Light amplification in DNA-surfactant complex films stained by hemicyanine dye with immersion method

Organic dye-doped deoxyribonucleic acid (DNA)-surfactant complex films for dye lasers were fabricated by immersing non-doped complex films into a solution of hemicyanine dye. The threshold pumping intensity for amplified spontaneous emission was found to be 0.3 mJ/cm(2), the value was one order smaller than those obtained for the samples made by conventional methods. Durability under pumping was also significantly improved and laser oscillation under optical excitation was observed. Dye concentration of the final products was estimated to be 10 wt% and there were no deformation of the samples, suggesting that dye molecules in the complex did not necessarily intercalate in DNA strand but replace with surfactant molecules. (C)2014 Optical Society of America