MD simulations were conducted; the electronic mobility within the system was related to different quantum parameters, EHOMO, ELUMO, η, μ and ω were about -7.671 eV, -5.241 eV, 1.215 eV, -6.456 eV and 17.1522 eV, respectively. DFT calculations indicated that R6G/PMMA has a characteristic lasing stability, so that the lasing lifetimes about 8000 pulses and efficiencies about 21% were obtained.

Circular, Plane-Directional Radiation from the Edges of Light-Excited Layer of a Laser Dye Solution with the Regular Geometric Form

Homogeneous light excitation of the Rhodamine 6G laser dye alcohol solution layer of rectangular and circular geometric form by the second harmonic of Nd:YAG (532 nm) laser is realized. A circular, plane-directed radiation from the edges of the excited layer with a small, vertical, divergence was obtained. Was investigated experimentally the spectral and spatial characteristics of radiation. The investigated layer is a part of the dye solution that is in direct

The Radiation of the light excited layer of the alcohol solution of the dye Rhodamine 6G

Was investigated experimentally the spectral and spatial characteristics of the radiation of a light-excited layer of an alcohol solution of the laser dye Rhodamine 6G (R6G) of rectangular and round geometric shape. The investigated layer is a part of the dye solution that is in direct contact with the bottom of the optical cells, the rectangular and circular sections of which determine geometric shape of the layer. Excitation of the layer was performed perpendicular to this layer by the second harmonic of the Nd+: YAG laser (λ = 532 nm) from the side of the cell bottom. Sufficiently strong, spectrally narrow-band radiation with a circular uniform distribution of intensity around the cells, in the plane of the luminescent layer, with a small divergence in the perpendicular plane was observed. It turned out that within the concentrations of the dye in the solution from 0.12w% to 0.03w%, the following processes are observed: Planely directed uniform, in intensity, radiation around the cell in the plane of the luminescent layer with a small vertical divergence; An increase in the amplitude of radiation pulses with a decrease in the concentration of the dye in the solution from 0.12w% to 0.03w%; Shifting of the maximum of the emission spectrum to the short-wave region and significant narrowing of the radiation spectrum and decrease of the vertical divergence of radiation.

Impact of PS/PMMA Polymer Ratios with Nanocomposite Material on Optical and Morphological Properties

In this work, nanocomposite material consisting of titanium dioxide (TiO2) nanoparticles and rhodamine 6G (R6G) laser dye was doped with different ratios of polystyrene (PS) and polymethylmethacrylate (PMMA) polymer blends (i.e. 40% PS/60% PMMA and 50% PS/50% PMMA) using the casting method. The optical properties of the prepared samples were measured using UV-visible spectroscopy. These measurements include the calculations of the absorption (A%), absorption coefficient (α), energy gap (Eg), refractive index (n), extinction coefficient (K) and real and imaginary parts. These nanocomposite materials were investigated using a scanning electron microscope and photoluminescence (PL) spectra emission. The SEM results show that the optimum results were at 50% PS/50% PMMA/TiO2/R6G with all the dye being decorated in the process blend, while the TiO2 nanoparticle demonstrated that the pores were incomplete in some places and complete in others. The optical results show that there are red shifts in all absorption peaks caused by the increased PS ratio. The Eg decreased from 3.2 eV to 2.8 eV as the concentration of PS in the polymer matrix increased. The PL spectrum for the nanocomposites, with a different ratio of PS, shows that sharp peaks of PL emission occur at a wavelength of 570 nm and shift towards longer wavelengths with an increased PS%.

Physical Properties of Rhodamine 6G Laser Dye Combined in Polyvinyl Alcohol films as Heat Sensor

Rhodamine 6G- polyvinylalcohol (Rh6G/PVA) films were prepared via casting route at room temperature with different volume of Rh6G dye solution (5, 10, 15, 20, 25 and 30 ml). The optical properties of as-prepared films were characterized using UV–Vis spectrophotometer at a wavelength range of 200-800 nm. The absorption peak of the pure PVA film does not affect by adding the Rh6G dye solution while exhibited increase in intensity of the absorption spectrum. Furthermore, the absorption peak of Rhodamine 6G demonstrated red-shift about 10 nm. Energy band gap slightly affected by adding Rh6G dye solution. The amazing influence of heat treatment on the physical properties of Rh6G/PVA films appeared due to red-shift and decrease the energy band gap. The results exposed that the best sensitivity calculated at temperature 40 °C for as-grown Rh6G (15 ml)/PVA film around 35.74%.

