Initial Photon Number Research Articles

Temperature effects on energy pooling in laser CO2 multiphoton dissociation

Temperature effects on collision induced energy pooling is discussed. The probability that a molecule will have energy above a threshold value E0 is calculated for 300 and 1000 K, different initial distributions, and E0 = 30 and E0 = 60 kcal/mol. Some of the distributions are truncated at E0. It is found that energy pooling does take place and that the fraction of molecules transported above E0 depends on the initial energy distribution, temperature, and number of photons absorbed as well as the number of degree of freedom.

The Density Matrix for Single‐mode Light after k‐Photon Absorption

AbstractIn order to continue and generalize the studies of the density matrix of a light field undergoing k‐photon absorption, in this paper we put the emphasis on the off‐diagonal elements. The solution obtained earlier for the diagonal elements describing the photon statistics can be found as a special case but will not be discussed again. The general solution calculated by recursion shows an asymptotic behaviour if the initial photon number is sufficiently high. Only the initial phase information survives. Illustrating the solution we start with coherent light and a generalized coherent state.

Exact analytical solution for the change of the photon statistics due tok-photon absorption

For unsaturatedk-photon absorption the exact solution of the master equation for the diagonal elements is presented. This solution is found by Laplace-transformation and recursion. It has the form of a double sum over the initial values. Commuting the order of summation we then show, that fork≧2 the photon distribution does not depend on the initial distribution if the initial mean photon number is sufficiently high and the square of the resulting photon number is small against the initial photon number.

Change of the photon statistics by one-photon absorption and by simultaneous one-photon and two-photon absorption

With the help of the generating function we investigate the change of photon statistics due to one-photon absorption. Photon distributions with antibunching approach by this process the Poisson distribution. In a second part we consider the simultaneous action of one-photon and two-photon absorption. We present the exact solution and the asymptotic state in the limit of great initial photon numbers.

Some remarks on saturation of amplified spontaneous emission

Analytical (approximate) solution of rate equations for amplified spontaneous emission in a two-level system, in the case of ’’fast’’ pumping, shows the mutual dependence of some parameters characterizing amplification and saturation, such as critical time (or critical length), saturation (or peak) time, and peak power. The spontaneous emission can be accounted for by an equivalent number of initial photons. These results are compared with numerical computer solutions for the N2 laser.

Veränderung der photonenstatistik eines beliebigen anfangszustandes durch zwei-photonen-absorption

Assuming high enough initial photon numbers two-photon absorption is shown to produce fields with the same photon statistics for arbitrary initial fields.