Investigations of Some Four-Field Parametric Interactions

E. B. Davies

David G. Sarkisyan, S O Sapondzhyan

An experimental investigation was made of a four-wave parametric interaction (FWPI) in a field of ultrashort optical pulses (λp ≈0.55 μ) acting on a 1S–1P0 two-level system of barium atomic vapor. It was observed that a pair of new frequencies ν3 and ν4 appeared as a result of FWPI, ν3 being close to ν'tps = 2νp – ν'sp and ν4 being close to ν'sp. This process was observed on approaching the resonance from the low-frequency side. When the resonance was approached from the high-frequency side, conical emission was recorded. It was found that a FWPI in a two-level system subjected to a strong pump field is governed by the third- and fifth-order nonlinear susceptibilities χ(3) and χ(5).

Loren R. Clifford

R. R. Badalian, Б. В. Крыжановский, David G. Sarkisyan

An investigation was made of a noncollinear transient four-wave parametric interaction in an atomic barium vapor subjected to the first and second harmonics of tunable neodymium-activated phosphate glass and YAG:Nd3+ lasers emitting picosecond pulses. Variation of the angle between the pump beams was used to control the characteristics of the signal and idler pulses. When the pump radiation was supplied only by a master oscillator, it was possible to generate relatively simply ultrashort pulses tunable near 0.98 μm. A comparison was made with a theory of transient four-wave parametric interaction, which was valid also in saturating pump fields.

M. P. DeFeo, Manuel A. Castellanos-Beltran, Adam J. Sirois +5 more

U. Hinze, Boris N. Chichkov, E. Tiemann +1 more

Summary form only given. Double-/spl Lambda/ level schemes offer rich possibilities to study the non-linear interaction of continuous resonant radiation fields with multi-level systems. Efficient four-wave mixing with up- and down-conversion has been demonstrated previously. We report on theoretical and experimental investigations related to four-wave difference-frequency mixing and parametric amplification. As a nonlinear medium Na/sub 2/ molecules produced in a sodium heatpipe are used.