Na(3 2P) sensitized Na2 emission spectra enhanced by polydimethylsiloxane vapors

D1 or D2 resonance excitation of atomic sodium in the presence of various polydimethylsiloxane vapors results in the emission of a structureless, broad band in the spectral range of 14500 to 11000 cm−1 attributed to A1Σu+→X1Σg+ emission of molecular Na2, promoted and modified by interaction with gaseous polydimethylsiloxane molecules. This unusual spectral feature was studied as a function of excitation frequency and laser power as well as a function of the vapor composition and density. Resonance excitation of potassium and rubidium atomic vapors in the presence of polydimethylsiloxane vapors also produce an enhanced broad band to the red of their atomic resonance transitions.