Abstract
The optical Autler-Townes effect (dynamic Stark splitting) induced by a single-mode CW dye laser has been observed in neon gas with a cascade level scheme and a He-Ne probe beam. The splitting is found to be proportional to the square root of the saturating laser power and independent of the detuning. The existence of two Rabi nutation frequencies due to level degeneracy is clearly shown by changing the polarization axis of the probe beam.