Doppler-free saturation fluorescence spectroscopy of Na atoms for atmospheric application.

The well-known theory of absorption and fluorescence is briefly reviewed in a systematic manner for the Na D transitions. The resulting formalism is applied to simulation of Doppler-free saturation fluorescence spectra. With only one adjusting parameter, the nonradiative rate chosen to represent the time a thermal atom takes to move across the laser beams, the simulated Doppler-free spectra match the measured ones well for both D(1) and D(2) transitions over one decade of excitation intensities. Relative to the weighted center of the six D(2) hyperfine transition lines, the frequencies of the dominant Doppler-free features have been determined from a simulated spectrum to within ±0.1 MHz to be -651.4, 187.8, and 1068.0 MHz, respectively, for D(2a), crossover, and D(2b) resonances. These features may be used as accurate frequency references for atmospheric spectroscopy. They are essential for the operation of the newly developed narrow-band Na fluorescence lidar for wind and temperature measurements in the mesopause region.

[1]  T. Hänsch,et al.  High-Resolution Saturation Spectroscopy of the SodiumDLines with a Pulsed Tunable Dye Laser , 1971 .

[2]  A. Schawlow,et al.  Laser spectroscopy using beam-overlap modulation. , 1985, Optics letters.

[3]  M. Feld,et al.  Saturation spectroscopy with laser optical pumping in atomic barium , 1980 .

[4]  S. A. Lee,et al.  Precision Wavelength Measurements and New Experimental Lamb Shifts in Helium , 1983 .

[5]  J. Lankard,et al.  FREQUENCY‐LOCKING OF ORGANIC DYE LASERS TO ATOMIC RESONANCE LINES , 1969 .

[6]  J. Mulders,et al.  Experimental comparison of two Doppler-free detection methods with a new technique: Differential saturation spectroscopy , 1985 .

[7]  M. Levenson,et al.  Hyperfine Interactions in Molecular Iodine , 1972 .

[8]  Chester S. Gardner,et al.  Two-frequency Lidar technique for mesospheric Na temperature measurements , 1990 .

[9]  W. Fairbank,et al.  Measuring the velocity of individual atoms in real time. , 1978, Optics letters.

[10]  A. Schawlow,et al.  Saturation spectroscopy in molecular iodine by intermodulated fluorescence , 1972 .

[11]  J. R. Yu,et al.  Lidar-observed temperature structures and gravity-wave perturbations of the mesopause region in the springs of 1990–1992 over Fort Collins, CO , 1993 .

[12]  W. Fairbank,et al.  Detection of individual atoms in helium buffer gas and observation of their real-time motion. , 1980, Optics letters.

[13]  A. Schawlow,et al.  High-contrast Doppler-free transmission spectroscopy. , 1986, Optics letters.

[14]  S. A. Lee,et al.  Continuous-wave Rayleigh-Brillouin-gain spectroscopy in SF(6). , 1987, Optics letters.

[15]  Chu,et al.  rf spectroscopy in an atomic fountain. , 1989, Physical review letters.

[16]  Theodor W. Hänsch,et al.  Doppler-Free Laser Polarization Spectroscopy , 1976 .

[17]  G. Bjorklund,et al.  Frequency-modulation spectroscopy: a new method for measuring weak absorptions and dispersions. , 1980, Optics letters.

[18]  H. Walther,et al.  High-resolution spectroscopy with and frequency stabilization of a cw dye laser , 1973 .

[19]  H. Moosmüller,et al.  Equal intensity and phase contours in focused Gaussian laser beams , 1991 .

[20]  S. Nakayama.  Doppler-free laser spectroscopic techniques with optical pumping in D 1 lines of alkali atoms , 1985 .

[21]  H Latifi,et al.  High-spectral-resolution fluorescence light detection and ranging for mesospheric sodium temperature measurements. , 1992, Applied optics.