Abstract

Optical phase conjugation in the hollow cathode lamp by degnerate four-wave mixing is a novel analytical laser spectroscopic method in which a laser beam is generated as the signal beam. With the use of a demountable hollow cathode discharge cell and a continuous-wave dye laser, the signal beam is clearly visible to the naked eye when 1 μg of sodium is placed inside the cathode cavity. Since the signal beam is a time-reversed replica of the probe laser beam, highly efficient optical signal detection can be performed with minimum optical background noise. Since the signal is Doppler-free with negligible Lorentzian broadening (30 Torr discharge pressure), it provides excellent spectral resolution. Sodium D₂ hyperfine lines of 3s ²S_1/2 (<i>F'</i> = 2) → 3p ²P_3/2 (<i>F</i> = 3) and 3s ²S_1/2 (<i>F'</i> = 1) → 3p ²P_3/2 (<i>F</i> = 0) were resolved. In addition to excellent spectral resolution and ease of signal detection, the technique also offers unique properties of optical phase conjugation.

Doppler-free continuous-wave phase-conjugate spectrum of SF₆ by resonant degenerate four-wave mixing at 10.6 μm

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Opt. Lett. 6(8) 383-385 (1981)

Vector phase conjugation by two-photon-resonant degenerate four-wave mixing

Michelle S. Malcuit, Daniel J. Gauthier, and Robert W. Boyd
Opt. Lett. 13(8) 663-665 (1988)

Optical phase conjugation of weak signals by using degenerate four-wave mixing

Irwin C. Winkler and Robert S. Mandra
Opt. Lett. 17(8) 568-570 (1992)

Phase conjugation by degenerate forward four-wave mixing

A. Khyzniak, V. Kondilenko, Yu. Kucherov, S. Lesnik, S. Odoulov, and M. Soskin
J. Opt. Soc. Am. A 1(2) 169-175 (1984)

Nearly degenerate four-wave mixing using phase-conjugate pump beams

Michael Winter and Peter P. Radi
Opt. Lett. 17(5) 320-322 (1992)