Continuously tunable sum-frequency generation involving sodium Rydberg states
Robert W. Boyd, Daniel J. Gauthier, Jerzy S. Krasiński +1 more
Broadly tunable sum-frequency generation has been observed in a vapor of atomic sodium in the presence of a dc electric field. This field induces a\chi^{(2)}nonlinearity which is resonantly enhanced when the sum frequency corresponds to the energy separation between the ground state and an atomic Rydberg state. In a vapor of number density4 \times 10^{14}cm-3, we obtain an energy conversion efficiency as large as3 \times 10^{-4}and a\chi^{(2)}as large as1.2 \times 10^{-8}ESU. We have also observed sum-frequency generation in the absence of an applied dc field, and we relate these observations to mechanisms that have been proposed to explain this effect.
IEEE Journal of Quantum Electronics•Sep 1, 1984•13 citations