INDEX luminescence intensity

When heat is produced in the sample after the photolytic flash, the refractive index of the liquid changes and the probe beam is deflected. The intensity of this probe beam measured by a photomultiplier tube placed behind the pinhole decreases as the temperature of the irradiated volume increases (then its density and its refractive index decrease). The total optical signal change is a measurement of all the heat produced in the sample, i.e. the sum of non-radiative transitions, chemical reactions and solvation energies. Luminescence does not contribute to this signal (nor does scattered light) and for this reason thermal lensing can be used to determine luminescence quantum yields. 

Optical biosensors can be defined as sensor devices which make use of optical principles for the transduction of a biochemical interaction into a suitable output signal. The biomolecular interaction on the sensor surface modulates the light characteristics of the transducer (i.e., intensity, phase, polarization, etc.), and the biosensing event can be detected by the change in diverse optical properties such as absorption, fiuorescence, luminescence or refractive index, among others. 

In nonpolar solvents, Eu chelates studied in the present work exhibited luminescence kinetics closely following the single exponential decay law over the intensity range of about three orders of magnitude. In agreement with the previous observations [5, 6], an increase in the refractive index of the nonpolar medium leads to a systematic decrease in the excited-state lifetime of the Eu ion. This effect is accounted for by the well-known refractive-index dependence of the radiative rate y where and are radiative rates in a dielectric medium and in vacuo, respectively, n is the refractive index of the medium, and/[ ) is the local-field correetion factor [4, 5]. 

Nonmetallic inorganic materials are widely used for optical purposes lenses, pigments, interference filters, laser hosts, luminescent coatings, displays, solar cells, fiber optics, lamp bulbs, and tubes. For optical applications use is made of the refractory index, light absorption, luminescence, and nonlinear optical behavior of materials. These are intrinsic but may depend on the concentration of impurities. Refraction index and optical absorptivity in insulators are atomic properties and are only indirectly related to the structure, but the structure affects the selection rules and the term splitting in the atomic chromophores. The coordination number determines the intensity and wavelength of absorption and... 

Optical devices Changes in light intensity, color, or emission spectra Absorbance Reflectance Luminescence Refractive index Optothermal effect Light scattering (Raman scattering, plasmon resonance)... 

Polyvinyl alcohol oxidation affected by hydrogen peroxide in the presence of ferrous sulfate (II) in aqueous solutions is accompanied by chemiluminescence in the visible spectrum (Fig. 23.6). In Fig. 23.6, it is seen that luminous intensity passes through a maximum. This facts shows that luminescence emitter is an intermediate product of liquid-phase PVA oxidation. The analysis of the kinetic curve of chemiluminescence intensity showed that its initial part is well linearized (Fig. 23.6, the correlation index r = 0.998) in the equation coordinates... 

The increase in luminescence emission intensity of the complexed Tb and Eu ions incorporated into sol-gel-based zirconia ormocer films is a result of energy transfer from the ligands to the RE ions. The matrix chosen in this work possesses high mechanical and thermal stability and a high refractive index due to zirconium oxide. 

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