Limits of Light Absorption

E. U. Condon

Christian Drago, John E. Sipe

We calculate the two-photon absorption for squeezed light pumped by a continuous-wave source, near or far from resonance, beyond the low intensity limit. For typical two-photon absorption parameters, we find no squeezed light enhancement.

Irwin Tobias, Peter M. Rentzepis, Nandor L. Balazs

Ohr Lahad, Ran Finkelstein, Omri Davidson +3 more

The resonant absorption of light by an ensemble of absorbers decreases when the resonance is inhomogeneously broadened. Recovering the lost absorption cross section is of great importance for various applications of light-matter interactions, particularly in quantum optics, but no recovery mechanism has yet been identified and successfully demonstrated. Here, we formulate the limit set by the inhomogeneity on the absorption, and present a mechanism able to circumvent this limit and fully recover the homogeneous absorption of the ensemble. We experimentally study this mechanism using two different level schemes in atomic vapors and demonstrate up to fivefold enhancement of the absorption above the inhomogeneous limit. Our scheme relies on light shifts induced by auxiliary fields and is thus applicable to various physical systems and inhomogeneity mechanisms.

Robert William Ditchburn, P. J. Jutsum, Geoffrey V. Marr

Abstract The first section of this paper is an account of some experiments on the absorption of light in sodium vapour from the series limit at 2412 Å to about 1600 Å (an energy difference of 2·6 eV). The absorption cross-section at the limit is 11·6 ± 1·2 x 10-20 cm2. The cross-section decreases giving a minimum of 1·3 ± 0·6 x 10-20 cm2 at 1900 Å and then increases to 1600 Å. A theoretical calculation by Seaton based on the dipole-length formula gives good agreement with the experiments at the series limit and also correctly predicts the wave-length for the minimum, but it predicts a significantly lower absorption at the minimum. The experiments described in the first section of the paper conclude a series on the absorption of light in the alkali metals. The second section consists of a general discussion of the results of these experiments and of their relation to theoretical calculations. There is good agreement between theory and experiment except in regard to the magnitude of the absorption at the minimum.

Hans Joachim Eichler, Jürgen Eichler, Oliver Lux