Degenerate four-wave mixing spectra in a two-level atomic system with phase-modulated time-delayed coherent fields

Journal Article · Mon Aug 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.72.023813· OSTI ID:20718212

Mills, A K; Elliott, D S ^[1]

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1. School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

We study phase-conjugate degenerate four-wave mixing (DFWM) in an optically pumped, two-level atomic system (the 3s {sup 2}S{sub 1/2}, F=2, m{sub F}=2{yields}3p {sup 2}P{sub 3/2}, F=3, m{sub F}=3 transition in a diffuse, collision-free, thermal beam of sodium) using phase-modulated laser beams. In this investigation, we study the detailed line shape of the four-wave mixing signal as a function of the temporal delay between the probe field and the pump fields at different intensities of the cw pump waves and modulation frequencies. We show that phase modulation of the pump and probe beams leads to strong amplitude modulation of the phase-conjugate beam and report excellent agreement between our experimental observations of the DFWM spectra and the results of numerical calculations. Our numerical results suggest an enhancement of the 'local' DFWM signal when the sidebands of the phase-modulated laser are resonant with dressed-state transitions, but that this resonance is less obvious in the total signal generated. We also show that the complex line shapes depend sensitively upon the delay of the probe beam, with the peak DFWM signal occurring when the probe beam is advanced compared to the pump beam.

• OSTI ID: 20718212
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AMPLITUDES
ENERGY LEVELS
FREQUENCY MIXING
LASER RADIATION
MODULATION
OPTICAL PUMPING
RESONANCE
SODIUM
TIME DELAY