Nature of "instantaneous" luminescence due to interaction of SiF4 molecules with a strong infrared field

A spectral investigation was made of the luminescence resulting from the interaction of a strong infrared field (generated at different frequencies by a CO₂ laser) with SiF₄ molecules. The "instantaneous" state of the luminescence was not due to possible dissociation products of SiF₄ but the later stage was due to the SiF radicals. The "instantaneous" luminescence spectrum was attributed to transitions between excited electronic states of the SiF₄ molecule.