共查询到10条相似文献,搜索用时 187 毫秒
1.
V. A. Donchenko Al. A. Zemlyanov N. S. Panamarev V. A. Kharenkov 《Russian Physics Journal》2011,54(4):493-499
Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions
in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and
aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the
optical properties of the laser beam propagation channel are transformed when low-power (20 mW) cw laser radiation passes
through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle
density in the laser beam center, on which diffraction of laser radiation is observed. 相似文献
2.
《Infrared Physics & Technology》2000,41(2):133-136
Fluorescence of solutions of rhodamine 6G in the form of single drops of millimeter sizes excited by the intense IR and visible laser radiation (with duration of laser pulses of ∼10 ns and wavelengths of 1064 and 532 nm) is experimentally investigated. It was found that the power thresholds of fluorescence excitation for drops comprising the dissolved dye are, by an order of magnitude, less than for a cell with dissolved dye. The dichromatic drop fluorescence has been revealed, which is manifested through the occurrence of two maxima in the fluorescence spectrum of drops comprising dissolved rhodamine 6G. The first maximum coincides with that of the dye fluorescence spectrum, while the second maximum is shifted by ∼1000 cm−1 and is on the slope of the fluorescence line profile. It is shown that the duration of drop fluorescence does not exceed the duration of the exciting pulse. 相似文献
3.
V. N. Moiseyenko O. O. Guziy V. S. Gorelik M. P. Dergachov 《Optics and Spectroscopy》2008,105(6):919-923
The photonic dispersion, the group-velocity dispersion, the effective mass, refractive index, and the spectral distribution of the density of photonic states near the edge of the photonic stop band are numerically calculated in the one-dimensional model for photonic crystals based on synthetic opals. The fluorescence spectra of rhodamine 6G and 2,5-bis(2-benzoxazolyl)hydroquinone molecules infiltrated into a synthetic opal are measured. For both substances, it is observed that the spontaneous emission intensity in the range of the photonic stop band is appreciably suppressed. A blue shift of the fluorescence spectrum of rhodamine 6G molecules is revealed. Secondary emission of synthetic opals infiltrated with colloidal silver is observed in the Stokes range under excitation of opals by radiation at λ = 400 nm. The spectrum of the secondary emission is located in the range 450–590 nm, which contains the stop band and intervals near its edges. 相似文献
4.
The intensity-dependent transmission of picosecond ruby laser pulses of different duration through methanolic and ethanolic solutions of rhodamine B and rhodamine 6G is analysed. The transmission is affected by S0-S
n
two-photon absorption, by stimulated emission at the pump-laser frequency, by amplified spontaneous emission and by excited-state absorption. Various parameters involving the two-photon absorption dynamics are determined by comparing experiments with numerical simulations. 相似文献
5.
Kopylova T. N. Samsonova L. G. Zemlyanov A. A. Ushakova V. G. Mayer G. V. Donchenko V. A. Vasil'ev A. V. 《Russian Physics Journal》2002,45(4):336-340
The possibility of remote atmospheric detection of an ecotoxicant (asymmetric dimethylhydrazine) by means of a fluorescing mark is considered. The effect of asymmetric dimethylhydrazine on the spectral-luminescent properties of rhodamine 6G, nonsubstituted rhodamine, and amino- and hydroxysubstituted derivative of phenalenone is studied. It is shown that the molecules containing amino groups change their spectral properties and lose emitting properties in the presence of dimethylhydrazine. The hydroxysubstituted derivative of phenalenone in dimethylhydrazine generates laser radiation when pumped by a Nd:YAG-laser and shows the stimulated fluorescence effect in aerosols. 相似文献
6.
Laser-Induced Silver Nanoparticles Deposited on Optical Fiber Core for Surface-Enhanced Raman Scattering 下载免费PDF全文
We report on surface-enhanced Raman scattering (SERS) probes based on silver nanopaxtieles which axe deposited on the core of the distal end of standard single mode fibers, by means of the very simple, versatile, and lowcost laser-induced nanoparticle technique. The morphological features of the Ag nanoparticles vary according to the experimental conditions such as laser power, illumination time, and concentration of the reaction solution. The SERS activity of the probes is demonstrated with the detections of rhodamine 6G aqueous solutions. The detections are made from both ends of the probes, i.e., in direct detection mode from the end with nanoparticles and in remote detection mode from the distal end, respectively. 相似文献
7.
The transmission of focused laser radiation with power densities in the range (1–250) MW/cm2 through solutions of laser dyes (substituted paraterphenyls and rhodamine 6G) is investigated. The dependence of the transmission on the exciting radiation power density is measured, and numerical modeling is used to estimate the lifetime of the fluorescent state of molecules and the influence of stimulated emission on the lifetime of the S
1 state. The effect of scattering on the transmission of highly absorbing media is demonstrated under nanosecond excitation. 相似文献
8.
J. R. Heldt J. Heldt M. Obarowska B. Mielewska J. Kamiński 《Journal of fluorescence》2001,11(4):335-342
The spectroscopic and laser parameters of a mixed donor (10-phenyl-9-acetoxyanthracene derivations)-acceptor (rhodamine 6G) solutions have been determined. The studies performed show that rhodamine 6G is responsible for the lasting of the mixed solution. The 10-phenyl-9-acetoxyanthracene added to the R6G lasing solution decreases the spectral range of lasing and the gain value, G(), of the solution. These changes in the lasing parameters are caused by electron energy transfer processes of different types. The results of fluorescence studies of the mixed donor-acceptor solutions point out that the long-range dipole-dipole interaction mechanism of the static quenching accompanied by the formation of nonemitting complexes in the dye mixture is responsible for the noted lasing and fluorescence changes. 相似文献
9.
10.
We measure the fluorescence quantum yields (q
fl) of complexes of Al, Sc, Y, In, Lu, and Gd with dibenzoylmethane in aqueous and isopropanol solutions at different concentration
ratios of ions and dike-tone. We reveal that, for the examined solutions, qfl of complexes varies more than by two orders of magnitude under the influence of the heavy atom. It is found that a considerable
decrease in q
fl and τfl of ligands of complexes of listed ions caused by the influence of heavy atoms weakly affects the intensity of sensitized
fluorescence of Nile red and rhodamine 6G molecules introduced into nanoparticles from these complexes in aqueous solutions.
The revealed result is explained by the comparability of the singlet exciton free path length and the dimension of nanoparticles
under study. We show that a lower fluorescence intensity of heavy metal complexes makes it possible to decrease its contribution
in the range of the cofluorescence maximum of rhodamine 6G and to monitor the occurrence of the dye in the aqueous solution
down to the concentration of 0.05 nM. We show that, in nanoparticles from Eu complexes, further fluorescence quenching of
dibenzoylmethane is observed, as well as the appearance of cofluorescence of rhodamine 6G, the intensity of which is comparable
with its intensity in nanoparticles of other complexes. The appearance of this cofluorescence cannot be explained by the existence
of S-S energy migration. 相似文献