POLARIZATION OF SPONTANEOUS AND STIMULATED RADIATION OF COMPLEX-MOLECULES IN THE GAS-PHASE

Polarized luminescence, superluminescence and laser emission of POPOP, TOPOT and p-quaterphenyl vapours caused by optically induced orientational anisotropy of excited molecules have been established and studied. The polarization is observed over the range of densities from the low-density limit, giving the free molecules, up to 0.8 of the liquid state density. In the free molecule limit the highest degree of fluorescence polarization equals 11%, being close to theoretically calculated value, and polarization of laser emission reaches 100%. Investigation has been carried out of polarization of superluminescence and stimulated emission on foreign gas pressure and on self-concentration of vapours. This anisotropy is concluded to be valuable source of information on relaxational and structural characteristics of polyatomic molecules in the gas phase. © 1979.