Effect of extraneous gases on the generation of coherent radiation by vapors of complex organic compounds

Lasing of Vapours of Complex Organic Compounds

“…One can tune the frequency of the radiation of a laser based on vapours of complex molecules by varying the pressure of the added gas [4,6,41]. Figure 4 shows the laser spectra of POPOP and TOPOT vapours.…”

“…The second harmonic of a ruby laser in the longitudinal mode was used as the pump. The vapours of these materials without an added gas generate at temperatures of 513-573 K bands with peak wavelengths 2A a the fact that the absorption and fluorescence spectra, and hence also the stimulated emission spectra, are shifted to longer wavelengths with increasing pressure of the added gas [42,43].The shift of Alax into the long-wavelength region has been traced [4] as the active medium was gradually changed from the rarefied vapour through the critical state into the solution. Figure 5 illustrates the shift of the peaks of the laser bands of POPOP and TOPOT and of the band of the 0-1 fluorescence spectrum of POPOP as a function of the concentration of pentane.…”

“…According to the literature, more than 200 organic compounds have been examined for the existence of laser action in the gas phase; of these more than 70 were found to exhibit the phenomenon [1,4,5,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Pumping was carried out by several different means: with second-harmonic radiation from a ruby laser (Ap = 347 nm) or a nitrogen laser (337 nm), with the third and fourth harmonics from a neodymium laser (357 and 266nm), and the radiation (308 and 248nm) from an excimer laser.…”

“…In 1974 there appeared several reports [3][4][5][6][7] of laser action with optical pumping in vapours of POPOP, 1,4-di[2-(5-n-tolyloxazolyl)]-benzene (TOPOT), dimethyl-POPOP, the properties of the radiation generated were also described. Since then have appeared a considerable number of papers on the theoretical study of the lasing capability of vapours of complex molecules, on the search for new classes of complex organic compounds that lase in the gas phase, and on the properties of the radiation generated by these lasers.…”