Embedded Spherical Microlasers for In Vivo Diagnostic Biomechanical Performances

Abstract In this article, we propose to use spherical microlasers that can be attached to the surface of bones for in vivo strain monitoring applications. The sensing element is made of mixing polymers, namely, PEGDA-700 (Sigma Aldrich, St. Louis, MO) and Thiocure TMPMP (Evan Chemetics, Teaneck, NJ) at 4:1 ratio in volume doped with rhodamine 6G (Sigma Aldrich, St. Louis, MO) laser dye. Solid-state microlasers are fabricated by curing droplets from the liquid mixture using ultraviolet (UV) light. The sensing principle relies on morphology-dependent resonances; any changes in the strain of the bone causes a shift of the optical resonances, which can be monitored. The specimen is made of a simulated cortical bone fabricated with photopolymer resin via an additive manufacturing process. The light path within the resonator is found to be about perpendicular to the normal stress' direction caused by a bending moment. Therefore, the sensor measures the strain due to bending indirectly using the Poisson effect. Two experiments are conducted: 1) negative bone deflection (called loading) and 2) positive bone deflection (called unloading) for a strain range from 0 to 2.35 × 10−3 m/m. Sensitivity values are ∼19.489 and 19.660 nm/ε for loading and unloading experiments, respectively (percentage difference is less than 1%). In addition, the resolution of the sensor is 1 × 10−3 ε (m/m) and the maximum range is 11.58 × 10−3 ε (m/m). The quality factor of the microlaser is maintaining about constant (order of magnitude 104) during the experiments. This sensor can be used when bone location accessibility is problematic.

Optical characterization of graphene-f-o-phenylenediamine and charge transfer interaction with organic dyes

Carbon based nanomaterials can effectively be doped to tailor their electronic and optical properties for various applications. In this work, we have synthesized and characterized the o-phenylenediamine doped graphene (G-f-OPD) to study the charge transfer with a standard laser dye rhodamine 6G (R6G). A comparison with pristine graphene shows that the static quenching efficiency of the graphene is 25 times higher than that of the G-f-OPD. Time-resolved measurements reveal the absence of dynamic quenching of the dye in presence of graphene and its nitrogen doped derivative. Nonlinear optical characterization of G-f-OPD has also been done in presence of R6G by degenerate four wave mixing (DFWM) technique. The measured values of third order optical nonlinearity (χ(3)) reveals the fact that the dominant contribution to the optical nonlinearity is due to its real part at the probe wavelength (532 nm). Furthermore, the nonlinear optical study by Z-Scan technique shows that G-f-OPD-R6G composite can be suitable for passive mode-locking applications.

Solid State Optical Microlasers Fabrication via Microfluidic Channels

In this paper, we propose the use of a microfluidic channel with flow focusing technique to fabricate solid state polymeric microlasers to precisely control sizes for mass production. Microlasers are made from a solution of UV curable polymer, namely polyethylene glycol diacrylate (PEGDA) with a molecular weight of 700 and rhodamine 6G laser dye at two different volumetric ratios (polymer to dye) of 4:1 and 2:1, respectively, which are used as the dispersed phase. A reservoir filled with liquid polydimethylsiloxane (PDMS) was used to cure the microlasers via UV lamp. A microchannel made of (PDMS) and size of 200 µm was used in this paper; mineral oil was selected as the continuous phase. Two experiments are conducted by fixing the pressure flow for the dispersed phase to 188 mbar and 479.9 mbar, respectively. In both experiments, the pressure of the continuous phase (mineral oil) was varied between 1666.9 mbar and 1996.9 mbar. The measurement of the fabricated microlasers’ size was performed with the aid of the MATLAB Image Processing Toolbox by using photographs taken with a CMOS camera. The tunability of the highest size, ranging from 109 µm to 72 µm, was found for the PEGDA to dye ratio of 2:1 (188 mbar) and average standard deviation of 1.49 µm, while no tunability was found for the 4:1 ratio (188 mbar). The tunability of the microlaser’s size, ranging from 139 µm to 130 µm and an average standard deviation value of 1.47 µm, was found for the 4:1 ratio (479.9 mbar). The fabricated microlasers presented a quality factor Q of the order 104, which is suitable for sensing applications. This technique can be used to control the size of the fabrication of a high number of solid state microlaser based UV polymers mixed with laser dyes.

