INTRACAVITY 2ND-HARMONIC GENERATION USING AN ELECTROMAGNETICALLY INDUCED TRANSPARENCY

We analyze the quantum-fluctuation properties of second-harmonic radia tion generated in the high-efficiency conversion process used in a rec ent experiment by Hakuta, Marmet, and Stoicheff [Phys. Rev. Lett. 66, 596 (1991)]. We extend their work by studying the second-harmonic gene ration inside an optical cavity. The active medium inside the cavity i s modeled by three-level atoms with degenerate upper levels (1s, 2p, a nd 2s states of atomic hydrogen) interacting with a strong constant el ectric field. An enhancement of the conversion efficiency and a reduct ion of the added noise are found as a result of an electromagnetically induced transparency. We show that the scheme is capable of producing light in a squeezed or coherent state close to a minimum-uncertainty state with a large mean amplitude.