Photon emission rate

An alternative way to calculate the SLE spectrum is to expand the molecular density matrix to second order in the field and compute the time-dependent photon emission rate. The resulting expression is [23]... 

The photon emission rate at time t into mode s is the expectation value of fl , that is,... 

Is measured for Lumlnol In the liquid scintillation counter, any strongly quenched scintillation cocktail will produce an equivalent Lumlnol photon emission rate given by... 

An alternate approach is to note that in quantum mechanics, according to Fermi s golden rule [22], the decay probability for an excited atom, that is, the photon emission rate F, is given by... 

The photon emission rate of a fluorophore is determined by the intensity dependent excitation rate, the lifetime of the fluorophore and its quantum efficiency. The excitation rate and the fluorophore lifetime allow the calculation of the saturation of the fluorophore. The photon emission rate as well as bleaching rate is directly proportional to it. 

These equations are useful for studying time-resolved fluorescence, in which case an jnHHpnt pulse of time-dependent intensity I(t) induces a transient response with a decay constant F — Fr Fnr- For a short pulse of excitation at t = 0 the photon emission rate will decay exponentially as expf-F( for t>0. However, we will concentrate here on the steady-state case where both I and Ne re constant, nien. 

At should be reduced by 2 and 3 per cent respectively, is clearly desirable that the decay rates of these highly-ionized atoms should be measured to an accuracy of one per cent or better. This would determine whether or not the discrepancy noted above was significant. It would also provide a more accurate check of the two-photon emission rates which so far have only been calculated using non-relativistic wavefunctions. 

---