High-Performance All-Organic DFB and DBR Waveguide Laser with Various Grating Height Fabricated by a Two-Photon Absorption DLW Method

Organic solid-state lasers (OSSLs) with distributed feedback (DFB) structures or distributed Bragg reflectors (DBRs) are promising for potential application in bio-sensing and hazardous materials detection. Here, the laser performances of the all-organic DFB waveguide lasers with various grating heights ranging from 0.4 to 4.7 μm were investigated. The grating structures used as the lasing cavity were fabricated using a two-photon absorption (TPA) direct laser writing (DLW) method with an SU-8 negative photoresist. The laser active layer consisted of a rhodamine 6G (R6G) laser dye and a cellulose acetate (CA) matrix. The R6G/CA solution was spin-coated onto the quartz substrate with the cavity (grating) structures to fabricate the DFB waveguide laser devices. The diffraction order of lasing ranged from m = 4 to 7. As the grating height was increased to 1.9 μm, the slope efficiency increased for all diffraction orders and the threshold decreases for each diffraction order. The dependence of the cavity (grating) length on the laser performances was investigated. The slope efficiency increased as the cavity length increased to 300 μm. The effect of the cavity (grating) position on the slope efficiency and the threshold position of the cavity (grating) was also studied. A maximum slope efficiency of 10.2% was achieved for the DFB waveguide laser device with a cavity (grating) length of 300 μm, a cavity position at 6 mm from the emission edge of the waveguide, and an aspect ratio ≈3 between the grating height of 1.74 μm and the grating width of 0.6 μm for the diffraction order m = 6 for lasing.

Fano Resonances and Photoluminescence in Self-Assembled High-Quality-Factor Microbottle Resonators

We demonstrate self-assembly of microbottle resonators (MBRs) that support high-quality-factor (high-Q) whispering gallery modes (WGMs). Polymethyl methacrylate (PMMA), a transparent organic polymer, has been used for the self-assembly. Active MBRs have been created by doping PMMA with laser dye rhodamine 6G. WGM-modulated photoluminescence has been observed from the active MBRs. The self-assembled passive MBRs show Q-factors of the order of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> . Fano- and electromagnetically induced transparency-type resonances have been observed in the transmission spectra.

Organic-inorganic hybrid microdisk laser with dye and silica mixed doping prepared by ink-jet printing method

We developed an ink-jet printing method for fabricating inorganic microdisks at room temperature, which is much lower than the melting point of solid-state inorganic oxide, and have fabricated an organic-inorganic hybrid microdisk laser. Silica was used as the inorganic disk material, and microdisk-shaped aggregates were formed by the ink-jet printing method using a solution in which nanosilica particles were dispersed in propylene glycol monomethylether (PGME) solvent. Then, a microdisk capable of laser oscillation was also prepared by preliminarily adding the laser dye rhodamine 6G to the ink to form a mixed organic material. The structural evaluation of the printed microdisk was first conducted using an optical microscope, a scanning electron microscope (SEM), and an atomic force microscope (AFM). The results of laser oscillation evaluation by optical excitation showed that the printed microdisk sufficiently functions as an optical resonator with a low optical loss. In these evaluations, excellent values such as a surface roughness of 5.83 nm from root mean square (R. M. S.) which is one forth smaller than the particle diameter, and a laser oscillation threshold of 4.76 µJ/mm2 at a wavelength of 601.4 nm were obtained. To the best of our knowledge, this is the first time that an inorganic microdisk has been fabricated at room temperature to realize an organic-inorganic hybrid microdisk laser.

Solvent effect on the femtosecond laser induced two-photon emission from Rhodamine 6G

Abstract Two-photon fluorescence microscopy attains widespread importance because of its applications in biological imaging. This technology provides a non-invasive study of biological specimens with better resolution in three dimensions with less photo damage. We report on two-photon excited emission from a widely used laser dye Rhodamine 6G in five different polar solvents using a mode-locked Ti: Sapphire pulsed laser. Solvent plays a major role in the photo physical properties of the lasing dye. There is a shift in the peak fluorescence wavelength as the concentration is varied. A solvent based shift in peak fluorescence wavelength is also observed. Maximum peak intensity is observed for the sample in the solvent ethanol. It was found that lifetime is varied depending on the nature of the solvent used.

