A three-dimensional vector model for the three-state system interacting with a bichromatic electromagnetic field is presented. The model is used to relate and provide a visual representation for two topics of current interest, electromagnetically induced transparency and adiabatic population transfer. (C) 1996 Optical Society of America

Two related methods for determining the Lorentzian linewidth of one- and two-photon transitions in an atomic medium are presented. in each method, the linewidth is determined by the relationship between the energy transmission and propagation delay of a series of laser pulses sent through the medium; precise knowledge of the laser frequency, atom density, or matrix elements is not required.

An external-cavity diode laser is used to seed a pulsed Ti:sapphire laser from 839 to 860 nm. Because this wavelength range is off the gain peak of Ti:sapphire, a bandpass filter is used in the cavity to permit seeded operation. We describe a tunable, wide-field-of-view birefringent filter especially suited for use in seeded lasers. Measurements of the ratio of unseeded to seeded output as a function of seed power are also presented and demonstrate an approximately reciprocal dependence on the seed power.

Electromagnetically induced transparency is applied to isotope discrimination. By adjusting the intensity of a coupling laser, one isotope is made resonantly opaque while another is rendered transparent to a probe. Experimental results are shown in isotopically enriched atomic lead, where 0.03% Pb-207 is clearly seen against a background of Pb-208.

We demonstrate a method for eliminating optical self-focusing and defocusing for a copropagating pair of intense laser beams whose frequencies differ by a Raman resonance. The lasers force the atoms of the medium into a population trapped state, thereby eliminating their contribution to the nonlinear refractive index.

We describe the temporal and spatial dynamics of propagating electromagnetically induced transparency pulses in an optically thick medium. Results include pulse velocities as slow as $c/165$ with 55% transmission, strong-probe-field effects, and the observation of near diffraction-limited transmitted beam quality.

When narrowband probe radiation traveling through a bulk material is tuned to a resonance transition from the ground state of the material, the radiation experiences strong attenuation and dispersion. Recent theoretical1 and experimental2,3 work has demonstrated that this attenuation can be almost completely eliminated by the addition of a strong coherent coupling radiation field coupling a third state to the upper state of the resonance transition. In effect, a destructive quantum interference blocks the excitation of the atom from its ground state and renders the atom transparent. We term this effect “electromagnetically induced transparency.”

We report the observation of an ultra-slow group velocity of c/126 and transparency in lead vapor in the presence of a transparency-inducing field.

An atomic transition that has been made transparent by applying an additional electromagnetic field exhibits a rapidly varying refractive index with zero group velocity dispersion at line center. A 10-cm-long Pb vapor cell at an atom density of 7 x 10(15) atoms/cm3 and probed on its 283-nm resonance transition has a calculated optical delay of 83 ns [(c/V(G)) = 250].