Optical transition probability

Matsuda and Hata [287] have argued that the species that are detectable using OES only form a very small part (<0.1%) of the total amount of species present in typical silane deposition conditions. From the emission intensities of Si and SiH the number density of these excited states was estimated to be between 10 and 10 cm", on the basis of their optical transition probabilities. These values are much lower than radical densities. lO " cm . Hence, these species are not considered to partake in the deposition. However, a clear correlation between the emission intensity of Si and SiH and the deposition rate has been observed [288]. From this it can be concluded that the emission intensity of Si and SiH is proportional to the concentration of deposition precursors. As the Si and SiH excited species are generated via a one-electron impact process, the deposition precursors are also generated via that process [123]. Hence, for the characterization of deposition, discharge information from OES experiments can be used when these common generation mechanisms exist [286]. 

We are concerned with the dynamics of a molecule after optical excitation. If the state we excited is coupled only to the radation field, we will only see the exponential decay to that field by spontaneous emission, and this is too well known to warrant our interest. It is therefore necessary that the state we excite is coupled to other states. We then arrive at the conventional model for radiationless transitions a light (optical transition probability carrying) state s> coupled to a more or less dense manifold of background states fc>. In pyrazine, s> is the lBiu state and fc> is the set of vibronic states arising from the 3B3u state. In addition, the state s> may be coupled to another... 

We are interested in the part c,(t), which determines the behavior of the fluorescence in time or its Fourier transform c,((o), which will determine the absorption spectrum, since only the state s> carries optical transition probability. 

A rather different model for the trapped electron in alkane glasses has been proposed recently by Funabashi and Moruyama [151]. The excess electron is described in the tight-binding approximation in which its wavefunction is expressed as a linear combination of the wavefunctions for the individual negative ions. Optical transition probabilities between the lowest ground state and all the other states were computed. The calculated absorption spectrum is in qualitative agreement with the experimental one. More results and theoretical developments are needed in the field before a definite conclusion can be reached. 

ODMR is as a rule possible when an optical transition probability coupled to Ti depends on the orientation of the spin when for example the phosphorescence probabilities of the three components of the triplet state ( T ), Ty), and Tz) at Bo = 0 or T+), I To), and T ) at Bq 0) are different. Frequently, the sensitivity of optical detection is much greater than that of detection via the microwave absorp-... 

I. Meroz (Ed.) Optical Transition Probabilities. A Representative Collection of Russian Articles (Israel Program for Scientific Translations, Jerusalem 1962)... 

Na2 molecules on the transition X S+(v"=0, J"=28) -+ B IIy(v =3, J =27). Since the optical transition probability depends on the hfs components of the lower and upper states, the depletion of the lower levels ijj) differs for the different hfs components. The RF transitions change the population distribution and affect the monitored LIF signal. The hfs constant for the rotational level was determined to be 0.17 0.03 kHz( ) while the quadru-pole coupling constant was found to be eqQ = 463.7 0.9 kHz. 

Contrary to energy transfer between a couple of rare-earth ions, where the transfer probabilities can be obtained from optical transition probabilities using the Judd-Ofelt approach, in the present case the transfer probabilities cannot be predicted theoretically, as the optical transitions in the donor ions depend strongly on the ligand field and our present theoretical techniques do not allow a priori calculation of these transitions in the condensed phase. 

Light emitters based on nitride semiconductors typically consist of [0001]-oriented quantum wells (QWs) [1] where the quantum confinement Stark effect (QCSE) is caused by piezoelectric and spontaneous polarizations, which lower the optical transition probability [2, 3]. To circumvent this issue, several groups have tried to fabricate InGaN/GaN and GaN/AlGaN QWs on nonpolar planes such as the 1100 plane (m-plane) [4] and the (1120) plane (a-plane) [5-7]. However, owing to the difficulty in growing high-quality crystals in nonpolar directions, the layers contain numerous nonradiative recombination centers. 

From a reading of this chapter, which methods do you find are best suited, in terms of accuracy and economy of time, for computation of the following properties of CPs bandgaps band structures band structure evolutions rotational barriers UV-Vis-NIR absorption spectra far-IR absorption and Reflectance spectra Pauli susceptibility optical transition probabilities (intensities). 

Ostrovsky, V.I. and Penkin, N.P. (1957). Optical transition probabilities (ed. I. Meroz) Vol.I. p.332, Israel Program for Scientific Translations, S. Monson, Jerusalem. 

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