Low threshold random lasing actions in natural biological membranes

We report random lasing actions stemming from natural biological membranes doped with Rhodamine 6G (Rh6G) laser dye which were then stimulated by a pulsed laser. The membranes have concave–convex structures and are expected to form resonators for weak light scatterings. The laser emission varies with the type of membrane and is also closely related to the dye concentration and pump energy. The threshold for the laser generation obviously rises when the concentration of doped laser dye is increased. The simulation results show lasing distributions are localized, indicating that the laser modes are very sensitive to the indicant angles of pump light.

Effect of Pore Size and Film Thickness on Gold-Coated Nanoporous Anodic Aluminum Oxide Substrates for Surface-Enhanced Raman Scattering Sensor.

A sensitive surface enhanced Raman scattering chemical sensor is demonstrated by using inexpensive gold-coated nanoporous anodic aluminum oxide substrates. To optimize the performance of the substrates for sensing by the Surface-enhanced Raman scattering (SERS) technique, the size of the nanopores is varied from 18 nm to 150 nm and the gold film thickness is varied from 30 nm to 120 nm. The sensitivity of gold-coated nanoporous surface enhanced Raman scattering sensor is characterized by detecting low concentrations of Rhodamine 6G laser dye molecules. The morphology of the SERS substrates is characterized by atomic force microscopy. Optical properties of the nanoporous SERS substrates including transmittance, reflectance, and absorbance are also investigated. Relative signal enhancement is plotted for a range of substrate parameters and a detection limit of 10−6 M is established.

Fluorescence quenching of rhodamine 6G by 1,3,5-Trinitroperhydro-1,3,5- triazine entrapped in porous sol–gel silica

Fluorescence quenching of laser dye rhodamine 6G by codoping 1,3,5-Trinitroperhydro-1,3,5-triazine (RDX) in porous sol–gel silica is reported. It was found that the fluorescence intensity of rhodamine 6G decreases with increase in the concentration of RDX. Both the samples, predoped cylindrical shaped and postdoped thick film on glass substrate with RDX show the similar fluorescence quenching behavior. Emission spectra show slight red shifting with the increase in RDX concentration. An electron-transfer donor–acceptor mechanism is proposed for the observed fluorescence quenching. On the basis of these results, candidature of dye doped porous sol–gel silica as a sensor for explosive detection seems to be promising.

The development of polymer laser-active media with improved performances

The influence of modification of organic glass by additives new derivatives of thiazole and thiourea on the spectral-fluorescent and lasing characteristics of the Rhodamine 6G laser dye has been investigated. For the sample modified by additive - N-(4-carbomethoxy- 5-phenyl-thiazol-2-yl)-N'-phenylthiourea taken in amounts of 0.01 mol% the maximum rise of the absorption and fluorescence intensity to compare with the unmodified sample 1.3 and 2.3 times, respectively, was detected. The 8.3 times more lasing energy, and the 7.3 times higher laser photostability has been achieved.

Peculiarities of Lasing in Solutions of R6G with Agglomerated Metallic Nanoparticles

A physical interpretation is given for the experimentally observed substantial lowering of the lasing thresholds and the blue shift of the peak of the stimulated emission spectrum of a solution of the laser dye rhodamine 6G (R6G) with agglomerated silver nanoparticles. Results of a study of the influence of nonlinear thermal processes on the lasing of a solution of R6G with silver nanoparticles are presented. The dynamic range of the pump energies at which breakdown of the working medium does not take place under the influence of thermal processes is determined.

Unique photoactive nanocomposites based on rhodamine 6G/polymer/montmorillonite hybrid systems

ABSTRACTAn organo‐montmorillonite (MMT) complex [poly‐diallyldimethyl(PDDA)‐Kunipia F] with various loadings of polycation was modified with a laser dye Rhodamine 6G (R6G) to obtain a photofunctional hybrid materials for monitoring of dye‐polymer‐MMT nanocomposite interactions. The polymer‐MMTs were prepared in a colloidal state via ion‐exchange reaction. The content of polycation (PDDA) in suspensions varied from 20 mg to 1000 mg per 1 g of Kunipia F (KF) MMT. Dramatic changes was observed in the structure of PPDA‐MMT containing 200–300 mg of polymer per 1 g of KF, which was the saturation point of the polycation for this system. The PDDA molecules were able to suppress the formation of nonluminescent H‐aggregates and to enhance the overall luminescence properties. The PDDA/MMT nanocomposite systems are the novel ones that have not been studied before in order to prepare highly fluorescence hybrid systems. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2013, 51, 1672–1679