Investigation of the spectral characteristics of a dye laser with modes locked to atomic absorption lines

It is shown that a dye laser with forced mode locking and intracavity neon-filled discharge tube may be used for selective intracavity laser spectroscopy. Locking, stabilization of the position, and narrowing of the locked mode band were observed near the neon absorption line λ₀. It was found that one of the possible mechanisms for these effects may be diffraction by an optically induced refractive index grating in the material placed in the laser resonator. It was established that intracavity interaction between the laser radiation and this grating results in self-locking of the radiation to two wavelengths symmetric with respect to λ₀. As a result of competition in the active medium, only one of these frequencies may be observed in the emission. It was shown that the spectral position of the locked frequencies may be altered by altering the absorbing atom concentration and also by means of a longitudinal magnetic field applied to the intracavity discharge cell.