Hemicyanine-DNA-complex: Application to Solid-state Dye Lasers
Toshifumi Chida and Yutaka Kawabe
Many cationic cyanine dyes show strong fluorescence enhancement when they interact with DNA double strand. In this paper, we studied a hemicyanine dye, 4-[4-(dimethylamino)stylyl] -1-dococylpyridnium bromide (DMASDPB), which is a typical nonlinear optical compound but has not been attracted as a light emitter because of its low fluorescence efficiency. We fabricated DNA-CTMA-DMASDPB complex thin films by spin coating from chloroform/ethanol solution, and demonstrated laser emissions from the films. Their wavelength tuning (600-630 nm) was achieved by changing the angle between two pumping beams interfering on the samples. We also made a durability test under continuous excitation of 3 mJ/cm2 with 10 Hz about an hour, showing that the degradation of the emission was about 20%.
Keywords: solid state dye laser, DNA complex, amplified spontaneous emission, hemicyanine, cyanine, tunable laser