A. Flusberg

Optical second-harmonic generation in atomic thallium vapor

Abstract We observe coherent optical second-harmonic generation in atomic thallium vapor when the fundamental is tuned to half the resonance frequency of the following transitions: 6 2 P 1 2 − 7 2 P 3 2 and 6 2 P 1 2 − 8 2 P 3 2 in the presence of a static magnetic field; and 6 2 P 1 2 − 7 2 P 1 2 , 6 2 P 1 2 − 8 2 P 1 2 in the absence of any external field .

Observation of Dicke superradiance at 1.30 μm in atomic Tl vapor

Abstract Dicke superradiance in the 1.30-μm 7 2 P 1 2 → 7 2 S 1 2 transition in Tl vapor has been induced by a 379.1-nm pulsed dye laser. Superradiant delays of up to 12 nsec have been observed.

Spontaneous Raman scattering in atomic thallium vapor

Abstract Using a cw argon-ion laser, we have measured the spontaneous Raman scattering cross section, σ R , and linewidth in atomic thallium vapor. For 4880-A excitation, σ R = 1.6 × 10 −27 cm 2 . We observe no pressure broadening of the Raman line at vapor pressures to 100 torr.

Hyperfine structure of the 72P states of thallium by doppler-free two-photon absorption☆

Abstract Using Doppler-free two-photon absorption, we have measured the hyperfine splittings (hfs) and isotope shifts of the 7 2 P states of natural thallium. We obtain A(7 2 P 3 2 = 310(8) Mhz , and A(7 2 P 1 2 = 2131(60) Mhz . Surprisingly, the 7 2 P 3 2 state hfs is larger than that of the 6 2 P 3 2 state.

Electronic stimulated Raman scattering in atomc thallium vapor

Abstract Non-resonant stimulated electronic Raman scattering has been observed in atomic thallium vapor. The Stokes shift is 7793 cm -1 . Approximately 12% of the laser photons were converted. The Stokes polarization was measured and laser-beam self-focusing was observed.

Cooperative Effects in Atomic Metal Vapors

In this article we present a summary of some of the preliminary work we have done at Columbia University on the observation of Dicke superradiance in atomic metal vapors. In addition we discuss optical three-wave mixing, a novel effect which is often observed to occur simultaneously with the Dicke superradiance.