In a recent article1to which we shall refer as [S&B], a two-photon laser was proposed and analyzed. This device consists of a cavity resonant at frequency vAand containing ions of type B with an inverted population NB/V between levels separated by an energy difference hvBsuch that vB= 2vA; it is necessary that the system not lase at vB, which criterion can be satisfied by low reflectivity of the cavity at frequency vB, by strong parasitic absorption in the laser material near frequency vB, or preferably by a choice of ion such that the transition vBis highly forbidden to a single-quantum process. The authors of [S&B] thus show that a certain priming density of photons of frequency vAwill provoke the simultaneous emission from the inverted population NBof pairs of photons vAat a rate exceeding the cavity loss,t he process diverging until the population inversion is eliminated.In a recent article1to which we shall refer as [S&B], a two-photon laser was proposed and analyzed. This device consists of a cavity resonant at frequency vAand containing ions of type B with an inverted population NB/V between levels separated by an energy difference hvBsuch that vB= 2vA; it is necessary that the system not lase at vB, which criterion can be satisfied by low reflectivity of the cavity at frequency vB, by strong parasitic absorption in the laser material near frequency vB, or preferably by a choice of ion such that the transition vBis highly forbidden to a single-quantum process. The authors of [S&B] thus show that a certain priming density of photons of frequency vAwill provoke the simultaneous emission from the inverted population NBof pairs of photons vAat a rate exceeding the cavity loss,t he process diverging until the population inversion is eliminated.

IBM Journal of Research and DevelopmentJul 1, 196423 citations

Population Inversion in a High-Energy Collision Excited in Ion Beam

W. Shearer-Izumi

Physics of Electronic and Atomic Collisions: ICPEAC IXJan 1, 19750 citations

Super Radiant Narrowing in Fluorescence Radiation of Inverted Populations

Amnon Yariv, R. C. C. Leite

The effect of resonance reabsorption of fluorescent radiation on the spectral distribution has been considered as early as 1913 by Laudenburg and Reivhe [1]. Schein [2] and Zemansky [3] recognized that the reabsorption causes a broadening of the light emitted by resonance lamps. \n \nIn this note we report an experimental and theoretical study of the complementary effect, i.e., of resonance radiation originating in a system in which the population of the upper level of the resonance transition is made to exceed that of the lower one (inverted population system).The effect of resonance reabsorption of fluorescent radiation on the spectral distribution has been considered as early as 1913 by Laudenburg and Reivhe [1]. Schein [2] and Zemansky [3] recognized that the reabsorption causes a broadening of the light emitted by resonance lamps. \n \nIn this note we report an experimental and theoretical study of the complementary effect, i.e., of resonance radiation originating in a system in which the population of the upper level of the resonance transition is made to exceed that of the lower one (inverted population system).

Journal of Applied PhysicsNov 1, 196376 citations

Four-wave parametric mixing in optically inverted barium ions

Richard R. Freeman, Jeffrey Bokor A, William E. Cooke

Optically inverted barium ions in the $6{p}_{(\frac{1}{2})}$ excited state served as the nonlinear medium for doubly resonant four-wave parametric generation of coherent radiation at 167 nm. The excited barium ions were produced via selective autoionization. Stimulated-emission photons at 650 nm corresponding to the $6{p}_{(\frac{1}{2})}\ensuremath{-}5{d}_{(\frac{3}{2})}$ transition were mixed with input 451-nm laser photons turned to the $6{p}_{(\frac{1}{2})}\ensuremath{-}6{f}_{(\frac{5}{2})}$ two-photon resonance to produce the 167-nm output photons.Optically inverted barium ions in the $6{p}_{(\frac{1}{2})}$ excited state served as the nonlinear medium for doubly resonant four-wave parametric generation of coherent radiation at 167 nm. The excited barium ions were produced via selective autoionization. Stimulated-emission photons at 650 nm corresponding to the $6{p}_{(\frac{1}{2})}\ensuremath{-}5{d}_{(\frac{3}{2})}$ transition were mixed with input 451-nm laser photons turned to the $6{p}_{(\frac{1}{2})}\ensuremath{-}6{f}_{(\frac{5}{2})}$ two-photon resonance to produce the 167-nm output photons.

Physical Review ANov 1, 198215 citations

Short pulse-induced population inversion for continuum-continuum transitions

Jerlyn L. Swiatlowski, W. Leoński

AIP conference proceedingsJan 1, 19900 citations

Optically inverted barium ions in the

6{p}_{(\frac{1}{2})}

excited state served as the nonlinear medium for doubly resonant four-wave parametric generation of coherent radiation at 167 nm. The excited barium ions were produced via selective autoionization. Stimulated-emission photons at 650 nm corresponding to the $6{p}_{(\frac{1}{2})}\ensuremath{-}5{d}_{(\frac{3}{2})}$ transition were mixed with input 451-nm laser photons turned to the $6{p}_{(\frac{1}{2})}\ensuremath{-}6{f}_{(\frac{5}{2})}$ two-photon resonance to produce the 167-nm output photons.