Organic Salt Displays Laserlike Emission

Researchers have ascribed the laserlike emission from organic dye molecules and conjugated polymers to mechanisms such as cooperative emission, amplified spontaneous emission and the formation of local cavities. A team at Auburn University in Alabama has reported a conversion efficiency of up to 40 percent in the organic molecular salt styrylpyridinium cyanine dye, which it attributes to cooperative emission.

The research team pumped the salt with 55-ps pulses from a frequency-doubled Nd:YAG laser. The threshold pump energy was less than 1 µJ, and the sample yielded a photoluminescence spectrum with a center at 620 nm. A report of the work appeared in the Aug. 6 issue of Applied Physics Letters.