Pulsed frequency-modulation spectroscopy at 3302 Å

We report the first known demonstration of frequency-modulation spectroscopy outside the visible spectral region. Specifically, we report the use of second-harmonic generation on a frequency-modulated visible dye-laser beam to produce a frequency-modulated ultraviolet beam that is used to observe the Na 3S → 4P absorption at 3302 Å. © 1983 Optical Society of America.