Transformation of spatial modulation of a light field into amplitude modulation in the interaction of a superposition of transverse modes of a He-Ne laser with iodine-127 vapors

The observation of "spatial-modulation" resonances of saturated absorption in the interaction of iodine-127 vapors with a superposition of frequency-n ondegenerate TEM01 and TEM10 transverse modes of a linear laser is reported . The modulation of the total radiation power of the probing wave, recorded at twice the beating frequency of transverse modes of the laser, is interp reted to be the result of the transformation of modulation of the spatial d istribution of the field into its amplitude modulation under the action of nonlinearly absorbing iodine vapors. Resonances of saturated absorption of the weak line R(127)11-5 of iodine-127 (633 nm) in an extracavity cell are observed by the method proposed. (C) 2000 MAIK "Nauka/Interperiodica".